Perioperative outcome after laparoscopic radiofrequency ablation of liver tumors: an analysis of 521 cases

BACKGROUND

Radiofrequency thermal ablation (RFA) is gaining increased acceptance for the treatment of unresectable primary and metastatic liver tumors. Understanding the morbidity and laboratory changes after RFA is important for operative indications and perioperative management.

METHODS

The authors prospectively analyzed the 30-day morbidity and mortality rates of patients undergoing laparoscopic RFA for liver tumors in a 10-year period. Laboratory studies included a complete blood count, electrolytes, liver function tests, prothrombin time/international normalized ratio (INR), and tumor markers obtained preoperatively, on postoperative days (PODs) 1 and 7, then at 3 months.

RESULTS

A total of 521 RFA procedures were performed for 428 patients (286 men and 142 women) with a mean age of 61 years (range, 25-89 years). A total of 346 patients underwent a single operation, and 82 patients had two or more operations. The pathology was metastatic colon cancer for 244 patients (47%), hepatocellular cancer for 109 patients (21%), metastatic neuroendocrine cancer for 74 patients (14%), and other noncolorectal, nonneuroendocrine liver metastasis for 94 patients (18%). A total of 1,636 lesions (mean, 3.1 per patient; range, 1-16) were ablated. The mean tumor size was 2.7 +/- 1.6 cm (range, 0.3-11.5 cm). All cases were managed laparoscopically. The 30-day mortality rate was 0.4% (n = 2), and the morbidity rate was 3.8 % (n = 20). The average length of hospital stay was 1 day for RFA-only cases and 2.1 days when another surgical procedure was combined with RFA. Serum aspartate aminotransferase (AST) increased 14-fold, alanine aminotransferase (ALT) increased 10-fold, and bilirubin levels increased 2-fold on POD 1, with return to baseline in 3 months. Serum alkaline phosphatase and gamma-glutamyltransferase (GGT) levels showed a 25% increase on POD 7, with return to baseline in 3 months. There were no significant changes in platelet counts or prothrombin times postoperatively.

CONCLUSIONS

This large series provides valuable insight into the perioperative period and allows the expected morbidity of the procedure to be understood. Despite significant patient comorbidities, this procedure was tolerated with low morbidity and mortality rates. Postoperative coagulopathy was not observed. A postoperative rise in liver function tests is expected, reflecting the liver injury response to RFA. This information can be used to expand the patient population that may benefit from laparoscopic RFA.

Prognostic scoring systems in patients with follicular thyroid cancer: a comparison of different staging systems in predicting the patient outcome

BACKGROUND

The use of prognostic scoring systems is important for predicting the survival of individuals with thyroid carcinoma. Relatively few studies have addressed this issue for patients with follicular thyroid cancer. The goal of this retrospective study was to establish the best and most pertinent prognostic scoring system to predict survival in patients with follicular thyroid cancer.

METHODS

We selected 86 patients with follicular thyroid cancer treated at University of California, San Francisco (UCSF) hospitals from January 1954 to April 1998. The mean follow-up time was 11.5 years. There were 60 women (70%) and 26 men (30%), with a mean age if 48.6 years. Prognostic scoring systems included tumor, node, metastases (TNM), European Organization for Research and Treatment of Cancer (EORTC), Age, Grade, Extent, Size (AGES), Age, Metastases, Extent, Size (AMES), and the Metastases, Age, Completeness of resection, Invasion, Size (MACIS). Survival time was calculated using the Kaplan-Meier method. Using Cox proportional hazards analysis, the relative importance of each scoring method was determined by calculating the proportion of variation in survival time explained (PVE).

RESULTS

Kaplan-Meier analysis indicated that all scoring systems were significant predictors of survival time (p < 0.0001). The PVE associated with each system was (from highest to lowest) 0.48 for MACIS, 0.46 for AGES, 0.44 for EORTC, 0.40 for AMES, and 0.33 for TNM. These results indicate that the MACIS scoring system accounted for a great proportion of explained variance in survival and is a more precise predictor of survival compared to the other scoring systems.

CONCLUSIONS

TNM, EORTC, AGES, AMES, and MACIS, all provided useful prognostic information about the survival in our 86 patients with follicular thyroid cancers. The MACIS classification, however, was the most accurate predictor using PVE as a method of evaluation. Future scoring systems considering additional prognostic factors, may obtain a higher PVE.

Laparoscopic radiofrequency ablation of hepatic tumors: Prospective clinical evaluation of ablation size comparing two treatment algorithms

BACKGROUND

Radiofrequency ablation (RFA) is gaining increased acceptance for the local control of liver tumors. Essential for achieving local tumor control are reproducible volumes of ablation that encompass the tumor and a margin of normal liver parenchyma. The technical algorithm for performing ablations was arrived at in an animal model using normal liver. Limited amounts of data exist as to whether this translates to the human tumor model.

METHODS

We analyzed 531 ablated lesions in 154 patients undergoing laparoscopic RFA using RITA Medical Systems Starburst XL catheter deployed to a final diameter of 2-5 cm. The first 54 patients (algorithm 1) were treated with a larger initial deployment to 3 cm and incremental advancement of the catheter to the final diameter with a 20-min ablation time for a 5-cm lesion. The subsequent 100 patients (algorithm 2) were treated with a smaller initial deployment of 2 cm, incremental advancement to the final diameter, and 14-min total ablation time for a 5-cm lesion. Lesion size was measured on 1 week postablation CT scans. Analysis was performed using the two-tailed t-test.

RESULTS

Ablation zones tended to be larger with the second method. On 1 week postablation CT scans, mean +/- SEM lesion sizes created using the first and second algorithms were 3.7 +/- 0.1 cm vs 4.0 +/- 0.1 cm at 3 cm deployment ( p < 0.05); 4.3 +/- 0.1 cm vs 4.8 +/- 0.1 cm at 4 cm deployment ( p < 0.05), and 5.5 +/- 0.1 cm vs 5.6 +/- 0.2 cm at 5 cm deployment ( p > 0.05), respectively. The mean +/- SEM total ablation times for the first and second algorithms were 7.9 +/- 0.3 min vs 7.0 +/- 0.2 min at 3 cm deployment ( p < 0.05); 13.3 +/- 0.3 min vs 11.1 +/- 0.02 min at 4 cm deployment ( p < 0.05); and 27.8 +/- 1.2 min vs 21.4 +/- 1.2 min at 5 cm deployment ( p < 0.05), respectively. The small SEM values indicate little variation in lesion size.

CONCLUSIONS

These results show that both algorithms create dependable and reproducible zones of ablation, essential for reliable tumor destruction. Algorithm 2 demonstrates that creating an initial small core of ablation with rapid coagulation of the center of the lesion allows for equivalent, if not larger, final volumes to be performed in less time.

Accuracy of fine-needle aspiration cytology in patients with radiation-induced thyroid neoplasms

BACKGROUND

Fine-needle aspiration cytology (FNAC) is useful for selecting patients with thyroid nodules for thyroidectomy. Its value in patients who have been exposed to low-dose therapeutic radiation is questionable because these patients have an increased risk of multifocal benign and malignant tumours, and thyroid cancer is common in such patients.

METHODS

Between 1960 and 1999, 171 patients with one or more thyroid nodules who had a history of exposure to radiation underwent operation; 49 of these patients had preoperative FNAC. The cytology results in these 49 patients were compared with those of an age- and sex-matched control group of patients with thyroid nodules who did not have a history of radiation exposure.

RESULTS

Of those who had been exposed to radiation, six of 20 patients with 'benign' cytology by FNAC and six of 16 patients with 'suspicious' cytology had thyroid cancer. All 13 specimens considered to be malignant on FNAC were indeed malignant. There was a higher rate of false-negative cytological examinations among patients with a history of irradiation that in those without.

CONCLUSION

FNAC of thyroid nodules in patients with a history of irradiation is not as accurate as that in non-irradiated patients, primarily because of coexisting occult thyroid cancers.

A simple device for measuring the resolution of videoscopic cameras and laparoscopes in the operating room

BACKGROUND

There is a need for a device that can be used to objectively evaluate the image quality provided by laparoscopic camera units in the operating room.

METHODS

The device that we developed consists of a regular 10-mm or 5-mm laparoscopic port with a rectangular test unit built at the end. A standard test pattern slide with resolution bars is used for measurements. Using this assembly, a single-chip laparoscopic camera was compared with a three-chip laparoscopic camera at different wiring formats and camera settings by measuring the resolution on the monitor screen.

RESULTS

Vertical resolution was found to be constant at 550 lines, regardless of the type of camera and wiring used. Of the three wiring formats, composite wiring provided the poorest image with both cameras. When enhancement was off, the horizontal resolution obtained with Y/C or RGB wiring was the same for the one-chip camera at 640 lines of horizontal resolution, whereas RGB cabling provided the best image for the three-chip camera at 800 lines.

CONCLUSION

Using basic broadcasting principles, we have developed a simple device that is useful for the comparison of different camera, cabling, and laparoscope configurations in the operating room. This information can be used as objective criteria to judge the image quality in laparoscopic video- systems.

A critical analysis of intraoperative time utilization in laparoscopic adrenalectomy

BACKGROUND

Time and efficiency analysis is a technique common in industry that is being applied to surgical procedures. The aim of this study is to analyze the time spent performing the component parts of laparoscopic adrenalectomy by both the lateral transabdominal and the posterior retroperitoneal approaches.

METHODS

Operational videotapes of 33 patients undergoing laparoscopic adrenalectomy (12 lateral, 21 posterior) were reviewed. The operation was divided into six steps: trocar entry, laparoscopic ultrasonography, exposure of the adrenal gland, dissection of the adrenal, extraction of specimen, and irrigation-aspiration. Time spent for each step and the relation with age, gender, body mass index (BMI), tumor size, side, and histology were assessed using Student's t-test, Pearson correlation, and regression analysis.

RESULTS

Although tumor size was larger in the lateral compared to the posterior approach (5.5 vs 2.5 cm, p < 0.001), there was no difference between the groups regarding total operating time (116.1 vs 112.8 min). Most of the operating time was spent on dissection of the adrenal gland with both techniques (lateral, 60%; posterior, 66%). Exposure of the adrenal gland was longer in the lateral compared to the posterior approach (15.1 vs 5.8 min, respectively; p < 0.05). In the transabdominal technique, this step was longer on the right side than on the left (18.9 vs 11.4 min, respectively; p < 0.05). In the lateral approach, dissection time was dependent on tumor size (r = 0.90, p < 0.05) but not on BMI, whereas in the posterior approach both tumor size and BMI were positively correlated (r = 0.56 and r = 0.64, respectively).

CONCLUSIONS

To our knowledge, this is the first study to apply time analysis techniques to laparoscopic adrenal surgery. Understanding the variables that affect operative time may influence the choice of the surgical approach in a given patient. This study also suggests that efforts to improve operative efficiency are best directed at the dissection of the adrenal.

Laparoscopic adrenalectomy: the optimal surgical approach

BACKGROUND AND PURPOSE

Laparoscopic adrenalectomy has emerged as the treatment of choice for most adrenal surgical disorders. We describe our experience with 176 laparoscopic operations.

PATIENTS AND METHODS

The patients were treated for hyperaldosteronism (N = 62), pheochromocytoma (N = 43), "incidentaloma" (N = 21), Cushing's syndrome (N = 20), suspected adrenal metastasis (N = 16), Cushing's disease (N = 8), adrenal hemorrhage (N = 3), or virilizing tumor (N = 1). In 154 of the 176 laparoscopic operations, a lateral transabdominal approach (15 bilateral, 76 left, and 63 right) was used. In the remaining 22, a posterior laparoscopic approach (3 bilateral, 10 left, and 9 right) was used.

RESULTS

The average total operating time for unilateral laparoscopic adrenalectomy was 2.8 hours, and for bilateral adrenalectomy, it was 5.2 hours. The mean tumor size was 4.6 cm (range 1-15 cm). There was no significant difference in operating time according to the tumor size. The average length of hospitalization was 1.7 days (range 1-9 days). The perioperative complication rate was 5.1%. There were no conversions to an open procedure. The operating time, length of hospitalization, and perioperative complication rate were stable over the period. Although we used the posterior laparoscopic approach only for smaller tumors (<6 cm), we found no differences in patient outcome between the lateral and posterior laparoscopic approaches.

CONCLUSION

For almost all adrenal surgical disorders, an initial laparoscopic approach is optimal. It is safe and is associated with the best patient outcome.

Cryoablation, percutaneous alcohol injection, and radiofrequency ablation for treatment of neuroendocrine liver metastases

Neuroendocrine liver metastases are associated with slow clinical progression, prolonged patient survival, and symptoms of hormone oversecretion. Although surgical resection is the gold standard of treatment, most of the patients are not candidates for resection, and the 5-year survival of patients with neuroendocrine liver metastases is 11% to 40%. Cryotherapy, percutaneous alcohol injection, and radiofrequency thermal ablation are among the alternative regional treatment options available for these patients. The current role of these treatment options for neuroendocrine liver tumors are discussed in this review. Cryosurgery is the classic technique for local tumor destruction, mostly performed with open surgery. There has been limited experience with percutaneous alcohol injection for neuroendocrine liver metastasis. Radiofrequency thermal ablation is a relatively new modality that can be performed percutaneously or laparoscopically, and encouraging results have been obtained with it for treatment of neuroendocrine liver metastases.

Association between residual thyroid carcinoma and diffuse hepatic uptake of 131I following radioiodine ablation in postoperative total thyroidectomy patients

In patients with differentiated thyroid cancer (DTC) total or near-total thyroidectomy, postoperative 131I ablation, and thyroid suppression therapy are reported to be associated with fewer recurrences than other treatments. Many patients with DTC after total thyroidectomy and radioablation therapy have diffuse hepatic uptake of radioiodine, and its clinical importance is debated. Some investigators report that diffuse liver uptake correlates with uptake in the thyroid bed or the presence of metastatic thyroid cancer somewhere in the body, whereas others note no such correlation. The purpose of this research was to determine the clinical importance of diffuse hepatic uptake of radioiodine after 131I ablative therapy in patients with DTC. We retrospectively reviewed 141 posttherapy scans done in 118 patients with DTC. Patients had had total thyroidectomy and were hypothyroid when serum thyroglobulin (Tg) levels were obtained, and they were treated with 30 to 200 mCi of 131I. Scans were performed 3 to 21 days after radioablation therapy. Information was collected regarding the patients' age and gender, the interval between the ablation therapy and scan, uptake of radioiodine, serum thyroglobulin level, thyroid-stimulating hormone (TSH) level, thyroglobulin antibodies, TNM classification, mortality, and recurrence. Diffuse liver uptake was classified from 0 to 4 depending on hepatic brightness. Radioiodine scans were done to determine whether there was uptake in the thyroid bed or elsewhere. Statistical analyses included analysis of variance and Kaplan-Meier survival analysis. Diffuse hepatic uptake was observed (grades 1-4) in 96.4% of the patients; thus 3.6% had no hepatic uptake. There was no significant association between liver uptake and the uptake in the thyroid bed, the dose of 131I administered for ablation therapy, thyroglobulin levels, age, stage of the disease, presence of local or distant metastases, recurrence, or survival. Diffuse hepatic uptake was therefore not associated with residual normal thyroid or metastases as suggested by some but not all previous investigators.

Understanding and optimizing laparoscopic videosystems

As tactile feedback and degree of freedom for instrument movement are restricted in laparoscopic surgery, the video image plays the most crucial role in giving the surgeon information about the performance of the operation. The development of small, reliable, high-resolution imaging systems is essential for the surgeon's acquisition detailed information about the tissues being manipulated. Image quality depends on each component of the laparoscopic imaging unit. In this context, it is crucial for the surgeon to have an understanding of how the video signal is formed, transmitted, and displayed. Moreover, the surgeon also needs to have an idea about the basic principles and specifications of the surgical video systems (i.e. charge-coupled device (CCD) camera, monitors, and digitizers). This knowledge is essential for choosing pieces of equipment and knowing how to assemble them into a functional operating suite. The aim of this review is to provide the surgeon with the basics of video signaling, and to familiarize him or her with the technical principles of the surgical video systems. An insight into the future of laparoscopic video systems also is made, and practical tips for improving image quality and troubleshooting are given throughout the article.

Can localization studies be used to direct focused parathyroid operations?

BACKGROUND

There is considerable controversy today concerning the most appropriate surgical approach for patients with primary hyperparathyroidism. The conventional surgical operation involves a bilateral neck exploration through a collar incision with identification of all parathyroid tissue and removal of abnormal parathyroid glands while the patient is under general anesthesia. The success rate of this operation is about 95% or greater in the hands of an experienced endocrine surgeon. Preoperative localization techniques are generally considered to be unnecessary before initial parathyroid operations. The purpose of this investigation was (1) to evaluate the individual and combined accuracy of ultrasonography and technetium 99m sestamibi scans in localizing abnormal parathyroid glands and (2) to determine whether such scans could be used to direct a focused operation.

METHODS

We retrospectively studied 338 patients with sporadic primary hyperparathyroidism who had preoperative neck localization studies, ultrasonography and/or technetium 99m sestamibi scans, and parathyroid exploration (238 patients or, reexploration, 60 patients) from January 1996 to April 2000 at the University of California San Francisco/Mount Zion Medical Center. The preoperative localization studies were recorded as true-positive, false-positive, and false-negative and compared with the surgical and pathologic findings and with the outcome of the operation.

RESULTS

All of the abnormal parathyroid glands were correctly identified by ultrasonography in 184 of 303 patients (60.7%) and by technetium 99m sestamibi scanning in 183 of 237 patients (77.2%). The sensitivities of ultrasonography and sestamibi were 65% and 80%, respectively. Among the 202 patients who received both ultrasonography and sestamibi scans, a parathyroid tumor was identified at the same site in 105 (52%) of them. When both techniques identified a parathyroid tumor at the same site, the tests were correct in 101 of 105 patients and the sensitivity increased to 96%.

CONCLUSIONS

When both the ultrasonography and sestamibi scans identified the same, solitary parathyroid tumor in patients with sporadic primary hyperparathyroidism, this was the only abnormal parathyroid gland in 96% of the patients. A focused parathyroidectomy could therefore be performed in such patients with an acceptable ( approximately 95%) success rate.

Use of the optical access trocar for safe and rapid entry in various laparoscopic procedures

BACKGROUND

The use of the Veress needle in laparoscopy to create the pneumoperitoneum has inherent risks; it may cause vascular and visceral injuries. The open technique is compromised by the leakage of carbon dioxide and can also be time consuming. One alternative is to enter the abdomen using an optical trocar under direct view. Our aim was to determine whether the optical access trocar can be used to effect a safe and rapid entry in various laparoscopic procedures.

METHODS

Over a 4-year period, the Optiview trocar was used for initial entry in 650 laparoscopic procedures. The procedures included cholecystectomy (n = 282), transabdominal inguinal hernia repair (n = 76), radiofrequency ablation of liver tumors (n = 73), adrenalectomy (n = 54), appendectomy (n = 41), colorectal surgery (n = 39), and various other procedures (n = 85). The following parameters were analyzed: presence of previous abdominal operations, site and duration of entry, and complications.

RESULTS

Of the 650 patients, 156 (24%) had had previous abdominal operations. In 25 cases, previous trocar sites were reused for optical access. The optical trocar was inserted at the umbilicus in 495 patients (76%), in the right upper quadrant in 77 (12%), in the left upper quadrant in 26 (4%), in the upper midline in eight (1%), in the right lower quadrant in six (0.9%), and in the left lower quadrant in three (0.5%). In 35 patients undergoing posterior adrenalectomy, optical trocars were used to enter Gerota's space. Mean (SD) entry times were 92 (45) sec at the umbilical site, 114 (30) sec at the back, and 77 (35) sec at the remaining sites. Complications (0.3%) included one injury to the bowel and one injury to the gallbladder; however, they were recognized and repaired immediately.

CONCLUSIONS

To our knowledge, this report comprises the largest series in which the optical access trocar was used for laparoscopic surgery. This device provides the basis for a safe and fast technique for initial trocar placement: it also has the potential to reduce costs. Thanks to our favorable experience, the optical trocar method has become the standard technique for abdominal access in our laparoscopic practice since 1995.

Intraoperative thermal regulation in patients undergoing laparoscopic vs open surgical procedures

BACKGROUND

Although perioperative hypothermia is a well-known consequence of general anesthesia, it has been hypothesized that laparoscopic surgery exacerbates hypothermia to a greater extent than open surgery. The aim of this study was to demonstrate that laparoscopic surgery does not represent an increased risk for hypothermia.

METHODS

A case-controlled retrospective study was conducted on 45 patients, 25 undergoing laparoscopic cholecystectomy and 20 undergoing parathyroid surgery under endotracheal general anesthesia. Data were collected regarding age, sex, weight, height, American Society of Anesthesiologists (ASA) status, length of surgery, and anesthesia. In addition, we analyzed the type of intraoperative intravenous fluids, anesthetics and perioperative drugs, and temperature, blood pressure, and heart rate recordings during anesthesia.

RESULTS

There was no significant difference between the two groups with respect to age, sex, body mass index (BMI), ASA status, type or amount of intravenous fluids infused, length of anesthesia or surgery, changes in mean blood pressure, or heart rate. Core body temperatures in both groups decreased significantly over time (p 0.05). There was no difference between the groups in terms of maximum drop in temperature (lowest temperature recorded vs baseline temperature) (1.1 +/- 0.7 vs 1.0 +/- 0.7 degrees C, p > 0.05).

CONCLUSION

This study demonstrates that patients who undergo laparoscopic and open procedures of similar duration under endotracheal general anesthesia have similar profiles in terms of perioperative hypothermia.

A critical analysis of intraoperative time utilization in laparoscopic cholecystectomy

BACKGROUND

Most of the expense of laparoscopic cholecystectomy (LC) is incurred while the patient is in the operation room; however, heretofore there has been no critical analysis of the time required to perform the various steps of the operation. An understanding of how operative time is used is the first step toward improving the efficiency of the procedure and decreasing costs while maintaining an acceptable standard of care.

METHODS

Of 194 patients undergoing LC at a university hospital between 1994 and 1997, operational videotapes of 48 randomly chosen patients were reviewed. Three groups of patients were identified: those undergoing LC for chronic cholecystitis (n = 27), those undergoing LC for acute cholecystitis (n = 11), and those with common bile duct stones (CBDS), (n = 10) undergoing LC with transcystic common bile duct exploration. The procedure was divided into the following seven steps; trocar entry, laparoscopic ultrasound, dissection of the triangle of Calot, cholangiogram, dissection of the gallbladder, extraction of the gallbladder, and irrigation-aspiration with removal of ports. Time spent for camera cleaning, bleeding control, and insertion of the cholangiocatheter into the cystic duct was also calculated. The groups were compared in terms of time spent for each step using the Kruskal-Wallis and Mann-Whitney U tests.

RESULTS

The mean +/- SD operating time was 66.5 +/- 20.5 min. The acute group had the longest operating time, followed by the CBDS and chronic groups. Dissection of the gallbladder, insertion of the cholangiocatheter, and irrigation-aspiration were longer steps in the acute group than in the other groups (p < 0.05). Dissection of the triangle of Calot took longer in acute cholecystitis than in chronic cholecystitis (p < 0.05). CBDS cases took longer (p < 0.05) than chronic cases because stone extraction added an average of 17.5 min to the time required for the cholangiogram in chronic cholecystitis. Laparoscopic ultrasound took longer in the CBDS group than in the other groups (p < 0.05). The mean +/- SD time spent for the cholangiogram and laparoscopic ultrasound in chronic cholecystitis was 7.5 +/- 4.3 and 4.8 +/- 1.9 min, respectively.

CONCLUSIONS

This time analysis study demonstrates that acute cholecystitis requires a longer operating time because most of the individual steps in the procedure take longer. In patients with choledocholithiasis, stone extraction was responsible for longer operating times. This study should serve as a basis for future studies focusing on time utilization in laparoscopic surgery.

Laparoscopic ultrasonographic appearance of the common bile duct mucosa: a predictor of choledocholithiasis

Previously we reported on the use of laparoscopic ultrasonography in detecting common bile duct stones during laparoscopic cholecystectomy. The aim of this study is to describe the laparoscopic ultrasonographic appearance of the common bile duct mucosa in patients with choledocholithiasis. Medical records of 44 patients with an increased risk for common bile duct stones undergoing laparoscopic cholecystectomy between 1993 and 1998 were reviewed. In the operating room, the laparoscopic ultrasonographic appearance of the common bile duct mucosa was scored in real time as normal, mild changes (hyperechoic mucosa), or severe changes (hyperechoic with mucosal thickening). Of the 31 patients (70%) with stones or sludge in the biliary tree, 29 (94%) had either severe (58%) or mild (36%) hyperechoic and 2 (6%) had normal-appearing common bile duct mucosa on laparoscopic ultrasonography. Of the 13 patients (30%) with no documented stones or sludge, 11 (85%) had normal and 2 (15%) had mild hyperechoic common bile duct mucosa on laparoscopic ultrasonography. Both of these patients had laboratory values indicating recent passage of common bile duct stones. The association between common bile duct stones and the presence of hyperechoic common bile duct mucosa was statistically significant (P < .0001, Fisher's exact test). This is the first report of hyperechoic common bile duct mucosa demonstrated by laparoscopic ultrasonography as a predictor of common bile duct stones. This finding is evident in the majority of patients with common bile duct stones and also may be associated with recent passage of a stone into the duodenum.

Is familial non-medullary thyroid carcinoma more aggressive than sporadic thyroid cancer? A multicenter series

BACKGROUND

The aggressiveness of familial non-medullary thyroid cancer (FNMTC) has been a subject of debate. The purpose of the study was to determine whether FNMTC is more aggressive than sporadic thyroid cancer.

METHODS

A multicenter retrospective matched-case control study of FNMTC versus sporadic non-medullary thyroid cancer was conducted. Disease-free survival (time to recurrence) for both groups was compared.

RESULTS

Forty-eight familial cases were compared with 144 age-, gender-, and stage-matched controls. Patients with FNMTC had a significantly shorter disease-free survival compared with sporadic non medullary thyroid cancer. Patients with FNMTC who presented with evidence of distant metastasis, or who were from families with more than 2 thyroid cancer-affected members, had the worst prognosis. The available staging systems were less likely to predict the outcome in patients with FNMTC than in patients with sporadic non-medullary thyroid cancer unless one accounted for the strength of family history in the staging system.

CONCLUSIONS

FNMTC is more aggressive than sporadic non-medullary thyroid cancer. The best predictors of a poor outcome in patients with FNMTC are the number of family members affected by thyroid cancer and evidence of distant metastasis.

Intraoperative parathyroid aspiration and parathyroid hormone assay as an alternative to frozen section for tissue identification

Most people would agree that successful parathyroidectomy depends on two important variables: the surgeon's recognition and excision of the abnormal parathyroid gland(s) and the pathologist's confirmation that the removed tissue is parathyroid tissue. Frozen section is usually employed to confirm the identity of parathyroid tissue, but occasionally confirmation cannot be made without a permanent section, as with intrathyroidal glands. This study proposes a new method of expeditious and easy confirmation of parathyroid tissue utilizing the immunoassay for quick measurement of intraoperative parathyroid hormone (IOPTH). By directly aspirating the suspected adenoma, the assay becomes a rapid diagnostic tool that can be used as an alternative to frozen section. In cases where the surgeon is already planning to employ the assay, the elimination of frozen section is cost-effective. Intraoperative aspiration of histologically confirmed parathyroid adenomas was performed on 12 consecutive patients undergoing parathyroid surgery. Parathyroid glands were aspirated with a 22-gauge syringe after gland excision. Aspirates were placed in 1 to 3 ml of buffered saline. A similar process was performed on 12 thyroid controls. Specimens were centrifuged, aliquotted, and stored at -70 degrees C. The parathyroid hormone value was analyzed electively by rapid assay and the values recorded. For all parathyroid aspirates, the rapid assay value was > 1500 pg/ml, exceeding the uppermost limit of the diagnostic chart. Values for thyroid aspirates ranged from 58 to 85 pg/ml (mean 75.7 pg/ml). In all cases tissue confirmation was achieved with permanent section. Values were 100% sensitive and specific. Measurement of PTH from intraoperative aspiration of suspected parathyroid adenomas is clinically useful in patients for whom frozen section would routinely be employed. Values > 1500 pg/ml secure the tissue diagnosis. There is no additional cost in cases where IOPTH monitoring is already being utilized to confirm cure. The elimination of frozen section could be cost-effective and, for some institutions, actually decrease the operating time as the IOPTH assay takes only 15 minutes. PTH assay is an accurate diagnostic technique and to date is 100% sensitive and specific for differentiating between parathyroid tumors and thyroid nodules.

Recurrent or persistent thyroid cancer of follicular cell origin

Most patients with differentiated thyroid cancer of follicular cell origin have a favorable postoperative course, and their prognosis often appears to be unrelated to the extent of initial surgical treatment in some studies. Important questions that need to be addressed include whether the extent of the initial operation has any impact on the subsequent tumor-free survival and total survival, and whether patients with persistent or recurrent disease benefit from reoperation.

Use of CT Hounsfield unit density to identify ablated tumor after laparoscopic radiofrequency ablation of hepatic tumors

BACKGROUND

When attempting to interpret CT scans after radiofrequency thermal ablation (RFA) of liver tumors, it is sometimes difficult to distinguish ablated from viable tumor tissue. Identification of the two types of tissue is specially problematic for lesions that are hypodense before ablation. The aim of this study was to determine whether quantitative Hounsfield unit (HU) density measurements can be used to document the lack of tumor perfusion and thereby identify ablated tissue.

METHODS

Liver spiral CT scans of 13 patients with 51 lesions undergoing laparoscopic RFA for metastatic liver tumors within a 2-year time period were reviewed. HU density of the lesions as well as normal liver were measured pre- and postoperatively in each CT phase (noncontrast, arterial, portovenous). Statistical analyses were performed using Student's paired t-test and ANOVA.

RESULTS

Normal liver parenchyma, which was used as a control, showed a similar increase with contrast injection in both pre- and postprocedure CT scans (56.4 +/- 2.4 vs 57.1 +/- 2.4 HU, respectively; p = 0.3). In contrast, ablated liver lesions showed a preablation increase of 45.7 +/- 3.4 HU but only a minimal postablation increase of 6.6 +/- 0.7 HU (p < 0.0001). This was true for highly vascular tumors (neuroendocrine) as well as hypovascular ones (adenocarcinoma).

CONCLUSIONS

This is the first study to define quantitative radiological criteria using HU density for the evaluation of ablated tissues. A lack of increase in HU density with contrast injection indicates necrotic tissue, whereas perfused tissue shows an increase in HU density. This technique can be used in the evaluation of patients undergoing RFA.

Laparoscopic posterior adrenalectomy: technical considerations

HYPOTHESIS

Although laparoscopic posterior adrenalectomy (LPA) offers a more direct access to the adrenal gland, it is not as popular as laparoscopic transabdominal adrenalectomy, and the worldwide experience has been limited. We hypothesized that LPA is a safe and efficacious procedure that could best serve certain patients with adrenal tumors.

DESIGN

Case series of patients undergoing laparoscopic adrenalectomy in a single institution.

SETTING

University teaching hospital.

PATIENTS

Medical records of 31 patients with 33 tumors who underwent LPA were reviewed. Indications for operation included hormone secretion in 23 patients (74%), suspected or known malignant neoplasms in 7 patients (23%), and local symptoms in 1 patient (3%).

INTERVENTION

The LPAs were performed with the patients in prone position. Preoperative ultrasonography localized the adrenal tumor and kidney to guide balloon trocar placement for the creation of a working retroperitoneal space. The LPAs were performed with three 10-mm trocars using laparoscopic ultrasound to localize the tumor and the harmonic scalpel to perform the dissection.

MAIN OUTCOME MEASURES

Demographic data, type and size of tumor, operative time, blood loss, intraoperative and postoperative complications, and hospital stay were analyzed.

RESULTS

All operations were successfully completed without conversion. Excluding the bilateral cases, the mean +/- SD operative time was 176 +/- 104 minutes. Estimated blood loss averaged 32 mL (range, 10-200 mL). There were no intraoperative complications. The mean +/- SD tumor size was 3.2 +/- 1.8 cm (range, 0.8-7.0 cm). Pathological evaluation revealed benign tumors in 25 patients (81%) and malignant tumors in 6 patients. The average hospital stay was 1.4 days (range, 1-3 days). There were no deaths.

CONCLUSIONS

Although technically more demanding, LPA should be considered in patients with tumors less than 6 cm, bilateral tumors, or extensive previous abdominal surgery.

Laparoscopic ultrasound vs triphasic computed tomography for detecting liver tumors

BACKGROUND

Accurate staging of malignant tumors in the liver has major implications in defining prognosis and guiding both surgical and nonsurgical therapy. Intraoperative ultrasound in open surgery compares favorably with computed tomography (CT) in the detection of liver tumors; however, there is little experience with laparoscopic ultrasound (LUS).

HYPOTHESIS

Laparoscopic ultrasound is more sensitive than triphasic CT for detecting primary and metastatic liver tumors.

DESIGN

Prospective study.

SETTING

University hospital.

PATIENTS

Fifty-five patients with a total of 222 lesions, including primary and metastatic liver tumors, who underwent both CT examinations and LUS as a part of a tumor ablation procedure.

INTERVENTIONS

Triphasic spiral CT scans of the liver were obtained within 1 week before surgery. Liver LUS was performed with a linear 7.5-MHz side-viewing laparoscopic transducer.

RESULTS

The LUS detected all 201 tumors seen on preoperative CT and detected 21 additional tumors (9.5%) in 11 patients (20.0%). These tumors missed by CT ranged in size from 0.3 to 2.7 cm. Smaller tumors tended to be missed by CT scan (28.6% of the lesions <1 cm, 15.8% of those 1-2 cm, 4% of those 2-3 cm, and 0% of those >3 cm), as did those in segments III and IV. There was good correlation between the size of lesions imaged by the 2 modalities (Pearson r = 0.86; P<.001).

CONCLUSION

Laparoscopic ultrasound offers increased sensitivity over CT for the detection of liver tumors, especially for smaller lesions. This study documents the ability of LUS in detecting liver tumors and argues for more widespread use in laparoscopic staging procedures.

Hyperparathyroidism after thyroid surgery and autotransplantation of histologically normal parathyroid glands

BACKGROUND

Parathyroid autotransplantation is a well-established method to prevent hypoparathyroidism during parathyroid and thyroid operations. The reported success rate of parathyroid autotransplantation ranges from 75% to 100%. Recurrent hyperparathyroidism may develop after parathyroid autotransplantation, especially after the transplantation of hyperplastic or adenomatous parathyroid tissue. Hyperparathyroidism recurs most frequently after subtotal parathyroidectomy or total parathyroidectomy and autotransplantation, in patients with renal failure and secondary hyperparathyroidism, and in patients with familial primary hyperparathyroidism or MEN I or MEN II syndrome. We report three patients who experienced primary hyperparathyroidism after autotransplantation of normal parathyroid tissue during thyroid operations (two patients) or after a long period of hypoparathyroidism.

STUDY DESIGN

We reviewed our records from 1983 to May 1998 and identified three patients in whom hyperparathyroidism developed after thyroid operations.

RESULTS

One patient had a thyroidectomy with left modified radical neck dissection for papillary thyroid cancer, followed by radioiodine ablative therapy. Two patients had thyroid operations for benign thyroid disease. One of these patients had a history of radiation exposure for acne, and in the other one secondary hyperparathyroidism arose 6 years after a thyroidectomy for hyperthyroidism.

CONCLUSIONS

Our study documents that hyperparathyroidism may develop after autotransplantation of histologically normal parathyroid tissue and after a period of hypoparathyroidism after thyroid operations. For this reason, it is important to mark the site of the parathyroid transplantation.

Medullary thyroid carcinoma: clinical characteristics, treatment, prognostic factors, and a comparison of staging systems

BACKGROUND

The clinical courses of patients with medullary thyroid carcinoma (MTC) vary, and a number of prognostic factors have been studied, but the significance of some of these factors remains controversial.

METHODS

The study group consisted of 104 patients with MTC or C-cell hyperplasia managed at the hospitals of the University of California, San Francisco, between January 1960 and December 1998. Patients were classified as having sporadic MTC, familial non-multiple endocrine neoplasia (MEN) MTC, MEN 2A, or MEN 2B. The TNM, European Organization for Research and Treatment of Cancer (EORTC), National Thyroid Cancer Treatment Cooperative Study (NTCTCS), and Surveillance, Epidemiology, and End Results (SEER) extent-of-disease stages were determined for each patient. The predictive values of these staging or prognostic scoring systems were compared by calculating the proportion of variance explained (PVE) for each system.

RESULTS

Fifty-six percent of the patients had sporadic MTC, 22% had familial MTC, 15% had MEN 2A, and 7% had MEN 2B. The overall average age at diagnosis was 38 years, and patients with sporadic MTC presented at an older age (P < 0.05). Thirty-two percent of the patients with hereditary MTC were diagnosed by screening (genetic and/or biochemical). These patients had a lower incidence of cervical lymph node metastasis (P < 0.05) and 94.7% were cured at last follow-up (P < 0.0001) compared with patients not screened. Patients with sporadic MTC who had systemic symptoms (diarrhea, bone pain, or flushing) had widely metastatic MTC and 33.3% of those patients died within 5 years. Overall, 49.4% of the patients were cured, 12.3% had recurrent MTC, and 38.3% had persistent MTC. The mean follow-up time was 8.6 years (median, 5.0 years) with 10.7% (n=11) and 13.5% (n=14) cause specific mortality at 5 and 10 years, respectively. Patients with persistent or recurrent MTC who died of MTC lived for an average of 3.6 years (ranging from 1 month to 23.7 years). Patients who had total or subtotal thyroidectomy were less likely to have persistent or recurrent MTC (P < 0.05), and patients who had total thyroidectomy with cervical lymph node clearance required fewer reoperations for persistent or recurrent MTC (P < 0.05) than patients who underwent lesser procedures. In univariate analysis, age, gender, clinical presentation, TNM stage, sporadic/hereditary MTC, distant metastasis, and extent of thyroidectomy were significant prognostic factors. Only age and stage, however, remained independent prognostic factors in multivariate analysis. The TNM, EORTC, NTCTCS, and SEER staging systems were all accurate predictors of survival, but the EORTC prognostic scoring system had the highest PVE in this cohort.

CONCLUSIONS

Screening for MTC and early treatment (total thyroidectomy with central neck lymph node clearance) had nearly a 100% cure rate. Patients with postoperative hypercalcitoninemia without clinical or radiologic evidence of residual tumor after apparently curative surgery may enjoy long term survival but have occult MTC. Only patient age at presentation and TNM stage were independent predictors of survival. The EORTC criteria, which included the greatest number of significant prognostic factors in our cohort, had the highest predictive value.

Selective use of tube cholecystostomy with interval laparoscopic cholecystectomy in acute cholecystitis

HYPOTHESIS

Tube cholecystostomy followed by interval laparoscopic cholecystectomy is a sale and efficacious treatment option in critically ill patients with acute cholecystitis.

DESIGN

Retrospective cohort study within a 4 1/2%-year period.

SETTING

University hospital.

PATIENTS

Of 324 patients who underwent laparoscopic cholecystectomy, 65 (20%) had acute cholecystitis; 15 of these 65 patients (mean age, 75 years) underwent tube cholecystostomy.

INTERVENTION

Thirteen patients at high risk for general anesthesia because of underlying medical conditions underwent percutaneous tube cholecystostomy with local anesthesia. Laparoscopic tube cholecystostomy was performed on 2 patients during attempted laparoscopic cholecystectomy because of severe inflammation. Interval laparoscopic cholecystectomy was attempted after an average of 12 weeks.

MAIN OUTCOME MEASURES

Technical details and clinical outcome.

RESULTS

Prompt clinical response was observed in 13 (87%) of the patients after tube cholecystostomy. Twelve patients (80%) underwent interval cholecystectomy. Laparoscopic cholecystectomy was attempted in 11 patients and was successful in 10 (91%), with 1 conversion to open cholecystectomy. One patient had interval open cholecystectomy during definitive operation for esophageal cancer and another had emergency open cholecystectomy due to tube dislodgment. Two patients (13%) had complications related to tube cholecystostomy and 2 patients died from sepsis before interval operation. One patient died from sepsis after combined esophagectomy and cholecystectomy. Postoperative minor complications developed in 2 patients. At a mean follow-up of 16.7 months (range, 0.5-53 months), all patients were free of biliary symptoms.

CONCLUSIONS

Tube cholecystostomy allowed for resolution of sepsis and delay of definitive surgery in selected patients. Interval laparoscopic cholecystectomy was safely performed once sepsis and acute infection had resolved in this patient group at high risk for general anesthesia and conversion to open cholecystectomy. Just as catheter drainage of acute infection with interval appendectomy is accepted in patients with periappendiceal abscess, tube cholecystostomy with interval laparoscopic cholecystectomy should have a role in the management of selected patients with acute cholecystitis.

Reliability of fine-needle aspiration in patients with familial nonmedullary thyroid cancer

In this case-control study we describe how often thyroid cancers and occult cancers are diagnosed or not diagnosed by fine-needle aspiration (FNA) in patients with thyroid nodules and a family history of nonmedullary thyroid cancers (FNMTC). Our hypothesis is that patients with thyroid nodules and a family history of FNMTC seem to be similar to patients with thyroid nodules and a history of exposure to low-dose therapeutic radiation. Both have been reported to have multifocal thyroid neoplasms and malignant tumors are common. Cytological examination may therefore be less accurate. From 1979 to 1996, 27 patients from 24 families with FNMTC were examined histologically after a preoperative cytological examination in all of them. A positive cytology examination was defined when biopsy documented thyroid cancer. It was interpreted as a false-negative study when a benign diagnosis was made and thyroid cancer was present anywhere within the thyroid, including in areas sampled or not sampled by FNA and not palpable preoperatively. A randomized control group, matched for age and gender, contained 27 patients with papillary thyroid cancer without familial disease. In our study group, 25 patients were treated with total thyroidectomy, including 7 with neck dissection, and 2 by thyroid lobectomy. At final histological examination 17 of 27 patients (63%) in this study group had multiple nodules and 25 of 27 (92.6%) had thyroid cancer. Thyroid cancer was diagnosed by FNA in 22 of 25 patients (88%), with 3 (12%) false-negative biopsies due to sampling errors (thyroid cancer not in the index nodule), versus 1 (3.7%) false-negative biopsy in the control group. Two patients in the study group with benign nodules were accurately diagnosed. In patients with false-negative biopsies and a history of FNMTC, the cancer was situated in one or more small nodules. Only one cancer was occult (< 1.0 cm). One-third of the patients in our study group (33%) had a history of radiation; 44% of the irradiated group had a single nodule; 56% had multiple nodules. In the control group, 9 of 27 patients (33%) also had a history of radiation; 33% of the irradiated group had a single nodule, 67% had multiple nodules. In conclusion, the reliability of FNA in patients with FNMTC appears to be less accurate than it is for other patients because of the high incidence of multifocal thyroid cancer and coexistence of benign nodules. Patients with thyroid nodules and a family history of thyroid cancer are more likely to have thyroid cancer and because they also have more coexistent benign nodules, they must be followed closely or treated with total or near-total thyroidectomy.

Phenylacetate inhibits growth and vascular endothelial growth factor secretion in human thyroid carcinoma cells and modulates their differentiated function

There is increasing evidence that phenylacetate inhibits growth and modulates differentiation in a variety of tumors with effects on gene expression, and protein prenylation and glycosylation at concentrations that have been safely used in humans. We evaluated the antineoplastic effects of phenylacetate in five thyroid cancer cell lines of follicular cell origin in vitro. We found early growth inhibition occurred with phenylacetate treatment at a dose of 2.5-10 mmol/L. The growth inhibition was cytostatic with the thyroid carcinoma cells arrested in the G0-1 cell phase. When evaluating the effect of phenylacetate on the differentiated functions of thyroid carcinoma cells, phenylacetate exposure: 1) decreased the TSH (10 mU/mL) growth response; 2) increased radioactive iodine (125I) uptake in two out of five cell lines; and 3) inhibited thyroglobulin secretion. Phenylacetate also inhibited the secretion of vascular endothelial growth factor (a glycoprotein dependent on glycosylation for efficient cellular excretion) from the thyroid cancer cell lines. Our results support that phenylacetate has an antiproliferative effect in many cell types, but the differentiating effects were not uniform. Importantly, we have identified that phenylacetate inhibits the secretion of vascular endothelial growth factor, which possibly mediates the antiangiogenic effects observed in vivo. Because of the minimal toxicity associated with phenylacetate treatment in humans, at concentrations we show to have a significant antineoplastic effect in thyroid carcinoma cells, phenylacetate could be useful in patients with differentiated thyroid cancer who fail conventional therapy or as an adjuvant to radioactive iodine therapy in patients with aggressive tumors.

Localization of insulinomas

HYPOTHESIS

Intraoperative ultrasonography is more sensitive than preoperative and other intraoperative techniques for localizing insulinoma.

DESIGN

Retrospective review.

SETTING

A tertiary referral center.

PATIENTS

All patients with a biochemical diagnosis of organic hyperinsulinism who were referred to University of California, San Francisco, from 1975 to 1998.

METHODS

Sensitivities of the localization techniques for insulinoma were evaluated.

RESULTS

The sensitivities of tumor localization with arteriography, computed tomography, preoperative ultrasonography, magnetic resonance imaging, magnetic resonance imaging with gadolinium, transhepatic venous sampling, palpation, and intraoperative ultrasonography were 47%, 24%, 50%, 30%, 40%, 55%, 76%, and 91%, respectively. Nine of the 11 nonpalpable and nonvisible tumors at operation were localized by intraoperative ultrasonography.

CONCLUSION

The currently available preoperative localization tests are not reliable enough to be recommended when intraoperative ultrasonography is available.

Value of stimulated serum thyroglobulin levels for detecting persistent or recurrent differentiated thyroid cancer in high- and low-risk patients

BACKGROUND

Serum thyroglobulin determination has been reported to be a sensitive indicator of persistent or recurrent differentiated thyroid cancer of follicular cell origin (DTC) after total thyroidectomy. The purpose of this investigation was to determine the accuracy of serum thyroglobulin levels in predicting persistent or recurrent DTC in euthyroid and hypothyroid patients.

METHODS

One hundred ninety consecutive patients with DTC of follicular cell origin who had 4 or more thyroglobulin levels measured after total thyroidectomy were retrospectively evaluated. One hundred fifteen patients had serum thyroglobulin levels measured when hypothyroid for radioiodine scanning or ablation. Serum thyroglobulin levels were determined by commercial assays. One hundred twenty-two patients less than 45 years old were considered at low risk, whereas 68 patients more than or equal to 45 years old were considered at high risk on the basis of TNM classification. The mean follow-up period was 62 months.

RESULTS

After thyroidectomy with or without central or modified radical neck dissection 120 patients had normal thyroglobulin levels (< or = 3 ng/mL) while receiving thyroid hormone. One hundred thirteen of the 120 patients (94%) with normal serum thyroglobulin levels had no evidence of recurrent tumor, whereas 6% (7 patients) had persistent or recurrent disease. Among 76 patients with persistent (28 patients) or recurrent (48 patients) disease, 70 had a serum thyroglobulin level > 3 ng/mL while receiving thyroid hormone. Overall, 14 of 115 patients, including 2 of 61 (3%) in the high-risk group and 12 of 54 (22%) in the low-risk group, only had elevated serum thyroglobulin levels when hypothyroid with high serum thyroid-stimulating hormone (TSH) levels documenting persistent or recurrent disease. In 1 patient the serum thyroglobulin level (240 ng/mL) was falsely elevated probably as a result of interfering antibodies because no tumor was identified surgically or pathologically, and the thyroglobulin concentration was < 3 ng/mL when analyzed in 3 other laboratories.

CONCLUSION

Serum thyroglobulin testing is sensitive (91%) and specific (99%) for identifying patients with persistent or recurrent differentiated thyroid cancer. Serum thyroglobulin levels are most precise when patients are hypothyroid (high TSH) and may be unreliable in patients with antithyroglobulin antibodies. We recommend TSH-stimulated thyroglobulin testing for all patients after total thyroidectomy for differentiated thyroid cancer of follicular cell origin regardless of patient age or risk group.

Laparoscopic vs open adrenalectomy for the treatment of primary hyperaldosteronism

HYPOTHESIS

That the clinical presentations, biochemical profiles, and surgical outcomes of patients treated with laparoscopic vs open adrenalectomy for primary hyperaldosteronism are different. DESIGN, SETTINGS, PATIENTS, AND INTERVENTIONS: The medical records of 80 patients with primary hyperaldosteronism who underwent open adrenalectomy between 1975 and 1986 or laparoscopic adrenalectomy between 1993 and 1998 at the University of California-San Francisco were reviewed by a single unblinded researcher (W.T.S.).

MAIN OUTCOME MEASURES

Severity of hypertension and hypokalemia at diagnosis, their improvement after adrenalectomy, and operative complications.

RESULTS

Thirty-eight patients underwent open adrenalectomy and 42 patients underwent laparoscopic adrenalectomy. The patients who underwent open adrenalectomy had documented hypertension for a median of 5 years before surgery; all had diastolic blood pressures greater than 100 mm Hg. Laparoscopically treated patients had documented hypertension for a median of 2.5 years preoperatively, and 20 (48%) had diastolic blood pressures greater than 100 mm Hg. The median preoperative serum potassium levels for the open and laparoscopic groups were 2.6 mmol/L and 3.3 mmol/L, respectively; the mean serum aldosterone levels were 1.47 nmol/L and 1.30 nmol/L. Thirty-two (84%) of the 38 patients who underwent open surgery and 41 (98%) of the 42 patients treated laparoscopically had adrenal adenomas. The sensitivity of preoperative computed tomographic scanning for adenomas was 83% for the patients treated with open adrenalectomy and 93% for those treated laparoscopically. There were 4 postoperative complications in the open surgery group and none in the laparoscopic group. Postoperatively, 30(81%) of 37 patients (excluding 1 patient who died of adrenocortical carcinoma) in the open surgery group and 37 (88%) of 42 patients treated laparoscopically were normotensive. Post-operative values were 3.6 to 5.0 of serum potassium per liter and 3.5 to 4.9 of serum potassium per liter in the open and laparoscopic groups, respectively.

CONCLUSIONS

Patients who are treated with laparoscopic adrenalectomy for primary hyperaldosteronism are being referred with less severe hypertension and hypokalemia than patients formerly treated with open adrenalectomy. Patients treated laparoscopically had fewer postoperative complications and were equally likely to improve in blood pressure and hypokalemia. Laparoscopic adrenalectomy has become the treatment of choice for patients with primary hyperaldosteronism because of lower morbidity.

Development of reverse transcription-competitive polymerase chain reaction method to quantitate the expression levels of human sodium iodide symporter

The sodium iodide symporter (NIS) is the plasma membrane protein that mediates active iodide uptake into thyroid follicular cells. To investigate whether human NIS (hNIS) mRNA levels in papillary thyroid carcinomas (PCs) correlate with the ability of tumors to concentrate radioiodide, we developed a reverse transcription-competitive polymerase chain reaction (RT-cPCR) method to quantify the hNIS mRNA levels in thyroid tissues. We studied 7 normal thyroid tissues, 8 PCs, and 1 follicular adenoma. hNIS mRNA levels in PCs were generally lower than those found in normal thyroid tissues. The reduced radioiodide concentrating activity of PCs is due, at least in part, to the reduced expression and/or the decreased stability of hNIS mRNA.

Laparoscopic gastrostomy and jejunostomy: safety and cost with local vs general anesthesia

BACKGROUND AND HYPOTHESIS

General anesthesia is used for laparoscopic enteral access because pneumoperitoneum requires relaxation of the abdominal muscles. We wanted to determine whether these procedures could be performed with similar results and cost under local anesthesia.

DESIGN

Randomized controlled study with 30-day follow-up including a cost-benefit analysis.

SETTING

University-affiliated hospitals.

PATIENTS

Forty-eight patients (32 men, 16 women; mean age, 67 years) undergoing laparoscopic gastrostomies (n = 32) and jejunostomies (n = 16).

INTERVENTION

Twenty-four patients underwent laparoscopic gastrostomy (n = 15) and jejunostomy (n = 9) under local anesthesia with intravenous conscious sedation and monitored anesthesia care. Twenty-four patients had general anesthesia.

MAIN OUTCOME MEASURES

Conversion to general anesthesia, complications, and cost.

RESULTS

Ten patients under local anesthesia had periods of deep sedation and 1 required conversion to general anesthesia. One patient under general anesthesia required conversion to open gastrostomy. No patients had intraoperative aspiration; however, 4 aspirated after the procedure. One patient died of myocardial infarction during the 30-day follow-up. We found no significant difference in the total mean cost and actual procedure time. The surgeon's fee accounted for 31% of the total cost.

CONCLUSIONS

Some patients undergoing laparoscopic enteral access may require deep sedation and a rare patient may require general anesthesia. Clinical conditions and surgeon preference, therefore, should determine whether local anesthesia is suitable for laparoscopic gastrostomies and jejunostomies, and in what setting, since there is no difference in success rate or complications when compared with general anesthesia. Potential savings are possible from the operating room (26% of total cost) or anesthesiologist (12% of total cost) if these procedures are performed in an endoscopy suite without monitored anesthesia care.

Normal thyroid pathology in patients undergoing thyroidectomy for finding a RETgene germline mutation: a report of three cases and review of the literature

Genetic screening for germline RET proto-oncogene mutation in hereditary medullary thyroid cancer (MTC) is accurate and allows for preventive total thyroidectomy to be performed early in patients who are gene carriers. We report 3 children who underwent preventive total thyroidectomy based on the finding of a RETgene germline mutation, but who had no evidence of MTC or C-cell hyperplasia on permanent histology, even after calcitonin immunostaining. Review of the English literature of patients undergoing preventive thyroidectomy for a positive RETgene germline mutation, shows that 3.4% of these patients (a total of 209 patients) had normal thyroid glands. Also, 8.6% of patients undergoing preventive total thyroidectomy with prophylactic central neck node dissection had cervical node metastases. We conclude that preventive thyroidectomy in patients screened early for germline RETgene mutation allows for earlier diagnosis and treatment of patients, sometimes even before any hyperplasia or neoplasia can be demonstrated because cervical node metastases can occur early and be demonstrated even with small tumors (< 1 cm), we recommend prophylactic central neck node dissection at the time of preventive thyroidectomy.

Insulinoma--experience from 1950 to 1995

Insulinomas are rare tumors that originate from the islet cells of the pancreas. The purpose of this study was to analyze our experience in patients with insulinoma and present our approach to these patients. Medical records of 67 patients treated at the University of California, San Francisco (UCSF) Medical Center, 56 surgically and 11 medically, from 1954 to 1995 were retrospectively reviewed. Presenting symptoms, physical findings, laboratory data, pre and intraoperative localization studies, operative management, operative success, and post-operative complications were analyzed. Among the entire cohort, there were 11 patients with Multiple Endocrine Neoplasia type I (MEN 1) and 7 patients with multiple tumors. 46 out of 48 patients (96%) having first operations for benign tumors and 5 out of 8 patients (63%) having reoperations for benign tumors were successful, as were 6 out of 12 patients (50%) having operations for islet cell carcinoma. Overall, preoperative localization studies were positive in only 46% of patients and therefore failed to improve our surgical outcome. Careful palpation with intraoperative ultrasonography gave the best localization results. Enucleation of solitary tumors is curative in sporadic cases and gives the lowest complication rate. In patients with MEN 1, subtotal pancreatectomy with enucleation of tumours from the pancreatic head and uncinate process is recommended over simple enucleation because of frequent multiple tumors.

Establishment of a highly differentiated thyroid cancer cell line of Hürthle cell origin

Hürthle cell carcinomas (HCC) of the thyroid are a variant of follicular thyroid tumors. In contrast to follicular thyroid carcinoma, HCC rarely take up radioiodine and frequently metastasize to the lymph nodes. Histologically they are indistinguishable from Hürthle cell adenomas except for evidence of invasion and metastasis. How these carcinomas develop and why they behave differently than other follicular tumors is not known. Although some differentiated thyroid cancer cell lines exist, none are from Hürthle cell tumors. We have established a well-differentiated thyroid cancer cell line from a metastasis of a HCC, designated XTC.UC1. In vitro, XTC cells display epitheloid morphology, grow with a population doubling time of 4.3 +/- 0.3 days, migrate, and invade through reconstituted basement membranes. The cells are immunoreactive for and release thyroglobulin, respond to thyrotropin (TSH) with increase of intracellular cyclic adenosine monophosphate (cAMP), proliferation, and invasion of reconstituted basement membrane, thus exhibiting characteristics of well-differentiated thyroid carcinoma. In vivo, xenografted XTC cells grow with a doubling time of 9.8 +/- 0.8 days. Tumors spontaneously metastasize to the lymph nodes and less frequently to the lungs and the liver. The cells retained their differentiated function in vivo as assessed by human thyroglobulin (hTG) secretion and immunohistochemistry. This is a first report of the establishment of a unique, highly differentiated thyroid carcinoma cell line derived from an HCC. Based on the ability to invade through reconstituted basement membrane in vitro and the potential to metastasize in vivo, this cell line may provide a unique model to study invasion and metastazation of well-differentiated thyroid cancer.

Heterologous desensitization in neoplastic thyroid cells: influence of the phospholipase C signal transduction system on the thyrotropin-adenylate cyclase signal transduction system

Desensitization is defined as a decreased functional response after continuous or repetitive stimulation of a receptor with its agonist. Thyrotropin (TSH) increases cAMP levels in normal and neoplastic thyroid tissue. The tumor promoter 12-O-tetradecanoyl-phorbol-13-acetate (TPA) activates protein kinase C (PKC). The aim was to determine whether TPA induces heterologous desensitization of the TSH-adenylate cyclase (AC) signal transduction system. Three human thyroid neoplasms in culture for 6 months or longer (one papillary carcinoma, one Hurthle cell carcinoma, one follicular adenoma) were incubated with TSH (10 mU/ml) and TPA (1.6 x 10(-8) M) separately and together for various time periods (from 10 minutes to 24 hours). The mixture was subsequently incubated for 30 minutes with TSH. TPA alone had no effect on cAMP levels, but co-incubation of TPA and TSH caused a significant reduction in cAMP response when compared to the cAMP response that resulted after stimulation with only TSH (p < 0.001). cAMP levels in response to TSH decreased by 31%, 44%, and 57% after preincubation with TSH for 10 minutes, 4 hours, and 24 hours, respectively (p < 0.01; ANOVA). Co-incubation of cells with TPA and staurosporine (10 ng/ml), a PKC inhibitor, prevented the effect of TPA on desensitization at 10 minutes and blunted the effect at 4 hours. This is the first demonstration in human neoplastic thyroid cells that TPA induced heterologous desensitization of the cAMP response to TSH. This TPA-induced effect appears to involve PKC activation, as it can be blocked by staurosporine.

Desensitization in normal and neoplastic human thyroid cell lines

Because some papillary thyroid cancers continue to grow when thyroid-stimulating hormone (TSH) levels are suppressed, we questioned whether desensitization (i.e., a decreased cAMP response to repeat stimulation with TSH) occurs in normal and neoplastic thyroid tissue. If desensitization does occur, is it similar or different in these human thyroid cells? Normal and papillary thyroid cancer cells from the same patient were cultured as we have previously described. Normal and neoplastic thyroid tissues responded to TSH (0.01-10.0 mU/ml) by increasing cAMP production and growth in a dose-dependent manner. In normal cells there was an 11-fold mean increase in cAMP production at 4 hours, and all thyroid cultures responded. In neoplastic cells cAMP production increased from 1.5-fold to 3.0-fold with a mean 2.0-fold increase at 4 hours. In normal thyroid cells the cAMP response to a second TSH stimulus (desensitization) decreased up to 75% (range 25-75%), and desensitization occurred in all normal thyroid cell cultures. In neoplastic thyroid cells, however, the cAMP response to a second TSH stimulus decreased up to 17% (range 0-17%); and desensitization occurred in only two of the five neoplastic thyroid cell cultures. Thus when normal thyroid and neoplastic cells from the same patients were studied, greater desensitization occurred in the normal cells (75% vs. 17%). These studies document that there is greater desensitization in normal tissue than in neoplastic thyroid tissue, which may account for the increased growth of thyroid neoplasms in the presence of ever-changing low levels of TSH.

A unique allogenic model of metastatic pheochromocytoma: PC12 rat pheochromocytoma xenografts to nude mice and establishment of metastases-derived PC12 variants

Local invasion and metastatic spread to distant sites are major causes of death in patients with malignant pheochromocytoma. Since appropriate in vivo models do not exist, little is known about the underlying mechanisms of tumor growth and invasion. We, therefore, developed an animal model of malignant pheochromocytoma and established organotropic metastatic variants of PC12 rat pheochromocytoma cells. PC12 cells were established as xenografts to BALB/c NCR-NU mice. Subsequent to development of tumors or metastases, primary cultures from local tumors, metastases to lymph nodes, lungs and liver were established. These were subcultured in vitro and reinjected for up to five successive in vivo/in vitro cycles. Xenografted PC12 cells grew tumors with a doubling time of 6.78 +/- 0.58 days during log phase of tumor growth, killing hosts within 5-12 weeks depending on the experimental conditions. Tumors reproducibly metastasized to lymph nodes and the lung. Spontaneous metastases to the liver were not observed, but were achieved by intrasplenic injection of parent PC12 cells. In vitro, the metastatic cell lines displayed striking differences in morphology, overall growth patterns and nutritional requirements as well as binding to purified extracellular matrix proteins compared to the parent cell line. In vivo, the metastatic variants showed marked enhancement of metastatic ability. This is the first report of PC12 rat pheochromocytoma cells to exhibit the malignant phenotype in vivo. We also established variant PC12 cell lines that preferentially metastasized to specific sites and that had acquired different in vitro behavior and ability to metastasize. This unique model system should be useful for further studies relating to the invasion and metastases of pheochromocytoma and may prove valuable for investigations of novel antineoplastic therapies in vitro and in vivo.

Laparoscopic thermal ablation of hepatic neuroendocrine tumor metastases

BACKGROUND

Neuroendocrine tumor metastases to the liver are generally slow growing, but patients suffer from hormone hypersecretion despite aggressive multimodality therapy. A minimally invasive method of tumor ablation affords symptomatic improvement with minimal morbidity.

METHODS

Radiofrequency electrical energy is delivered to tissues via a 4-prong catheter resulting in tissue heating to 60 to 70 degrees C and cell death. Porcine studies were conducted to define appropriate parameters for energy delivery and then applied to patients using laparoscopic techniques.

RESULTS

In the porcine model 3.5 to 4 cm lesions were reproducibly created in 15 minutes using 30 to 50 W of power. The ablation process was monitored via temperature feedback from thermocouples in the catheter tips and by a hyperechoic blush noted on ultrasonography. Laparoscopic thermal ablation of 13 tumors in six patients with carcinoid (two patients), gastrinoma, insulinoma, nonsecreting islet cell cancer, or medullary thyroid cancer was performed. There were no intraoperative complications, and all patients were discharged the next day. Successful ablation was confirmed by spiral-computed tomography and by symptomatic improvement in patients with secreting tumors.

CONCLUSIONS

Laparoscopic thermal ablation of hepatic tumors is a novel, minimally invasive method of providing effective cytoreduction of neuroendocrine tumors metastatic to the liver.

Vascular endothelial growth factor expression is higher in differentiated thyroid cancer than in normal or benign thyroid

Vascular endothelial growth factor (VEGF) is an angiogenic factor, and its expression has been rarely demonstrated in thyroid tumors. We, therefore, investigated the expression of VEGF messenger RNA (mRNA) and production of VEGF protein in cell lines from human primary and metastatic follicular (FTC-133, FTC-236, and FTC-238), papillary (TPC-1), Hürthle cell (XTC-1), and medullary thyroid cancers (MTC-1.1 and MTC-2.2), and in human thyroid tissues (papillary, follicular, medullary, and Hürthle cell cancers, follicular adenomas, and Graves' thyroid tissue) by Northern blot, immunohistochemistry, and enzyme-linked immunosorbent assay (ELISA) studies. All thyroid cell lines expressed a 4.2-kilobase VEGF mRNA. The VEGF mRNA levels were higher in the thyroid cancer cell lines than in primary cultures of normal thyroid cells, and higher in thyroid cancers of follicular than those of parafollicular cell origin. The VEGF mRNA levels were similar in primary and metastatic thyroid tumors. Immunohistochemical staining and Northern blot analysis of the cell lines correlated positively, thus thyroid cancer cell lines stained more intensely than normal thyroid cells and follicular tumor cells more intensely than parafollicular tumor cells. Again, no difference was noted in VEGF staining between primary and metastatic thyroid tumors. Deparafinized sections of papillary, follicular, and Hürthle cell cancers also stained much stronger than those of medullary thyroid cancers, benign, or hyperplastic (Graves' disease) thyroid tissue. Thyroid cancer cell lines (XTC-1 > TPC-1 > FTC-133 > MTC-1.1) also secreted more VEGF protein as measured by ELISA than did normal thyroid cells. VEGF secretion of cell lines derived from primary and metastatic thyroid tumors were similar. VEGF mRNA is therefore expressed, and VEGF protein is secreted by normal, hyperplastic, and neoplastic thyroid tissues. The higher levels of VEGF expression in differentiated thyroid cancers of follicular cell origin suggests a role in oncogenesis.

Sestamibi scanning is inadequate for directing unilateral neck exploration for first-time parathyroidectomy

OBJECTIVE

To determine whether technetium Tc 99m sestamibi scanning is accurate enough to allow surgeons to perform unilateral neck exploration for first-time parathyroidectomy in patients with primary hyperparathyroidism.

DESIGN

Retrospective review.

SETTING

University tertiary care center.

PATIENTS

Forty patients with primary hyperparathyroidism who underwent sestamibi scanning before first-time parathyroidectomy, of whom 28 had single adenomas, 9 had multiple adenomas, and 3 had hyperplasia.

INTERVENTIONS

All 40 patients underwent bilateral neck exploration with identification of 4 parathyroid glands.

MAIN OUTCOME MEASURES

We compared the results of preoperative sestamibi scanning with operative and histologic findings. We then used these data to calculate the projected success rates of parathyroidectomy if unilateral neck explorations had been performed based on the results of sestamibi scanning, instead of bilateral explorations.

RESULTS

Sestamibi scanning was correct in 20 (71%) of 28 patients with single adenomas, 4 (44%) of 9 patients with multiple adenomas, and 0 (0%) of 3 patients with hyperplasia. If unilateral neck explorations had been performed on the basis of localization by sestamibi scanning, parathyroidectomy would have failed in 4 (10%) of 40 patients.

CONCLUSIONS

Sestamibi scanning, although helpful, is inadequate for directing unilateral neck exploration for first-time parathyroidectomy. Surgeons who perform unilateral neck exploration based on the results of sestamibi scanning will record a higher failure rate and incur higher costs than those who perform bilateral neck exploration for first-time parathyroidectomy.

Antiproliferative effect of suramin on primary cultures of human pheochromocytomas and rat PC12 pheochromocytoma cells

BACKGROUND

Suramin inhibits growth of neural crest-derived cells and is used to treat adrenocortical cancer and neuroblastoma in clinical trials. The antiproliferative effect of suramin was evaluated in primary cultures of human pheochromocytoma and the PC12 rat pheochromocytoma cell line in vitro and in vivo.

METHODS

Human pheochromocytoma and PC12 rat pheochromocytoma cells were grown in medium supplemented with suramin at concentrations of 1-1,000 micrograms/ml (1.43-1.43 mM) for up to five generations. Suramin did not induce neuronal differentiation, but inhibited growth of cultured human pheochromocytoma cells with IC50 (inhibitory concentration at which a 50% reduction of proliferation is observed) of 50-250 micrograms/ml. Also, suramin inhibited proliferation of PC12 cells with IC50 of 228 micrograms/ml after 5 days and 161 micrograms/ml at 10 days of treatment. Colony formation assays demonstrated these effects to be cytotoxic rather than cytostatic. Thus when reproductive integrity of PC12 cells was taken into account, IC50 was calculated with 118 micrograms/ml and 129 micrograms/ml, respectively. In vivo experiments were performed with subcutaneously xenotransplanted PC12 cells (BALB/c NCR-NU mice). Suramin did not alter tumorigenicity and did not inhibit local tumor growth.

RESULTS

These data determine for the first time an antiproliferative effect of suramin in pheochromocytoma cells. Suramin is cytotoxic to pheochromocytoma cells in vitro at levels that are clinically achievable.

CONCLUSIONS

Suramin may have potential as an antiproliferative drug in nonresectable pheochromocytoma.

Familial hyperparathyroidism without multiple endocrine neoplasia

Hyperparathyroidism occurs sporadically, in association with multiple endocrine neoplasia (MEN) types I and II, or rarely as familial hyperparathyroidism (FHPT) without other manifestations. We analyzed our experience in 16 FHPT patients from 14 families treated between 1934 and 1991 and reviewed 51 other FHPT patients reported in the literature to determine the clinical course of these patients. Among our 16 patients, 7 (44%) had a serum calcium level >/= 3.75 mmol/L, 5 (31%) presented with hypercalcemic crisis, 3 (19%) had osteitis fibrosa cystica, 5 (31%) had nephrolithiasis, 1 had pancreatitis, 12 (75%) had multiple abnormal parathyroid glands, 3 (19%) had supernumerary glands, and 7 (44%) required reoperation for persistent (n = 4) or recurrent (n = 3) hyperparathyroidism. Three patients (19%) also had papillary thyroid cancer, and 7 (44%) had other coexistent thyroid disorders. Among 51 patients with FHPT reported in the literature, 23 (45%) had serum calcium >/= 3.75 mmol/L, and 23 (45%) had multiple abnormal parathyroid glands; 10 (20%) had recurrent hyperparathyroidism. FHPT without other endocrinopathies is a distinct entity. Patients with FHPT have multiple abnormal parathyroid glands and are prone to both recurrent and persistent hyperparathyroidism. They frequently present with profound hypercalcemia or hypercalcemic crisis, in contrast to patients with MEN-associated hyperparathyroidism or sporadic hyperparathyroidism.

Thyroid-stimulating hormone promotes the secretion of vascular endothelial growth factor in thyroid cancer cell lines

BACKGROUND

Vascular endothelial growth factor (VEGF) is a vascular endothelial cell-specific mitogen secreted by some cancer cells and is a major regulator of angiogenesis. Because thyroid-stimulating hormone (TSH) promotes growth and progression of thyroid cancers, we postulated that TSH may increase the production and secretion of VEGF by thyroid cancer cells.

METHODS

We examined primary cultures of normal human thyroid (NT 1.0), medullary thyroid cancer (MTC 1.1), and cell lines derived from the papillary (TPC-1), follicular (FTC-133), and Hürthle cell (XTC-1) thyroid cancer. We quantified the concentration of VEGF in conditioned medium by means of enzyme-linked immunosorbent assay.

RESULTS

Cell lines derived from thyroid secrete VEGF. Basal VEGF secretion was similar in normal and thyroid cancer cells, except XTC-1, which has high basal secretion (p < 0.01). All thyroid cancer cells secrete significantly more VEGF than normal thyroid cells after TSH (10 mIU/ml) stimulation (p < 0.05). TSH stimulated secretion of VEGF in FTC-133 (8.2 ng/dl versus 18.8 ng/dl), TPC-1 (5.5 ng/dl versus 26.9 ng/dl), and MTC 1.1 (5.9 ng/dl versus 13.4 ng/dl) cell lines (p < 0.01), but not in NT 1.0 (8.4 ng/dl versus 9.9 ng/dl) and XTC-1 (25.4 ng/dl versus 31.2 ng/dl) cells.

CONCLUSIONS

These results suggest that VEGF secretion is constitutively activated in some thyroid cancers and that VEGF secretion is stimulated by TSH; thus TSH may promote growth in some thyroid cancers by stimulating VEGF secretion and angiogenesis.

Desensitization of cyclic adenosine 3,5'-monophosphate response to thyrotropin in normal and primary or metastatic papillary thyroid cancer cells in vitro

BACKGROUND

Desensitization is an important physiologic process resulting in a decreased functional response after continuous or repeated stimulation. Prior exposure of normal human thyroid tissue to thyrotropin either in vivo or in vitro causes desensitization of adenylate cyclase. Little is known, however, about whether the thyrotropin-adenylate cyclase-cyclic adenosine 3,5'-monophosphate (cAMP) signal transduction system desensitizes in human thyroid carcinomas. Failure to desensitize could result in increased growth or metastases.

METHODS

Cell cultures from Chinese hamster ovary (CHO) cells transfected with normal human thyrotropin receptor (hTSHr) and thyroid neoplasms including one papillary carcinoma and one papillary lymph node metastases were evaluated for desensitization. CHO cells were stably transfected with plasmid DNA containing hTSHr. Cells were incubated with thyrotropin (10 mU/ml) for different periods (1 to 24 hours). A second incubation (30 minutes) was done with and without thyrotropin in medium including 3-isobutyl-1-methylxanthine (1 mmol/L). Intracellular cAMP accumulation was determined by means of radioimmunoassay.

RESULTS

Maximal stimulation and desensitization to thyrotropin were observed at 30 minutes and 4 hours, respectively. The cAMP response to a second incubation with thyrotropin was 52% and 48% lower than the initial response to thyrotropin in CHO-hTSHr and papillary thyroid cancer cells, respectively (p < 0.001). A papillary carcinoma lymph node metastases had an increased basal cAMP level and also an increased cAMP level in response to thyrotropin stimulation (227%) but failed to desensitize (p < 0.001).

CONCLUSIONS

Desensitization of the cAMP response to thyrotropin occurred in a papillary thyroid cancer but not in a metastatic thyroid cancer. Failure to desensitize might play a role in tumor progression.

Immunocytochemical detection of p53 in human thyroid carcinomas is associated with mutation and immortalization of cell lines

Mutations in the tumor suppressor gene p53 are the most-common mutations found in human cancers. In thyroid cancers, p53 mutations generally are found only in poorly differentiated and undifferentiated tumors and in cell lines. To determine the prevalence of p53 mutations in thyroid neoplasms and thyroid cell lines, we screened 58 thyroid tissues and 3 thyroid cell lines, p53 primers bracketing exons 4, 5/6, 7, and 8 were used to amplify genomic DNA using the PCR. Mutations were screened by denaturing gradient gel electrophoresis and confirmed by sequencing. The two papillary thyroid cancer cell lines and the follicular thyroid carcinoma cell line (positive control) had transitions (CGT->CAT) in exon 8, codon 273, resulting in the replacement of arginine with histidine. No normal thyroid tissues or primary tumors from which the cell lines were derived demonstrated exon 8 mutations, using this technique. p53 immunocytochemistry demonstrated a progression of p53 immunopositivity between synchronous and metachronous neoplasms, paralleling the neoplastic progression from a benign adenoma to primary carcinoma, regional, and distant metastasis and ultimately, the cell lines, where intense immunopositivity is noted. In addition, fluorescence in situ hybridization, using probes specific for the p53 locus, revealed the presence of 3 homologues of p53 in the follicular cell line and 2 homologues in the papillary and Hürthle cell lines. These results suggest that a point mutation present in a small number of original tumor cells and amplification of the mutant allele may be responsible for immortalizing well-differentiated thyroid cancer cells into cell lines.

Reoperation for persistent or recurrent primary hyperparathyroidism

OBJECTIVE

To analyze the causes and outcomes of reoperation for persistent or recurrent primary hyperparathyroidism.

DATA SOURCES

Medical records of 102 patients with persistent or recurrent primary hyperparathyroidism who underwent reoperation by 1 surgeon between 1985 and 1995.

STUDY SELECTION

Only patients with persistent or recurrent primary hyperparathyroidism were selected; patients with secondary hyperparathyroidism, parathyroid cancer, familial hyperparathyroidism, and previous thyroid operations were omitted.

DATA EXTRACTION

Performed by a single unblinded researcher.

DATA SYNTHESIS

Reasons for failed parathyroid operations included tumor in ectopic position (53%), incomplete resection of multiple abnormal glands (37%), adenoma in normal position missed during previous surgery (7%), and regrowth of previously resected tumor (3%). Of the ectopic glands, 28% were paraesophageal, 26% in the mediastinum (nonthymic), 24% intrathymic, 11% intrathyroidal, 9% in the carotid sheath, and 2% in a high cervical position. Eighty-three percent of ectopic glands were accessible via cervical incision. The success rate of reoperations was 95%. One patient (1%) became permanently hypocalcemic after reoperation; 1 patient (1%) suffered permanent unilateral vocal cord paralysis. The sensitivities of preoperative localization studies were as follows: technetium Tc 99m sestamibi scan, 77%; magnetic resonance imaging, 77%; selective venous catheterization for intact parathyroid hormone, 77%; thallium-technetium scan, 68%; ultrasonography, 57%; and computed tomography, 42%.

CONCLUSIONS

Repeated parathyroidectomy can be avoided in more than 95% of patients if an experienced surgeon performs bilateral cervical exploration during the initial parathyroid operation. For patients with persistent or recurrent primary hyperparathyroidism, preoperative localization studies and a focused surgical approach can result in a 95% success rate with minimum complications.

Laparoscopic adrenalectomy. Comparison of the lateral and posterior approaches

OBJECTIVE

To compare the lateral transabdominal and posterior retroperitoneal laparoscopic methods for performing adrenalectomy.

DESIGN

Nonrandomized.

SETTING

Hospitals affiliated with the University of California, San Francisco.

PATIENTS

Thirty-six patients (15 men and 21 women), aged 5 to 78 years (mean age, 49 years), were treated for the following conditions: aldosteronoma, 18 patients; pheochromocytoma, 4 patients; Cushing syndrome, 6 patients; androgen-secreting tumor, 1 patient; nonfunctioning adenoma, 3 patients; adrenal hemorrhage, 1 patient; metastatic neoplasm, 2 patients; and myelolipoma, 1 patient.

INTERVENTIONS

Twenty-three lateral and 14 posterior laparoscopic adrenalectomies.

MAIN OUTCOME MEASURES

Success rate, operating time, complications, and length of hospital stay.

RESULTS

The tumors, which ranged in size from 1 to 13 cm (mean, 4.2 cm; median, 2.5 cm), were all successfully resected laparoscopically. All 8 tumors larger than 6 cm were resected by the lateral approach. One critically ill patient died. No patient required blood transfusions or conversion to laparotomy. Mean operating time was 3.8 hours vs 3.4 hours (median, 3.5 hours vs 3 hours) and mean hospital stay was 2.2 days vs 1.5 days (median, 2 days vs 1 day) for the lateral and posterior approaches, respectively. All patients without concomitant procedures were ready to be discharged within 48 hours.

CONCLUSIONS

Both approaches were effective and safe. We prefer the lateral approach for tumors larger than 6 cm and the posterior approach for bilateral tumors.

Persistent or recurrent hyperparathyroidism in patients with double adenomas

BACKGROUND

Are double parathyroid adenomas a discrete clinical entity or are all hyperplastic parathyroid glands of varying size? This investigation was done to determine whether patients with persistent or recurrent hyperparathyroidism and double adenomas (DA) differ in clinical profile or in response to treatment from patients with hyperplasia.

METHODS

From 1982 to 1993, 37 unselected patients with persistent (11) or recurrent hyperparathyroidism (26) were treated. Twenty-one had DA and 16 had hyperplasia. DAs were defined as two abnormal and two normal parathyroid glands.

RESULTS

Patients with persistent or recurrent hyperparathyroidism caused by DA were older and had more muscle weakness, neuropsychiatric disorders, constipation, and weight loss (p < 0.001) than patients with persistent or recurrent hyperparathyroidism caused by hyperplasia. Nephrolithiasis was more common in patients with recurrent hyperparathyroidism caused by hyperplasia than in patients with recurrent hyperparathyroidism caused by DA (p < 0.001). Serum Ca2+ levels before operation were similar in these groups with variable parathyroid hormone levels. No recurrences occurred in either group (DA [mean, 6 yr]; hyperplasia [mean, 5 yr]). Postoperative levels of serum Ca2+ and parathyroid hormone were normal in both groups.

CONCLUSIONS

Patients with persistent or recurrent hyperparathyroidism caused by DA are older, have different clinical manifestations, and are cured by resection of the second adenoma. These findings support the concept that DA and hyperplasia are distinct entities.