Intraoperative abdominal ultrasonography

Diagnostic and procedural intraoperative ultrasound: technique, tips and tricks for optimizing results

Intraoperative ultrasound (IOUS) is a valuable adjunctive tool that can provide real-time diagnostic information in surgery that has the potential to alter patient management and decrease complications. Lesion localization, characterization and staging can be performed, as well as surveying for additional lesions and metastatic disease. IOUS is commonly used in the liver for hepatic metastatic disease and hepatocellular carcinoma, in the pancreas for neuroendocrine tumors, and in the kidney for renal cell carcinoma. IOUS allows real-time evaluation of vascular patency and perfusion in organ transplantation and allows for early intervention for anastomotic complications. It can also be used to guide intraoperative procedures such as biopsy, fiducial placement, radiation, or ablation. A variety of adjuncts including microbubble contrast and elastography may provide additional information at IOUS. It is important for the radiologist to be familiar with the available equipment, common clinical indications, technique, relevant anatomy and intraoperative imaging appearance to optimize performance of this valuable imaging modality.

The value of preoperative computed tomography combined with ultrasound in the investigation of small indeterminate liver lesions in patients with colorectal cancer

Background Computed tomography (CT) is used routinely for the preoperative detection of colorectal cancer (CRC) metastases. When small indeterminate focal liver lesions are detected that are too small to characterize (TSTC) on CT, additional imaging is usually needed, resulting in a potential delay in obtaining a complete diagnostic work-up. Purpose To determine the diagnostic accuracy of ultrasound (US) of the liver performed in direct conjunction to CT in the preoperative investigation among patients with newly diagnosed CRC when indeterminate liver lesions were found on CT. Material and Methods Preoperative investigations with CT and consecutive US where CT had shown at least one focal liver lesion in 74 patients diagnosed with CRC between June 2009 and February 2012 were retrospectively reviewed. Either histopathological findings or a combination of imaging and clinical follow-up one to three years after surgery was used as the reference. Results Liver metastases were diagnosed with CT/US in 13 out of 74 patients (17.6%). In one patient, a liver cyst was preoperatively regarded as liver metastasis by a combined CT/US. The sensitivity and specificity for the CT with consecutive US procedure was 100% (13/13) and 98.4% (60/61). Conclusion US performed in conjunction with CT in patients with indeterminate focal liver lesions on CT is an accurate work-up for detection of liver metastases in patients with newly diagnosed CRC. Although our results are promising, they cannot be considered safely generalizable to all hospitals.

Intraoperative Ultrasound as a Screening Modality for the Detection of Liver Metastases during Resection of Primary Colorectal Cancer - A Systematic Review

Colorectal cancer (CRC) is one of the most common cancer diseases worldwide. One in 4 patients with CRC will have a disseminated disease at the time of diagnosis and often in the form of synchronous liver metastases. Studies suggest that up to 30% of patients have non-recognized hepatic metastases during primary surgery for CRC. Intraoperative ultrasonography examination (IOUS) of the liver to detect liver metastases was considered the gold standard during open CRC surgery. Today laparoscopic surgery is the standard procedure, but laparoscopic ultrasound examination (LUS) is not performed routinely. Aim To perform a systematic review of the test performance of IOUS and LUS regarding the detection of synchronous liver metastases in patients undergoing surgery for primary CRC. Method The literature was systematically reviewed using the search engines: PubMed, Cochrane, Embase and Google. 21 studies were included in the review and the key words: intraoperative ultrasound, laparoscopic ultrasound, staging colon and rectum cancer. Results Intraoperative ultrasound showed a higher sensitivity, specificity, positive predictive value and overall accuracy for the detection liver metastases during surgery for primary CRC, compared to preoperative imaging modalities (ultrasound, computed tomography (CT) and contrast-enhanced computed tomography (CE-CT)). LUS showed a higher detection rate for liver metastases compared to CT, CE-CT and magnetic resonance imaging (MRI). Conclusion This systematic review found that both IOUS and LUS had a higher detection rate regarding liver metastases during primary CRC surgery, especially liver metastases<10 mm in diameter, when compared to US, CT, CE-CT and MRI.

Intraoperative ultrasonography and surgical strategy in hepatic resection: What difference does it make?

BACKGROUND

With modern advancements in preoperative imaging for liver surgery, intraoperative ultrasonography (IOUS) may be perceived as superfluous. Our aim was to determine if IOUS provides new information that changes surgical strategy in hepatic resection.

METHODS

We retrospectively analyzed 121 consecutive liver resections performed at a single institution. Preoperative computed tomography and/or magnetic resonance imaging determined the initial surgical strategy. The size, location and number of lesions were compared between IOUS and preoperative imaging. Reviewing the operative report helped determine if new IOUS findings led to changes in surgical strategy. Pathology reports were analyzed for margins.

RESULTS

Of 121 procedures analyzed, IOUS was used in 88. It changed the surgical plan in 15 (17%) cases. Additional tumours were detected in 10 (11%) patients. A change in tumour size and location were detected in 2 (2%) and 3 (4%) patients, respectively. Surgical plans were altered in 7 (8%) cases for reasons not related to IOUS. There was no significant difference (p = 0.74) in average margin length between the IOUS and non-IOUS groups (1.09 ± 1.18 cm v. 1.18 ± 1.05 cm).

CONCLUSION

Surgical strategy was altered owing to IOUS results in a substantial number of cases, and IOUS-guided resection planes resulted in R0 resections in nearly all procedures. The best operative plan in hepatic resection includes IOUS.

Pancreatic surgery: a multidisciplinary assessment of the value of intraoperative US

PURPOSE

To assess the value of intraoperative ultrasonography (US) for different types of pancreatic surgery.

MATERIALS AND METHODS

An institutional review board-approved, HIPAA-compliant retrospective review with waiver of informed consent was performed to evaluate all cases of pancreatic surgery with intraoperative US or laparoscopic US that occurred at a single institution during a 10-year period. Surgical notes, radiologic images, and clinical data for each surgical procedure and subsequent clinical course were reviewed by pancreatic surgeons and radiologists. Presumptive diagnosis, type of surgical procedure performed, and final pathologic data were recorded. A relative value score was established by consensus and assigned to each case with a grade of 0-3, which indicated the value of the intraoperative or laparoscopic US. The type of operation and pathologic data were compared in each of the value score groups. Categoric variables were compared by using either χ(2) or Fisher exact test.

RESULTS

One hundred ninety-three intraoperative or laparoscopic US procedures were performed in 189 patients. Of the patients, there were 102 men and 87 women. The mean age was 57.8 years (range, 18-86 years). Intraoperative or laparoscopic US value scores were as follows: value score 0, 3.6%; value score 1, 11.9%; value score 2, 31.1%; and value score 3, 53.4%. The most common contribution that resulted in a high score (value score 3) was facilitation of technical performance of the surgery (n = 60). High value score was significantly associated with performance of pancreatitis-related surgery (P < .001). The surgical indication that most commonly resulted in a low value score of 0 or 1 was staging of pancreatic cancers. All cases that received a score of 0 occurred in the laparoscopic adenocarcinoma surgical setting (staging or pancreatic biopsy).

CONCLUSION

Intraoperative or laparoscopic US can be a valuable procedure in multiple types of surgical procedures that involve the pancreas and shows clear patterns of value in the different types of surgery.

Navigation with the use of intraoperative ultrasonography in videoscopic adrenal surgery

The aim of the study was to assess the efficacy of intraoperative ultrasonography during videoscopic adrenalectomy.

MATERIAL AND METHODS

The study was conducted in patients undergoing extraperitoneal videoscopic adrenalectomy for adrenal tumours in the Department of Endocrine, General and Vascular Surgery of the Medical University in Łódź in 2008-2011.

RESULTS

The active group consisted of 20 patients in whom navigation with the use of intraoperative ultrasonography (IOUS) was used in the course of surgery. The comparison group consisted of 46 patients operated without the use of IOUS. In the active group, we managed to obtain a shorter time of surgery by almost 20 min (89.44 ± 27.11 min vs 109.12 ± 33.88 min; p=0.034) and a shorter lesion access time by more than 15 min (28.61 ± 14.93 min vs 45.98 ± 20.44 min; p=0.002). Intraoperative blood loss was also significantly lower in the active group (86.11 ± 157 ml vs 169.27 ± 201.04 ml; p=0.037). In contrast, the use of IOUS did not affect the hospitalisation time (4.39 ± 3.27 days vs 3.83 ± 3.67 days; p=0.227), the rate of intraoperative complications (0/18 vs 2/41; p=1) and the conversion rate (2/20 - 10% vs 5/46 - 10.87%; p=1).

CONCLUSIONS

1. Intraoperative ultrasonography is useful for determining the tumour relationship with the surrounding anatomical structures. 2. Intraoperative ultrasonography is a useful technique in the assessment of adrenal tumour infiltration of the surrounding tissues. 3. This technique facilitates finding the pathological lesion, shortening the time of access to the tumour and procedure duration (thus reducing the burden for the patient). 4. Reduced blood loss was also obtained owing to the use of IOUS.

Is intra-operative ultrasound still useful for the detection of a hepatic tumour in the era of modern pre-operative imaging?

BACKGROUND

The current role of intra-operative ultrasound (IOUS) is questioned because of recent progress in medical imaging. The aim of the present study was to determine the accuracy of IOUS in the detection of a hepatic tumour (HT) compared with a pre-operative multi-detector computed tomography (MDCT) scan and magnetic resonance imaging (MRI).

METHODS

This retrospective study included 418 patients evaluated using an 8-slice MDCT scan (SCAN8), 64-slice MDCT scan (SCAN64) and MRI alone or combined with a computed tomography (CT) scan. The pathological result was used as a gold standard.

RESULTS

Correlation rates for the number of detected lesions compared with pathology results were 0.627 for SCAN8, 0.785 for SCAN64, 0.657 for MRI and 0.913 for IOUS. Compared with pathology, the rate of concordance was significantly higher with IOUS (0.871) than with SCAN8 (0.736; P=0.011), SCAN64 (0.792; P<0.001) and MRI (0.742; P<0.001). IOUS was responsible for a change in operative strategy in 16.5% of patients. Surgery was extended in 12.4%, limited in 1.7% and abandoned in 2.4%.

CONCLUSIONS

Compared with cross-sectional pre-operative imaging, IOUS is still superior for the detection of HT and the planning of surgery. IOUS remains recommended as a routine procedure in patients having a hepatic resection in the era of modern pre-operative imaging.

Value of intraoperative ultrasonography in tonsil cancer

BACKGROUND

The exact assessment of a tonsil carcinoma's size is often difficult because of the tumour's submucosal extension and deep infiltration.

AIM

The aim of the study is to assess the usefulness of intraoperative ultrasonography in tonsil cancer.

MATERIAL

Twenty patients with carcinoma of the tonsil were included in the study (squamous cell carcinoma keratosis - 12, squamous cell carcinoma akeratosis - 6, diffuse large B cell lymphoma - 1, neoplasma malignum microcellulare - 1).

METHOD

Transcutaneous, endoscopic, and intraoperative ultrasonography were performed using a linear 7.5 MHz probe.

RESULTS

The difference in the results was statistically significant between palpation examination and intraoperative ultrasonographic examination, between transcutaneous ultrasonographic examination and intraoperative ultrasonographic examination, and between endoscopic ultrasonographic examination and intraoperative ultrasonographic examination in tonsil tumours. Generally, tumour size assessed by intraoperative ultrasonography was more advanced than those assessed by other methods.

CONCLUSIONS

Intraoperative ultrasonography is a safe, non-invasive method, which can be repeated at every stage of surgery. There were no contraindications or side effects. In all cases histological margins corresponded to sonographic margins. Intraoperative ultrasonography provides a quick and reliable orientation during resection of tonsil carcinoma.

The introduction of a simple maneuver to reduce the risk of postoperative bleeding after major hepatectomies

BACKGROUND/PURPOSE

In major hepatectomies, postoperative increases in central venous pressure (CVP) may cause suture failure and massive bleeding. The aim of our study is to test the application of an intraoperative maneuver to reduce the risk of postoperative bleeding.

METHODS

Our study included 172 consecutive patients who had major liver resection with selective hepatic vascular exclusion and sharp transection of the liver parenchyma. An intraoperative maneuver (5 s occlusion of the hepatic vein) was applied in an alternating way, and the patients were assigned to two groups: Cohort A (n = 86), that was granted the maneuver, and Cohort B (n = 86), that was used as a control group.

RESULTS

In Cohort A, application of the maneuver was successful in demonstrating bleeders under low CVP levels. Cohort A had lower rate of massive bleeding requiring emergency reoperation (2.3 vs 5.8%, P = 0.049), less postoperative blood transfusions (13 vs 24%, P = 0.042), lower morbidity (20 vs 35%, P < 0.045) and shorter hospital stay compared to Cohort B.

CONCLUSIONS

Hepatectomies conducted under low CVP are prone to postoperative hemorrhage which can be prevented if the final bleeding control is performed under high pressure in the hepatic veins. Application of our testing maneuver effectively unmasked previously undetectable bleeding veins.

The current role of PET-CT in the characterization of hepatobiliary malignancies

BACKGROUND

Surgery has become heavily dependent on accurate imaging in the assessment and treatment of suspected or confirmed intra-abdominal malignancy. Positron emission tomography-computed tomography (PET-CT) fuses uptake of a radiotracer combined with CT images to assess both functional tissue activity and anatomical detail. Since its introduction it has offered new ways of treating gastrointestinal cancers.

METHODS

The review analyses the present literature regarding the use of PET-CT in the assessment, diagnosis, staging and treatment of hepatobiliary malignancies.

RESULTS

PET-CT is widely used in pre-operative tumours staging for colorectal liver metastases. There is convincing data that it may also be applicable for neuroendocrine tumours, assessment of indeterminate pancreas lesions and clinical drug trials. PET-CT is of limited value in hepatocellular cancers, although new techniques in dual-tracer PET-CT may change this.

CONCLUSION

Knowledge of the strengths and limitations of PET-CT is important for all surgeons managing cancer of the hepatobiliary system. More clinical data are required on PET-CT, particularly its effect on long-term survival in PET-CT-staged patients undergoing resection.

Management of hepatic metastasis from colorectal cancers: an update

Approximately 50%-60% of patients with colorectal cancers will develop liver lesions in their life span. Despite the potential of surgical resection to provide long-term survival in this subset of patients, only 15%-20% are found to be resectable. The introduction of new neoadjuvant chemotherapeutic agents and the expanding criteria of resection have enhanced the overall 5-year survival from 30% to 60% in the past decade. The use of technical innovations such as staged resection; portal vein embolization, and repeat resection have allowed higher resection rates in patients with bilobar disease. Extrahepatic primary and liver-exclusive recurrent disease no longer represent an absolute contraindication to resection. The role of regional therapy using hepatic arterial infusion is being redefined for liver-exclusive unresectable disease. Adjuvant chemotherapy in combination with regional therapies is being looked at from fresh perspectives. Ablative approaches have gained a firm role both as an adjunct to surgical resection and in the management of patients who are not surgical candidates. Overall, the management of hepatic metastasis from colorectal cancers requires a multimodal approach.

Intraoperative sonography in patients with colorectal cancer and resectable liver metastases on preoperative FDG-PET-CT

BACKGROUND

Combined fluorine 18-fluorodeoxyglucose-positron emission tomography-CT imaging has been shown to be of good diagnostic value in the preoperative evaluation of patients with colorectal cancer and liver metastases. The adjunctive use of intraoperative sonography (IOUS) may have a limited impact on treatment selection in these patients.

PURPOSE

To compare the diagnostic performance of preoperative positron emission tomography (PET)-CT alone and PET-CT combined with IOUS in the evaluation of patients who are considered for curative resection of hepatic metastases from colorectal carcinoma.

MATERIALS AND METHODS

Patients with colorectal cancer who underwent resection of hepatic metastases and preoperative PET-CT (with or without contrast-enhanced CT) and IOUS were identified. The performance of the imaging techniques was evaluated through review of the radiologic reports, correlation with surgical and histopathologic findings, and clinical follow-up.

RESULTS

Thirty-one patients (mean age, 63.5 years [range, 53-82 years]) were analyzed. Fifteen patients had received preoperative chemotherapy. The mean interval between PET-CT and IOUS was 22.6 days (range, 1-56 days). In 4 cases, neither PET-CT nor IOUS correctly diagnosed the liver metastases. In all 31 patients, the sensitivity of PET-CT alone and PET-CT combined with IOUS was 63% (95% CI 44-80%) and 93% (95% CI 78-98%), respectively; the positive predictive value was 81% and 89%, respectively. In patients without preoperative chemotherapy (n = 16), the sensitivity of PET-CT alone and PET-CT combined with IOUS was 77% (95% CI 49-94%) and 100% (95% CI 79-100%), respectively. In 11 cases (35%), IOUS altered the surgical strategy.

CONCLUSION

In patients with colorectal carcinoma and potentially resectable liver metastases on preoperative PET-CT, IOUS can provide additional information that may alter decision making with regard to surgical technique.

Echogenic appearance of colorectal liver metastases on intraoperative ultrasonography is associated with survival after hepatic resection

Survival after resection of colorectal liver metastases has traditionally been associated with clinicopathologic factors. We sought to investigate whether echogenicity of colorectal liver metastasis as assessed by intraoperative ultrasound (IOUS) was a prognostic factor after hepatic resection. Prospective data on tumor IOUS appearance were collected in 84 patients who underwent hepatic resection for colorectal liver metastasis. Images were digitally recorded, blindly reviewed, and scored for echogenicity (hypo-, iso-, or hyperechoic). The median tumor number was 1 and the median tumor size was 5.0 cm. At the time of surgery, the IOUS appearance of the colorectal liver metastases were hypoechoic in 35 (41.7%) patients, isoechoic in 37 (44.0%) patients, and hyperechoic in 12 (14.3%) patients. Traditional clinicopathologic prognostic factors were similarly distributed among the three echogenicity groups (all p > 0.05). Patients with a hypoechoic lesion had a significantly shorter median survival (30.2 months) compared with patients who had either an isoechoic (53.2 months) or hyperechoic (42.3 months) lesion (p = 0.005). The 5-year survival after hepatic resection of colorectal liver metastasis was also associated with the echogenic appearance of the lesion (hypoechoic 14.4 vs isoechoic 37.4 vs hyperechoic 46.2%) (p < 0.05). Intraoperative ultrasound echogenicity should be considered a prognostic factor after hepatic resection of metastatic colorectal cancer.

Surgical therapy for colorectal metastases to the liver

Colorectal cancer is the fourth most common type of cancer in the West and the second leading cause of cancer-related deaths in the United States. Approximately 35 to 55% of patients with colorectal cancer develop hepatic metastases during the course of their disease. Surgical resection of colorectal liver metastases represents the only chance at potential cure, and long-term survival can be achieved in 35 to 58% of patients after resection. The goal of hepatic resection should be to resect all metastases with negative histologic margins while preserving sufficient functional hepatic parenchyma. In patients with extensive metastatic disease who would otherwise be unresectable, ablative approaches can be used instead of or combined with hepatic resection. The use of portal vein embolization and preoperative chemotherapy may also expand the population of patients who are candidates for surgical treatment. Despite these advances, many patients still experience a recurrence after hepatic resection. More active systemic chemotherapy agents are now available and are being increasingly employed as adjuvant therapy either before or after surgery. Modern treatment of colorectal liver metastasis requires a multidisciplinary approach in an effort to increase the number of patients who may benefit from surgical treatment of colorectal cancer liver metastasis.

Intraoperative ultrasonography in detecting and assessment of colorectal liver metastases

OBJECTIVE

to assess the clinical value of intraoperative ultrasonography (IOUS) in detecting and assessment of liver metastatic tumours in colorectal cancer patients.

METHODS

a study is a retrospective analysis of 388 patients operated on for colorectal carcinoma between 1997 and 2004. In all the patients intraoperative ultrasound was performed. The authors analyzed of sensitivity, specificity, PPV, NPV and accuracy of pre- and intraoperative ultrasonography in detecting and staging of colorectal metastatic lesions.

RESULTS

Intraoperative ultrasonography showed the highest sensitivity, specificity and accuracy in both, tumor detection (99.1, 98.5 and 98.9%, respectively) and assessment (95.4, 99.5 and 99.1%, respectively). Overall sensitivity of IOUS was significantly better in detection and staging compared with preoperative ultrasonography 91.1 and 72.2%, respectively).

CONCLUSIONS

IOUS should be used as routine diagnostic modality in colorectal cancer patients with hepatic metastases or suspected metastases. Transabdominal ultrasonography cannot be used as the only diagnostic tool in the evaluation of liver lesions, but may be helpful in preoperative screening.

Avaliação dos insulinomas pela ultra-sonografia intra-operatória: estado atual do tema

Os autores fazem uma revisão da literatura sobre a utilização da ultra-sonografia intra-operatória para a avaliação dos insulinomas pancreáticos. São referidos os resultados da ultra-sonografia intra-operatória, ultra-sonografia e tomografia computadorizada realizadas no pré-operatório, e os resultados da inspeção e palpação do pâncreas realizadas durante procedimentos cirúrgicos referidos na literatura.

Ultrasonography of the pancreas. 7. Intraoperative imaging

The usefulness of intraoperative ultrasonography (IOUS) has been documented in the Literature since the Eighties and, although its main applications are in hepatobiliary and pancreatic surgery, it has been used also in neurosurgery, cardiovascular and endocrine surgery. The continuous technical developments have led to an increase in the diagnostic accuracy of IOUS from the Eighties to now. The use of IOUS has increased in time together with the technical innovations until, mainly in the midnineties, its value was recognized by many surgeons. This results have been obtained with scanners that allow to depict fine anatomical details and detect small lesions in real time with extremely high spatial resolution. IOUS is able to shows fine details, such as primary or secondary lesions not detectable with other preoperative imaging modalities or tumor extension and its relationship with vessels. Assessment of resectability by IOUS may determine important changes in therapeutic planning. The role of IOUS, however, has recently been down-sized, especially in those centers where preoperative imaging is advanced. This article will review the clinical role of pancreatic IOUS in the different pancreatic pathologies.

Vascular control during hepatectomy: review of methods and results

The various techniques of hepatic vascular control are presented, focusing on the indications and drawbacks of each. Retrospective and prospective clinical studies highlight aspects of the pathophysiology, indications, and morbidity of the various techniques of hepatic vascular control. Newer perspectives on the field emerge from the introduction of ischemic preconditioning and laparoscopic hepatectomy. A literature review based on computer searches in Index Medicus and PubMed focuses mainly on prospective studies comparing techniques and large retrospective ones. All methods of hepatic vascular control can be applied with minimal mortality by experienced surgeons and are effective for controlling bleeding. The Pringle maneuver is the oldest and simplest of these methods and is still favored by many surgeons. Intermittent application of the Pringle maneuver and hemihepatic occlusion or inflow occlusion with extraparenchymal control of major hepatic veins is particularly indicated for patients with abnormal parenchyma. Total hepatic vascular exclusion is associated with considerable morbidity and hemodynamic intolerance in 10% to 20% of patients. It is absolutely indicated only when extensive reconstruction of the inferior vena cava (IVC) is warranted. Major hepatic veins/ and limited IVC reconstruction has been also achieved under inflow occlusion with extraparenchymal control of major hepatic veins or even using the intermittent Pringle maneuver. Ischemic preconditioning is strongly recommended for patients younger than 60 years and those with steatotic livers. Each hepatic vascular control technique has its place in liver surgery, depending on tumor location, underlying liver disease, patient cardiovascular status, and, most important, the experience of the surgical and anesthesia team.

Diagnostic laparoscopy and laparoscopic ultrasonography with local anesthesia in hepatocellular carcinoma

Diagnosis of hepatocellular carcinoma (HCC), a common digestive malignancy, remains a challenge. The aim of this study was to evaluate the feasibility of performing laparoscopy and laparoscopic ultrasound with local anesthesia as a diagnostic procedure in HCC. Laparoscopy and laparoscopic ultrasound with local anesthesia was performed in the gastrointestinal endoscopy unit in three patients diagnosed of HCC. Endoscopy staged diffuse liver disease. Laparoscopic ultrasonography identified all liver tumors not visible during endoscopy and guided needle biopsy in one case. No complications happened. In conclusion, laparoscopy and laparoscopic ultrasound, performed as a minimally invasive diagnostic procedure can be a safe and very promising tool in planning therapy of HCC.

Intraoperative ultrasonography of the liver in patients with abdominal tumors: a new approach

OBJECTIVES

To compare liver intraoperative ultrasonography (IOU), computed tomography (CT), preoperative ultrasonography (USG), and intraoperative inspection and palpation in the detection of hepatic lesions in patients with abdominal tumors.

METHODS

This was a prospective study including 60 patients with abdominal tumors evaluated by USG, CT, inspection and palpation, and hepatic IOU during exploratory laparotomy. Sensitivity, specificity, and positive and negative predictive values for all methods were calculated. Agreement of methods with histopathologic results was calculated by kappa statistics and the Spearman coefficient.

RESULTS

Of the 60 patients, 49 (81.6%) had positive findings for hepatic lesions. Lesions could not be counted in 3 patients. The 46 remaining cases were diagnosed by histologic examination. Sensitivity, specificity, and positive and negative predictive values were 42.9%, 88.9%, 90%, and 40% for USG; 59.5%, 77.8%, 86.2%, and 45.2% for CT; 69.0%, 88.9%, 93.5%, and 55.2% for inspection and palpation; and 90.5%, 77.8%, 90.5%, and 77.8% for IOU, with histologic examination used as a criterion standard. Fair to moderate agreement was found for USG, CT, and inspection and palpation (kappa = 0.24, 0.31, and 0.49, respectively). Substantial agreement was found for IOU (kappa = 0.68). Changes in surgical strategy were made in 19 (41.3%) of the 46 cases with positive findings.

CONCLUSIONS

High sensitivity associated with substantial agreement with histopathologic findings shows that IOU is an indispensable evaluation method for hepatic screening in patients with abdominal tumors who undergo laparotomy and should become a routine procedure wherever available.

Intraoperative ultrasound

Intraoperative ultrasound (IOUS) can provide various diagnostic information that is otherwise not available, and can guide or assist various surgical procedures in real time. With refinement of equipment, IOUS is currently used in a wide variety of surgical operations,such as hepatobiliary, pancreatic, endocrine, cardiovascular,and neurologic surgery. Our overview of IOUS, including instrumentation,techniques, indications, advantages, disadvantages,and future perspective, is described in this article. Being safe, quick, accurate, and versatile intraoperatively, IOUS is a valuable technique that surgeons are recommended to master to improve intraoperative decision making and surgical procedures.

Liver metastases in cancer: detection with contrast-enhanced ultrasonography

In patients with known or suspected malignancy, ultrasonography (US) is often the first choice for liver imaging because of its widespread availability and low cost. Compared with contrast-enhanced computed tomography (CT) and magnetic resonance imaging (MRI), the sensitivity of conventional US for detecting hepatic metastases is relatively poor. The advent of microbubble contrast agents changed this situation. Sensitivity and specificity increased substantially with the use of these contrast agents and contrast-specific imaging modes in recent years. Currently, numerous US imaging methods exist, based on Doppler techniques or harmonic imaging. They exploit the complex nonlinear behavior of microbubbles in a sound field to achieve marked augmentation of the US signal. Although microbubble contrast agents are essentially blood pool agents, some have a hepatosplenic specific late phase. Imaging during this late phase is particularly useful for improving the detection of malignant liver lesions and allows US to perform similarly to spiral CT as shown by recent studies. In addition, this late phase imaging is very helpful for lesion characterization. Low mechanical index imaging with the newer perfluor agents permits real-time imaging of the dynamic contrast behavior during the arterial, portal venous, and late phases and is particularly helpful for lesion characterization. The use of US for hemodynamic studies of the liver transit time may detect blood flow changes induced by micrometastases even before they become visible on imaging. In this field of functional imaging, further research is required to achieve conclusive results, which are not yet available.

Selective hepatic vascular exclusion versus Pringle maneuver in major liver resections: prospective study

Selective hepatic vascular exclusion (SHVE) and the Pringle maneuver are two methods used to control bleeding during hepatectomy. They are compared in a prospective randomized study, where 110 patients undergoing major liver resection were randomly allocated to the SHVE group or the Pringle group. Data regarding the intraoperative and postoperative courses of the patients are analyzed. Intraoperative blood loss and transfusion requirements were significantly decreased in the SHVE group, and postoperative liver function was better in that group. Although there was no difference between the two groups regarding the postoperative complications rate, patients offered the Pringle maneuver had a significantly longer hospital stay. The application of SHVE did not prolong the warm ischemia time or the total operating time. It is evident from the present study that SHVE performed by experienced surgeons is as safe as the Pringle maneuver and is well tolerated by the patients. It is much more effective than the Pringle maneuver for controlling intraoperative bleeding, and it is associated with better postoperative liver function and shorter hospital stay.

Análise evolutiva e perspectiva histórica da ultra-sonografia intra-operatória (USIO) nas afecções pancreáticas

A ultra-sonografia intra-operatória influencia a conduta cirúrgica em um número significante de pacientes operados por afecções malignas ou benignas. Ela constitui-se no método mais sensível para a detecção de pequenas lesões, especialmente no fígado e pâncreas. Nas cirurgias pancreáticas, a ultra-sonografia intra-operatória é importante na localização de tumores neuroendócrinos e na avaliação da ressecabilidade de adenocarcinomas. Ela também pode ser usada durante as cirurgias para pancreatite crônica. Os autores fazem uma revisão sobre a evolução da ultra-sonografia intra-operatória nas cirurgias pancreáticas desde o seu início até os dias atuais.

Current value of intraoperative sonography during surgery for hepatic neoplasms

Noninvasive liver imaging has developed rapidly resulting in increased accuracy for detecting primary and secondary hepatic tumors. Intraoperative ultrasonography (IOUS) was commonly considered to be the gold standard for liver staging, but the current value of IOUS is unknown in view of more sophisticated radiologic tools. The purpose of this prospective study was to evaluate the impact of IOUS on the treatment of 149 patients undergoing liver surgery for malignant disease (colorectal metastasis, 61 patients; hepatoma, 52 patients; other hepatic malignant tumors, 36 patients). The sensitivities of computed tomography (CT), helical CT, magnetic resonance imaging, and IOUS in patients with colorectal metastases were 69.2%, 82.5%, 84.9%, and 95.2% in a segment-by-segment analysis; in patients with hepatoma their sensitivities were 76.9%, 90.9%, 93.0%, and 99.3%; and in patients with other hepatic malignancies they were 66.7%, 89.6%, 93.3%, and 98.9%, respectively. Additional malignant lesions (AMLs) were first detected by inspection and palpation in 20 patients (13.4%). In another 18 patients (12.1%) IOUS revealed at least one AML. Overall, the findings obtained only by IOUS changed the surgical strategy in 34 cases (22.8%). It was concluded that IOUS, having undergone some refinement as well, still has immense diagnostic value in hepatectomy candidates. Frequently avoiding palliative liver resection and occasionally disproving unresectability as assessed by preoperative imaging, IOUS still has a significant impact on surgical decision making and should still be considered the gold standard.

Accuracy of multiphasic helical computed tomography and intraoperative sonography in patients undergoing orthotopic liver transplantation for hepatoma: what is the truth?

OBJECTIVE

To determine the real value of liver imaging in cirrhosis by macro- and histomorphologic examination of the entire organ after orthotopic liver transplantation for hepatocellular carcinoma (HCC).

SUMMARY BACKGROUND DATA

In comparative studies, a virtual sensitivity of up to 94% is described for helical computed tomography in HCC staging. The tumor detection rate of intraoperative ultrasonography (IOUS) is reported to be almost 100%.

METHODS

This prospective observational study comprised 23 patients with HCC in cirrhosis admitted for orthotopic liver transplantation. Results of preoperative triphasic helical computed tomography (HCT) and IOUS were correlated with histopathologic results after 3-mm-slicing of the explanted liver.

RESULTS

Overall, 179 liver segments were examined by HCT, IOUS, and MHM. Fifty-two malignant lesions and 10 dysplastic nodules were revealed by MHM. Using HCT, 13 HCCs could not be identified in 8 patients and 15 results were falsely positive in 10 patients. The detection rate of dysplastic nodes was 40% for HCT and 60% for IOUS. IOUS missed four HCCs in four patients and had six false-positive results in six patients. In a segment-based analysis, the overall accuracy of IOUS was significantly higher for IOUS (95.5%) versus HCT (89.9%). In the lesion-by-lesion analysis, the sensitivity was 92.3% for IOUS and 75.0% for HCT, with a significant difference.

CONCLUSIONS

Correlation of explanted liver pathologic results offers precise evaluation of imaging modalities. The data of this histopathologically based study confirm that IOUS is significantly superior in staging HCC in cirrhosis versus CT, even after technical refinements through enhanced multiphasic high-velocity helical scanning.