Emergent Esophagectomy in Patients with Esophageal Malignancy Is Associated with Higher Rates of Perioperative Complications but No Independent Impact on Short-Term Mortality

Background

Data on perioperative outcomes of emergent versus elective resection in esophageal cancer patients requiring esophagectomy are lacking. We investigated whether emergent resection was associated with increased risks of morbidity and mortality.

Methods

Data on patients with esophageal malignancy who underwent esophagectomy from 2005 to 2020 were retrospectively analyzed from the American College of Surgeons National Surgical Quality Improvement Program database. Thirty-day complication and mortality rates were compared between emergent esophagectomy (EE) and non-emergent esophagectomy. Logistic regression assessed factors associated with complications and mortality.

Results

Of 10,067 patients with malignancy who underwent esophagectomy, 181 (1.8%) had EE, 64% had preoperative systemic inflammatory response syndrome, sepsis, or septic shock, and 44% had bleeding requiring transfusion. The EE group had higher American Society of Anesthesiologists (ASA) class and functional dependency. More transhiatal esophagectomies and diversions were performed in the EE group. After EE, the rates of 30-day mortality (6.1% vs. 2.8%), overall complications (65.2% vs. 44.2%), bleeding, pneumonia, prolonged intubation, and positive margin (17.7% vs. 7.4%) were higher, while that of anastomotic leak was similar. On adjusted logistic regression, older age, lower albumin, higher ASA class, and fragility were associated with increased complications and mortality. McKeown esophagectomy and esophageal diversion were associated with a higher risk of postoperative complications. EE was associated with 30-day postoperative complications (odds ratio, 2.39; 95% confidence interval, 1.66-3.43; p<0.0001).

Conclusion

EE was associated with a more than 2-fold increase in complications compared to elective procedures, but no independent increase in short-term mortality. These findings may help guide data-driven critical decision-making for surgery in select cases of complicated esophageal malignancy.

Cooperation between PRMT1 and PRMT6 drives lung cancer health disparities among Black/African American men

Lung cancer is the third most common cancer with Black/AA men showing higher risk and poorer outcomes than NHW men. Lung cancer disparities are multifactorial, driven by tobacco exposure, inequities in care access, upstream health determinants, and molecular determinants including biological and genetic factors. Elevated expressions of protein arginine methyltransferases (PRMTs) correlating with poorer prognosis have been observed in many cancers. Most importantly, our study shows that PRMT6 displays higher expression in lung cancer tissues of Black/AA men compared to NHW men. In this study, we investigated the underlying mechanism of PRMT6 and its cooperation with PRMT1 to form a heteromer as a driver of lung cancer. Disrupting PRMT1/PRMT6 heteromer by a competitive peptide reduced proliferation in non-small cell lung cancer cell lines and patient-derived organoids, therefore, giving rise to a more strategic approach in the treatment of Black/AA men with lung cancer and to eliminate cancer health disparities.

Chest vs. neck anastomotic leak post esophagectomy for malignancy: rate, predictors, and outcomes

BACKGROUND

Anastomotic leak is a major contributor to comorbidity and mortality following esophagectomy. We sought to assess rate and predictors of leak after esophagectomy and compare outcomes of chest versus neck anastomotic leaks.

METHODS

A retrospective review was performed utilizing National-Surgical-Quality-Improvement-Program data from 2016-2019 for patients undergoing esophagectomy for malignancy. Preoperative characteristics and postoperative outcomes were compared. Patients were classified into two groups: Ivor Lewis esophagectomy [ILE, chest leak (CL)] and transhiatal esophagectomy (THE)/McKeown esophagectomy [ME, neck leak (NL)]. Multivariable regression models were constructed to determine predictors of each type of leak and postoperative complications.

RESULTS

A total of 1,665 patients underwent esophagectomy with 14.1% reported post-operative leak, 61% of patients underwent ILE while 39% underwent THE or ME. Of patients who underwent ILE, 13.8% had CL with complications including significantly higher length of stay and mortality compared to patients without leak. Independent predictors of CL included: diabetes, hypertension, advanced disease stage, chronic steroid use, and operative time. Ninety-five patients (14.6%) who underwent either THE or ME had NL with similar complications. Diabetes, pre-operative white blood cell (WBC), and operative time were independent predictors for NL. On multivariable regression, CL was associated with greater odds of requiring intervention compared with NL.

CONCLUSIONS

Post-esophagectomy CL and NL are associated with higher morbidity and mortality. Diabetes and operative time were independent predictors for both leaks while steroid use, hypertension, and advanced disease stage predicted CL. CL was associated with greater odds of needing an intervention, but contrary to conventional wisdom, was not associated with higher morbidity or mortality.

Trends of utilization and perioperative outcomes of robotic and video-assisted thoracoscopic surgery in patients with lung cancer undergoing minimally invasive resection in the United States

OBJECTIVE

The objective of this study was to evaluate utilization and perioperative outcomes of video-assisted thoracoscopic surgery (VATS) or robotic-assisted thoracoscopic surgery (RATS) for lung cancer in the United States using a nationally representative database.

METHODS

Hospital admissions for lobectomy or sublobar resection (segmentectomy or wedge resection) using VATS or RATS in patients with nonmetastatic lung cancer from October 2015 through December 2018 in the National Inpatient Sample were studied. Patient and hospital characteristics, perioperative complications and mortality, length of stay (LOS), and total hospital cost were compared. Logistic regression was used to assess whether the surgical approach was independently associated with adverse outcomes.

RESULTS

There were 83,105 patients who had VATS (n = 65,375) or RATS (n = 17,710) for lobectomy (72.7% VATS) or sublobar resection (84.2% VATS). Utilization of RATS for lobectomy and sublobar resection increased from 19.2% to 34% and 7.3% to 22%, respectively. Mortality, LOS, and conversion rates were comparable. The cost was higher for RATS (P <.01). Multivariate analyses showed comparable RATS and VATS complications with no independent association between the minimally invasive surgery approach used and adverse surgical outcomes, except for a decreased risk of pneumonia with RATS, relative to VATS sublobar resection (P <.01). Thoracic complication rates and LOS decreased after RATS lobectomy in 2018, compared with previous years (P <.005).

CONCLUSIONS

The utilization of robotic-assisted lung resection for cancer has increased in the United States between 2015 and 2018 for sublobar resection and lobectomy. In adjusted regression analysis, compared with VATS, patients who underwent RATS had similar complication rates and LOS. The robotic approach was associated with increased total hospital cost. LOS and thoracic complication rates trended down after RATS lobectomy.

Diffuse Pulmonary Meningotheliomatosis: A Case Report

Introduction/Objective

Diffuse pulmonary meningotheliomatosis (DPM) is a pulmonary disease characterized by the presence of widespread bilateral minute pulmonary meningothelial-like nodules (MPMNs). It is exceedingly rare and predominantly seen in females. The nodules are typically asymptomatic and detected incidentally on imaging.

Methods/Case Report

We present a case of a 57-year-old woman with a history of chronic cough and CT imaging findings of bilateral multiple ground-glass nodules. Wedge resections from the right upper and right lower lobes were obtained, which revealed gross changes suggestive of interstitial lung disease. Histologic evaluation of the wedges showed similar morphology, consisting of discrete areas with variable interstitial expansion of the stroma with ovoid/spindle cells, collagen, elastosis, and mild chronic inflammatory cells, in a somewhat perivascular pattern. Some areas were also cystic. This appeared in a background of emphysematous change and focal foreign body giant cell reaction to non-polarizable material. Immunohistochemical stains were diffusely positive for vimentin, EMA , and PR, and CD163 highlighted increased cells that were S100 and CD1a negative. Additionally, the ovoid/spindle cells were negative for desmin, SMM, HMB-45, HHV8, pan-CK, chromogranin, and multiplex SOX10-MART1.

Results (if a Case Study enter NA)

NA

Conclusion

Diffuse pulmonary meningotheliomatosis is a rare entity that requires sufficient histological evaluation to identify the ovoid/spindle cell component histologically and immunohistochemically. This disease should be considered in the differential for cases of diffuse interstitial pulmonary infiltrates. Few cases have been reported in the literature, requiring further research to understand the mechanisms of this disease and its clinical significance.

Utilization of Supplemental Regional Anesthesia in Lobectomy for Lung Cancer in the United States: A Retrospective Study

Background

Pulmonary lobectomy is the standard of care for the treatment of early-stage non-small cell lung cancer. This study investigated the rate of utilization of supplemental anesthesia in patients undergoing video-assisted thoracoscopic surgery (VATS) or open lobectomy using a national database and assessed the effect of regional block (RB) on postoperative outcomes.

Methods

Patients who underwent lobectomy for lung cancer between 2014–2019 were identified in the American College of Surgeons National Surgical Quality Improvement Program. The patients’ primary mode of anesthesia and supplemental anesthesia were recorded. Preoperative characteristics and postoperative outcomes were compared between 2 surgical groups those who underwent general anesthesia (GA) alone versus GA with RB. Multivariable regression analyses were performed on the outcomes of interest.

Results

In total, 13,578 patients met the study criteria, with 87% undergoing GA and the remaining 13% receiving GA and RB. The use of neuraxial anesthesia decreased over the years, while RB use increased up to 20% in 2019. Age, body mass index, and preoperative comorbidities were comparable between groups. Patients who underwent VATS were more likely to receive RB than those who underwent thoracotomy. RB was most often utilized by thoracic surgeons. An adjusted analysis showed that RB use was associated with shorter hospital stays and a reduced likelihood of prolonged length of stay, but a higher rate of surgical site infections (SSIs).

Conclusion

In a large surgical database, there was underutilization of supplemental anesthesia in patients undergoing lobectomy for lung cancer. RB utilization was associated with a shorter length of hospital stay and an increase in SSI incidence.

Bochdalek Hernia with Gastric Necrosis Requiring Roux-en-Y Esophagojejunostomy

Bochdalek hernias are the most common congenital diaphragmatic hernias and are usually diagnosed during childhood¹. They can present in adulthood and, in uncommon circumstances, result in gastric herniation with strangulation. We present a case of an adult Bochdalek hernia resulting in total gastric necrosis necessitating Roux-en-Y esophagojejunostomy in an otherwise healthy 39-year-old male. This case highlights the potential morbidity associated with unrepaired congenital diaphragmatic hernias and the need for appropriate referral.

Trends in open lobectomy outcomes for lung cancer over the last 15 years: national cohort

OBJECTIVE

Adoption of thoracoscopic lobectomy has been increasing in the US; however, open lobectomy (OL) is still performed in half of the cases. Postoperative care and enhanced recovery after surgery (ERAS) pathways have evolved and improved outcomes. The study aims to evaluate postoperative outcomes of OL over the last 15 years.

METHODS

Patients who underwent lobectomy for lung cancer between 2005 and 2019 were identified in the National Surgical Quality Improvement Program and divided into three groups; pre-ERAS (2005-2011), transitional period (2012-2015), and wider ERAS implementation (2016-2019). Preoperative characteristics and postoperative outcomes were compared and multivariable regression analysis was constructed to assess independent predictors of outcomes.

RESULTS

OL was comprised of 40% of lobectomies for lung cancer. 10,021 patients met inclusion criteria. 49% were males and mean age was 67. Patients who belonged to the (2016-2019) period group had significantly higher comorbidities and ASA classification. General surgeons performed < 10% of OL in 2016-2019 compared to over 30% during 2005-2011. Patients in the 2016-2019 period were less likely to experience unplanned intubation, surgical site infections, and sepsis. Mortality was also significantly lower than the previous groups (1.9% vs 2.0% and 2.8%, p = 0.05). The rate of discharge to facility as well as length of hospital stays improved over the years. The surgeon specialty served as an independent predictor for length of stay, unplanned intubation, and home discharge.

CONCLUSION

The outcomes of OL are improving over the years. Increasing number of these surgeries being performed by dedicated thoracic surgeons and ERAS pathways are likely helping improve outcomes.

A narrative review of the health disparities associated with malignant pleural mesothelioma

Malignant pleural mesothelioma (MPM) is a cancer of the mesothelial lining of the pleura that has traditionally been associated with asbestos exposure in an industrial setting. Asbestos usage has fortunately been banned or phased out in most industrialized countries resulting in its decline in countries such as the United States. Despite this, MPM continues to place significant burden on its affected patients resulting in overall poor prognosis and survival. Questions arise as to what factors, especially what health disparities, contribute to the disease’s dismal prognosis. This article will present a narrative review of recent literature that identifies the impact age, sex, race, access to medical centers, and economics have on the diagnosis, treatment, and prognosis of MPM. As will be discussed, research has shown that factors including younger age, female sex, non-white race, private insurance, Medicare, and higher income have been associated with better survival in MPM. Whereas older age, male sex, white race, lack of insurance, and lower income are associated with worse survival. The identification of these and other health disparities related to MPM may allow for future research, clinical guidelines, and policies to be implemented to decrease the burden health disparities create in the diagnosis, treatment, and prognosis of patients with MPM.

Does Race or Ethnicity Impact Complications After Pulmonary Lobectomy for Patients With Lung Cancer?

BACKGROUND

Racial disparity in surgical access and postoperative outcomes after pulmonary lobectomy continues to be a concern and target for improvement; however, evidence of independent impact of race on complications is lacking. The objective of this study was to investigate the impact of race/ethnicity on surgical outcomes after lobectomy for lung cancer and estimate the distribution of racial/ethnic groups among expected resectable lung cancer cases using a large national database.

METHODS

Patients who underwent lobectomy for lung cancer between 2005 and 2016 were identified in the American College of Surgeon National Surgical Quality Improvement Program. Preoperative characteristics and postoperative outcomes were compared between race/ethnicity groups in all patients and in propensity-matched cohorts, controlling for pertinent risk factors. Distribution of each race/ethnicity in the database was calculated relative to estimated numbers of patients with resectable lung cancer in the United States.

RESULTS

A total of 10,202 patients (age 67.6 ± 9.7, 46.7% male, 86.4% white) underwent nonemergent lobectomy (46.8% thoracoscopic). Blacks had higher rates of baseline risk factors. In propensity score-matched cohorts of whites, blacks, and Hispanics/Asians (n = 498 each), postoperatively, blacks had higher rates of prolonged intubation and longer hospital stay while whites had a higher rate of pneumonia. Race was independently associated with these adverse outcomes on multivariate analysis. Proportion of blacks and Hispanics in the American College of Surgeon National Surgical Quality Improvement Program was lower than their respective proportion of resectable lung cancer in the United States.

CONCLUSIONS

In a large national-level surgical database, there was lower than expected representation of black and Hispanic patients. Black race was independently associated with extended length of stay and prolonged intubation, whereas white was independently associated with postoperative pneumonia.

Five-Year Experience with VATS Versus Thoracotomy Segmentectomy for Lung Tumor Resection

OBJECTIVE

Segmentectomy for lung tumors has been performed with either video-assisted thoracoscopic surgery (VATS) or thoracotomy; however, there is a lack of contemporary, multicenter study that compares both approaches. The aim of this study was to compare the 30-day surgical outcomes of VATS versus thoracotomy for segmentectomy using a large national database.

METHODS

We performed a retrospective analysis of prospectively maintained American College of Surgeons National Surgical Quality Improvement Program database. Patients who underwent segmentectomy for benign or malignant tumors between 2013 and 2017 were included and divided into 2 groups based on whether they received a thoracotomy or VATS approach. All VATS patients were then into 2 subgroups: early (2013 to 2015) and late (2016 to 2017). Propensity-matched analysis was conducted, and the perioperative variables and outcomes were compared.

RESULTS

A total of 1,785 patients met the inclusion criteria. VATS segmentectomy was associated with shorter hospital stays (3.9 vs 5.8 days, P < 0.001) and higher rates of home discharge (94% vs 89%, P = 0.002) compared to thoracotomy segmentectomy. VATS was also associated with less postoperative pneumonia (2.8% vs 5.8%, P = 0.007), unplanned intubation (1.5% vs 3.5%, P = 0.016), prolonged intubation (0.6% vs 2.7%, P = 0.001), transfusion requirement (1.7% vs 5.8%, P < 0.001), and deep venous thrombosis (0.1% vs 1.1%, P = 0.03). Compared to the earlier VATS group, the late group was associated with less cardiac arrests (0% vs 0.8%, P = 0.025) and shorter hospital stays (3.3 vs 4.2 days, P < 0.001).

CONCLUSIONS

When compared with thoracotomy, VATS segmentectomy is associated with less postoperative complications and shorter hospital length of stay. VATS segmentectomy has been used more frequently and with improved outcomes.

Deglutition Syncope Treated With Peroral Endoscopic Myotomy

Deglutition syncope is a rare, neurally mediated reflex syncope associated with swallowing. It is typically associated with pharyngoesophageal disorders with secondary abnormal vagal reflex causing atrioventricular cardiac block and cerebral hypoperfusion. Diagnosis can be delayed and challenging. Various treatment options have been reported, including withholding cardiac blocker agents, diet modifications, and pacemaker placement. We present a case of persistent deglutition syncope secondary to esophagogastric junction outflow obstruction that failed medical therapy and was managed successfully with peroral endoscopic myotomy with excellent long-term outcome.

Use of endoloop in video-assisted thoracoscopic enucleation of a very rare esophageal tumor

A gastrointestinal stromal tumor is an infrequent tumor of the gastrointestinal tract with very rare involvement of the esophagus. We present a case of a patient with dysphagia and a 4 cm submucosal mass. The patient underwent thoracoscopic enucleation with complete resection of the mass. We present case details and operative video highlighting the important surgical steps of exposure and retraction. We believe that the Endoloop is a very useful tool in providing countertraction needed during minimally invasive resection of such lesions.

Spontaneous transmural perforation in eosinophilic esophagitis: RARE case presentation and role of esophageal stenting

Eosinophilic esophagitis (EoE) is a rare disease of the esophagus that is characterized by eosinophilic infiltrate within the esophageal mucosa resulting in chronic inflammation and stenosis. It typically presents with symptoms of esophageal dysfunction with dysphagia and food impaction being the most common presenting complaints. Herein we describe a rare case presentation of a young patient with spontaneous esophageal perforation in the setting of undiagnosed EoE. We suggest that the placement of a covered esophageal stent can provide full closure of the perforation and restoration of the integrity of the GI tract without the need for more invasive open repair. The patient had a short recovery time with no reported postoperative complications upon 30 months follow up. We believe that it’s important to consider and rule out EoE in patients with a history of dysphagia and esophageal perforation.

Modern impact of video assisted thoracic surgery

With advancement in technology, experience and training over the last two decades, video assisted thoracic surgery (VATS) has become widely accepted and utilized all over the world. VATS started as a diagnostic tool in the early 1990s, technique of VATS lobectomy evolved and became safer over the next 10-15 years and now it is being used for more advanced and hybrid operations. VATS has contributed to the development of minimally invasive surgical interventions for other thoracic disorders like mediastinal tumors and esophageal cancer as well. This article looks at the advantages of VATS, technique advancements and its applications in other thoracic operations and its influence on the present and future of thoracic surgery.

Neoadjuvant therapy for esophageal cancer

Esophageal cancer is increasing in incidence more than any other visceral malignancy in North America. Adenocarcinoma has become the most common cell type. Surgery remains the primary treatment modality for locoregional disease. Overall survival with surgery alone has been dismal, with metastatic disease the primary mode of treatment failure after an R0 surgical resection. Cure rates with chemotherapy or radiation therapy alone have been disappointing as well. For these reasons, over the last decade multi-modality treatment has gained increasing acceptance as the standard of care. This review examines the present data and role of neoadjuvant treatment using chemotherapy and radiation therapy followed by surgery for the treatment of esophageal cancer.

Neoadjuvant therapy for esophageal cancer

Esophageal cancer is increasing in incidence more than any other visceral malignancy in North America. Adenocarcinoma has become the most common cell type. Surgery remains the primary treatment modality for locoregional disease. Overall survival with surgery alone has been dismal, with metastatic disease the primary mode of treatment failure after an R0 surgical resection. Cure rates with chemotherapy or radiation therapy alone have been disappointing as well. For these reasons, over the last decade multi-modality treatment has gained increasing acceptance as the standard of care. This review examines the present data and role of neoadjuvant treatment using chemotherapy and radiation therapy followed by surgery for the treatment of esophageal cancer.

Applications of regional anaesthesia in paediatrics

Advances in the field of paediatric regional anaesthesia have specific applications to both acute and chronic pain management. This review summarizes data regarding the safety of paediatric regional anaesthetic techniques. Current guidelines are provided for performing paediatric regional techniques, with a focus on applications for postoperative pain management. Brief descriptions of relevant anatomy followed by indications for commonly performed blocks are highlighted along with the potential of adverse side-effects.

Peritonitis from peg tube insertion in surgical intensive care unit patients: identification of risk factors and clinical outcomes

BACKGROUND

Percutaneous endoscopic gastrostomy (PEG) tubes are routinely inserted in the surgical intensive care unit (SICU). Poor tissue healing or technical issues after tube insertion can lead to peritonitis requiring a laparotomy. This study aimed to identify risk factors leading to peritonitis.

METHODS

A retrospective study reviewed of PEG tubes inserted in SICU patients from 2003 to 2006. Age, sex, body mass index (BMI), organ dysfunction, vasopressor use, fluid balance, steroid use for medical reasons, and nutritional status of the patients were noted. The patients with acute spinal cord injury who received high-dose steroids were excluded from the study. Mortality and peritonitis requiring laparotomy were the outcomes. Logistic regression performed with SAS version 9.1 (Cary, NC) was used for analysis.

RESULTS

Of 322 patients, 16 (5%) required a laparotomy for peritonitis, and 74 (23%) died during the hospital stay. The major predictors of the need for a laparotomy were higher BMI (p = 0.0005) and a serum albumin level lower than 2.5 gm/dL (p = 0.0008). Patients with both a BMI exceeding 30 kg/m(2) and an albumin level lower than 2.5 gm/dL were 25 times more likely to need a laparotomy (95% confidence interval [CI], 7.74-83.3). The mean time from tube placement to laparotomy was 11 days. Of the 16 patients who required laparotomy, 9 died during the hospitalization. Patients requiring a laparotomy were five times more likely to die during the hospitalization than patients not requiring a laparotomy (p = 0.004; 95% CI, 1.68-13.07). The mean time from laparotomy to death was 23 days. Signs of sepsis and worsening abdominal examination developed in all 16 laparotomy patients. Dislodged tube with gastric wall not opposed to the abdominal wall was the most common finding at laparotomy.

CONCLUSION

Approximately 5% of patients undergoing PEG insertion in the SICU require laparotomy for peritonitis and are more likely to die during the hospitalization. Higher BMI and a lower serum albumin level, by contributing to poor healing, increase the risk of peritonitis.

Factors affecting the severity of spontaneous retroperitoneal hemorrhage in anticoagulated patients

BACKGROUND

Clinical manifestations of spontaneous retroperitoneal hemorrhage (SRH) range from a small decrease in hemoglobin to hypotension requiring transfer to the intensive care unit (ICU). Our goal was to identify which anticoagulated patients are at increased risk for SRH and its complications.

METHODS

We conducted a retrospective review of 180 patients with SRH. Age, sex, presence of comorbidities, hemoglobin decrease, transfusion requirement, ICU stay, and length of ICU stay were recorded. Patients were divided into 5 groups based on their anticoagulants: (1) heparin and Coumadin, (2) heparin only, (3) Coumadin only, (4) heparin +/- Coumadin and aspirin (ASA) +/- Plavix, and (5) other anticoagulants.

RESULTS

Group 4 patients were more likely to require ICU admission and have longer ICU stay compared to others (P = .021 & P < or = 0.0001, respectively, by Kruskall-Wallis test). Patients with coronary artery disease were more likely to require ICU admission (P = .01 by chi-square test).

CONCLUSIONS

Patients on combined anticoagulant-antiplatelet therapy are more likely to require ICU admission and longer ICU stay. Close observation is warranted in these patients for early detection of SRH.

Long-term outcomes after external beam irradiation and brachytherapy boost for base-of-tongue cancers

PURPOSE

To assess long-term efficacy and toxicity associated with external beam irradiation (EBRT) and interstitial (192)Ir implantation for the treatment of squamous carcinoma of the base of tongue.

METHODS AND MATERIALS

Between April 1975 and December 1993, 41 patients with base-of-tongue carcinomas were treated with (192)Ir interstitial implants after EBRT at Stanford University. One patient had Stage I, 6 had Stage II, 7 had Stage III, and 27 had Stage IV tumors. Twenty-eight patients had cervical lymph node involvement at diagnosis. All received EBRT to a median dose of 50 Gy (range 48.9-68 Gy) to the primary tumor and regional lymph nodes before brachytherapy. Interstitial implant was performed 2-4 weeks after EBRT. Intraoperatively, nylon catheters were placed via steel trocars into the base of tongue, glossotonsillar groove, and pharyngo-epiglottic fold using a catheter looping technique. Twenty-three of 28 node-positive patients also underwent simultaneous neck dissections. Postoperatively, the (192)Ir seeds were inserted and allowed to remain in place for approximately 35 h to achieve a median tumor dose of 26 Gy (range 20-34 Gy) to a median volume of 73 cc. Survival, local control, and complications were assessed.

RESULTS

With a median follow-up of 62 months (range 9-215) for all patients and 90 months for alive patients, the 5-year Kaplan-Meier survival estimate was 66%. The 5-year local control rate was 82%, with 7 patients recurring locally, 2 of whom were salvaged with surgery. Nodal control was achieved in 93% of patients with either EBRT alone or in combination with neck dissection. The 5-year freedom from distant metastasis rate was 83%. Acute complications included transient bleeding (5%) and infection (8%). Late complication included soft-tissue necrosis/ulceration (7%), osteoradionecrosis (5%), and xerostomia.

CONCLUSION

Base-of-tongue carcinoma can be effectively treated with EBRT and (192)Ir implant boost. Local control is excellent and complication rates are acceptable.

Spectroscopic methods for determining enantiomeric purity and absolute configuration in chiral pharmaceutical molecules

Analytical support, such as methods development, along with identification and characterization of intermediates and impurities, are critical in the development of a chemical process. The preparation of a drug substance requires the development of analytical methods for monitoring reactions and identifying impurities. Methods development for a chiral drug molecule is more difficult as the method must be capable of monitoring the overall reaction as well as possible racemization of starting materials and products. Chiral methods are often required to monitor the reaction steps of a synthesis, however, the development of enantiomeric purity methods are time-consuming and expensive. The use of chiroptical detectors, such as circular dichroism (CD), optical rotation (OR) and vibrational circular dichroism (VCD), can help to reduce or eliminate the need to develop chiral monitoring methods and also to predict absolute configuration. Recently, VCD has shown remarkable success with the latter and currently holds the most promise as a general, direct method that can be used as an alternative to X-ray crystallography. Each of the mentioned techniques can help analytical chemists to reduce the time associated with traditional enantiomeric purity methods development and to determine absolute configuration. This review will discuss the scope and limitations of these techniques for the rapid and routine determination of both enantiomeric excess and absolute configuration.

Combined CT venography and pulmonary angiography in suspected thromboembolic disease: diagnostic accuracy for deep venous evaluation

OBJECTIVE

Combined CT venography and pulmonary angiography is a new diagnostic test that evaluates both pulmonary embolism and deep venous thrombosis (DVT) in a single study. Our purpose was to compare the CT venous findings with lower extremity venous sonography.

SUBJECTS AND METHODS

Seventy-one consecutive patients with suspected pulmonary embolism underwent helical CT pulmonary angiography during rapid i.v. infusion of contrast medium. Axial scans at 5-cm intervals from the patient's upper calves to the diaphragm were generated 3.5 min after the beginning of contrast medium injection. CT venous phase images were interpreted prospectively and compared with subsequent bilateral lower extremity venous sonography performed within 12 hr.

RESULTS

DVT was revealed by CT venous phase images in 19 patients, 12 of whom also had pulmonary embolism. CT and sonographic findings correlated exactly in the femoropopliteal deep venous system, where most pulmonary emboli originate. CT venous phase images also revealed pelvic extension of DVT in six patients and isolated vena cava thrombus in one patient.

CONCLUSION

CT venous phase imaging at the time of CT pulmonary angiography is comparable with venous sonography in the evaluation of femoropopliteal DVT. The iliac veins and vena cava, vessels poorly shown on sonography but sometimes the source of significant pulmonary emboli, are also depicted by CT venography.

Potent, orally active GPIIb/IIIa antagonists containing a nipecotic acid subunit. Structure-activity studies leading to the discovery of RWJ-53308

Although intravenously administered antiplatelet fibrinogen receptor (GPIIb/IIIa) antagonists have become established in the acute-care clinical setting for the prevention of thrombosis, orally administered drugs for chronic use are still under development. Herein, we present details from our exploration of structure-activity surrounding the prototype fibrinogen receptor antagonist RWJ-50042 (racemate of 1), which was derived from a unique approach involving the gamma-chain of fibrinogen (Hoekstra et al. J. Med. Chem. 1995, 38, 1582). Our analogue studies culminated in the discovery of RWJ-53308 (2), a potent, orally active GPIIb/IIIa antagonist. To progress from RWJ-50042 to a suitable candidate for clinical development, we conducted a series of optimization cycles that employed solid-phase parallel synthesis for the rapid, efficient preparation of nearly 250 analogues, which were assayed for fibrinogen receptor affinity and inhibition of platelet aggregation induced by four different activators. This strategy produced several promising analogues for advanced study, including 3-(3,4-methylenedioxybenzene)-beta-amino acid analogue 3 (significant improved in vivo potency) and 3-(3-pyridyl)-beta-amino acid 2 (significantly improved potency, oral absorption, and duration of action). In dogs, 2 displayed significant ex vivo antiplatelet activity on oral administration at 1.0 mg/kg, 16% systemic oral bioavailability, minimal metabolic transformation, and an excellent safety profile. Additionally, 2 was found to be efficacious in three in vivo thrombosis models: canine arteriovenous (AV) shunt (0.01-0.1 mg/kg, iv), guinea pig photoactivation-induced injury (0.3-3 mg/kg, iv), and guinea pig ferric chloride-induced injury (0.3-1 mg/kg, iv). On the basis of its noteworthy preclinical data, RWJ-53308 (2) was selected for clinical evaluation.

A prospective, randomized comparison of preoperative and continuous balanced epidural or paravertebral bupivacaine on post-thoracotomy pain, pulmonary function and stress responses

Both epidural and paravertebral blocks are effective in controlling post-thoracotomy pain, but comparison of preoperative and balanced techniques, measuring pulmonary function and stress responses, has not been undertaken previously. We studied 100 adult patients, premedicated with morphine and diclofenac, allocated randomly to receive thoracic epidural bupivacaine or thoracic paravertebral bupivacaine as preoperative bolus doses followed by continuous infusions. All patients also received diclofenac and patient-controlled morphine. Significantly lower visual analogue pain scores at rest and on coughing were found in the paravertebral group and patient-controlled morphine requirements were less. Pulmonary function was significantly better preserved in the paravertebral group who had higher oxygen saturations and less postoperative respiratory morbidity. There was a significant increase in plasma concentrations of cortisol from baseline in both the epidural and paravertebral groups and in plasma glucose concentrations in the epidural group, but no significant change from baseline in plasma glucose in the paravertebral group. Areas under the plasma concentration vs time curves for cortisol and glucose were significantly lower in the paravertebral groups. Side effects, especially nausea, vomiting and hypotension, were troublesome only in the epidural group. We conclude that with these regimens, paravertebral block was superior to epidural bupivacaine.

Pleural bupivacaine placement for optimal postthoracotomy pulmonary function: a prospective, randomized study

OBJECTIVE

To determine dependent chest tube losses of bupivacaine with paravertebral versus interpleural administration, thereby helping to explain the significant differences in pulmonary function that exist between these two techniques.

DESIGN

A prospective, randomized study.

SETTING

A single hospital.

PARTICIPANTS

Twelve adult patients undergoing posterolateral thoracotomies.

INTERVENTIONS

Paravertebral or interpleural administration of bupivacaine.

MEASUREMENTS AND MAIN RESULTS

Analgesia, as assessed by visual analog pain scores and patient-controlled morphine requirements, was similar in both groups. Postoperative spirometric values were significantly better at most times with the paravertebral route of administration. Dependent chest tube bupivacaine losses were approximately four times higher in the interpleural group.

CONCLUSION

Local anesthetic on the diaphragm might actively impair respiratory function through diaphragmatic and abdominal muscle weakness, while failing to contribute to pain relief.

Extrusion/spheronization--effect of moisture content and spheronization time on pellet characteristics

As part of a larger effort aimed at optimizing the properties of pellets produced by spheronization of extruded masses, the effect of the moisture content of wet masses on extrusion force and torque was studied. The wet masses were composed of either microcrystalline cellulose (MCC) or mixtures of MCC with lactose or dicalcium phosphate. Based on the force and torque data, a moisture content "window" was defined for consistent extrusion. Moisture exerts a lubricant effect, and a moisture level of 100-120% w/w dry solid seemed necessary for the extrusion of MCC into rod-shaped, discrete pieces. Screen force clearly depended on the moisture content but was relatively insensitive to extruder speed, especially at 80% and 100% moisture content. The physical properties of pellets as a function of spheronization time were studied by sampling the material at known intervals. The percent yield, tapped density, and a two-dimensional sphericity index of an 18/20 mesh fraction of pellets were measured. Maximum yield, tapped density, and sphericity were achieved within 60 sec in the spheronizer. With increasing residence time, the shape and density were unchanged while the yield was severely reduced. Among the formulations studied, pellets with equal amounts of lactose and MCC were superior to those of pure MCC in yield, density, and sphericity. Based on these results, an outline to optimize the endpoint of the spheronization process for formulations containing MCC is suggested.

A prospective, randomized comparison of interpleural and paravertebral analgesia in thoracic surgery

We have undertaken a prospective, randomized comparison of the superficially similar techniques of interpleural and paravertebral (extrapleural) analgesia in 53 patients undergoing posterolateral thoracotomy. Local anaesthetic placed anterior to the superior costotransverse ligament and posterior to the parietal pleura produces a paravertebral block and instilled between the parietal and visceral pleurae produces an interpleural block. Patients received preoperative and postoperative continuous bupivacaine paravertebral blocks in group 1 and interpleural blocks in group 2. Premedication comprised diclofenac and morphine, and after operation all patients had regular diclofenac and patient-controlled morphine (PCM). Analgesia was assessed by visual analogue pain scores (VAS), PCM requirements, ratio of preoperative to postoperative spirometric values (PFT), rates of postoperative respiratory morbidity (PORM) and hospital stay, all recorded by blinded observers. Eight patients were withdrawn and data from 45 patients were analysed. Patient characteristics, surgery, VAS scores and PCM use were similar in both groups. PFT were significantly better (P = 0.03-0.0001) in group 1, and PORM was lower and hospital stay approximately 1 day less in this group. Five patients in group 2 became temporarily confused, probably because of bupivacaine toxicity (P = 0.02). We conclude that bupivacaine deposited paravertebrally produced greater preservation of lung function and fewer side effects than bupivacaine administered interpleurally.

Physico-mechanical characterization of the extrusion-spheronization process. Part II: Rheological determinants for successful extrusion and spheronization

Spheres are widely used as the basis for the design of multiparticulate drug delivery systems. Although the extrusion and spheronization processes are frequently used to produce such spheres, there is a lack of basic understanding of these processes and of the requisite properties of excipients and formulations. It is hypothesized that the rheological or mechanical properties of the wet mass may address the requirements of both extrusion and spheronization. The fact that certain formulations can be extruded, yet not be successfully spheronized, suggests that the two processes depend on different formulation attributes, and that there are different rheological criteria that must be met for each process to be successful. As a preliminary test of these hypotheses, methods were developed to measure the rheological behavior and mechanical properties (plastic yield value, tensile strength, yield loci) of the wet mass and/or extrudate for a model formulation system (microcrystalline cellulose, lactose, hydroxypropylmethylcellulose). The finished spheres were characterized in terms of particle size, bulk density, individual bead crushing strength, and sphericity. A Box-Behnken experimental design was employed by which the independent formulation variables could be related to the dependent rheological/mechanical properties and finished pellet characteristics. It was observed that there was a critical range of rheological/mechanical variables within which pellets having desirable criteria such as yield of 18/25 mesh cut > 60%, a shape factor > 0.85, etc., can be prepared. Screen pressure was shown to be the most critical variable affecting the yield of 18/25 mesh cut, while the yield value and tensile strength markedly influenced the shape factor. Thus, for the formulations studied, it was possible to define a "window" of rheological/mechanical properties within which both extrusion and spheronization can be successfully carried out.

Physicomechanical characterization of the extrusion-spheronization process. I. Instrumentation of the extruder

Extrusion-spheronization is a popular means of producing spheres which can be coated to form a controlled-release system. In the extrusion process, stress is necessary to force a wet mass through small orifices, and as a result, frictional heat builds up at the screen. Therefore, the quantitative measurement of the screen pressure and screen temperature is described and shown to provide objective measures of extrudability. A strain gauge load cell was mounted tangentially to the screen of a Luwa EXDS-60 extruder with a specifically fabricated holder. The load cell output was calibrated in terms of pressure inside the screen with a special rubber plug system. A fast-response thermocouple was used to measure the screen temperature. Experiments with 50/50 lactose/Avicel PH101 revealed that a linear relationship exists between the amount of water used in the granulation and the screen pressure, that the percentage open area of the screen determines the rank order of the screen pressure, and that the maximal yield of 18/25-mesh cut pellets was uniquely related to the screen pressure. Also, a high degree of correlation was observed between the screen pressure and the screen temperature.

Choledochal cyst (a case report)

A case of choledochal cyst is presented. The cyst was found in an infant aged 40 days and was treated surgically by resection followed by Roux en-Y hepaticojejunostomy.

Gas-Liquid Chromatographic Method for the Analysis of Microencapsulated Diazinon Insecticide: Collaborative Study

The determination of diazinon insecticide in Knox Out 2FM formulation was studied collaboratively by 18 laboratories. Knox Out 2FM is a flowable microencapsulated insecticide formulation containing 23 wt% active ingredient. Analytical samples are first treated by grinding in a tissue grinder and then extracted in situ with acetonitrile. This preparative step breaks the capsules and allows the active ingredient to dissolve in the solvent. Single determinations on each of 2 closely matched samples were made by flame ionization gas-liquid chromatography. The standard deviation by analysts was 0.18 wt% and the coefficient of variation was 0.76%. The combined laboratory and analyst variation gave a standard deviation of 0.59 wt% and a coefficient of variation of 2.49%. The method has been adopted official first action.