Kent W. Kercher

Long-term Outcomes of Laparoscopic Resection of Gastric Gastrointestinal Stromal Tumors

Objective:Gastric gastrointestinal stromal tumors (GISTs) are rare neoplasms that require excision for cure. Although the feasibility of minimally invasive resection of gastric GIST has been established, the long-term safety and efficacy of these techniques are unclear. We hypothesized that complete resection of gastric GISTs using a combination of laparoscopic or laparoendoscopic techniques results in low perioperative morbidity and an effective long-term control of the disease. Methods:Between August 1996 and June 2005, 50 consecutive patients undergoing laparoscopic or laparoendoscopic resection of gastric GISTs were identified in a prospectively collected database. Outcome measures included patient demographics and outcomes, operative findings, morbidity, and histopathologic characteristics of the tumor. Patient and tumor characteristics were analyzed to identify risk factors for tumor recurrence. Results:Fifty patients, mean age 60 years (range, 34–84 years), underwent 47 local and 3 segmental laparoscopic gastric resections. GI bleeding and dyspepsia were the most common symptoms. Mean tumor size was 4.4 cm (range, 1.0–8.5 cm) with the majority of the lesions located in the proximal stomach. Mean operative time was 135 minutes (range, 49–295 minutes), the mean blood loss was 85 mL (range, 10–450 mL), and the mean length of hospitalization was 3.8 days (range 1–10 days). There were no major perioperative complications or mortalities. All lesions had negative resection margins (range, 2–45 mm). Nine patients had 10 or more mitotic figures per 50 high power fields, while 11 had ulceration and/or necrosis of the lesion. At a mean follow-up of 36 months, 46 (92%) patients were disease free, 1 patient was alive with disease, 1 patient with metastases died of a cardiac event, and 2 (4%) patients died of metastatic disease. No local or port site recurrences have been identified. Patient age, tumor size, mitotic index, tumor ulceration, and necrosis were statistically associated with tumor recurrence. The presence of 10 or more mitotic figures per 50 high power fields was an independent predictor of disease progression (P = 0.006). Conclusion:A laparoscopic approach to surgical resection of gastric GIST is associated with low morbidity and short hospitalization. As found in historical series of open operative resection, the tumor mitotic index predicts local recurrence. The long-term disease-free survival of 92% in our study establishes laparoscopic resection as safe and effective in treating gastric GISTs. Given these findings as well as the advantages afforded by minimally invasive surgery, a laparoscopic approach may be the preferred resection technique in most patients with small- and medium-sized gastric GISTs.

Comparison of ultrasonic energy, bipolar thermal energy, and vascular clips for the hemostasis of small-, medium-, and large-sized arteries

Background: Advanced laparoscopic procedures have necessitated the development of new technology for vascular control. Suture ligation can be time-consuming and cumbersome during laparoscopic dissection. Titanium clips have been used for hemostasis, and recently plastic clips and energy sources such as ultrasonic coagulating shears and bipolar thermal energy devices have become popular. The purpose of this study was to compare the bursting pressure of arteries sealed with ultrasonic coagulating shears (UCS), electrothermal bipolar vessel sealer (EBVS), titanium laparoscopic clips (LCs), and plastic laparoscopic clips (PCs). In addition, the spread of thermal injury from the UCS and the EBVS was compared. Methods: Arteries in three size groups (2–3, 4–5 and 6–7 mm) were harvested from freshly euthanized pigs. Each of the four devices was used to seal 16 specimens from each size group for burst testing. A 5-Fr catheter was placed into the open end of the specimen and secured with a purse-string suture. The catheter was connected to a pressure monitor and saline was infused until there was leakage from the sealed end. This defined the bursting pressure in mmHg. The ultrasonic shears and bipolar thermal device were used to seal an additional 8 vessels in each size group, which were sent for histologic examination. These were examined with hematoxylin and eosin stains, and the extent of thermal injury, defined by coagulation necrosis, was measured in millimeters. Analysis of variance was performed and, where appropriate, a Tukey’s test was also performed. Results: The EBVS’s mean burst pressure was statistically higher than that of the UCS at 4 or 5 mm (601 vs 205 mmHg) and 6 or 7 mm (442 vs 175 mmHg). EBVS had higher burst pressures for the 4 or 5-mm group (601 mmHg) and 6 or 7-mm group (442 mmHg) compared with its pressure at 2 or 3 mm (128 mmHg) (p = 0.0001). The burst pressures of the UCS and EBVS at 2 or 3 mm were not significantly different. Both clips were statistically stronger than the thermal devices except at 4 or 5 mm, in which case the EBVS was as strong as the LC (601 vs 593 mmHg). The PC and LC were similar except at 4 or 5 mm, where the PC was superior (854 vs 593 mmHg). The PC burst pressure for 4 or 5 mm (854 mmHg) was statistically higher than that for vessels 2 or 3 mm (737 mmHg) but not different from the 6 or 7 mm pressure (767 mmHg). Thermal spread was not statistically different when comparing EBVS and UCS at any size (EBVS mean = 2.57 mm vs UCS mean = 2.18 mm). Conclusions: Both the PC and LC secured all vessel sizes to well above physiologic levels. The EBVS can be used confidently in vessels up to 7 mm. There is no difference in the thermal spread of the LigaSure vessel sealer and the UCS.

Laparoscopic vs open resection of gastric stromal tumors.

BackgroundGastric stromal tumors are rare neoplasms that may be benign or malignant. Given that malignant gastric stromal tumors rarely involve lymph nodes and require excision with negative margins, they appear amendable to laparoscopic excision. There are few reports of laparoscopic resection, and no comparisons have been done between laparoscopic and open surgery. This study compares the relative efficacy of the two approaches.MethodsBetween May 1994 and December 2000, 33 patients underwent 35 operations for gastric stromal tumors. Laparoscopic resections were performed in 21 patients; open resections were done in 12 patients. The medical records of the patients were reviewed retrospectively with regard to operating time, blood loss, length of stay, and clinical course.ResultsPatient demographics, tumor characteristics (mean tumor size, benign vs malignant), and presenting symptoms were similar for both groups. In the laparoscopic group, 15 wedge resections; three partial gastrectomies, and three transgastric needlescopic enucleations were performed. In the open group, six vedge resections, four antrectomies, and two partial proximal gastrectomies were performed. There were no significant differences in mean operative time (169 vs 160 min), mean estimated blood loss (106 vs 129 cc), or perioperative complication rate (9.5% vs 8.3%) between the laparoscopic and open groups, respectively. The mean length of stay was significantly less (p<0.05) in the laparoscopic group (3.8 vs 6.2 days). Average follow-up was 1.5 years. One patient in each group has died due to metastastic disease. There have been no trocar site recurrences.ConclusionsLaparoscopic resection of gastric stromal tumors is safe and appropriate. Tumor size, operating time, and estimated blood loss were equivalent to the open approach, and there was a statistically shorter hospital stay in the laparoscopic group.

Assessment of Adhesion Formation to Intra-Abdominal Polypropylene Mesh and Polytetrafluoroethylene Mesh

BACKGROUND The development of intra-abdominal adhesions, bowel obstruction, and enterocutaneous fistulas are potentially severe complications related to the intraperitoneal placement of prosthetic biomaterials. The purpose of this study was to determine the natural history of adhesion formation to polypropylene mesh and two types of polytetrafluoroethylene (ePTFE) mesh when placed intraperitoneally in a rabbit model that simulates laparoscopic ventral hernia repair. MATERIALS AND METHODS Thirty New Zealand white rabbits were used for this study. A 10-cm midline incision was performed for intra-abdominal access and a 2 cm x 2 cm piece of mesh (n = 60) was sewn to an intact peritoneum on each side of the midline. Two types of ePTFE mesh (Dual Mesh and modified Dual Mesh, W.L. Gore & Assoc., Flagstaff, AZ) and polypropylene mesh were compared. The rate of adhesion formation was evaluated by direct visualization using microlaparoscopy (2-mm endoscope/trocar) at 7 days, 3 weeks, 9 weeks, and 16 weeks after mesh implantation. Adhesions to the prosthetic mesh were scored for extent (%) using the Modified Diamond Scale (0 = 0%, 1 <or= 25%, 2 = 25-50%, 3 > 50%). At necropsy the mesh was excised en bloc with the anterior abdominal wall for histological evaluation of mesothelial layer growth. RESULTS The mean adhesion score for the polypropylene mesh was significantly greater (P < 0.05) than Dual Mesh at 9 weeks and 16 weeks and modified Dual Mesh at 7 days, 9 weeks, and 16 weeks. Fifty-five percent (n = 11) of the polypropylene mesh had adhesions to small intestine or omentum at necropsy compared to 30% (n = 6) of the Dual Mesh and 20% (n = 4) of the modified Dual Mesh. There was a significantly greater percentage (P < 0.003) of ePTFE mesh mesothelialized at explant (modified Dual Mesh 44.2%; Dual Mesh 55.8%) compared to the polypropylene mesh (12.9%). CONCLUSIONS Serial microlaparoscopic evaluation of intraperitoneally implanted polypropylene mesh and ePTFE mesh in a rabbit model revealed a progression of adhesions to polypropylene mesh over a 16 week period. The pore size of mesh is critical in the development and maintenance of abdominal adhesions and tissue ingrowth. The macroporous polypropylene mesh promoted adhesion formation, while the microporous nature of the visceral side of the ePTFE served as a barrier to adhesions.

The burden of Clostridium difficile in surgical patients in the United States.

BACKGROUND Clostridium difficile colitis is the predominant hospital-acquired gastrointestinal infection in the United States and has emerged as an important nosocomial cause of morbidity and death. Although several institutional studies have examined the effects of C. difficile on hospitalized patients, its nationwide impact on surgical patients has yet to be defined. METHODS To provide a national estimate of the burden of C. difficile, we performed a five-year retrospective analysis of the Agency for Healthcare Research and Qualitys National Inpatient Sample Database, which represents a stratified 20% sample of hospitals in the United States, from 1999 to 2003. All surgical inpatient discharge data from 997 hospitals in 37 states were analyzed to determine the association of C. difficile infections with patient demographics, hospital characteristics, surgical procedure, length of stay (LOS), total charges, and in-hospital mortality rate. Univariate analysis was performed to identify any association between the presence of C. difficile infection and the outcome variables using chi-square contingency table analysis or the Student t-test following the exclusion of patients with other medical complications. Multivariate regression analysis was used to determine whether the presence of C. difficile infection was an independent predictor of increased LOS, total charges, and in-hospital mortality rate when controlling for surgery type, age, sex, payor, and hospital characteristics. RESULTS Clostridium difficile infection was reported as a discharge diagnosis for 8,113 (0.52%) of all 1,553,597 inpatients who had undergone a general surgical procedure. The incidence increased significantly in 2002 (34% higher than in 2001; p < 0.0001). The following patient and hospital characteristics were associated with the highest incidence of C. difficile infection (all p < 0.0001): Age > 64 years (0.95%); Medicare beneficiary status (0.94%); north-eastern hospital location (0.73%); and large (0.55%), urban (0.56%), or teaching hospital (0.61%). Patients undergoing an emergency operation were at higher risk than those having operations performed electively (0.8% vs. 0.3%; p < 0.0001). Colectomy, small-bowel resection, and gastric resection were associated with the highest risk of C. difficile infection (incidence after colectomy 1.11%; odds ratio [OR] 2.77, 95% confidence interval [CI] 2.65, 2.89, p < 0.0001; small-bowel resection 1.17%, OR 2.40, 95% CI 2.26, 2.54, p < 0.0001; gastric resection 1.02%, OR 2.26, 95% CI 2.03, 2.52, p < 0.0001). Patients undergoing cholecystectomy and appendectomy had the lowest risk of C. difficile infection (cholecystectomy 0.41%, OR 0.37, 95% CI 0.35, 0.39, p < 0.0001; appendectomy 0.20%, OR 0.45, 95% CI 0.42, 0.49, p < 0.0001). Multivariable analysis demonstrated that C. difficile was an independent predictor of LOS, which increased by 16.0 days (95% CI 15.6, 16.4 days; p < 0.0001) in the presence of infection. Total charges increased by

Comparison of generic versus specific quality-of-life scales for mesh hernia repairs.

77,483 (95% CI

Laparoscopic Curative Resection of Pheochromocytomas

75,174,

A Comparison of Laparoscopic Bipolar Vessel Sealing Devices in the Hemostasis of Small-, Medium-, and Large-Sized Arteries

79,793; p < 0.0001), and there was a 3.4-fold increase in the mortality rate (95% CI 3.02, 3.77; p < 0.0001) compared with patients who did not acquire C. difficile. CONCLUSIONS Epidemiologic data suggest that the incidence of C. difficile infection is increasing in U.S. surgical patients and that the infection is most prevalent after emergency operations and among patients having intestinal tract resections. Infection with C. difficile is an independent predictor of increased LOS, total charges, and mortality rate after surgery and represents a considerable burden to both patients and hospitals. Preventing C. difficile infection offers a potentially significant improvement in patient outcomes, as well as a reduction in hospital costs and resource expenditures.

The susceptibility of prosthetic biomaterials to infection

BACKGROUND With the use of mesh shown to considerably reduce recurrence rates for hernia repair and the subsequent improvement in clinical outcomes, focus has now been placed on quality-of-life outcomes in patients undergoing these repairs, specifically, as they relate to the mesh prosthesis. Traditionally, quality of life after hernia surgery, like many other medical conditions, has been tested using the generic SF-36 survey. The SF-36 quality-of-life survey, although well studied and validated, may not be ideal for patients undergoing hernia repairs. We propose a new quality-of-life survey, the Carolinas Comfort Scale (CCS), pertaining specifically to patients undergoing hernia repair with mesh; our goal was to test the validity and reliability of this survey. STUDY DESIGN The CCS questionnaire was mailed to 1,048 patients to assess its acceptability, responsiveness, and psychometric properties. The survey sample included patients who were at least 6 months out after hernia repair with mesh. Patients were asked to fill out the CCS and the generic SF-36 questionnaires, four questions comparing the two surveys, and their overall satisfaction relating to their hernia repair and mesh. RESULTS The reliability of the CCS was confirmed by Cronbachs alpha coefficient (0.97). Test-retest validity was supported by the correlation found between two different administrations of the CCS; both Spearmans correlation coefficient and the kappa coefficient were important for each question of the CCS. Assessment of its discriminant validity showed that both the mean and median scores for satisfied patients were considerably lower than those for dissatisfied patients. Concurrent validity was demonstrated by the marked correlations found between the CCS and SF-36 questionnaire scales. When comparing the two surveys, 72% of patients preferred the CCS questionnaire, 80% believed it was easier to understand, 66% thought it was more reflective of their condition, and 69% said they would rather fill it out over the SF-36. CONCLUSIONS The CCS better assesses quality of life and satisfaction of patients who have undergone surgical hernia repair than the generic SF-36.

Laparoscopic splenectomy for massive splenomegaly

Purpose:Pheochromocytomas are relatively uncommon tumors whose operative resection has clear medical and technical challenges. While the safety and efficacy of laparoscopic adrenalectomy are relatively well documented, few studies with extended follow-up have been conducted to measure the success of the procedure for the most challenging of the adrenal tumors. In addition, several reports question the applicability of a minimally invasive approach for sizeable pheochromocytomas. The purpose of our investigation was to assess the outcomes of laparoscopic adrenalectomy for pheochromocytomas in the largest study to date when performed by experienced laparoscopic surgeons. Methods:All pheochromocytomas removed by the authors from January 1995 to October 2004 were reviewed under an Institutional Review Board approved protocol. Eighty-five percent were documented in a prospective fashion. Results:Eighty consecutive patients underwent laparoscopic resection of 81 pheochromocytomas. Seventy-nine were found in the adrenal (42 left, 35 right, 1 bilateral); 2 were extra-adrenal paragangliomas. Eight patients had multiple endocrine neoplasia syndrome. Two lesions were malignant. There were 48 females and 32 males with a mean age of 45 years (range, 15–79 years). Mean tumor size was 5.0 cm (range, 2–12.1 cm); 41 of these lesions were 5 cm in size or larger. Average operative time and blood loss were 169 minutes (range, 69–375 minutes) and 97 mL (range, 20–500 mL), respectively. Intraoperative hypertension (systolic blood pressure, >170 mm Hg) was reported in 53% of patients and hypotension (systolic blood pressure, <90 mm Hg) in 28% of patients. There were no conversions to open surgery. Mean length of stay was 2.3 days (range, 1–10 days). There were 6 perioperative morbidities (7.5%) and no mortalities. No patient required a blood transfusion. No recurrence of endocrinopathy has been documented at a mean follow-up of 21.4 months. Conclusion:Laparoscopic resection of pheochromocytomas, including large lesions, can be accomplished safely by experienced surgeons. A short hospital stay with minimal operative morbidity and eradication of endocrinopathy support the minimally invasive approach for adrenalectomy in the setting of pheochromocytoma.