Histologic evaluation of absorbable and non-absorbable barrier coated mesh secured to the peritoneum with fibrin sealant in a New Zealand white rabbit model

PURPOSE

The purpose of this study is to evaluate the histologic response to fibrin sealant (FS) as an alternative fixation method for laparoscopic ventral hernia repair.

METHODS

One non-absorbable barrier mesh (Composix™) and three absorbable barrier meshes (Sepramesh™, Proceed™, and Parietex™ Composite) were used for the study, with uncoated macroporous polypropylene mesh (ProLite Ultra™) as the control. Three methods of fixation were used: #0-polypropylene suture + FS (ARTISS™, Baxter Healthcare Corp.), FS alone (ARTISS™), or tacks alone (n = 10 for each group). Two pieces of mesh (of dimensions 4 × 4-cm) were secured intraperitoneally in 75 New Zealand white rabbits. After 8 weeks, hematoxylin and eosin (H&E)-stained specimens were evaluated for host tissue response. Statistical significance (P < 0.05) was determined using a one-way analysis of variance (ANOVA) with Fisher's least significant difference (LSD) post hoc test.

RESULTS

Composix™ with FS only showed significantly greater cellular infiltration than with suture + FS (P = 0.0007), Proceed™ with FS only had significantly greater neovascularization than with suture + FS (P = 0.0172), and ProLite Ultra™ with suture + FS had significantly greater neovascularization than with tacks only (P = 0.046). Differences due to mesh type showed that Composix™ exhibited less extensive cellular infiltration (P ≤ 0.0032), extracellular matrix (ECM) deposition, and neovascularization, and demonstrated less inflammatory cells and more fibroblasts compared to the other meshes (P < 0.05).

CONCLUSIONS

FS did not have a significant histologic effect compared to tacks when utilized for the fixation of mesh to the peritoneum of New Zealand White rabbits. However, the mesh type did have a significant histologic effect. The permanent barrier mesh (Composix™) was associated with less histologic incorporation than absorbable barrier and macroporous meshes, as evidenced by lower levels of cellular infiltration, ECM deposition, and neovascularization, independent of the fixation method used.

Early biocompatibility of crosslinked and non-crosslinked biologic meshes in a porcine model of ventral hernia repair

PURPOSE

Biologic meshes have unique physical properties as a result of manufacturing techniques such as decellularization, crosslinking, and sterilization. The purpose of this study is to directly compare the biocompatibility profiles of five different biologic meshes, AlloDerm(®) (non-crosslinked human dermal matrix), PeriGuard(®) (crosslinked bovine pericardium), Permacol(®) (crosslinked porcine dermal matrix), Strattice(®) (non-crosslinked porcine dermal matrix), and Veritas(®) (non-crosslinked bovine pericardium), using a porcine model of ventral hernia repair.

METHODS

Full-thickness fascial defects were created in 20 Yucatan minipigs and repaired with the retromuscular placement of biologic mesh 3 weeks later. Animals were euthanized at 1 month and the repair sites were subjected to tensile testing and histologic analysis. Samples of unimplanted (de novo) meshes and native porcine abdominal wall were also analyzed for their mechanical properties.

RESULTS

There were no significant differences in the biomechanical characteristics between any of the mesh-repaired sites at 1 month postimplantation or between the native porcine abdominal wall without implanted mesh and the mesh-repaired sites (P > 0.05 for all comparisons). Histologically, non-crosslinked materials exhibited greater cellular infiltration, extracellular matrix (ECM) deposition, and neovascularization compared to crosslinked meshes.

CONCLUSIONS

While crosslinking differentiates biologic meshes with regard to cellular infiltration, ECM deposition, scaffold degradation, and neovascularization, the integrity and strength of the repair site at 1 month is not significantly impacted by crosslinking or by the de novo strength/stiffness of the mesh.

Evaluation of fenestrated and non-fenestrated biologic grafts in a porcine model of mature ventral incisional hernia repair

INTRODUCTION

The purpose of this study is to compare the tissue incorporation of a novel fenestrated and non-fenestrated crosslinked porcine dermal matrix (CPDM) (CollaMend™, Davol Inc., Warwick, RI) in a porcine model of ventral hernia repair.

METHODS

Bilateral abdominal wall defects were created in 12 Yucatan minipigs and repaired with a preperitoneal or intraperitoneal technique 21 days after hernia creation. Animals were randomized to fenestrated or non-fenestrated CPDM for n = 6 pieces of each graft in the preperitoneal or intraperitoneal location. All animals were sacrificed at 1 month. Adhesion characteristics and graft contraction/growth were measured by the Garrard adhesion grading scale and transparent grid overlay. Histological analysis of hematoxylin and eosin (H&E)-stained slides was performed to assess graft incorporation. Tissue incorporation strength was measured by a T-peel tensile test. The strength of explanted CPDM alone and de novo CPDM was measured by a uniaxial tensile test using a tensiometer (Instron, Norwood, MA) at a displacement rate of 0.42 mm/s. Statistical significance (P < 0.05) was determined for histological analysis using a Kruskal-Wallis non-parametric test with a Bonferroni correction, and for all other analyses using a two-way analysis of variance (ANOVA) with a Bonferroni post-test or a Kruskal-Wallis non-parametric test with a Dunn's post-test.

RESULTS

Intraperitoneal placement of fenestrated CPDM resulted in a significantly higher area of adhesions and adhesion score compared to the preperitoneal placement of fenestrated CPDM (P < 0.05). For both preperitoneal and intraperitoneal placement, histological findings demonstrated greater incorporation of the graft due to the fenestrations. No significant differences were detected in the uniaxial tensile strengths of the graft materials alone, either due to the graft type (non-fenestrated vs. fenestrated) or due to the placement location (preperitoneal vs. intraperitoneal). The incorporation strength (T-peel force) was significantly greater for fenestrated compared to non-fenestrated CPDM when placed in the preperitoneal location (P < 0.01). The incorporation strength was also significantly greater for fenestrated CPDM placed in the preperitoneal location compared to fenestrated CPDM placed in the intraperitoneal location (P < 0.05).

CONCLUSIONS

Fenestrations in CPDM result in greater tissue incorporation strength and lower adhesion area and score when placed in the preperitoneal location. Fenestrations in CPDM allow for greater tissue incorporation without accelerating graft degradation. Fenestrations may be placed in CPDM while still allowing adequate graft strength for intraperitoneal and preperitoneal hernia repairs at 1 month in a porcine model.

Evaluation of acellular human dermis reinforcement of the crural closure in patients with difficult hiatal hernias

BACKGROUND

Biologic prosthetics may circumvent mesh-related complications at the esophageal hiatus by becoming remodeled by native cells. We present our experience with acellular human dermal matrix in the repair of difficult hiatal hernias (HH).

METHODS

Records of 17 patients who underwent laparoscopic HH repair using acellular human dermis to buttress the crural closure were analyzed. Hernias were paraesophageal (PEH) in 12 patients, large type 1 in 1 patient, and recurrent after prior HH repair in 4 patients. Barium swallow (BAS) was obtained 6-12 months after surgery. (Data are presented as mean +/- standard deviation.)

RESULTS

Mean patient age was 65 +/- 12 years and BMI was 31 +/- 4. Mean gastroesophageal (GE) junction distance above the diaphragm in the PEHs was 4.9 +/- 1.5 cm; 9 of 12 patients with PEH had more than 50% of the stomach in the chest. Mean operating time was 273 +/- 48 min. Average hiatal defect size was 4.7 x 2.7 cm, with 4.2 +/- 1.2 sutures used to close the crura. Nissen fundoplication was performed in all patients, esophageal lengthening in four patients, and anterior gastropexy in three patients. Mean hospital length of stay (LOS) was 2.3 +/- 0.8 days. Mean followup was 14.4 +/- 4.4 months. Postoperatively, only one (6%) patient had heartburn/regurgitation, one (6%) had mild dysphagia, and two (12%) take proton pump inhibitors. Followup BAS at 10.3 +/- 4.9 months after surgery showed small recurrent hernias in two patients (12%), but only one was symptomatic. In addition, there was one symptomatic failure of a redo Nissen in an obese patient. Reoperative gastric bypass 15 months later showed an intact crural closure with a remodeled buttress site.

CONCLUSIONS

Acellular human dermal matrix may be an effective method to buttress the crural closure in patients with large hiatal hernias. Longer followup in larger numbers of patients is needed to assess the validity of this approach.

Outcomes analysis of laparoscopic resection of pancreatic neoplasms

BACKGROUND

Experience with laparoscopic resection of pancreatic neoplasms remains limited. The purpose of this study is to critically analyze the indications for and outcomes after laparoscopic resection of pancreatic neoplasms.

METHODS

The medical records of all patients undergoing laparoscopic resection of pancreatic neoplasms from July 2000 to February 2006 were reviewed. Data are expressed as mean +/- standard deviation.

RESULTS

Laparoscopic pancreatic resection was performed in 22 patients (M:F, 8:14) with a mean age of 56.3 +/- 15.1 years and mean body mass index (BMI) of 26.3 +/- 4.5 kg/m2. Nine patients had undergone previous intra-abdominal surgery. Indications for pancreatic resection were cyst (1), glucagonoma (1), gastrinoma (2), insulinoma (3), metastatic tumor (2), IPMT (4), nonfunctioning neuroendocrine tumor (3), and mucinous/serous cystadenoma (6). Mean tumor size was 2.4 +/- 1.6 cm. Laparoscopic distal pancreatectomy was attempted in 18 patients and completed in 17, and enucleation was performed in 4 patients. Laparoscopic ultrasound (n = 10) and a hand-assisted technique (n = 4) were utilized selectively. Mean operative time was 236 +/- 60 min and mean blood loss was 244 +/- 516 ml. There was one conversion to an open procedure because of bleeding from the splenic vein. The mean postoperative LOS was 4.5 +/- 2.0 days. Seven patients experienced a total of ten postoperative complications, including a urinary tract infection (UTI) (1), lower-extremity deep venous thrombosis (DVT) and pulmonary embolus (1), infected peripancreatic fluid collection (1), pancreatic pseudocyst (1), and pancreatic fistula (6). Five pancreatic fistulas were managed by percutaneous drainage. The reoperation rate was 4.5% and the overall pancreatic-related complication rate was 36.4%. One patient developed pancreatitis and a pseudocyst 5 months postoperatively, which was managed successfully with a pancreatic duct stent. There was no 30-day mortality.

CONCLUSIONS

Laparoscopic pancreatic resection is safe and feasible in selected patients with pancreatic neoplasms. With a pancreatic duct leak rate of 27%, this problem remains an area of development for the minimally invasive technique.

Laparoscopic ventral hernia repair: a single center experience

A retrospective chart review at the Carolinas Medical Center was performed on all patients who underwent laparoscopic ventral hernia repair (LVHR) from July 1998 through December 2003. LVHR was successfully completed in 270 of the 277 patients, or 98%, in whom it was attempted. Half of the patients (138/277) had at least one previous failed repair. The average defect measured 143.3 cm(2), and mesh was used in all repairs. The mean operating time was 168.3 min, mean blood loss was 50 cc, and average length of hospitalization was 3.0 days. Thirty-four complications occurred in 31 patients (11%). Only two mesh infections occurred (0.7%). At a mean follow-up period of 21 months, the rate of hernia recurrence was 4.7%. As experience grows and length of follow-up expands, LVHR may become the preferred approach for ventral hernia in difficult patients, especially obese patients and patients who have failed prior open repairs.

Do patient or hospital demographics predict cholecystectomy outcomes? A nationwide study of 93,578 patients

BACKGROUND

The purpose of this study was to examine the influence of patient and hospital demographics on cholecystectomy outcomes.

METHODS

Year 2000 data from the Healthcare Cost and Utilization Project Nationwide Inpatient Sample database was obtained for all patients undergoing inpatient cholecystectomy at 994 nationwide hospitals. Differences (p < 0.05) were determined using standard statistical methods.

RESULTS

Of 93,578 cholecystectomies performed, 73.4% were performed laparoscopically. Length of hospital stay (LOS), charges, morbidity, and mortality were significantly less for laparoscopic cholecystectomy (LC). Increasing patient age was associated with increased LOS, charges, morbidity, mortality, and a decreased LC rate. Charges, LOS, morbidity, and mortality were highest for males with a lower LC rate than for females Mortality and LOS were higher, whereas morbidity was lower for African Americans than for whites. Hispanics had the shortest LOS, as well as the lowest morbidity and mortality rates. Laparoscopic cholecystectomy was performed more commonly for Hispanics than for whites or African Americans, with lower charges for whites. Medicare-insured patients incurred longer LOS as well as higher charges, morbidity, and mortality than Medicaid, private, and self-pay patients, and were the least likely to undergo LC. As median income decreases, LOS increases, and morbidity decreases with no mortality effect. Teaching hospitals had a longer LOS, higher charges, and mortality, and a lower LC rate, with no difference in morbidity, than nonteaching centers. As hospital size (number of beds) increased, LOS, and charges increased, with no difference in morbidity. Large hospitals had the highest mortality rates and the lowest incidence of LC. Urban hospitals had higher LOS and charges with a lower LC rate than rural hospitals. After control was used for all other covariates, increased age was a predictor of increased morbidity. Female gender, LC, and intraoperative cholangiogram all predicted decreased morbidity. Increased age, complications, and emergency surgery predicted increased mortality, with laparoscopy and intraoperative cholangiogram having protective effects. Patient income, insurance status, and race did not play a role in morbidity or mortality. Academic or teaching status of the hospital also did not influence patient outcomes.

CONCLUSIONS

Patient and hospital demographics do affect the outcomes of patients undergoing inpatient cholecystectomy. Although male gender, African American race, Medicare-insured status, and large, urban hospitals are associated with less favorable cholecystectomy outcomes, only increased age predicts increased morbidity, whereas female gender, laparoscopy, and cholangiogram are protective. Increased age, complications, and emergency surgery predict mortality, with laparoscopy and intraoperative cholangiogram having protective effects.

Laparoscopic management of median arcuate ligament syndrome

Median arcuate ligament syndrome is a rare disorder resulting from luminal narrowing of the celiac artery by the insertion of the diaphragmatic muscle fibers or fibrous bands of the celiac nervous plexus. The syndrome is characterized by weight loss, postprandial abdominal pain, nausea, vomiting, and an epigastric bruit. Surgical management entails complete division of the median arcuate ligament. The video demonstrates the laparoscopic release of the median arcuate ligament in a patient with median arcuate ligament syndrome. The patient is a 22-year-old male with a 6-month history of epigastric abdominal pain, nausea, vomiting, a 140-lb. weight loss, and an epigastric bruit on physical exam. Aortography demonstrated a >or=90% extrinsic compression of the celiac artery. A full laparoscopic skeletonization of the celiac artery and branch vessels was performed. Intraoperative duplex U/S demonstrated flow rate reduction after the median arcuate ligament release. A postoperative CT angiogram demonstrated no residual stenosis. The patient was discharged on postoperative day 3 and remained asymptomatic after 7 months of follow-up. Laparoscopic release of the median arcuate ligament is a novel approach to the management of celiac artery compression syndrome. The role of minimally invasive techniques to manage median arcuate ligament syndrome is evolving but they appear to be a safe alternative to open surgery.

Evaluation of adhesion formation, mesh fixation strength, and hydroxyproline content after intraabdominal placement of polytetrafluoroethylene mesh secured using titanium spiral tacks, nitinol anchors, and polypropylene suture or polyglactin 910 suture

BACKGROUND

The purpose of this study is to evaluate fixation methods for polytetrafluoroethylene (ePTFE) mesh with an in vivo model of laparoscopic ventral hernia repair.

METHODS

In 40 New Zealand white rabbits, a 4 x 4-cm ePTFE mesh (n = 80, two per animal) was attached to an intact peritoneum with polyglactin 910 (PG 910) (n = 20) or polypropylene (PP) (n = 20) suture, titanium spiral tacks (TS) (n = 20), or nitinol anchors (NA) (n = 20). Mesh was harvested at 8 and 16 weeks for fixation strength testing, adhesion assessment, and collagen (hydroxyproline) content. Fixation strength on day 0 was determined with mesh attached to harvested abdominal wall. Statistical significance was determined as p < 0.05.

RESULTS

There was no difference in fixation strength between PP (39.1 N) and PG 910 (40.0 N) sutures at time zero. At week 8, PP (25.7 N) was significantly stronger (p < 0.05) than PG 910 (11.4 N) suture, but not at week 16. The fixation strength of TS and NA (day 0, 15.4 vs 7.4 N; week 8, 17.5 vs 15.3 N; week 16, 19.1 vs 13.8 N) was not significantly different. Fixation with PP suture was significantly (p < 0.05) stronger than that with TS and NA at day 0 (39.1, 15.4, and 7.4 N, respectively) but not at weeks 8 or 16. The fixation strength of suture decreased significantly (p < 0.05) from day 0 to week 16 (PP: day 0 = 39.1 N, week 8 = 25.7 N, week 16 = 21.4 N; PG 910: day 0 = 40.0 N, week 8 = 11.4 N, week 16 = 12.8 N). The fixation strength of NA and TS did not change significantly (NA: day 0 = 7.4 N, week 8 = 15.3 N, week 16 = 13.8 N; TS: week 0 = 15.4 N, week 8 = 17.5 N, week 16 = 19.1 N). There were no differences in adhesion area based on fixation device used; however, there were more (p < 0.05) mesh samples using NA with adhesions compared to TS and adhesion tenacity was greater (p < 0.05) compared to that of TS, PP, and PG. Hydroxyproline content at weeks 8 and 16 was similar for all fixation devices.

CONCLUSIONS

The initial fixation strength for nonabsorbable suture is significantly greater than that of the metallic fixation devices, but after 8 weeks there is no difference. Laparoscopic ventral hernia repair without transabdominal suture fixation may be predisposed to acute failure. The metallic devices have similar fixation strength, although the incidence of adhesions and tenacity of adhesions appear to be greater with the nitinol anchors. Since these devices have similar fixation strengths and most likely provide adequate supplementation to transabdominal sutures for mesh fixation after laparoscopic ventral hernia repair, their use should be based on other factors, such as their propensity for adhesions, ease of application, and cost.

Laparoscopic resection of splenic artery aneurysms

BACKGROUND

Laparoscopic techniques used to manage asymptomatic splenic artery aneurysms have been reported infrequently.

METHODS

A laparoscopic splenic artery aneurysm resection was attempted for six consecutive patients.

RESULTS

One patient underwent conversion to laparotomy because of a tear in the splenic vein. Among the five successful laparoscopic splenic artery aneurysm resections, the mean estimated blood loss was 37 +/- 12.6 ml, the mean operative time was 187.6 +/- 79.2 min, and the mean postoperative length of hospital stay was 1.8 +/- 1.3 days. The mean time to a clear liquid diet was 5.3 +/- 0.5 h, and the mean time to a regular diet was 1 +/- 0 day. The mean duration of narcotic analgesic use was 5.4 +/- 1.5 days, and the mean time to resumption of regular activities was 12.7 +/- 1.6 days.

CONCLUSIONS

These cases illustrate the benefit of a laparoscopic approach with brief hospitalizations, early resumption of diet and regular activity, and minimal use of postoperative narcotic analgesics.

Effect of carbon dioxide pneumoperitoneum and wound closure technique on port site tumor implantation in a rat model

BACKGROUND

The purpose of this study was to evaluate the effects of carbon dioxide (CO2) pneumoperitoneum and wound closure technique on port site tumor implantation.

METHODS

A standard quantity of rat mammary adenocarcinoma (SMT2A)was allowed to grow in a flank incision in Wistar-Furth rats (n = 90) for 14 days. Thereafter, 1-cm incisions were made in each animal in three quadrants. There were six control animals. The experimental animals were divided into a 60-min CO2 pneumoperitoneum group (n = 42) and a no pneumoperitoneum (n = 42) group. The flank tumor was lacerated transabdominally in the experimental groups. The three wound sites were randomized to closure of (a) skin; (b) skin and fascia; and (c) skin, fascia, and peritoneum. The abdominal wounds were harvested en bloc on postoperative day 7.

RESULTS

Histologic comparison of the port sites in the pneumoperitoneum and no-pneumoperitoneum groups did not demonstrate a statistically significant difference in tumor implantation for any of the closure methods. Evaluation of the closure techniques showed no statistical difference between the pneumoperitoneum group and the no-pneumoperitoneum group in the incidence of port site tumor implantation. Within the no-pneumoperitoneum group, there was a significant increase (p = 0.03) in tumor implantation with skin closure alone vs all three layers. Additionally, when we compared all groups by closure technique, the rate of tumor implantation was found to be significantly higher (p = 0.01) for skin closure alone vs closure of all three layers.

CONCLUSIONS

This study suggests that closure technique may influence the rate of port site tumor implantation. The use of a CO2 pneumoperitoneum did not alter the incidence of port site tumor implantation at 7 days postoperatively.

Cirrhosis is not a contraindication to laparoscopic surgery

BACKGROUND

Cirrhosis of the liver contributes significantly to morbidity and mortality in abdominal surgery. The proven benefits of laparoscopy seem especially applicable to patients with this complex disease. This study evaluates the safety and efficacy of laparoscopic procedures in a series of consecutively treated patients with biopsy-proven cirrhosis.

METHODS

The medical records of all patients with biopsy-proven cirrhosis undergoing laparoscopic surgery at the authors' medical center between January 2000 and December 2003 were retrospectively reviewed.

RESULTS

A total of 50 patients (27 men and 23 women) underwent 52 laparoscopic procedures. Among these 50 patients were 39 patients with Child-Pugh classification A cirrhosis, 10 with classification B, and 1 with classification C, who underwent a variety of laparoscopic procedures including cholecystectomy (n = 22), splenectomy (n = 18), colectomy (n = 4), diagnostic laparoscopy (n = 3), ventral hernia repair (n = 1), Nissen fundoplication (n = 1), Heller myotomy (n = 1), Roux-en-Y gastric bypass (n = 1), and radical nephrectomy (n = 1). There were two conversions (4%) to an open procedure. The mean operative time was 155 min. Estimated blood loss averaged 124 ml for all procedures, and 20 patients (40%) required perioperative transfusion of blood products. One patient required a single blood transfusion postoperatively because of anemia. No one experienced hepatic decompensation. Overall morbidity was 16%. There were no deaths. The mean length of hospitalization was 3 days.

CONCLUSIONS

Although technically challenging because portal hypertension, varices, and thrombocytopenia frequently coexist, basic and advanced laparoscopic procedures are safe for patients with mild to moderate cirrhosis of the liver.

The laparoscopic repair of suprapubic ventral hernias

BACKGROUND

The complexity of dissection and the close proximity of the hernia to bony, vascular, nerve, and urinary structures make the laparoscopic repair of suprapubic hernias (LRSPH) a formidable operation. We performed a prospective evaluation of the outcomes of patients undergoing LRSPH.

METHODS

The study population comprised 36 patients undergoing LRSPH from July 1996 to January 2004. Patient demographics, hernia sizes, mesh types and sizes, perioperative outcomes, and recurrences were documented. After our early experience with this operation, the repair evolved to include transabdominal suture fixation to the pubic bone, Cooper's ligament, and above the iliopubic tract.

RESULTS

There were 26 women and 10 men. They had a mean age of 55.9 years (range, 33-76) and a mean body mass index (BMI) of 31.0 kg/m2 (range, 22-67). Twenty-two (61%) of the repairs were for recurrent hernias, with an average of 2.3 previously failed open repairs each (range, 1-11). The mean hernia size was 191.4 cm2 (range, 20-768), and the average mesh size was 481.4 cm2 (range, 193-1,428). All repairs were performed with expanded polytetrafluoroethylene (ePTFE) mesh. Mean operating time was 178.7 min (range, 95-290). Mean blood loss was 40 cc (range, 20-100). One patient undergoing her fifth repair required conversion due to adhesions to a polypropylene mesh. Hospital stay averaged 2.4 days (range, 1-7). Mean follow-up was 21.1 months (range, 1-70). Complications (16.6%) included deep venous thrombosis (n = 1), prolonged pain for >6 weeks (n = 1), trocar site cellulitis (n = 1), ileus (n = 1), prolonged seroma (n = 1), and Clostridium difficile colitis (n = 1). Hernias recurred in two of our first nine patients, for an overall recurrence rate of 5.5%. Since we began using the technique of applying multiple sutures directly to the pubis and Cooper's ligament (in the subsequent 27 patients), no recurrences have been documented.

CONCLUSIONS

Although technically demanding and time-consuming, the LRSPH is safe and technically feasible. Moreover, it results in a low recurrence rate and is applicable to large or multiply recurrent hernias. Transabdominal suture fixation to the bony and ligamentous structures produces a more durable hernia repair.

The susceptibility of prosthetic biomaterials to infection

BACKGROUND

Despite the use of a sterile technique and the administration of prophylactic antibiotics during surgical procedures, mesh infection continues to complicate the use of biomaterials. The purpose of this study was to compare the susceptibility to infection of prosthetic biomaterials in a live-animal model.

METHODS

The following seven prosthetic mesh biomaterials were used in this study. Expanded polytetrafluoroethylene (ePTFE) with silver/chlorhexidine (DM+), ePTFE (DM), porcine intestinal submucosa (S), polypropylene (M), ePTFE/polypropylene (X), hyaluronate/carboxymethylcellulose/polypropylene (SM), and human acellular dermal matrix (A). Lewis rats (n = 108) underwent creation of a single ventral hernia; 105 of them were repaired with a different mesh (2-cm2 piece). Twelve pieces of each mesh were inoculated at the time of hernia repair with 10(8) Staphylococcus aureus (n = 84). Three pieces of each mesh were placed without bacterial inoculation (n = 21). In three animals, no mesh was placed; instead, the peritoneum of the hernia defect was inoculated (n = 3). After 5 days, the animals were killed and the mesh was explanted (peritoneum for the nonmesh control). The mesh was vortex-washed and incubated in tryptic soy broth. Bacterial counts were determined using serial dilutions and spot plates and quantified in colony-forming units (CFU) per square centimeter of mesh present in the vortex wash fluid (wash count) and the soy broth (broth count). Data are presented as the mean log(10), with analysis of variance (ANOVA) and Tukey's test used to determine significance (p < 0.05).

RESULTS

The DM+ material had no detectable live bacteria in the wash or broth counts in 10 of 12 tested samples (p = 0.05). Of the samples that showed bacterial growth, the peritoneum control group had a lower wash count than A (p = 0.05) and the lowest broth count of all the materials except for DM+ (p = 0.05). In addition, SM had a significantly lower wash count than A (p = 0.05), with no broth count difference. In regard to wash and broth counts, DM, M, X, SM, S, and A were no different (p = NS).

CONCLUSIONS

The DM+ material was the least susceptible to infection. Impregnation with silver/chlorhexidine killed the inoculated bacteria, preventing their proliferation on the mesh surface. Other than DM+, native peritoneal tissue appears to be the least susceptible to infection. Silver/chlorhexidine appears to be an effective bactericidal agent for use with mesh biomaterials.

A novel technique of lumbar hernia repair using bone anchor fixation

Lumbar hernias are difficult to repair due to their proximity to bone and inadequate surrounding tissue to buttress the repair. We analyzed the outcome of patients undergoing a novel retromuscular lumbar hernia repair technique. The repair was performed in ten patients using a polypropylene or polytetrafluoroethylene mesh placed in an extraperitoneal, retromuscular position with at least 5 cm overlap of the hernia defect. The mesh was fixed with circumferential, transfascial, permanent sutures and inferiorly fixed to the iliac crest by suture bone anchors. Five hernias were recurrent, and five were incarcerated; seven were incisional hernias, and three were posttraumatic. Back and abdominal pain was the most common presenting symptom. Mean hernia size was 227 cm(2) (60-504) with a mesh size of 620 cm(2) (224-936). Mean operative time was 181 min (120-269), with a mean blood loss of 128 ml (50-200). Mean length of stay was 5.2 days (2-10), and morphine equivalent requirement was 200 mg (47-460). There were no postoperative complications or deaths. After a mean follow-up of 40 months (3-99) there have been no recurrences. Our sublay repair of lumbar hernias with permanent suture fixation is safe and to date has resulted in no recurrences. Suture bone anchors ensure secure fixation of the mesh to the iliac crest and may eliminate a common area of recurrence.

Gastrointestinal stromal tumors of the stomach

Gastrointestinal stromal tumors (GIST) comprise a rare group of neoplasms of unpredictable malignant potential with an annual incidence of 4/million persons. The stomach is the most common site of occurrence in the gastrointestinal tract. A combination of prognostic factors (patient age, histologic grade, mitotic rate, tumor size, and DNA analysis) have been utilized to predict their biologic behavior. Lymphatic spread of gastrointestinal stromal tumors is uncommon therefore a formal lymph node dissection is not standard surgical management. Consequently, complete surgical resection of the primary tumor is the most definitive treatment. An increasing number of cases have been reported utilizing a combination of laparoscopic and endoscopic techniques to resect these tumors. The manuscript will characterize the biologic behavior of gastrointestinal stromal tumors of the stomach, discuss the preoperative evaluation and minimally invasive surgical management of these patients, and review recent, encouraging adjuvant treatment strategies.

Plastic wound protectors do not affect wound infection rates following laparoscopic-assisted colectomy

BACKGROUND

Wound protectors are plastic sheaths that can be used to line a wound during surgery. Wound protectors can facilitate retraction of an incision without the need for other mechanical retractors and have been proposed as deterrents to wound infection. The purpose of this study was to define the ability of wound protectors to reduce the rate of infection when used in laparoscopic-assisted colectomy.

METHODS

We completed a retrospective review of the medical records of patients undergoing nonemergent laparoscopic-assisted colectomy between February 1999 and November 2002. All completely laparoscopic cases were excluded. The wound protector, when used, was applied to the extraction incision during the externalized portion of the procedure (colon and mesentery transection, anastomosis). Outcomes for patients with and without the use of a wound protector were compared.

RESULTS

A total of 141 patients underwent laparoscopic-assisted colectomy (98 for benign/malignant tumors, 35 for diverticular disease, and eight for Crohn's disease). There were no differences between the wound protector group ( n = 84) and the no wound protector group ( n = 57) with respect to mean age (55 vs 58 years), average body mass index (27 vs 29 kg/m2), gender, indication for surgery, comorbidities, antibiotics used, or mean operative time (185 vs 173 min). Nine patients in the wound protector group and eight in the no wound protector group developed a wound infection at the colon extraction site ( p = 0.42). Patients undergoing resection for Crohn's disease or diverticulitis had a higher infection rate (18.6%) than patients undergoing resection for polyps or cancer (9.2%; p < 0.05). No wound recurrence of cancer was observed in either group at a mean follow-up of 23 months (range, 3-48).

CONCLUSIONS

The wound protector, although useful for mechanical retraction of small wounds, does not significantly diminish the rate of wound infection at the bowel resection/anastomotic site. Patients undergoing elective resection for inflammatory processes have higher infection rates than patients undergoing laparoscopic-assisted colectomy for polyps or cancer.

Laparoscopic versus open nephrectomy in 210 consecutive patients: Outcomes, cost, and changes in practice patterns

BACKGROUND

Initially slow to gain widespread acceptance within the urological community, laparoscopic nephrectomy is now becoming the standard of care in many centers. Our institution has seen a dramatic transformation in practice patterns and patient outcomes in the 2 years following the introduction of laparoscopic nephrectomy. We compare the experience with laparoscopic and open nephrectomy within a single medical center.

METHODS

Data were collected for all patients undergoing elective nephrectomy (live donor, radical, simple, partial, and nephroureterectomy) between August 1998 and September 2002. Data were analyzed by Wilcoxon rank sum, chi-square, and Fisher's exact test. A p-value <0.05 was considered significant.

RESULTS

Of the patients, 92 underwent open nephrectomy, and 118 were treated laparoscopically (87 hand-assisted laparoscopic nephrectomy, 31 totally laparoscopic). There was one conversion (0.8%). Patient demographics and indications for surgery were equivalent for both groups. Mean operative time for laparoscopic nephrectomy (230 min) was longer than for open (187 min, p = 0.0001). Blood loss (97 ml vs 216 ml, p = 0.0001), length of stay (3.9 days vs 5.9 days, p = 0.0001), perioperative morbidity (14% vs 31%, p = 0.01), and wound complications (6.8% vs 27.1%, p = 0.0001) were all significantly less for laparoscopic nephrectomy. For live donors, time to convalescence was less (12 days vs 33 days, p = 0.02), but hospital charges were more for patients treated laparoscopically (19,007 dollars vs 13,581 dollars, p = 0.0001).

CONCLUSIONS

Laparoscopic nephrectomy results in less blood loss, fewer hospital days, fewer complications, and more rapid recovery than open surgery. We believe that these benefits outweigh the higher hospital charges associated with the laparoscopic approach.

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 repair of traumatic diaphragmatic injuries

BACKGROUND

The purpose of this study was to evaluate the feasibility and limitations of laparoscopic repair of traumatic diaphragmatic injuries.

METHODS

Laparoscopic repair of an acute traumatic diaphragmatic laceration or chronic traumatic diaphragmatic hernia was attempted in 17 patients between January 1997 and January 2001. The patients in the study included 13 men and 4 women with a mean age of 33.2 years (range, 15-63 years). Nine patients had a blunt injury, and eight patients had a penetrating injury. Laparoscopic repair was attempted for eight patients during their hospitalization for the traumatic injury (mean, 2.3 days; range, 0-6 days) and for ten patients with a chronic diaphragmatic hernia (mean, 89 months; range, 5-420 months). The chronic diaphragmatic hernias-presented with abdominal pain (9/9), or vomiting (3/9).

RESULTS

Thirteen traumatic diaphragmatic injuries were repaired laparoscopically, and four (2 acute and 2 chronic) required conversion. Among the laparoscopically repaired diaphragmatic injuries, three defects (chronic) were repaired using expanded polytetrafluoroethylene (ePTFE), and nine were repaired primarily. The mean length of the diaphragmatic defects was 4.6 cm (range, 1.5-12 cm). The mean operative time was 134.7 min (range, 55-200 min). The mean estimated blood loss was 108.5 ml (range, 30-500 ml), and the postoperative length of stay was 4.4 days (range, 1-12 days). There were no intraoperative complications, but three patients developed pulmonary complications (atelectasis/pneumonia). Follow-up evaluation was available for 11 patients. There were no documented recurrences after a mean follow-up period of 7.9 months (range, 1 week to 24 months). Conversion resulted from a reluctance or inability to perform laparoscopic suture of transverse diaphragmatic lacerations longer than 10 cm anterior to the esophageal hiatus and adjacent to the pericardium (n = 2) or communicating with the esophageal hiatus (n = 2). One patient also required spleneotomy for an unrecognized splenic laceration that had occurred at the time of the original trauma. The four patients undergoing laparotomy had a mean postoperative discharge date of 8.7 days (range, 6-14 days).

CONCLUSIONS

Laparoscopy is an alternative approach to repairing acute traumatic diaphragmatic lacerations and chronic traumatic diaphragmatic hernias. Large traumatic diaphragmatic injuries adjacent to or including the esophageal hiatus are best approached via laparotomy.

Prospective randomized evaluation of surgical resident proficiency with laparoscopic suturing after course instruction

BACKGROUND

Laparoscopic suturing is required to develop competency in advanced laparoscopy.

METHODS

Manuals detailing laparoscopic suturing were give to 17 Surgery residents. One week later they performed a suture on a training model. Time (s), accuracy (mm), and knot strength (lb) were recorded. The residents were blindly randomized to intervention (n = 9) and control (n = 8) groups. The intervention residents attended a 60-min course with lecture, video, and individual proctoring. Two weeks later they performed a stitch with standard laparoscopic instruments and a stitch with a suturing assist device. Statistical analysis included a Wilcoxon rank-sum test.

RESULTS

The intervention residents decreased their suturing time from the first to the second stitich (732.4-257.6s), the control and residents decreased their time from 500.2 s to 421.8 s. The time required to perform the second stitch showed no significant difference between the two groups (p = 0.46), but the difference in reduced time between the first and second stitch was significant (p = 0.001). Using the suturing assist device for the third suture, the intervention and control groups both decreased their times significantly. The control residents performed almost as quickly as the intervention residents with the suturing; device (p = 0.11). Accuracy and knot strength were not different in any test.

CONCLUSIONS

Residents can improve suturing skill with a short didactic course and individual proctoring. A suturing assist device decreases time required by inexperienced surgeons to device perform an intracorporeal tie.

Outcomes for Laparoscopic Bilateral Adrenalectomy

BACKGROUND AND PURPOSE

Laparoscopic adrenalectomy has become the preferred surgical approach to manage adrenal disorders. Bilateral adrenalectomy is performed for diseases that are unresponsive to medical management and, frequently, for neoplastic disease. The aim of this study was to review our experience with laparoscopic bilateral adrenalectomy and to evaluate its safety, efficacy, and outcomes.

PATIENTS AND METHODS

Between July 1996 and May 2001, five male and two female patients with a mean age of 46 years (range 15-69 years) presented for bilateral adrenalectomy (pheochromocytoma [N = 3], Cushing's disease [N = 3], and metastatic cancer [N = 1]). All procedures were performed using a lateral transperitoneal approach. One gland was excised, the patient was repositioned to the opposite lateral decubitus position, and the remaining gland was removed.

RESULTS

Laparoscopic bilateral adrenalectomy was completed in all seven patients. The mean tumor/gland size on the right was 5.0 cm (range 3.1-7.0 cm) and on the left was 5.6 cm (range 3.6-7.0 cm). The mean operative time was 308 minutes (range 190-430 minutes), and the mean estimated blood loss was 138 mL (range 30-300 mL). One patient with a pheochromocytoma experienced intraoperative hypertension necessitating treatment. There were no postoperative complications. The mean postoperative hospital stay was 5.1 days (range 3-9 days). All patients have been treated postoperatively with daily hydrocortisone and fludrocortisone replacement. After a mean follow-up of 33 months (range 2-45 months), six patients are alive. The patient undergoing bilateral adrenalectomy for metastatic lung cancer died from recurrent disease 13 months after resection.

CONCLUSION

Laparoscopic bilateral adrenalectomy is safe and effective. Patients are discharged postoperatively in a relatively short time with few complications. Appropriate steroid replacement and close follow-up allows these patients to return to self-reliance.

Laparoscopic vs open resection of gastric stromal tumors

BACKGROUND

Gastric 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.

METHODS

Between 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.

RESULTS

Patient 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 wedge 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 metastatic disease. There have been no trocar site recurrences.

CONCLUSIONS

Laparoscopic 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.

Optimal teaching environment for laparoscopic ventral herniorrhaphy

The introduction of laparoscopic techniques after residency training has created a new paradigm dependent on laparoscopic workshops. This study tested the benefit of an animate course and evaluated the role of proctoring in learning to perform laparoscopic ventral hernia repair (LVHR). Surgeons who had taken a 1-day LVHR course (n = 59) were polled to determine previous experience with laparoscopic procedures and experience with LVHR after the course. Forty-eight (81%) surgeons completing the course responded. Thirty-two (67%) surgeons had performed 179 LVHRS (mean 5.6) since the course. There were no statistically significant differences between the groups performing and not performing LVHR regarding academic/private practice (P=0.8) or opportunities to perform a ventral herniorrhaphy (P = 0.6). Fifteen (31%) surgeons were precepted in their hospital operating room by the lead author. Thirteen (87%) of precepted surgeons had performed a LVHR compared with 19 (58%) of the 33 surgeons taking the course without a precepted intervention (P = 0.05). Surgeons with experience performing laparoscopic inguinal hernia repair, Nissen fundoplication, and common bile duct exploration were more likely to perform LVHR (P=0.0001). Surgeons performing only laparoscopic cholecystectomy tended to be less likely to perform LVHR, nearing statistical significance (P=0.08). Surgeons with prior advanced laparoscopic surgery experience are thus more likely to perform LVHR after participating in a 1-day course. Surgeons precepted in their hospital operating room were also more likely to perform LVHR. Participation in an animate laboratory and a precepted experience can impact the future performance of advanced laparoscopic surgery.

Laparoscopic adrenalectomy for pheochromocytoma

BACKGROUND

Laparoscopic adrenalectomy for Conn's syndrome, Cushing's disease, cortisol-producing adenomas, and nonfunctioning adenomas has been well established. This study was intended to evaluate the clinical outcomes of patients undergoing laparoscopic adrenalectomy for pheochromocytoma, and to assess the efficacy and safety of a minimally invasive approach.

METHODS

Data were collected prospectively on all patients undergoing laparoscopic adrenalectomy for pheochromocytoma over a 5-year period.

RESULTS

In this study, 39 consecutive patients underwent laparoscopic resection of a pheochromocytoma: 38 adrenal (23 left, 15 right) and 1 extraadrenal paraganglioma. There were no conversions to open surgery. The mean tumor size was 5.2 cm (range, 2-12.1 cm). Average operative time was 159 min (range, 100-265 min), and average estimated blood loss was 72 ml (range, 30-350 ml). Intraoperative hypertension (systolic blood pressure > 170 mmHg) occurred in 67% of the patients, and hypotension (systolic blood pressure < 90 mmHg) in 39% of the patients. The mean length of stay was 2.1 days (range, 1-4 days). There were three minor postoperative complications. During a mean follow-up period of 14 months, there were no mortalities or recurrences of endocrinopathy.

CONCLUSIONS

Laparoscopic resection of pheochromocytomas can be accomplished safely despite frequent episodes of hemodynamic variability equal to those of historic open control subjects. A short hospital stay with expedient recovery,minimal wound complications, and lack of endocrinopathy recurrence makes a minimally invasive approach the procedure of choice for the management of pheochromoctyoma.

Management of oxygenation in pediatric acute hypoxemic respiratory failure

The prognosis for patients with acute respiratory distress syndrome (ARDS) in adults and children has improved since its formal acceptance as a clinical entity in 1967. Because acute hypoxemic respiratory failure is the hallmark of acute lung injury and ARDS, the management of oxygenation is crucial. Physicians managing pediatric patients with acute lung injury or ARDS are faced with a complex array of options influencing oxygenation. Certain treatment strategies can influence clinical outcomes, such as a lung-protective ventilation strategy that specifies a low tidal volume (6 mL/kg) and a plateau pressure limit (30 cm H(2)O) (Acute Respiratory Distress Network, N Engl J Med 2000;342:1301-1308). Other lung-protective strategies such as different levels of positive end-expiratory pressure, altered inspiratory:expiratory ratios, recruitment maneuvers, prone positioning, and extraneous gases or drugs may impact clinical outcomes but require further clinical study. This paper reviews state-of-the-art strategies on the management of oxygenation in acute hypoxemic respiratory failure and attempts to guide pediatric pulmonologists in managing children with respiratory failure.

Minilaparoscopic appendectomy

The purpose of this study was to evaluate the feasibility of using 2-mm laparoscopic instruments in the treatment of appendicitis and to identify risk factors that may limit their use. Minilaparoscopic appendectomy was performed through a 2-mm port in the umbilicus for a videoendoscope, a 2-mm working port in the right upper quadrant, and a 5/12-mm suprapubic port for an endoscopic stapler. Minilaparoscopic appendectomy was attempted in 26 consecutive patients with appendicitis. Thirty-two consecutive patients undergoing conventional laparoscopic appendectomy with 5- and 10-mm instruments and videoendoscopes before the availability of 2-mm instrumentation were analyzed for comparison. Statistical comparisons were made by the Student t test and Fisher exact test. Differences were considered statistically significant at a P value less than 0.05. There were no conversions to an open appendectomy in the minilaparoscopic appendectomy or conventional laparoscopic appendectomy group. The mean operative time was 69.5 minutes for the minilaparoscopic appendectomy group and 85.5 minutes for the conventional laparoscopic appendectomy group (P = 0.02). The mean postoperative length of stay was 1.7 days for the minilaparoscopic appendectomy group and 2.5 days for the conventional laparoscopic appendectomy group (P = 0.08). There was no significant difference in the complication rates (P = 0.31). Minilaparoscopic appendectomy was completed in 13 (50.0%) patients. Independent risk factors (P = 0.05) for conversion to 5- or 10-mm ports were a retrocecal appendix and increasing patient age. There were no differences in the mean postoperative length of stay (P = 0.12) or complication rate (P = 0.39) between the two groups, but mean operative time was longer (P = 0.05) in the converted group. Perioperative outcomes for minilaparoscopic appendectomy are comparable to those of conventional laparoscopic appendectomy. The use of 2-mm instrumentation in the management of appendicitis is limited in patients with retrocecal appendicitis. Increasing patient age and a history of abdominal surgery may influence the need to convert 2-mm ports to 5- or 10-mm ports.

Minimally invasive management of paraesophageal herniation in the high-risk surgical patient

BACKGROUND

Traditional management of symptomatic paraesophageal herniation involves hernia reduction, hiatal closure, and an antireflux procedure or gastropexy. Patients with significant comorbidities may not tolerate operative repair. A new technique, laparoscopic-assisted endoscopic reduction and fixation of the stomach, may provide a minimally invasive treatment alternative.

METHODS

Eleven elderly patients with symptomatic paraesophageal herniation were managed with flexible endoscopy and double percutaneous endoscopic gastrostomy (PEG) tube insertion with or without laparoscopic assistance.

RESULTS

All patients presented with a symptomatic paraesophageal hernia. Mean age was 78.3 years (range 72 to 84). Each was deemed at high risk for definitive repair due to preexisting coronary artery disease as well as at least two other serious comorbidities. Hernia reduction and intra-abdominal fixation of the stomach was achieved in each case using flexible endoscopy and double PEG insertion. Laparoscopic assistance for reduction and gastropexy was utilized in 9 cases. Mean operative time was 61 minutes (range 28 to 104). Average length of stay was 2.8 days (range 0 to 12). One minor and three major postoperative complications occurred. Over a mean follow-up of 4.1 months (range 2 to 7), all patients have resumed oral intake and achieved weight gain.

CONCLUSIONS

Patients with symptomatic paraesophageal herniation require intervention to alleviate symptoms and avoid the complications of gastric incarceration. For the high-risk patient, endoscopic reduction and PEG with laparoscopic assistance appears to provide effective treatment.

Laparoscopic anterior esophageal myotomy and toupet fundoplication for achalasia

Achalasia is an esophageal motility disorder characterized by the failure of lower esophageal sphincter relaxation and the absence of esophageal peristalsis. The purpose of this study was to evaluate the clinical outcomes of patients undergoing laparoscopic esophageal myotomy and Toupet fundoplication for achalasia. A 9-cm myotomy was performed in most cases extending 7 cm above and 2 cm below the gastroesophageal junction. Severity of dysphagia, heartburn, chest pain, and regurgitation was graded preoperatively and postoperatively using a five-point symptomatic scale (0-4). Patients also graded their outcomes as excellent, good, fair, or poor. Between December 1995 and November 2000 a total of 49 patients (23 male, 26 female) with a mean age of 44.3 years (range 23-71 years) were diagnosed with achalasia. Mean duration of symptoms was 40.2 months (range 4-240 months). Thirty-seven patients (76%) had had a previous nonsurgical intervention or combinations of nonsurgical interventions [pneumatic dilation (23), bougie dilation (five), and botulinum toxin (19)], and two patients had failed esophageal myotomies. Forty-five patients underwent laparoscopic esophageal myotomy and Toupet fundoplication. Two patients received laparoscopic esophageal myotomies without an antireflux procedure, and two were converted to open surgery. One patient presented 10 hours after a pneumatically induced perforation and underwent a successful laparoscopic esophageal myotomy and partial fundoplication. Mean operative time was 180.5 minutes (range 145-264 minutes). Mean length of stay was 1.98 days (range 1-18 days). There were five (10%) perioperative complications but no esophageal leaks. There was a significant difference (P < 0.05) between the preoperative and postoperative dysphagia, chest pain, and regurgitation symptom scores. All patients stated that they were improved postoperatively. Eighty-six per cent rated their outcome as excellent, 10 per cent as good, and 4 per cent as fair. Laparoscopic anterior esophageal myotomy and Toupet fundoplication effectively alleviates dysphagia, regurgitation, and chest pain accompanying achalasia and is associated with high patient satisfaction, a rapid hospital discharge, and few complications.

Effectiveness of the ultrasonic coagulating shears, LigaSure vessel sealer, and surgical clip application in biliary surgery: a comparative analysis

Advancements in laparoscopic surgery are often dictated by the limitations of technical instrumentation. Energy sources other than electrosurgery have become popular with the promise of quick and effective vascular control. With their success surgeons have begun using these on structures other than blood vessels with little or no data establishing their efficacy or safety. This study evaluates alternative energy sources in sealing ductal structures for possible use in liver or gallbladder surgery. After elective cholecystectomy cystic ducts (n = 45) were resealed ex vivo with surgical clips (n = 14), ultrasonic coagulating shears (n = 16), or electrothermal bipolar vessel sealer (n = 15), and bursting pressures were measured. Nineteen additional human cystic ducts were randomized to seal by ultrasonic coagulating shears (n = 9) or electrothermal bipolar vessel sealer (n = 10) and fixed in 10 per cent buffered formalin for histologic evaluation of thermal spread (mm). After this nine adult pigs were randomized to laparoscopic ligation and transection of the common bile duct using surgical clips (n = 3), ultrasonic coagulating shears (n = 3), or electrothermal bipolar vessel sealer (n = 3). The animals underwent necropsy for assessment of seal integrity on the sixth postoperative day. In the ex vivo study the mean cystic duct bursting pressure was 621 mm Hg with surgical clips and 482 mm Hg with the electrothermal bipolar vessel sealer (P = 0.39). The mean cystic duct bursting pressure after ultrasonic coagulating shears was 278 mm Hg, which was statistically less than surgical clips (P = 0.007) and electrothermal bipolar vessel sealer (P = 0.02). The mean thermal spread was 3.5 mm for ultrasonic coagulating shears and 13.4 mm for electrothermal bipolar vessel sealer (P = 0.0002). All animals undergoing ligation and transection of the common bile duct with ultrasonic coagulating shears and electrothermal bipolar vessel sealer developed bile peritonitis by postoperative day 6 as a result of seal leak. All animals undergoing surgical clip ligation and transection of the common bile duct maintained seal integrity. The mean common bile duct pressure above the surgical clip was 12 mm Hg (range 10-14). In conclusion the acute ex vivo study demonstrated a significant difference in the cystic duct bursting pressure between surgical clips and ultrasonic coagulating shears and between electrothermal bipolar vessel sealer and ultrasonic coagulating shears. The ultrasonic coagulating shears and electrothermal bipolar vessel sealer failed to maintain seal integrity in the in vivo animal study. Given the failure of the ultrasonic coagulating shears and electrothermal bipolar vessel sealer in the animal model these energy sources should not be used for transection of the cystic duct or major hepatic ducts during hepatobiliary surgery.

Laparoscopic splenectomy in patients with normal-sized spleens versus splenomegaly: does size matter?

Laparoscopic resection has become the standard means for removal of normal-sized spleens in many medical centers. The application of minimally invasive techniques in the setting of splenomegaly is less well defined and was previously considered a contraindication to the laparoscopic approach. The purpose of this prospective study of consecutive patients was to compare the outcomes of patients undergoing laparoscopic splenectomy for normal-sized spleens (150 g or less) versus those with clear evidence of splenomegaly (500 g or greater). One hundred forty-two patients met the inclusion criteria. The most common diagnosis in the normal-sized spleen group was idiopathic thrombocytopenia purpura (67 of 82, 82%). Malignant hematologic diseases (lymphoma and leukemia) were the most common diagnoses in the splenomegaly group (35 of 60, 58%). Mean operative times (127 vs 172 minutes) and estimated blood loss (123 vs 173 cm3) were lower for those patients with normal-sized spleens (P < 0.05). There were no statistical differences in conversion rates, lengths of stay, or complications between the two groups. We conclude that laparoscopic splenectomy is safe and effective in the setting of splenomegaly despite modest but statistically longer operative times and increased operative blood loss when compared with laparoscopic splenectomy for normal-sized spleens.

Initial results with an electrothermal bipolar vessel sealer

BACKGROUND

An electrothermal bipolar vessel sealer (EBVS; Ligasure, Valleylab, Boulder, CO, USA) was developed as an alternative to suture ligatures, hemoclips, staplers, and ultrasonic coagulators for ligating vessels and tissue bundles. The EBVS seals vessels up to 7 mm in diameter by denaturing collagen and elastin within the vessel wall and surrounding connective tissue. This study is the first to determine the clinical efficacy and safety of this instrument and delineate its potential timesavings in both experimental (animal) and clinical scenarios.

METHODS

A prospective review of the author's clinical experience with the EBVS in laparoscopic and open operations from October 1998 to March 2000 was performed. In addition, five Yorkshire domestic pigs underwent 150-cm small intestine resections (n = 10) using the EBVS (n = 5) and suture ligatures (n = 5). Measurements included time to complete intestinal resection, the number of applications per minute for each method, and the presence of postapplication bleeding. Statistical analysis was performed using Student's t-test.

RESULTS

The EBVS was used in 98 cases (46 laparoscopic and 52 open) with a mean of 43 applications (range, 10-150 applications) per case. The operations included 53 colon and/or small bowel resections (54.1%), 24 fundoplications (24.5%), 12 gastric resections (12.2%), 3 splenectomies, 2 pancreatectomies, 1 adrenalectomy, 1 bilateral salpingo-oopherectomy, 1 pancreatic cyst-jejunostomy, and 1 vagotomy with gastrojejunostomy. In all these cases, the EBVS was intended to be the only means of vessel ligation. An alternative ligation technique was required for bleeding in only 13 (0.3%) of more than 4,200 applications of the EBVS. No postoperative hemorrhagic complications occurred. There was an estimated mean reduction in operative time of 39 min per open procedure, and a mean prolongation in operative time of 8 min per laparoscopic procedure when the EBVS was used in lieu of suture ligatures, hemoclips, staplers, or ultrasonic coagulators. In the animal model, the mean time for completion of the intestinal resection was 251.9 s for the EBVS and 702.0 s for ligatures (p < 0.001). The mean number of applications per minute was 7.6 for the EBVS and 1.8 for ligatures (p < 0.001). No postapplication bleeding was seen.

CONCLUSIONS

Initial clinical results from the use of EBVS in laparoscopic and open procedures demonstrate it to be safe and effective, reducing operative time in open procedures. Suture ligatures, ties, hemoclips, and other ligating techniques were used rarely (0.3%) after an application of the EBVS. In an experimental animal model, the EBVS was significantly faster and more efficient (more applications per minute) than ligatures for intestinal resection.

Lateral approach to laparoscopic cholecystectomy in the previously operated abdomen

BACKGROUND

In the past, prior abdominal surgery was often felt to be a contraindication to laparoscopic cholecystectomy. The presence of adhesions precludes using a simple paraumbilical open approach for insufflation and initial trocar insertion because of an increased risk of bowel perforation and the difficulty in obtaining adequate exposure.

PATIENTS AND METHODS

We report 32 consecutive patients with previous upper midline incisions who underwent laparoscopic cholecystectomy with cholangiography and describe the technique and lateral positioning to facilitate this approach.

RESULTS

In our series, there were no complications. The mean length of hospital stay was 1.3 days, and the conversion rate to an open procedure was 3%: one patient who had had 22 previous abdominal operations.

CONCLUSION

Laparoscopic cholecystectomy performed with the patient in the lateral position is safe and effective for patients who have had previous midline incisions.

Laparoscopic splenectomy for malignant diseases

A variety of malignant diseases involving the spleen, both primary and metastatic, may require splenectomy for diagnosis or therapeutic reasons. The role of minimally invasive surgery in the management of malignant diseases involving the spleen is not well defined because of a lack of reported experience with laparoscopic splenectomy in this group. A reluctance to perform laparoscopic splenectomy in these patients may be explained by the technical and oncological challenges that often accompany malignant splenic diseases such as splenomegaly, perisplenitis, hilar lymphadenopathy, and fear of splenic disruption and tumor spillage. In our experience, the adoption of a lateral technique and the use of hand-assisted devices has allowed for the successful completion of laparoscopic splenectomy for malignant hematologic diseases including spleens up to 28 cm in length and greater than 3 kg morcellated weight. Laparoscopic splenectomy reliably alleviates the symptoms related to splenomegaly and reverses the hematologic abnormalities of hypersplenism. Although laparoscopic splenectomy for malignant diseases is feasible, the role of minimally invasive surgery in the staging of Hodgkin's lymphoma remains undetermined.

Optimal teaching environment for laparoscopic splenectomy

BACKGROUND

Traditional surgical teaching depends on graduated acquisition of skill learned in residency. The introduction of minimal access techniques after residency training has created a new paradigm dependent on animate course experiences and limited preceptor training. The outcome of performance of a new skill "learned" in these settings has not been assessed. The purpose of this study was to test the benefit of an animate course compared with a precepted operating room experience in learning to perform a laparoscopic splenectomy.

METHODS

All attending surgeons who had taken a 1-day course to learn laparoscopic splenectomy (n = 37) and those who had undergone an intraoperative preceptorship (in their hospital) by the lead author (n = 15) were polled to ascertain their previous experience with laparoscopy and with laparoscopic splenectomy since the intervention. The course included lectures, operative videos, and an animal lab. Statistical differences were measured using a t test.

RESULTS

Thirty-two of the 37 (86.5%) taking the course and all 15 of the precepted surgeons responded. There was no difference between the groups regarding prior laparoscopic experience (P = 0.73), laparoscopic training during residency (P = 0.74), academic or private practice (P = 0.48), or follow-up since the intervention (P = 0.36). The participants graded the courses (1 to 5, 5 = excellent) at an average of 4.72. Fourteen of 15 precepted surgeons have performed laparoscopic splenectomy as compared with 2 of 32 taking courses (nonprecepted surgeons; P <0.0001). The number of laparoscopic splenectomies performed totaled 112 for precepted surgeons and 4 for nonprecepted surgeons (P = 0.0003). The nonprecepted surgeons performed significantly more open splenectomies than laparoscopic (95 versus 13 respectively, P = 0.02). Reasons quoted not to proceed with laparoscopic splenectomy included waiting for the perfect patient, concern of hilar management, and splenic size.

CONCLUSION

Surgeons precepted in their own operating room performed a laparoscopic splenectomy more readily than those gaining experience from a course only (93% versus 6%, respectively) despite no difference in their preintervention experience and having the opportunity to do so. The expectation of the eventual performance of advanced laparoscopic techniques depends on a precepted experience.

Preperitoneal Richter hernia after a laparoscopic gastric bypass

Trocar-site incisional hernias are potentially dangerous because of their susceptibility to become Richter hernias. The authors describe a morbidly obese patient in whom developed an unusual type of Richter hernia after a laparoscopic isolated Roux-en-Y gastric bypass at a 10-mm trocar site. Although the fascial closure of the trocar hernia site was intact, a hernia developed through the peritoneum into the preperitoneal space. For morbidly obese patients, the thick preperitoneum is a potential space that allows for the development of a Richter hernia, despite adequate fascial closure. It is recommended that all 10-mm and 12-mm trocar sites be closed, incorporating the peritoneum into the fascial closure to obliterate the preperitoneal space, to prevent this postoperative complication.

Surgical experience with nonfunctioning neuroendocrine tumors of the pancreas

Nonfunctioning neuroendocrine tumors of the pancreas are rare slow-growing tumors with a more indolent natural history compared with pancreatic adenocarcinoma. This retrospective report reviews the surgical experience with nonfunctioning neuroendocrine tumors in an academic referral center. Statistical analysis was performed using Student's t test and Kaplan-Meier method compared with log-rank tests. Thirty-eight patients (24 males and 14 females) underwent surgery for a neuroendocrine tumor of the pancreas from 1984 through 1999. Twenty-eight patients with a mean age of 59.9 years had nonfunctioning islet cell tumors and 10 patients with a mean age of 59.1 years had functioning islet cell tumors (four gastrinomas, three glucagonomas, two insulinomas, and one vipoma). The nonfunctioning islet cell tumors were located in the head, neck, or uncinate process in 14 patients (50%), the body in seven (25%), and the tail in seven (25%). Operative procedures for the nonfunctioning islet cell tumors included nine pancreaticoduodenectomies, 12 distal pancreatectomies, three palliative bypasses, and four exploratory laparotomies without a resection or bypass. Mean survival for the four patients explored and not resected or bypassed was 7 months. Median survival for node-negative patients was 124 months, for node-positive patients 75 months, and for patients with metastasis to the liver 9 months. Estimated 2-year actuarial survival for the node-negative patients was 77.8 per cent, for node-positive patients 71.4 per cent, and for patients with metastasis to the liver 36.4 per cent. Six patients (60%) with node-negative disease, three (43%) with node-positive disease, and one (9%) with metastasis to the liver are alive at a mean follow-up of 41.8 months (range 1-167). Significant differences in median survival and 2-year survival were demonstrated between the node-positive/node-negative patients and those with metastasis to the liver (P = 0.003). Patients with localized nonmetastatic disease should be considered for pancreatic resection as estimated median survival is 75 months or greater. Hepatic metastasis is a major predictor of survival.

Laparoscopic lumbar interbody spinal fusion

Laparoscopic ALIF is an evolving technique requiring the participation of a laparoscopic surgeon experienced in advanced laparoscopic techniques and knowledgeable in anterior lumbar spinal exposures. Initial enthusiasm for this technique was fostered by the development of interbody fusion devices and a method of exposing the anterior lumbar spine, which takes advantage of the ability of minimally invasive surgeries to improve exposure and visualization while minimizing collateral tissue damage and injury to healthy tissue. Preliminary studies have demonstrated laparoscopic ALIF feasibility. These same studies have been able to prove only minor advantages with the laparoscopic versus open technique using the current implants and bone grafting techniques for single-level disc disease. General acceptance of laparoscopic ALIF awaits further investigation. Reasons for a lack of general acceptance include the expense of the interbody fusion devices and laparoscopic equipment, the unfamiliarity of this advanced laparoscopic technique to spine and general surgeons, and the steep learning curve of the procedure. Intraoperative complications that arise are often severe, such as vascular injuries. Many skeptics appropriately believe that initial enthusiasm and zealousness must be tempered with scientific effort that provides data from long-term follow-up. For laparoscopic ALIF to gain general acceptance, randomized comparisons of laparoscopic ALIF to open ALIF and posterior lumbar spinal fusion and controlled studies with long-term follow-up documenting symptomatic outcome variables and spinal fusion rates must be completed. As new modalities are developed, minimally invasive techniques may facilitate their utility. The indications, procedures, and surgical principles of ALIF are unchanged, and physicians must not invent indications to justify the technique; however, eventually we may be able to redefine the indications to take full advantage of the endoscopic techniques and biological advances.

Mini-laparoscopic splenectomy

BACKGROUND AND PURPOSE

Since the introduction of mini-laparoscopic instruments (2- to 3-mm diameter), their utility and safety have been questioned. Their application in cholecystectomy has recently been documented. This study determined the adequacy and safety of these minimally invasive instruments in laparoscopic splenectomy.

METHODS

Retrospective review of all 16 mini-laparoscopic splenectomies performed by the authors was carried out. Diagnoses included immune thrombocytopenia (5), spherocytosis (6), and beta-thalassemia, sickle-cell disease, splenic mass, cyst, and splenomegaly in 1 case each. The average age of the patients was 20.1 years (range 4-70 years); seven patients were adults. Ten of the patients were female. The patients' body mass index ranged from 17 to 25 kg/m2. Splenomegaly (at least two times normal size: 100-200 g for children, 400-600 g for adults) was present in each case. A three-trocar technique was used in 15 patients, and a fourth trocar was required in only one case.

RESULTS

The average operative time and blood loss were 114 minutes (range 60-195 minutes) and 44 mL (range 10-150 mL), respectively. There were no intraoperative complications, and no patient required transfusion. Conversion to standard laparoscopy or laparotomy did not occur. The mean hospital stay was 1.4 days (range 1-2 days). With an average 20-month follow-up, no wound, septic, or other complications have been identified. All patients or their families (in the case of children) graded the cosmetic outcome as excellent.

CONCLUSION

The use of mini-laparoscopic instruments for splenectomy is safe and effective in children and adults with a normal body mass index, even in the case of splenomegaly. Operative times are reasonable, and hospital stays are brief. The postoperative cosmetic appearance is excellent.

Geometry and reproducibility in 360 degrees fundoplication

BACKGROUND

In this study, we set out to precisely define two symmetrical points-a on the anterior fundic wall and b on the posterior fundic wall. These points, when advanced around a 60-Fr bougie-filled esophagus, will meet on the right side, to the right of the anterior vagus nerve, to create a reliable, reproducible, loose (i.e., or "floppy") 360 degrees fundoplication (FP).

METHODS

For the terms of this study, circumference = c; diameter = d; c/d = pi; pi = 3.14; and d(cm) = Fr/30. Using a flexible plastic ruler, we measured, in cadavers (n = 5) and intraoperatively (n = 16), esophageal c at the gastroesophageal junction (GEJ) with a 60-Fr bougie in place; d was calculated from c.

RESULTS

The smallest measured value for c was 7.5 cm (d = 2.39 cm); the largest value for c was 10.0 cm (d = 3.18 cm). The mean value was 8.35 cm (d = 2.66 cm). Points a and b are established by measuring laterally from a point where the greater curve meets the GEJ in the bougie-filled esophagus. Point a is 6.0 cm laterally and 6.0 cm below the short gastric vessels on the anterior fundus; point b is 6.0 cm laterally in a symmetrical position on the posterior fundus. Connecting these three points as a line defines the inner c of the completed FP and measures 12.0 cm. This gives an internal d of 3.82 cm for the FP. This is >1 cm larger than d for the mean measured external esophageal c of 8.35 cm where d = 2.66 cm. This technique creates a correctly oriented, symmetrical, "floppy," true fundoplication. It avoids wrapping or twisting the fundus around the GEJ. The technique is easily taught and reproducible.

CONCLUSIONS

Two points, measured a horizontal distance of 6.0 cm from the GEJ, symmetrically placed on the anterior (point a) and posterior (point b) fundus can be brought anterior (a) and posterior (b) to the esophagus and sutured to the right of the anterior vagus nerve to reliably and reproducibly create a "floppy" 360 degrees fundoplication.

Laparoscopic splenectomy for malignant diseases

A variety of malignant diseases involving the spleen, both primary and metastatic, may require splenectomy for diagnosis or therapeutic reasons. The role of minimally invasive surgery in the management of malignant diseases involving the spleen is not well defined because of a lack of reported experience with laparoscopic splenectomy in this group. A reluctance to perform laparoscopic splenectomy in these patients may be explained by the technical and oncological challenges that often accompany malignant splenic diseases such as splenomegaly, perisplenitis, hilar lymphadenopathy, and fear of splenic disruption and tumor spillage. In our experience, the adoption of a lateral technique and the use of hand-assisted devices has allowed for the successful completion of laparoscopic splenectomy for malignant hematologic diseases including spleens up to 28 cm in length and greater than 3 kg morcellated weight. Laparoscopic splenectomy reliably alleviates the symptoms related to splenomegaly and reverses the hematologic abnormalities of hypersplenism. Although laparoscopic splenectomy for malignant diseases is feasible, the role of minimally invasive surgery in the staging of Hodgkin's lymphoma remains undetermined.

Laparoscopic repair of a chronic diaphragmatic hernia

Diaphragmatic injuries that remain undetected after an acute traumatic event may lead to the formation of a diaphragmatic hernia. Symptoms of a chronic diaphragmatic hernia are related to the incarceration of abdominal contents in the defect or to impingement of the lung, heart, or thoracic esophagus by abdominal viscera. A 49-year-old woman with a symptomatic chronic diaphragmatic hernia from an unrecognized iatrogenic injury to the left hemidiaphragm sought treatment. The diaphragmatic injury occurred 2 years earlier when a low, left-sided chest tube was placed for a persistent pleural effusion 2 weeks after a lower lobectomy for an aspergilloma. The patient's diaphragmatic hernia was diagnosed after an upper gastrointestinal series and an esophagogastroduodenoscopy. Approximately 75% of her stomach was incarcerated in the diaphragmatic defect. The diaphragmatic hernia was repaired laparoscopically using a 9 cm x 10-cm polytetrafluoroethylene patch sewn with nonabsorbable, interrupted, horizontal mattress sutures. Improvement of video technology, laparoscopic instruments, and surgical skills has allowed surgeons to expand the boundaries of advanced therapeutic laparoscopy. These factors facilitated the authors' standard tension-free prosthetic repair of a chronic diaphragmatic hernia using minimally invasive techniques.