Alfredo M. Carbonell

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

INTRODUCTION The development of new energy sources for hemostasis has facilitated advanced laparoscopic procedures. Few studies, however, have documented the strength of the vessels sealed or the extent of surrounding lateral thermal injury, two important factors in maintaining hemostasis while preventing injury to surrounding structures. This study compared the burst pressure and extent of thermal injury of vessels sealed with the 5-mm laparoscopic PlasmaKinetics trade mark sealer (PK) (Gyrus Medical, Maple Grove, Minnesota) and the 5-mm laparoscopic LigaSure trade mark sealing device (LS) (Valleylab, Boulder, Colorado). METHODS Arteries in three sizes (2-3 mm, 4-5 mm, and 6-7 mm) were harvested from domestic pigs. Eight to 17 specimens from each size were randomly sealed with the PK, and the same number with the LS. Burst pressures were measured in mm Hg. The extent of thermal injury, determined by coagulation necrosis, was measured microscopically in millimeters after staining the transected vessels with hematoxylin and eosin. Descriptive statistics, including means and standard deviations, are reported. Students t-test and ANOVA were performed to determine significance (P <.05). RESULTS The mean bursting pressures of the PK and the LS were equal in the 2-3 mm vessels (397 vs. 326 mm Hg, P =.49). The PK bursting pressures were significantly less than the LS in the 4-5 mm (389 vs. 573 mm Hg, P =.02) and the 6-7 mm groups (317 vs. 585 mm Hg, P =.0004). As vessel size increased, the PK was associated with significantly lower burst pressures, while the LS was associated with progressively higher burst pressures (P =.035). Thermal spread was not significantly different between the PK and the LS in the 2-3 mm (1.5 vs. 1.2 mm, P =.27), the 4-5 mm (2.4 vs. 2.4 mm, P =.79), or the 6-7 mm vessel size groups (3.2 vs. 2.5 mm, P =.32). Increasing vessel size, regardless of instrument used, was associated with increased thermal injury (P <.0001). CONCLUSION The LS produces supraphysiologic seals with significantly higher bursting pressures than the PK in vessels ranging from 4 to 7 mm. The PK seals become progressively weaker while the LS seals increase in strength as the vessel size increases. Although thermal spread increases with vessel size, the degree of lateral thermal injury is no different between the two instruments.

The susceptibility of prosthetic biomaterials to infection

BackgroundDespite 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.MethodsThe 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 108 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 log10, with analysis of variance (ANOVA) and Tukey’s test used to determine significance (p < 0.05).ResultsThe 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).ConclusionsThe 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.

Cirrhosis is not a contraindication to laparoscopic surgery

BackgroundCirrhosis 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.MethodsThe 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.ResultsA 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.ConclusionsAlthough 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.

Criteria for definition of a complex abdominal wall hernia

AbstractPurpose A clear definition of “complex (abdominal wall) hernia” is missing, though the term is often used. Practically all “complex hernia” literature is retrospective and lacks proper description of the population. There is need for clarification and classification to improve patient care and allow comparison of different surgical approaches. The aim of this study was to reach consensus on criteria used to define a patient with “complex” hernia.MethodsThree consensus meetings were convened by surgeons with expertise in complex abdominal wall hernias, aimed at laying down criteria that can be used to define “complex hernia” patients, and to divide patients in severity classes. To aid discussion, literature review was performed to identify hernia classification systems, and to find evidence for patient and hernia variables that influence treatment and/or prognosis.ResultsConsensus was reached on 22 patient and hernia variables for “complex” hernia criteria inclusion which were grouped under four categories: “Size and location”, “Contamination/soft tissue condition”, “Patient history/risk factors”, and “Clinical scenario”. These variables were further divided in three patient severity classes (‘Minor’, ‘Moderate’, and ‘Major’) to provide guidance for peri-operative planning and measures, the risk of a complicated post-operative course, and the extent of financial costs associated with treatment of these hernia patients.ConclusionCommon criteria that can be used in defining and describing “complex” (abdominal wall) hernia patients have been identified and divided under four categories and three severity classes. Next step would be to create and validate treatment algorithms to guide the choice of surgical technique including mesh type for the various complex hernias.

Laparoscopic splenectomy reverses thrombocytopenia in patients with hepatitis C cirrhosis and portal hypertension

Pegylated-interferon (IFN) plus ribavirin remains the most effective therapeutic regimen for patients with chronic hepatitis C infection. Thrombocytopenia is a common side effect of this treatment, often leading to discontinuation of a potentially curative therapy. We sought to determine the safety and efficacy of laparoscopic splenectomy in correcting thrombocytopenia, thus allowing completion of IFN therapy. Data were collected prospectively from September 2000 to May 2003 on all patients undergoing laparoscopic splenectomy for thrombocytopenia associated with IFN therapy and/or hepatitis C cirrhosis with portal hypertension. Demographic data, model of end-stage liver disease (MELD) score, platelet count, operative time, blood loss, spleen weight, complications, length of stay, and follow-up time were calculated. Eleven patients (7 men, 4 women) underwent laparoscopic splenectomy; their mean age was 45.4 years (range 27 to 55 years) and mean body mass index was 27 kg/m2 (range 21 to 44 kg/ m2). All patients were Child’s class A, with a mean preoperative MELD score of 9.1 (range 6 to 11). Mean operative time was 189 minutes (range 70 to 245 minutes), and blood loss averaged 141 ml (range 10 to 600 ml). A hand-assisted laparoscopic technique was used in four cases. Six patients received empiric intraoperative platelet administration. None required transfusion with packed red cells. Splenic weight averaged 1043 g (range 245 to 1650 g). Average length of stay was 2.6 days (range 1 to 6 days). Four patients had the following minor postoperative complications: self-limited atrial fibrillation (n = 1), trocar site cellulitis (n = 1), and atelectasis (n = 2). There have been no major complications over an average follow-up of 11 months (range 1 to 18 months). Mean postoperative MELD score was 8.3 (range 6 to 10). Platelet counts improved from a preoperative mean of 55,000/ul (16,000 to 88,000/μl) to 439,000/μl (200,000 to 710,000/μl) postoperatively and have remained above 100,000/μl (104,000 to 397,000/μl) during subsequent pegylated-IFN therapy. Three patients have completed a full course of IFN therapy and have obtained a sustained virologic response. Treatment is ongoing in the remaining patients. Laparoscopic splenectomy is safe in the setting of portal hypertension and thrombocytopenia associated with chronic hepatitis C infection. It can be performed with little blood loss, no need for red cell transfusion, and minimal perioperative morbidity. Laparoscopic splenectomy appears to effectively reverse thrombocytopenia and may allow these patients to safely complete IFN therapy.

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 [1, 3]. The syndrome is characterized by weight loss, postprandial abdominal pain, nausea, vomiting, and an epigastric bruit [2]. Surgical management entails complete division of the median arcuate ligament [4]. 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 ≥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 [2]. 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.

Mesh terminology 101

In any collaborative endeavor, when fields like medicine and bioengineering overlap, the proper use of technical vocabulary takes on added importance. It is important that scientists and clinicians, while coming from different backgrounds and educational systems, agree upon and utilize a common language based on mutually understood concepts and definitions. Regarding biomaterial testing applications, numerous terms are used to describe a wide variety of material behaviors when test specimens are subjected to mechanical, chemical, electrical and thermal stressors. In this discussion we will limit ourselves to the mechanical properties of materials which are utilized for soft tissue or fascial-based repairs. Following a literature search combining the keywords surgical mesh and biomaterials testing, common terms used to describe the mechanical properties of mesh were selected. Our analysis seeks to define the following terms and describe their applicability within the context of biomaterials for hernia repair: elasticity, stiffness, flexibility, tensile strength, distension, deformation, bending stiffness, and compliance. Unfortunately, in the technical literature, terms are often altered or extrapolated without adequate explanation. In other cases, related but technically different terms are mistakenly used interchangeably. With the mounting interest in biomaterials for the use in repair of abdominal wall defects, there is a need to standardize the terminology used to describe the biomechanical properties of mesh.

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

AbstractsBackgroundThe purpose of this study was to examine the influence of patient and hospital demographics on cholecystectomy outcomes.MethodsYear 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.ResultsOf 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.ConclusionsPatient 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 splenectomy for splenic abscess.

Splenic abscess is a rare clinical entity, and splenectomy remains the treatment of choice. We sought to determine the safety and efficacy of laparoscopic splenectomy in this setting. Using a prospective database of laparoscopic splenectomy, we identified 4 patients who underwent surgery for splenic abscess (3 male, 1 female). Mean age was 55.5 (range 42-78) years. Patient symptoms included: fever and abdominal pain in 4 patients, pleural effusions in 2, and nausea and leukocytosis in 1. Risk factors for splenic abscess included septic emboli from bacterial endocarditis in 2 patients and acquired immune deficiency syndrome in 1. All patients underwent successful laparoscopic splenectomy. Mean operative time was 200 (range 160-220) minutes, and blood loss was 220 (range 100-450) mL. There were no postoperative complications or deaths; postoperative length of stay averaged 14 (range 2-26) days. Despite the difficulty of the operation, the laparoscopic approach appears to be a safe and effective treatment of splenic abscess.

The laparoscopic repair of suprapubic ventral hernias

BackgroundThe 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.MethodsThe 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.ResultsThere 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.ConclusionsAlthough 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.