Effects of pneumoperitoneum on hemodynamic and systemic immunologic responses to peritonitis in pigs.

BACKGROUND: Experimental evidence supporting the safety of laparoscopic intervention during sepsis is limited. The purpose of this study was to evaluate the effects of pneumoperitoneum on immunologic and hemodynamic responses to peritoneal sepsis. MATERIALS AND METHODS: A porcine model of peritonitis was created using an intraperitoneal autologous fecal inoculum. Pigs were then subjected to one of four procedures 24 h postinoculation (n = 6 per group): laparotomy, CO(2) laparoscopy, helium laparoscopy, and anesthesia only (1.5% isoflurane in 100% O(2), mechanical ventilation). Venous blood samples were obtained prior to inoculation, and at 24 (prior to procedure), 30, 48, 72, and 96 h postinoculation to determine white blood count (WBC) with differential, C-reactive protein (CRP), tumor necrosis factor, and bacteremia. Heart rate, end-tidal CO(2) (ETCO(2)), mean arterial blood pressure (MAP), and arterial blood gas variables were also measured at baseline and every 30 min throughout the procedure. RESULTS: Postoperative blood cultures confirmed systemic bacteremia in all groups at all time periods postinoculation. Following inoculation, WBC, band cell count, and CRP remained elevated above baseline in all groups throughout the study (P < 0.01). However, no significant differences in these parameters were observed among groups. In the CO(2) laparoscopy group, MAP, ETCO(2), and arterial pCO(2) were increased above baseline, while pH was decreased throughout the procedure (P < 0.01). CONCLUSIONS: In this animal model of peritonitis, CO(2) pneumoperitoneum induced hypercapnia, acidemia, and systemic hypertension intraoperatively, without a discernable effect on systemic immune function.

A canine model of gastroesophageal reflux disease (GERD).

BACKGROUND: Although a variety of antireflux procedures and medications are used to treat gastroesophageal reflux disease (GERD), reliable large-animal models of GERD that can be used to objectively compare the efficacy of these treatments are lacking. METHODS: Esophageal manometry and 24-h gastroesophageal pH monitoring with event data were performed in 18 mongrel dogs with a cervical esophagopexy. We then calculated a modified DeMeester score: The Duke Canine reflux score (DCR). Thereafter, the animals underwent a 4-cm anterior distal esophageal myotomy, incision of the left diaphragmatic crus, and intrathoracic gastric cardiopexy. Postoperative 24-h pH and manometry were obtained 2 weeks later. RESULTS: The postoperative 24-h pH results showed a significant increase in the mean DCR score (5.9 +/- 4.5 vs 84.9 +/- 56.1, p < 0.0002), and manometry indicated a significant decrease in mean lower esophageal sphincter (LES) pressure (7.1 +/- 2.9 vs 3.2 +/- 2.5 mmHg, p < 0.0001). CONCLUSION: This technique reliably creates a canine model of GERD.

Intraperitoneal immunity and pneumoperitoneum.

BACKGROUND: Carbon dioxide (CO(2)) pneumoperitoneum has been implicated as a possible factor in depressed intraperitoneal immunity. Using in vitro functional assays, CO(2) has been shown to decrease the function of peritoneal macrophages harvested from insufflated mice. However, an effective in vivo assessment is lacking. Listeria monocytogenes (LM), an intracellular pathogen, has served as a well-established in vivo model to study cell-mediated immune responses in mice. This study examines the immune competence of mice based on their ability to clear intraperitoneally administered LM following CO(2) vs helium (He) insufflation. METHODS: Eighty-five mice (C57Bl/6, males, 4-6 weeks old) were divided between the following four treatment groups: CO(2) insufflation, He insufflation, abdominal laparotomy (Lap), and control (anesthesia only). Immediately postoperatively, each group was inoculated percutaneously and intraperitoneally with a sublethal dose (.015 x 10(6) org) of virulent LM (EGD strain). Half of the animals were killed on postoperative day 3 and half on day 5. Spleens and livers (sites of bacterial predilection) were harvested, homogenized, and plated on TSB agar. The amount of bacteria (1 x 10(6) LM/spleen and liver) from each group was then compared. Statistical significance was set at p

Laparoscopy and mesothelioma.

Malignant mesothelioma is a well-recognized long-term sequela of chronic asbestos exposure. Asbestos use in the United States began in the 1950s and was widespread until the mid-1970s. Although currently only 2.2 cases per million population per year are diagnosed, disease incidence is increasing because of the long latency of this neoplasm. A latency of 15-50 years means that a higher incidence of this neoplasm can be anticipated in the future. The authors report a patient with peritoneal mesothelioma and no known prior exposure to asbestos. The diagnosis was confirmed by exploratory laparoscopy, which entailed biopsies of the diaphragm and of the peritoneal and abdominal walls, and by cytologic evaluation of 700 ml ascitis fluid. At present, exploratory laparoscopy offers the quickest, safest, and least invasive way to confirm the clinical diagnosis of peritoneal malignant mesothelioma.

Conversion factors for laparoscopic splenectomy for immune thrombocytopenic purpura.

BACKGROUND: Since 1994, 27 patients at our institution have undergone laparoscopic splenectomy for immune thrombocytopenic purpura (ITP). Laparoscopic splenectomy was completed in 22 of these patients. We sought to identify factors that precluded successful laparoscopic splenectomy in the remaining 5 patients. METHODS: Retrospective review of 27 patients with ITP undergoing laparoscopic splenectomy was performed at Duke University Medical Center from August, 1994 to September, 1997. RESULTS: Laparoscopic splenectomy was performed in 16 women and 11 men with a mean age of 47.2 years. Five (18%) of these procedures were converted to open splenectomy. There was no significant difference in age, ASA score, gender, weight, height, or splenic size between the converted and laparoscopic groups. However, preoperative and postoperative platelet counts were significantly higher in the laparoscopic group than in the converted group (p < 0.001). Operative times also were significantly longer for the laparoscopic group than for the converted group (p < 0.001). Adherent adjacent structures, associated comorbidities, and technical errors prohibited laparoscopic completion in five patients. Technical errors with subsequent bleeding required conversion in two patients. A thickened greater omentum blanketing the splenic capsule and a densely adherent pancreatic tail extending well into the splenic hilum prevented laparoscopic completion in two patients. Increased peak airway pressures greater than 60 mmHg after pneumoperitoneum necessitated conversion in the remaining patient, who had a previous history of pulmonary insufficiency. Regardless of surgical approach, all patients achieved a therapeutic response after splenectomy. Splenectomies completed laparoscopically resulted in a significantly shorter length of hospital stay (p < 0.01). CONCLUSIONS: Densely adherent adjacent structures, technical errors, and cardiopulmonary instability may preclude successful completion of laparoscopic splenectomies. Thorough preoperative evaluation with an emphasis on the cardiopulmonary system may elicit a cohort of individuals with ITP who are unlikely to undergo laparoscopic splenectomy successfully. This cohort also may include individuals with preoperative platelet counts less than 35,000 mm(-3).

Laparoscopic biliary and enteric bypass.

Very few patients with a periampullary neoplasm present with resectable disease. Consequently, various operative and non-operative techniques have been developed to palliate patients with unresectable periampullary disease. Laparoscopic biliary (cholecystojejunostomy) and enteric bypass (gastrojejunostomy) are reasonable options as compared to their open counterparts for operative palliation. However, only a limited number of carefully selected patients meet selection criteria for laparoscopic palliation.

The laparoscopic management of gastroesophageal reflux disease.

Laparoscopic fundoplication has replaced open fundoplication as the gold standard for the surgical management of patients with GERD. The improvements in technique that have led to the excellent results on long-term follow-up have broadened the indications for surgical involvement along the continuum of severity in GERD. Therefore, the importance of accurate preoperative testing for appropriate patient classification must be emphasized to all who care for these patients.

Unusual complications following laparoscopic Nissen fundoplication.

Laparoscopic Nissen fundoplication is commonly used to treat medically refractory gastroesophageal reflux disease. The most frequent severe complications following laparoscopic Nissen fundoplication are pneumothorax, gastroesophageal leak, and splenic injury. Prompt recognition and treatment of complications are important in reducing subsequent morbidity and mortality. This report describes two postoperative complications: (1) delayed diagnosis of a postoperative gastric perforation despite an unrevealing work-up for postoperative fever and abdominal pain; and (2) postoperative pancreatitis following revision of a fundoplication.

Small bowel intussusception and laparoscopy.

Adult intussusception is rare and is usually caused by a tumor serving as a lead point. Surgery is necessary to treat obstruction and rule out malignancy. However, if a benign cause (lipoma, fibroma, or Meckel's diverticulum) is suspected preoperatively, a minimally invasive surgical approach should be considered. This case illustrates the laparoscopic management of benign small bowel intussusception due to lipoma.