Transgastric biologic mesh delivery and abdominal wall hernia repair in a porcine model.

BACKGROUND AND STUDY AIMS: Incisional abdominal wall hernias currently require repair with open or laparoscopic surgery, which is associated with wound complications and recurrent hernia formation. Natural orifice transluminal endoscopic surgery (NOTES) techniques may have the potential to decrease the morbidity associated with hernia repair. The aim of this study was to repair a chronic ventral hernia with a biologic mesh placed transgastrically in a porcine model. MATERIALS AND METHODS: Six pigs underwent creation of an incisional abdominal wall hernia. At least 4 weeks later, transgastric repair was done using an underlay biologic mesh with at least 5 cm of overlap from the hernia fascial edge. The mesh was secured with transfascial sutures and the stomach was closed with a sutured gastropexy. Pigs were evaluated 2 weeks later by laparoscopy. Pigs were sacrificed and necropsy wa s performed 4 weeks after the repair. RESULTS: Six pigs underwent hernia repair lasting a mean (+/- SD) of 204 +/- 123 minutes, with one perioperative death. At 2 weeks after hernia repair, laparoscopy showed significant adhesions in all pigs; one pig had extensive mesh infection and was sacrificed. Necropsy on one pig at 2 weeks and four pigs at 4 weeks showed complete coverage of the hernia defect in all pigs. All pigs had mesh abscesses or a positive mesh culture. CONCLUSION: Transgastric repair of a chronic ventral hernia is technically feasible. Difficulties with mesh delivery and infection need to be overcome before this approach can be used in humans.

Retrorectus polyester mesh repair for midline ventral hernias.

PURPOSE: To evaluate the effectiveness of the retrorectus mesh repair for midline ventral hernias. METHODS: A retrospective review of all consecutive patients having a retrorectus mesh repair by a single surgeon in a standardized fashion from 1991 to 2005. All procedures used polyester (Mersilene) mesh with at least 5-cm overlap beyond the repair in all directions. RESULTS: Ninety patients were identified, 56% of which were female. Major postoperative complications occurred in 23 (26%) patients, including nine (10%) patients requiring reoperative treatment due to skin flap necrosis, wound infection, hematoma, or fascial dehiscence. Partial mesh excision was required in four patients. The hernia recurrence rate was 7% at a mean of 53 months. CONCLUSION: The retrorectus repair with polyester mesh is an effective and durable repair for midline ventral hernias. The disadvantage of this repair is the large number of wound complications.

Evaluation of a novel endoluminal stapling procedure to restrict the lower esophageal sphincter and reduce reflux.

BACKGROUND AND STUDY AIMS: An effective, safe, and long-lasting endoluminal treatment for gastroesophageal reflux disease (GERD) would be an attractive prospect. We developed an endoluminal technique to restrict and tighten the lower esophageal sphincter (LES), by using a transoral endoscopic stapling device in a porcine model. PATIENTS AND METHODS: Pre-interventional evaluation comprised endoscopy, manometry, and 48-hour pH measurement of the distal esophagus using the catheterless BRAVO pH capsule. By placing the endoluminal stapling device at the LES and firing a 2.5-cm staple line, a vertical plication was created. In five pilot pigs (phase 1), plications were placed in various locations at the LES. In another five pigs (phase 2), plications were placed uniformly at the mid level of the LES on the lesser curvature side. Measurements were repeated 2 weeks after the procedure. Necropsy and histological analysis were performed. RESULTS: Endoluminal stapling was successfully completed in all animals. In phase 2, the median procedure time was 15 minutes (range 10-55 minutes). LES pressure increased from 10.5 mmHg (+/- 2.5 mmHg) to 14.3 mmHg (+/- 3.8 mmHg) (P = 0.038). Median percentage of time with pH below 4 decreased from 6.6% (range 2.9%-48.8%) to 2.2% (range 0%-10.4%) (P = 0.043). Histology showed the staple line involving the muscular layer in all pigs. A gap was present in the central part of the staple line in three pigs resulting in a mucosa-muscular bridge of tissue. This bridge did not influence the results. CONCLUSION: This novel endoluminal technique is feasible and safe in a porcine model over 2 weeks. It is appealing due to its simplicity and ease of application. Further studies aimed at eliminating the gap in the staple line and investigating more animals over longer survival periods are needed.

Endoscopic colotomy closure after full thickness excision: comparison of T fastener with multiclip applier.

BACKGROUND AND STUDY AIMS: Safe, reliable, and efficient endoscopic closure of a colotomy is paramount for endoscopic full thickness excision of the colon. Two newly developed devices, the Tissue Apposition System (TAS) and the InScope Multi-Clip Applier (IMCA), may help to achieve this. The aim of this study was to determine the feasibility of using each device to close colotomies after full thickness wall excisions. MATERIAL AND METHODS: 12 pigs were used in the study. After laparoscopic full thickness excision of the colonic wall, the defect was closed using either the TAS or the IMCA. Closure was performed under laparoscopic vision. Success of colotomy closure, time taken for colotomy closure, postoperative infections, and complication rates were recorded. RESULTS: Complete closure was achieved in 6/6 pigs in the TAS group. In 5/6 pigs in the IMCA group closure was successful; in one pig laparoscopic assistance was used. Median closure time (range) was significantly lower in the TAS group at 48 minutes (15 - 51) vs. 76 minutes (43 - 145) in the IMCA group. There were no postoperative infections or complications. CONCLUSIONS: Endoscopic closure after full thickness colonic wall excision is feasible with both the TAS and the IMCA. Closure times are significantly shorter and handling is easier with the TAS. Combined use of both systems might be beneficial.

A prospective trial of primary inguinal hernia repair by surgical trainees.

The main hypotheses were that the Lichtenstein inguinal hernia repair has a lower recurrence rate and similar incidence of chronic groin pain compared to sutured repairs when performed by surgical trainees. In a U.S. Veterans Administration Hospital, 150 primary hernia repairs were randomized to a Lichtenstein, McVay, or Shouldice repair. The Shouldice repair included a routine relaxing incision. First- and second-year residents, under the supervision of an experienced general surgeon, performed the procedure. Long-term follow-up was obtained in 81% of patients. Hernia recurrence rate was Lichtenstein 8%, McVay 10%, Shouldice 5% ( P>0.1) at 6-9 years follow-up. More patients had chronic groin pain following Lichtenstein repair (38%) than after Shouldice repair (7%) ( P<0.05). More information is needed on long-term groin pain following anterior mesh repair. The Shouldice inguinal hernia repair may have a role in open primary herniorrhaphy to decrease the risk of chronic groin pain.

Jejunal manometry predicts tube feeding intolerance in the postoperative period.

Postoperative nutrition is best provided enterally; however, patients often develop intolerance to enteral feedings. Our aim was to prospectively identify abdominal examination and jejunal pressure activity associated with postoperative intolerance of enteral feedings. Twenty-nine patients underwent abdominal operation and needle catheter jejunostomy placement. Elemental tube feedings were started on the day after surgery and advanced to the caloric goal rate over three days. Patients whose feedings were slowed at the attending surgeon's discretion were defined as intolerant. Jejunal manometry and a standardized abdominal exam were performed on postoperative days 1, 3, and 5. Fifteen patients (52%) were intolerant of tube feedings and had decreased jejunal motor activity but more active bowel sounds prior to feedings. After feedings, intolerant patients developed abdominal distension, but other abdominal findings were inconsistent. A marked decrease in phase II of the migrating motility complex (MMC) and the lack of a fed response were present in both groups. The overall jejunal motility present on day 1 following surgery identifies patients that will not tolerate enteral feedings. The abdominal examination, MMC parameters, and motor response to feeding did not predict feeding intolerance.

A randomized, pharmacokinetic and pharmacodynamic, cross-over study of duodenal or jejunal administration compared to nasogastric administration of omeprazole suspension in patients at risk for stress ulcers.

OBJECTIVES: The aim of this study was to characterize absorption and pH control of simplified omeprazole suspension (SOS), 2 mg/ml in 8.4% sodium bicarbonate, administered via the nasogastric versus jejunal or duodenal route. METHODS: Nine critically ill surgical patients, NPO and mechanically ventilated, were enrolled in this randomized cross-over study. Patients received a single 40 mg dose of SOS by the nasogastric and either the jejunal or duodenal route. Twenty-four-hour continuous intragastric pH monitoring was performed during the study period. Sequential blood samples were collected over 24 h to characterize SOS absorption and pharmacokinetic parameters. RESULTS: Nasogastric administration of SOS resulted in lower maximum mean +/- SD serum concentrations compared to jejunal/duodenal dosing (0.970 +/- 0.436 vs 1.833 +/- 0.416 microg/ml, p = 0.006). SOS absorption was significantly slower when administered via nasogastric tube (108.3 +/- 42.0 vs 12.1 +/- 7.9 min, p < 0.001). However, all routes of administration resulted in similar SOS area under the serum concentration-time curves (AUC(0-infinity)) (415.1 +/- 291.8 vs 396.7 +/- 388.1 microg x min/ml, p = 0.91) [corrected]. Mean intragastric pH values remained >4 at 1 h after SOS administration and remained >4 for the entire 24-h study (6.32 +/- 1.04, 5.57 +/- 1.15, nasogastric vs jejunal/duodenal, p = 0.015), regardless of administration route. CONCLUSIONS: In critically ill surgical patients, pharmacokinetic parameters and subsequent pH control after the administration of SOS are similar by the jejunal, nasogastric, or duodenal route. SOS suspension offers an alternative acid control measure when patients are unable to take oral medications, yet have an enteral tube in place.

Uroguanylin treatment suppresses polyp formation in the Apc(Min/+) mouse and induces apoptosis in human colon adenocarcinoma cells via cyclic GMP.

The enteric peptides, guanylin and uroguanylin, are local regulators of intestinal secretion by activation of receptor-guanylate cyclase (R-GC) signaling molecules that produce cyclic GMP (cGMP) and stimulate the cystic fibrosis transmembrane conductance regulator-dependent secretion of Cl- and HCO3-. Our experiments demonstrate that mRNA transcripts for guanylin and uroguanylin are markedly reduced in colon polyps and adenocarcinomas. In contrast, a specific uroguanylin-R-GC, R-GCC, is expressed in polyps and adenocarcinomas at levels comparable with normal colon mucosa. Activation of R-GCC by uroguanylin in vitro inhibits the proliferation of T84 colon cells and elicits profound apoptosis in human colon cancer cells, T84. Therefore, down-regulation of gene expression and loss of the peptides may interfere with renewal and/or removal of the epithelial cells resulting in the formation of polyps, which can progress to malignant cancers of the colon and rectum. Oral replacement therapy with human uroguanylin was used to evaluate its effects on the formation of intestinal polyps in the Min/+ mouse model for colorectal cancer. Uroguanylin significantly reduces the number of polyps found in the intestine of Min/+ mice by approximately 50% of control. Our findings suggest that uroguanylin and guanylin regulate the turnover of epithelial cells within the intestinal mucosa via activation of a cGMP signaling mechanism that elicits apoptosis of target enterocytes. The intestinal R-GC signaling molecules for guanylin regulatory peptides are promising targets for prevention and/or therapeutic treatment of intestinal polyps and cancers by oral administration of human uroguanylin.

Percutaneous cholecystostomy is an effective treatment for high-risk patients with acute cholecystitis.

We sought to determine the safety, efficacy, and outcome of percutaneous cholecystostomy (PC) in all patients undergoing the procedure at our institutions. We reviewed 53 consecutive cases of acute cholecystitis seen at our hospitals over 5.5 years in which PC was performed at the initial treatment. Follow-up was obtained by chart review and telephone questionnaire. Acute cholecystitis was the primary admitting diagnosis in 18 cases. In the remaining 35, cholecystitis developed during hospitalization. All patients were considered high surgical risks on the basis of the presence of comorbid conditions. The gallbladder was successfully catheterized under radiologic guidance in all patients and with no immediate procedure-related morbidity. Acute cholecystitis resolved in 44 of 53 patients (83%), whereas nine patients (17%) did not improve clinically after PC and died during the same hospitalization. A total of 33 (62%) eventually survived hospitalization. Elective cholecystectomy was done in 25 patients with no mortality. After cholecystectomy, three of these patients subsequently died of other causes, whereas 22 are alive. Eight patients did not undergo cholecystectomy because of underlying medical conditions or because they had acalculous cholecystitis. These patients remained free of biliary problems after removal of their cholecystostomy tube, but two have subsequently died of nonbiliary conditions. Percutaneous cholecystostomy is a safe, effective treatment for high-risk patients with acute cholecystitis. Cholecystostomy can be followed by elective cholecystectomy at a later time if the patient's condition permits or by expectant conservative management in patients who have had acalculous cholecystitis or have a very high mortality risk with surgery.

Immediate postoperative 5-FU does not decrease colonic anastomotic strength.

BACKGROUND AND OBJECTIVES: The use of continuous infusion 5-Fluorouracil (5-FU) immediately after surgery may improve the adjuvant treatment of resected colon cancer and is the subject of a national phase III trial (Intergroup no. 0136). The aim was to determine the effect of continuous infusion 5-FU on the bursting pressure of a colon anastomosis. METHODS: Twenty Lewis rats weighing approximately 300 g were subject to sigmoid colectomy and single-layer anastomosis. Ten rats received 5-FU continuously at 600 mg/m2 per day for 7 days; 10 rats served as controls. Ten days postoperatively, the rats were sacrificed and bursting pressure of the colon containing the anastomosis was determined. RESULTS: No anastomotic leaks or intra-abdominal abscesses were identified. Burst pressure of the colon in controls (124+/-13 mm Hg; mean+/-SEM) was not significantly different from those animals receiving 5-FU (115+/-9, P > 0.05). The control rats gained weight (13+/-7 g), which is significantly different from the rats receiving 5-FU (-19+/-13, P=0.04). CONCLUSIONS: Continuous infusion 5-FU postoperatively results in weight loss, but does not affect anastomotic bursting strength in rats. This evidence supports the safety of continuous infusion 5-FU postoperatively in humans.

Endoscopic sphincterotomy for the treatment of gallstone pancreatitis during pregnancy.

BACKGROUND: Gallstones are the most common cause of acute pancreatitis during pregnancy. Without intervention, gallstone pancreatitis during pregnancy is associated with an antepartum recurrence rate of 70%, which exposes the mother and fetus to an increased risk of morbidity and mortality. A safe, effective means to prevent recurrent gallstone pancreatitis during pregnancy is desirable. METHODS: Since 1991, we have managed gallstone pancreatitis in three pregnant patients with endoscopic retrograde cholangiogram (ERC), followed by spincterotomy, despite the absence of common bile duct stones. RESULTS: All patients were judged to have mild pancreatitis by modified Ranson criteria and the Multiorgan System Failure criteria. During cholangiogram, fetal shielding was employed and fluoroscopy times ranged from 36 s to 7.2 min. One patient experienced postprocedure pancreatitis of 48-h duration. None of the patients experienced further episodes of pancreatitis and none underwent predelivery cholecystectomy. CONCLUSIONS: In pregnancy-associated gallstone pancreatitis, endoscopic sphincterotomy prevents recurrence of pancreatitis and the need for cholecystectomy during gestation. We believe endoscopic sphincterotomy represents a promising management alternative for gallstone pancreatitis during pregnancy. Further investigation is warranted.

Micrometastasis in colorectal carcinoma: a review.

Lymph node metastasis is the most important predictor of prognosis, after surgery, in colorectal carcinoma. The term "micrometastasis" has evolved from a morphological definition to one that is used with molecular-based techniques. We review the literature to evaluate the significance of detecting micrometastases in colorectal carcinoma, either by morphological or molecular techniques, and address technical difficulties encountered with both. Routine use of immunohistochemistry is not recommended as most studies show little change in staging or prognosis. Radioimmunoguided surgery may prove beneficial, but problems of false positives in benign diseases need to be addressed. Immunohistochemical detection of micrometastatic deposits in bone marrow aspirates holds the most promise for clinical practice. Molecular techniques are more sensitive than immunohistochemistry, but prognostic value needs to be determined. Molecular diagnostics can also determine genetic alterations and mutations that should improve our understanding of metastatic colon cancer and staging accuracy.

Preoperative perfusion of bypassed ileum does not improve postoperative function.

This study evaluated whether twice daily isotonic perfusion of the bypassed ileum for six weeks would enhance its motor activity and its absorption of fluids, electrolytes, and vitamin B12. The study also determined if patients undergoing perfusion had improved bowel function and decreased hospital stay after ileostomy closure. Following proctocolectomy, ileal pouch-anal canal anastomosis, and diverting loop ileostomy, six patients self-infused an isotonic solution (sucrose and sodium chloride) into the bypassed ileum twice daily, while seven patients did not (controls). Two months following proctocolectomy, and just prior to ileostomy closure, a manometric catheter assembly was placed into the unused distal ileum via the stoma and the distal ileum perfused with an isotonic sodium chloride solution for 3 hr during fasting and 3 hr after a meal. Absorption was measured, single and clustered pressure waves were identified, and a motility index was calculated. Water absorption, motility index, and cluster parameters did not improve in perfused patients compared to controls during fasting or after a meal, nor did perfused patients have improved vitamin B12 absorption. The perfused patients also did no better clinically following ileostomy takedown; the onset of bowel movements, their frequency, time to tolerate a diet, and hospital stay were similar to controls. We conclude that six weeks of twice daily isotonic perfusion did not improve motor activity or water, electrolyte, and vitamin B12 absorption in the bypassed distal ileum after proctocolectomy, ileal pouch-anal canal anastomosis, and loop ileostomy. The perfusion also did not improve bowel function after ileostomy takedown.

Cholecystectomy alleviates acalculous biliary pain in patients with a reduced gallbladder ejection fraction.

BACKGROUND: We sought to determine whether a reduced gallbladder ejection fraction, (GBEF) ascertained by cholecystokinin-cholescintigraphy (CCK-CS), predicts symptomatic improvement after cholecystectomy. METHODS: Medical records of patients who had had CCK-CS as well as negative results of gallbladder ultrasonography were reviewed, and patients were contacted by telephone to determine whether they had benefited from cholecystectomy. RESULTS: There were 35 patients (33 female, 2 male) who had a decreased GBEF. Cholecystectomy was done in 30, of whom 20 (67%) had resolution of pain, 8 (27%) had partial improvement, and 2 (7%) had no change. The 5 who declined cholecystectomy included none (0%) who were pain free, 2 (40%) who had partial improvement, and 3 (60%) who had no change. The clinical outcome of the two groups was significantly different. There were 14 patients (10 female, 4 male) with a normal GBEF. The 2 patients who had cholecystectomy were asymptomatic. Of the 12 patients who did not have cholecystectomy, 9 (75%) were asymptomatic, 1 (8%) had some improvement, and 2 (17%) had no change. CONCLUSIONS: Cholecystectomy is indicated for patients with acalculous biliary pain and reduced GBEF, since symptoms will likely resolve with surgery and will persist without it. Cholecystectomy for patients with a normal GBEF should be considered only after failure of a nonoperative trial, since improvement usually occurs over time.

High mortality after abdominal operation in patients with large-volume malignant ascites.

Advanced intra-abdominal cancers are frequently associated with malignant ascites. The aim of this study was to document the frequency and clinical course of patients found to have large-volume ( > or = 3 L) malignant ascites when undergoing a major abdominal operation. Between October 1, 1987 and September 1, 1992, 385 patients with malignant ascites were admitted to hospitals associated with a university medical center. Seventeen with large volume ascites underwent exploration for palliation of bowel obstruction or debulking of tumor. Operative mortality was 41% and mortality correlated with the presence of a nonovarian primary and advanced age. We conclude that patients with large volume nonovarian malignant ascites have a high mortality rate following a major abdominal operation. New approaches such as neoadjuvant or intraperitoneal chemotherapy or possibly peritoneovenous shunt placement at the time of the abdominal operation, are needed to improve the dismal results in this subgroup of patients.

Laparoscopic assisted percutaneous endoscopic gastrostomy.

Percutaneous endoscopic gastrostomy (PEG) cannot be accomplished in some patients and should not be performed if a distinct indentation in the stomach is not seen with finger pressure on the abdominal wall. We describe a technique of laparoscopic assisted PEG as an alternative to evaluate the intraabdominal organs after failed PEG placement. A needle is placed percutaneously into the stomach under laparoscopic and gastroscopic control. A wire is placed through the needle, encircled with a snare, and the PEG completed. We have performed this technique in three patients without complication. This simple and safe procedure has become our technique of choice for gastrostomy tube placement in those patients where upper endoscopy is possible but a PEG alone cannot be performed safely.

Ascites and secondary bacterial peritonitis associated with small bowel obstruction.

Wide albumin gradient (transudative) ascites is usually due to liver disease but may also result from many other disorders, including heart failure, hepatic infiltration by tumor, hepatic vein thrombosis, and veno-occlusive disease. It has not been linked with small bowel obstruction. Narrow albumin gradient (exudative) ascites, usually due to peritoneal carcinoma or inflammation, has been noted in cases of necrotic or perforated bowel, but simple small bowel obstruction has not previously been appreciated as a possible cause for ascites. We report a patient who developed wide albumin gradient ascites and secondary bacterial peritonitis in association with small bowel obstruction. The small bowel obstruction, ascites, and peritonitis resolved with lysis of a single abdominal adhesion.

Rectal cancer. Treatment advances that reduce recurrence rates and lengthen survival.

The risk of malignant disease arising in rectal mucosa is high. Surgery is the most effective form of treatment but results in cure in only 50% of patients. Adjuvant preoperative radiation therapy reduces the likelihood of local recurrence but does not improve survival rates. Fluorouracil is the most effective agent for adjuvant chemotherapy and slightly improves survival when given after surgery. Combining radiation therapy with chemotherapy appears to have a synergistic effect, and recent studies show that providing this combination after surgery improves survival. Future trends in the treatment of rectal cancer are expected to include expanded use of local excision to preserve anal sphincter function, preoperative use of a combination of radiation therapy and chemotherapy, perioperative use of chemotherapy combined with immunostimulating therapy, and use of tumor antibodies for diagnostic and therapeutic purposes.