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Biomedical subjects

L M Brunt

Publications and source records attributed to L M Brunt.

At least 19 recordsLinked to original sources

Experimental development of an endoscopic approach to neck exploration and parathyroidectomy.

BACKGROUND: Recent advances in minimally invasive surgical technology have the potential to lead to new applications outside body cavities. The purpose of the present study was to develop techniques for obtaining endoscopic exposure and access to the pretracheal space in the neck with the goal of performing neck exploration and parathyroidectomy and to evaluate the safety and efficacy of such an approach experimentally. METHODS: The technique for endoscopic neck exploration was developed in eight adult mongrel dogs and was further evaluated in a survival dog model and in human cadavers. The pretracheal space was accessed by a 2.5 cm midline incision in the lower neck. This space was expanded with a balloon dissector, and exposure was maintained with an external lift device. A 5 or 10/12 mm midline port and two to four lateral 5 mm cervical ports were placed, and dissection was carried out with pediatric endoscopic instruments and an ultrasonic coagulator. Excised parathyroid tissue was verified histologically. RESULTS: Two-gland parathyroidectomy was successfully completed in five of six dogs; inadequate exposure led to a failed procedure in one animal. Mean operative time was 130 +/- 6 minutes, and there were no operative complications. Serum calcium levels did not change significantly after operation (p = not significant). At autopsy, approximately 20 ml of clear sterile fluid was present in the pretracheal space of every dog. In five human cadavers mean dissection time for attempted four-gland parathyroidectomy was 69 +/- 38 minutes (range, 45 to 135 minutes). Four of four parathyroids were identified and removed in two patients, three of three parathyroids in one patient, three of four parathyroids in one patient, and two of four parathyroids in one patient. CONCLUSIONS: Parathyroidectomy may be performed safely and reliably in an animal model with minimally invasive techniques that can be applied to parathyroid dissection in human cadavers. These results suggest that an endoscopic approach to neck exploration and parathyroidectomy is potentially feasible and may warrant further study in clinical trials.

Animals

Comparative analysis of laparoscopic versus open splenectomy.

BACKGROUND: Laparoscopic splenectomy (LS) has been used to treat a variety of splenic disorders. However, there have been few direct comparisons of this approach with open splenectomy (OS). METHODS: Results and outcomes were compared retrospectively in 46 consecutive patients treated by laparoscopic (n = 26) or open splenectomy (n = 20) from January 1990 through March 1996. The two groups were similar in age, sex, and American Society of Anesthesiology classification. Splenectomy was performed for a variety of indications, and the majority of patients in both groups had normal or near-normal size spleens. All data are expressed as mean +/- standard deviation. RESULTS: Laparoscopic splenectomy was successfully completed in all 26 attempted cases. Operative times were significantly longer for LS (202 +/- 55 minutes) than for OS (134 +/- 43 minutes) (P < 0.001); however, operative times in the last 13 LS cases (176 +/- 48 minutes) averaged 51 minutes less than in the first 13 cases (227 +/- 51 minutes). Estimated operative blood loss was less for LS (222 +/- 280 mL) than for OS (376 +/- 500 mL) (P = not significant). A mean of 2.0 units of red blood cells was transfused in 4 (15%) of 26 patients during LS vs 1.0 unit transfused in 2 (10%) of 20 patients who had OS (P = NS). Patients who underwent LS required significantly less parenteral pain medications, had a more rapid return to regular diet, and were discharged sooner than patients who had OS. Complication rates were similar in the two groups. CONCLUSIONS: These results suggest that LS is technically safe and has several advantages over OS. Laparoscopic splenectomy should become the procedure of choice for the removal of normal and near-normal size spleens.

Adolescent

Laparoscopic adrenalectomy compared to open adrenalectomy for benign adrenal neoplasms.

BACKGROUND: Laparoscopic adrenalectomy has recently been used for removing a variety of adrenal neoplasms. The purpose of the present study was to compare results and outcomes in patients who underwent either laparoscopic or open adrenalectomy at our institution from 1988 to the present. STUDY DESIGN: The records of 66 consecutive patients with benign adrenal neoplasms who underwent adrenalectomy from 1988 through 1995 were retrospectively reviewed. Patients were divided into three groups based on the operative approach: group I (n = 25), open anterior transabdominal approach; group II (n = 17), open posterior retroperitoneal approach; and group III (n = 24), laparoscopic transabdominal flank approach. Various parameters were compared and statistical analyses were performed. RESULTS: The three groups were similar in age, gender, American Society of Anesthesiologists class, and distribution of unilateral compared with bilateral adrenalectomy. Mean tumor size was slightly larger in group I (3.4 +/- 1.4 cm) than in group II (2.4 +/- 1.4 cm) or group III (2.7 +/- 1.4 cm) (p = NS). Mean operative times for unilateral adrenalectomy were 142 +/- 38 minutes in group I, 136 +/- 34 minutes in group II, and 183 +/- 35 minutes in group III (p < 0.001, groups I and II compared with group III). For bilateral adrenalectomy, mean operative times were 205 +/- 71 minutes (group I), 328 +/- 11 minutes (group II), and 422 +/- 77 minutes (group III). Patients who underwent laparoscopic adrenalectomy had significantly less operative blood loss (mean, 104 mL compared to 408 mL in group I and 366 mL in group II, p < 0.001) and a lower incidence of perioperative blood transfusion. Laparoscopic adrenalectomy was also associated with significantly reduced parenteral pain medication requirements (p < or = 0.001) and more rapid resumption of a regular diet (p < or = 0.01) compared to open adrenalectomy. Postoperative length of stay was significantly longer in group I (8.7 +/- 4.5 days) and in group II (6.2 +/- 3.9 days) after open adrenalectomy than after laparoscopic adrenalectomy (3.2 +/- 0.9 days) (p < 0.01). Total hospital charges were similar for groups II and III but somewhat higher for group I. Patients were able to resume 100 percent activity an average of 10.6 +/- 4.9 days after laparoscopic adrenalectomy and returned to work a mean of 16.0 +/- 6.1 days postoperatively. CONCLUSIONS: Laparoscopic adrenalectomy is a safe and effective procedure and has several advantages over open adrenalectomy. Laparoscopic adrenalectomy should become the preferred operative approach for the treatment of patients with small, benign adrenal neoplasms.

Adrenal Gland Neoplasms

Chronic acalculous cholecystitis: laparoscopic treatment.

From 1990 through 1993, we treated 36 patients with recurrent typical biliary colic but who showed no ultrasonic evidence of cholelithiasis by laparoscopic cholecystectomy. Associated symptoms included nausea (75%), bloating (56%), fatty-food intolerance (53%), vomiting (17%), weight loss (31%), bowel irregularity (28%), reflux or dyspepsia (25%), and fever (17%). Diagnostic evaluation included ultrasound (100%), upper gastrointestinal series (36%), oral cholecystogram (14%), computed tomographic scan (39%), endoscopic retrograde cholangiopancreatography (17%), upper gastrointestinal endoscopy (14%), and hepatobiliary scan (92%). Quantitative hepatobiliary scans in 33 patients revealed a low gallbladder ejection fraction (EF) of less than 35% in 29 patients (88%; mean EF = 9%), and 13 patients experienced reproducible pain after cholecystokinin provocation. All patients underwent attempted laparoscopic cholecystectomy; one case of unsuspected acute acalculous cholecystitis was converted to open laparotomy because of unclear anatomy. Gross and histological examination of the gallbladders revealed chronic inflammation (83%), cholesterolosis (31%), cholesterol crystals or small stones (17%), acute inflammation (8%), polyps (6%), and normal histology (6%); however, blind retrospective scoring of gallbladders revealed significant chronic inflammation in only 38%. In the 2 to 40 months (mean, 14 months) since operation, there have been no deaths (97% follow-up). Laparoscopic cholecystectomy relieved pain in 93% of patients with a low preoperative EF compared with 75% of patients with a normal EF (nonsignificant p value). Persistent abdominal or gastrointestinal complaints included flatulence (31%), loose stools or fecal urgency (29%), belching (29%), indigestion (20%), nausea (11%), and "typical" gallbladder pain (9%). We conclude that many patients with symptoms of biliary colic and scintigraphic evidence of biliary dyskinesia have histologic findings of chronic cholecystitis. Although laparoscopic cholecystectomy usually eliminates biliary colic, persistent nonbiliary complaints are frequent.

Adult

Fascial closure of laparoscopic port sites: a new technique.

The laparoscopic operative procedure is not complete until the port sites are closed with a fascial suture. Herein, we report a simple new technique that uses a venous catheter for suture placement and direct laparoscopic visualization to secure the abdominal wall fascia and peritoneum.

Fasciotomy

Laparoscopic Billroth II gastrectomy in the canine model.

The feasibility and safety of laparoscopic Billroth II gastrectomy were evaluated in an animate model. After developing the technique in acute animal experiments, laparoscopic antrectomy and Billroth II anastomosis was performed in six mongrel dogs. Video laparoscopic access to the peritoneal cavity was accomplished with six ports (five, 10 mm; one, 12-18 mm). The operations were performed without complication in 150-200 min (mean +/- SEM, 171 +/- 10 min). The animals tolerated solid oral meals on the 2nd or 3rd postoperative day. One dog developed frequent diarrheal stools and lost 3.4 kg prior to sacrifice 18 days postoperatively when a gastroileostomy was discovered. The remaining five animals did well and were sacrificed at 49-77 days postoperatively. Adhesions were minimal and the gastrojejunostomy was widely patent in all animals without evidence of leakage or obstruction. Laparoscopic Billroth II gastrectomy in the canine model is thus feasible and safe. Using laparoscopic guidance, it may be more difficult to identify the ligament of Treitz, which must be assured at the time of operation.

Anastomosis, Surgical

Laparoscopic distal pancreatectomy in the porcine model.

Our aim was to assess the feasibility and safety of laparoscopic distal pancreatectomy in an animate model. After developing the technique in acute animal experiments, laparoscopic distal pancreatectomy was performed in five young domestic pigs. Five trocars were used (2-10 mm, 2-12 mm, 1-11 mm) for video laparoscopic access to the peritoneal cavity. The operations were performed without complication in 62-95 min (mean +/- SEM, 77 +/- 7 min). Each animal tolerated oral feedings on the first postoperative day and subsequently gained 6-11 kg (10 +/- 2 kg) in the 4-7-week interval prior to sacrifice. Although there was a significant increase in serum amylase on the first postoperative day, this was associated with a comparable increase in hematocrit, possibly representing hemoconcentration. The weight of the laparoscopically resected pancreatic segment ranged from 16 to 36 g (19 +/- 2 g) while that of the pancreatic head at sacrifice was 13-29 g (21 +/- 3 g). At the time of sacrifice, there were few intraabdominal adhesions and no evidence of fluid collection or pancreatitis. The staple line across the body of the pancreas was grossly intact in all animals. We conclude that laparoscopic distal pancreatectomy in the porcine model is feasible and safe. It may therefore be possible to perform laparoscopic distal pancreatectomy in humans.

Animals

Role of laparoscopic cholecystectomy in the management of acute gallstone pancreatitis.

Laparoscopic cholecystectomy has rapidly become the prime modality for removal of the gallbladder. However, as laparoscopic techniques for treating choledocholithiasis are evolving, we reviewed our experience with acute gallstone pancreatitis since the inception of laparoscopic cholecystectomy. Between November 1989 and March 1993, we treated 57 patients with acute gallstone pancreatitis. Cholecystectomy was performed during the initial admission in 46 patients (81%, group I), while 11 (19%) underwent delayed cholecystectomy at a second admission 2 to 9 weeks later (group II). Within group I, eight patients (17%) were thought to have contraindications to laparoscopic cholecystectomy and underwent open cholecystectomy. In the remaining 38 patients of group I, laparoscopic cholecystectomy was completed successfully. Preoperative endoscopic retrograde cholangiopancreatography (ERCP) was performed in 23 of these patients (61%) and endoscopic sphincterotomy was performed in 6 patients (26%). In four other patients, the intraoperative cholangiogram revealed common bile duct stones that were removed using laparoscopic techniques. The 11 patients in group II were all treated by laparoscopic cholecystectomy; of these patients, 3 underwent preoperative endoscopic stone removal and 1 had choledocholithiasis managed laparoscopically. Postoperative hospitalization averaged 4 +/- 1 days (mean +/- SEM), and there was no major morbidity or 30-day mortality. This is the first large series of acute gallstone pancreatitis in the era of laparoscopic cholecystectomy. Our experience suggests that laparoscopic cholecystectomy with or without ERCP should be the primary approach for treating acute gallstone pancreatitis in the 1990s.

Acute Disease

The case for routine operative cholangiography during laparoscopic cholecystectomy.

The debate over routine versus selective intraoperative cholangiography during laparoscopic cholecystectomy continues because of a paucity of objective data to support or refute the case for either approach. The introduction of fluoroscopic techniques during the performance of cholangiography is an important step forward because it decreases the operative time for the technique and because real-time visualization may also diminish the number of false-positive and false-negative results. Routine cholangiography improves the surgeon's ability to delineate the biliary anatomy when the need arises and undoubtedly facilitates the development of skills useful for the laparoscopic management of common bile duct calculi. Normal results on intraoperative cholangiography are also reassuring to the surgeon, given the current visual and tactile limitations of laparoscopy. As a result of these considerations as well as our procurement of a digital fluoroscopic system and the need to train surgical residents in cholangiographic techniques, we have adopted a policy of routine fluoroscopic intraoperative cholangiography on all patients undergoing laparoscopic cholecystectomy.

Cholangiography

Stimulation of vasoactive intestinal peptide and neurotensin secretion by pentagastrin in a patient with VIPoma syndrome.

BACKGROUND: Pancreatic endocrine tumors (PETs) may secrete a variety of peptide hormones, either alone or in combination, and intravenously administered provocative agents have been used to stimulate hormone release to aid in the diagnosis and localization in suspected cases. These features of PETs led us to perform detailed biochemical investigations and provocative testing in a 26-year-old man with a 5 cm vasoactive intestinal peptide (VIP)-secreting tumor of the head of the pancreas. METHODS: Plasma hormone radioimmunoassays and immunohistochemical studies were performed for a panel of peptide hormones, including VIP, neurotensin, and pancreatic polypeptide (PP). Acid alcohol extracts of tumor specimens were analyzed for these peptide hormones as well. Before operation, four provocative test regimens were administered intravenously after an overnight fast: pentagastrin (0.5 microgram/kg/5 sec); rapid calcium infusion (2 mg/kg/min); a combination of calcium (2 mg/kg/min) followed by pentagastrin (0.5 microgram/kg/min); and secretin (2 clinical units/kg bolus). Blood samples were collected before each test and 1, 2, 3, 5, and 10 minutes after the infusions. RESULTS: Measurement of plasma hormone levels and tumor immunohistochemistry and hormonal extraction studies indicated secretion of VIP, neurotensin, and PP by the tumor. Coexpression of VIP and neurotensin was seen immunohistochemically within some individual tumor cells. Provocative testing resulted in maximal stimulation of VIP and neurotensin secretion with pentagastrin administration, which produced increases in plasma levels of VIP and neurotensin over basal levels of 81% and 87%, respectively. After operation, plasma levels of VIP, neurotensin, and PP were undetectable before and after administration of pentagastrin. CONCLUSIONS: The results emphasize the importance of comprehensive biochemical evaluation in patients with VIPoma syndrome to detect the production of a range of peptide hormones. Administration of intravenous pentagastrin appears to stimulate release of VIP and NT and should be evaluated further as a provocative agent for the diagnosis and follow-up of patients with these tumors.

Adult

Diagnosis and management of biliary complications of laparoscopic cholecystectomy.

Laparoscopic cholecystectomy has become the operation of choice for symptomatic cholelithiasis. However, this operation may result in serious biliary complications. Our aims were to review our experience with biliary complications of laparoscopic cholecystectomy and to document the mechanisms of the injuries and the techniques of managing these complications. We treated 20 patients with biliary complications of laparoscopic cholecystectomy. Symptomatic collections of bile (bilomas) were present in five patients. One of these patients underwent operative ligation of an accessory bile duct in the gallbladder bed, whereas the others had percutaneous or endoscopic therapy. In the remaining 15 patients (of whom 13 were referred from other hospitals), injuries to the major bile ducts were managed by combined radiologic, endoscopic, and operative therapies. In 10 of these patients (67%), the mechanism of injury was the misidentification of the common bile duct as the cystic duct. In 3 of 15 patients, a noncircumferential injury to the lateral aspect of the common bile duct occurred. The Bismuth levels of the remaining bile duct injuries were type I in 3, type II in 4, type III in 3, and type IV in 2. Early outcome of therapy for these bile duct injuries has been favorable. One patient was lost to follow-up, and 2 died of nonbiliary causes, whereas 12 patients are alive and well with normal serum liver enzyme levels at 4 to 19 months postoperatively (mean: 14 months). The most common cause of major bile duct injury during laparoscopic cholecystectomy is mistaking the common bile duct for the cystic duct. Most bilomas can be managed successfully with noninvasive methods. Coordinated efforts by radiologists, endoscopists, and surgeons are necessary to optimize the management of patients with major bile duct injury, suggesting that patients with biliary complications of laparoscopic cholecystectomy should be referred to specialty centers for optimal care.

Abdominal Pain

Intraoperative pneumothorax during laparoscopic cholecystectomy: a complication of prior transdiaphragmatic surgery.

Pulmonary complications of laparoscopic surgery include subcutaneous emphysema, mediastinal emphysema, hypercarbia, and pneumothorax. Pneumothorax is a rare complication that may occur in patients with diaphragmatic defects. We report a case of intraoperative left-sided pneumothorax in a patient who had undergone an esophagogastrectomy for carcinoma 16 years previously. The mechanisms for development of this complication and its management are discussed.

Aged

Laparoscopic small bowel resection and anastomosis.

Our aim was to assess the feasibility and safety of performing totally intracorporeal laparoscopic small bowel resection and anastomosis using a linear stapling device. Laparoscopic small bowel resection and anastomosis were performed in five young domestic pigs. Five trocars were used (2-5 mm, 2-11 mm, and 1-12 mm) for video laparoscopic access to the peritoneal cavity. Segments of jejunum 5 to 10 cm long were excised using two firings of a 30-mm linear stapler (Endo-GIA). The bowel was anastomosed with the stapler in a functional end-to-end fashion, and the enterotomy was stapled closed. The excised bowel segment was then placed in a nylon entrapment sack, morcellated, and aspirated with an automatic electrical tissue morcellator. The pigs recovered uneventfully, were allowed oral feedings on the day after the operation, and gained weight normally in the postoperative period. Sacrifice after 4 to 10 weeks revealed few adhesions, no evidence of anastomotic leaks, and the anastomoses to be widely patent. Clinical application will be facilitated by the use of longer laparoscopic staplers, but surgeons must also develop suturing skills to assure safe performance of advanced laparoscopic surgery.

Anastomosis, Surgical

Laparoscopic anterior resection of the rectum using a triple stapled intracorporeal anastomosis in the pig.

Laparoscopic anterior resection of the rectum was performed in the porcine model. Colorectal anastomosis was accomplished with a closed triple staple technique using a circular stapler. The anvil and shaft were passed beyond the level of resection and retrieved through the proximal transverse linear cutter staple line. The stapler post was passed through the distal rectal staple line transanally. The resulting stapled anastomosis contained portions of three staple lines. There were no anastomotic leaks or strictures at one month follow-up autopsy. The triple-stapled anastomosis via a laparoscopic approach after an anterior resection of the rectum in a pig is a safe, reliable technique.

Anastomosis, Surgical

Retroperitoneal endoscopic adrenalectomy: an experimental study.

Laparoscopic approaches to adrenalectomy have been limited by the retroperitoneal (RP) location of the adrenal glands and their relative inaccessibility transabdominally. We developed a technique for endoscopic adrenalectomy in a domestic swine model using insufflation of the RP space with CO2 and retroperitoneoscopy. The technique for retroperitoneal endoscopic adrenalectomy was first developed in an acute study of three animals. A chronic survival study was then undertaken in six pigs. Unilateral right (n = 3) or left (n = 3) adrenalectomy was performed. Mean RP insufflation time was 14.5 min (range, 7-30 min), and mean dissection time after insufflation was 100 min (range, 80-120 min). Two additional animals died under anesthesia after RP insufflation and placement of the trocars for retroperitoneoscopy but before dissection of the adrenal gland. One death was unexplained at autopsy. The other death was associated with a right-sided pneumothorax attributable to penetration of the diaphragm by a trocar. The remaining six pigs recovered uneventfully from the procedure. Autopsies performed 37 to 51 days postoperatively showed minimal scarring of the adrenalectomy bed. The results suggest that posterior adrenalectomy using RP CO2 insufflation and direct retroperitoneoscopy is potentially applicable to the treatment of small adrenal lesions in humans.

Adrenalectomy

Interleukin 1 participates in the development of anti-Listeria responses in normal and SCID mice.

Using T- and B-cell deficient C.B-17 mice with the scid mutation, we have previously documented the existence of a T-cell-independent but interferon gamma-dependent pathway of macrophage activation that confers upon the host partial resistance to the facultative intracellular bacterium Listeria monocytogenes. This pathway is operative in both normal and SCID mice and consists of at least four components: interferon gamma, tumor necrosis factor, macrophages, and natural killer cells. Here we demonstrate that interleukin 1 also participates in this pathway but at a different site of action. Using monoclonal antibodies that neutralize the biologic activities of interleukin 1 alpha and interleukin 1 beta, we document that interleukin 1 participates neither directly in the induction of interferon gamma from isolated SCID natural killer cells nor in the antigen-specific activation of CD4+ T cells derived from Listeria-immune C.B-17 mice. In contrast, injection of a mixture of anti-interleukin 1 alpha, anti-interleukin 1 beta, and a newly derived monoclonal antibody specific for the murine type I interleukin-1 receptor into either SCID or normal C.B-17 mice blocked the in vivo elaboration of class II major histocompatibility complex-positive macrophages after infection of the animals with Listeria. Moreover, SCID mice treated with the anti-interleukin-1 mixture failed to control the growth of Listeria in vivo and eventually succumbed to the infection. These results document that endogenously produced interleukin 1 plays an obligate role in the Listeria-dependent induction of activated macrophages in vivo and demonstrate that the action of interleukin 1 is distinct from the generation of natural killer cell-derived interferon gamma.

Animals

Laparoscopic ureterolysis.

We report a case of an obstructed right kidney due to retroperitoneal fibrosis. Ureterolysis, biopsy of the retroperitoneal tissue and intraperitonealization of the ureter were accomplished laparoscopically.

Adolescent