Biomedical subjects

L W Way

Publications and source records attributed to L W Way.

At least 37 records · Page 2Linked to original sources

PubMed1998

Laparoscopic repair of paraesophageal hiatal hernias.

BACKGROUND: Regardless of symptoms, paraesophageal hiatal hernias should be repaired in order to prevent complications. This study reports the University of California San Francisco experience with laparoscopic repair of paraesophageal hiatal hernias, emphasizing the technical steps essential for good results. PATIENTS AND METHODS: From May 1993 to September 1997, 55 patients, 27 women and 28 men, with a mean age of 67 years (range, 35-102 years) underwent laparoscopic repair of paraesophageal hernias at the University of California San Francisco. Symptoms, which had been present an average of 85 months before surgery, consisted mainly of pain (55%), heartburn (52%), dysphagia (45%), and regurgitation (41%). Of the four patients who presented with acute illness, two had gastric obstruction, one had severe dyspnea, and one had gastric bleeding. Endoscopy demonstrated esophagitis in 25 (69%) of 36 patients, and 24-hour pH-monitoring demonstrated acid reflux in 22 (67%) of 33 patients. Manometry detected severely impaired distal esophageal peristalsis in 17 (52%) of 33 patients. The preferred operation consisted of reduction of the hernia, excision of the sack and the gastric fat pad, closure of the enlarged hiatus without mesh, and construction of a fundoplication anchored by sutures within the abdomen. RESULTS: Of the 55 patients, the operations of 49 were completed laparoscopically using the following reconstructions: Guarner (270-degree) fundoplication (30 patients); Nissen fundoplication (10 patients); and gastropexy (9 patients). Five (9%) operations were converted to laparotomies. The average operating time was 219 minutes; the average blood loss was less than 25 mL; resumption of an unrestricted diet, 27 hours; and mean hospital stay, 58 hours. Intraoperative technical complications occurred in five (9%) patients. One patient died during surgery from a sudden pulmonary embolus. Two (4%) patients required a second operation for recurrent paraesophageal hernias. CONCLUSIONS: Laparoscopic repair of paraesophageal hiatal hernias is safe and effective, but the operation is difficult and good results hinge on details of the operative technique and the surgeon's experience. In this series, the crus could always be closed securely without using mesh. We realized early that a fundoplication should be a routine step, because it corrects reflux and is the best method to secure the gastroesophageal junction in the abdomen.

Adult↗

PubMed1998

Virtual environments for training critical skills in laparoscopic surgery.

Surgical training simulations must incorporate not only advanced technical features, such as detailed geometric organ models and physically-based modeling techniques, but also a thorough understanding of the major training issues relating to a particular procedure. We have developed a prototype environment for training laparoscopic cholecystectomy, or gallbladder removal surgery, which focuses a student's attention on the critical steps performed during the procedure and provides feedback as to the common errors committed during a session. The current version of our system runs in real-time on a mid-range graphics workstation. The simulation also provides a platform for research into a variety of different areas, including tissue modeling, finite element methods, and generalized simulation authoring.

Algorithms↗

PubMed1997

Comparison of laparoscopic imaging systems and conditions using a knot-tying task.

Pilot experiments to determine the important factors in the engineering of laparoscopic (videoscopic) imaging systems are described in this paper. In the first set of experiments, three videoscopic systems were compared by using a knot-tying task: monoscopic, monoscopic with digital contrast enhancement, and stereoscopic. Direct viewing was used as a control. In both experienced and novice subject groups, no difference was found in completion time or errors between the videoscopic conditions. Performance with direct viewing was significantly better, however, indicating that there are factors in videoscopic imaging that degrade perception or distort the relationship between vision and motor response. In the second set of experiments, the effects of contrast and spatial resolution were examined by varying working distance and camera exposure while experienced subjects tied knots on high- and low-contrast surfaces. Good contrast was found to be most important at longer working distances. This result shows that performance of knot tying, a complex task, is affected by contrast sensitivity, which is a fundamental property of human vision.

Abdomen↗

PubMed1997

Partial fundoplication for gastroesophageal reflux.

BACKGROUND: About 20% of patients with gastroesophageal reflux disease (GERD) have severely impaired esophageal peristalsis in addition to an incompetent lower esophageal sphincter. In these patients a total fundoplication corrects the abnormal reflux, but it is often associated with postoperative dysphagia and gas bloat syndrome. We studied the efficacy of partial fundoplication in such patients. METHODS: A partial fundoplication (240 degrees -270 degrees ) was performed laparoscopically in 26 patients (11 men, 15 women; mean age 50.5 years) with GERD (mean DeMeester score: 92 +/- 16) in whom manometry demonstrated severely abnormal esophageal peristalsis. RESULTS: All operations were completed laparoscopically and the patients were dicharged an average of 39 h after surgery. The preoperative symptoms resolved or improved in all patients, and no patient developed dysphagia or gas bloat syndrome. Postoperative pH monitoring showed complete or nearly complete resolution of the abnormal reflux in every patient. CONCLUSIONS: Partial fundoplication is an excellent treatment for patients with GERD and weak peristalsis, for it corrects the abnormal reflux and avoids postoperative dysphagia.

Endoscopy, Digestive System↗

PubMed1997

Surgery of the esophagus. Anatomy and physiology.

The esophagus can be divided into three parts: cervical, thoracic, and abdominal. Its blood supply, lymphatic drainage, innervation, and architecture of the esophageal wall are described. The topographic relationships of the esophagus and the gastroesophageal junction with neighboring structures are illustrated from the right and left thoroscopic and the laparoscopic viewpoints. Functionally, the esophagus consists of the upper esophageal sphincter; the esophageal body; and the lower esophageal sphincter. Their coordinated muscular activity transports the food bolus into the stomach, while maintaining a barrier against reflux of esophageal contents into the pharynx and gastric juice into the esophagus.

Esophagogastric Junction↗

PubMed1997

Evaluation and treatment of primary esophageal motility disorders.

Achalasia, diffuse esophageal spasm, and nutcracker esophagus constitute the main primary esophageal motility disorders. During the past decade major progress has been made in understanding their pathophysiology and in the ability to establish a precise diagnosis. In addition, minimally invasive surgical intervention has radically changed the therapeutic approach, and thoracoscopic or laparoscopic myotomy is probably the best treatment for most patients.

Diagnosis, Differential↗

PubMed1996

Laparoscopic adrenalectomy. Comparison of the lateral and posterior approaches.

OBJECTIVE: To compare the lateral transabdominal and posterior retroperitoneal laparoscopic methods for performing adrenalectomy. DESIGN: Nonrandomized. SETTING: Hospitals affiliated with the University of California, San Francisco. PATIENTS: Thirty-six patients (15 men and 21 women), aged 5 to 78 years (mean age, 49 years), were treated for the following conditions: aldosteronoma, 18 patients; pheochromocytoma, 4 patients; Cushing syndrome, 6 patients; androgen-secreting tumor, 1 patient; nonfunctioning adenoma, 3 patients; adrenal hemorrhage, 1 patient; metastatic neoplasm, 2 patients; and myelolipoma, 1 patient. INTERVENTIONS: Twenty-three lateral and 14 posterior laparoscopic adrenalectomies. MAIN OUTCOME MEASURES: Success rate, operating time, complications, and length of hospital stay. RESULTS: The tumors, which ranged in size from 1 to 13 cm (mean, 4.2 cm; median, 2.5 cm), were all successfully resected laparoscopically. All 8 tumors larger than 6 cm were resected by the lateral approach. One critically ill patient died. No patient required blood transfusions or conversion to laparotomy. Mean operating time was 3.8 hours vs 3.4 hours (median, 3.5 hours vs 3 hours) and mean hospital stay was 2.2 days vs 1.5 days (median, 2 days vs 1 day) for the lateral and posterior approaches, respectively. All patients without concomitant procedures were ready to be discharged within 48 hours. CONCLUSIONS: Both approaches were effective and safe. We prefer the lateral approach for tumors larger than 6 cm and the posterior approach for bilateral tumors.

Adolescent↗

PubMed1996

Radially expanding dilatation. A superior method of laparoscopic trocar access.

Trocars used in laparoscopic surgery occasionally produce serious complications, such as bleeding, visceral injury, or incisional hernia. We report the evaluation of a new, potentially safer laparoscopic access device in which the cutting obturator of a standard trocar is replaced by a blunt, radially expanding device. Conventional and radially expanding trocars were used in laparoscopic cholecystectomies in 12 pigs. Their abdominal walls were excised and the defects caused by the trocars were examined. The defects caused by the radially expanding devices were about 50% narrower (P < 0.001), and the incidence of abdominal wall bleeding was considerably less (0% vs 21%) with the radially expanding trocars. Since incisional hernias at trocar sites are related to the size of the abdominal wall defect, the use of radially expanding trocars should decrease the incidence of this complication. There should also be less risk of visceral injury.

Abdominal Muscles↗

PubMed1996

General surgery in evolution: technology and competence.

This paper addresses the current status of General Surgery, the direction in which it is moving, and how to prepare for future changes. The paper points out that, since the predicted effects of new technology on the practice of General Surgery are more technical complexity, decreasing invasiveness, and fewer traditional operations, the consequences for the training of surgeons, the division of responsibilities among specialists, and the organization of surgical care will be substantial. In light of the current difficulty in dealing with the stresses within General Surgery, the paper discusses how changes in residency training and an increased use of Fellowships will enable the specialty to handle such disruptive changes in the future.

Clinical Competence↗

PubMed1996

Hiatal hernia size affects lower esophageal sphincter function, esophageal acid exposure, and the degree of mucosal injury.

BACKGROUND: Since the role of a hiatal hernia in the pathophysiology of gastroesophageal reflux disease (GERD) has not been fully elucidated, we studied the effects of hiatal hernias on the function of the lower esophageal sphincter (LES) and esophageal acid clearance. PATIENTS AND METHODS: Ninety-five consecutive patients with GERD diagnosed by 24-hour pH monitoring underwent upper gastrointestinal series (UGI), endoscopy, and esophageal manometry. Based on the presence (H+) or absence (H-) of a hiatal hernia on UGI series, they were divided into two groups: H+ (n = 51) and H- (n = 44). Then, using the size of the hiatal hernia, the H+ group was divided into three subgroups: I, H < 3 cm (n = 31); II, H 3.0 to 5 cm (n = 14); and III, H > 5 cm (n = 6). RESULTS: Esophageal manometry showed that patients with larger hiatal hernias (groups II and III) had a weaker and shorter LES and less effective peristalsis compared to patients with a small or no hiatal hernia. Prolonged pH monitoring showed that patients with larger hiatal hernias were exposed to more refluxed acid and had more severely abnormal acid clearance. Endoscopy showed more severe esophagitis among patients with GERD and hiatal hernia compared with GERD patients without hiatal hernia, and the degree of esophagitis was proportionate to the size of the hernia. CONCLUSIONS: Among patients with proven GERD, those with a small hiatal hernia and those with no hiatal hernia had similar abnormalities of LES function and acid clearance. In patients with larger hiatal hernias, however, the LES was shorter and weaker, the amount of reflux was greater, and acid clearance was less efficient. Consequently, the degree of esophagitis was worse in the presence of a large hiatal hernia.

Adolescent↗

PubMed1996

Intestinal immunisation with Escherichia coli protects rats against Escherichia coli induced cholangitis.

BACKGROUND: Cholangitis, an infection of the biliary tract, is most commonly caused by Gram negative bacteria, particularly Escherichia coli. Factors governing the severity of cholangitis, including the role of biliary IgA, are poorly understood. AIMS: The aim of this work was to find out if biliary IgA directed against E coli protects rats against hepatobiliary infection with E coli. SUBJECTS: Male Sprague-Dawley rats weighing 270-350 grams were used in all of the experiments. METHODS: At laparotomy, rats were immunised by injecting killed E coli or normal saline (controls) into Peyer's patches. With or without subsequent antigenic boosting (by oral administration of killed E coli), bile was collected at a second laparotomy, and rats were infected by introducing viable E coli into the bile duct. Production of IgA anti-E coli antibody was measured by enzyme linked immunosorbent assay of bile, and the presence of hepatobiliary infection was determined by quantitative culture of liver homogenates. RESULTS: Systemic infection was present in six of 12 control rats and in one of 24 immunised rats (p = 0.005) after death. There was an inverse correlation between immunisation and E coli colony counts in cultured liver homogenates (p = 0.024). CONCLUSION: The findings suggest that biliary IgA directed against E coli protected rats against hepatobiliary E coli infection and systemic sepsis.

Animals↗

PubMed1995

Comparison of medical and minimally invasive surgical therapy for primary esophageal motility disorders.

OBJECTIVE: To compare medical with minimally invasive surgical therapy in the treatment of primary esophageal motility disorders. DESIGN: Prospective study. SETTING: University-based tertiary care center. PATIENTS: Eighty-nine patients (46 men and 43 women) with either achalasia or nutcracker esophagus and diffuse esophageal spasm (DES). Choice of treatment was based not on randomization but on the preference of the referring physician, the patient's choice, and/or the patient's eligibility to access the University of California, San Francisco, for treatment. INTERVENTIONS: Nineteen patients with achalasia and 30 patients with nutcracker esophagus and DES were treated with dilatations and/or medications. Thirty patients with achalasia and 10 with nutcracker esophagus and DES underwent a thoracoscopic myotomy. MAIN OUTCOME MEASURES: Dysphagia, pain, and overall quality of life. RESULTS: In the surgical group, 80% of the patients with nutcracker esophagus and DES and 87% of the patients with achalasia had good or excellent results. In contrast, in the medical group, 26% of the patients with nutcracker esophagus and DES and 26% of the patients with achalasia had good or excellent results. CONCLUSIONS: Surgery by minimally invasive techniques offers a better chance than does medical therapy or dilatation of rendering the patient with achalasia, nutcracker esophagus, and DES asymptomatic.

Adult↗

PubMed1995

Bile duct injuries during laparoscopic cholecystectomy. Factors that influence the results of treatment.

OBJECTIVE: To analyze the treatment of bile duct injuries during laparoscopic cholecystectomy to discern the factors affecting outcome. DESIGN: An analysis of the treatment of 88 patients with laparoscopic bile duct injuries. SETTING: A university hospital. PATIENTS: Eighty-eight patients with major bile duct injuries following laparoscopic cholecystectomy. MAIN OUTCOME MEASURES: Success of treatment, morbidity rate, mortality rate, and length of illness. RESULTS: Operations to repair bile duct injuries were unsuccessful in 27 (96%) of 28 procedures when cholangiograms were not obtained preoperatively, and they were unsuccessful in 69% when cholangiographic data were incomplete. In some cases, lack of complete cholangiographic information led to an inappropriate and harmful operation. When cholangiographic data were complete, the first repair was successful in 16 (84%) of 19 patients. A primary end-to-end repair over a T tube (13 patients) was unsuccessful in every case in which the duct had been divided. Direct closure of a partial defect in the duct was successful in four of seven patients. Fifty-four (63%) of 84 Roux-en-Y hepaticojejunostomies were successful. Factors responsible for the unsuccessful outcomes were the following: incomplete excision of the scarred duct, use of nonabsorbable suture material, use of two-layer anastomosis, and failure to eradicate subhepatic infection before the attempted repair. Dilatation and stenting was uniformly unsuccessful as primary treatment (three patients) and was unsuccessful in only seven of 26 patients following a previous operative repair. Patients first treated by the primary surgeon had an average length of illness of 222 days (P < .01). Only 17% of primary repair attempts and no secondary repair attempts performed by the laparoscopic surgeon were successful. Patients whose first repair was performed by tertiary care biliary surgeons had a length of illness of 78 days (P < .01), and 45 (94%) of 48 repairs by tertiary care biliary surgeons were successful. CONCLUSIONS: Surgeons who specialize in the repair of bile duct injuries achieve much better results than those with less experience. The worse results of other surgeons could be attributed in many instances to specific correctable errors. Nonsurgical treatment was usually unsuccessful and substantially increased the duration of disability.

Adult↗

PubMed1995

Minimally invasive surgery for gastroesophageal reflux disease.

BACKGROUND: The goal of this study was to determine if the outcome of antireflux surgery can be improved by: (1) conducting a careful preoperative workup to characterize gastroesophageal reflux disease (GERD) in the individual patient; and (2) tailoring the operation to the results of the preoperative function tests. PATIENTS AND METHODS: Sixty-eight patients had operations for GERD by minimally invasive techniques. RESULTS: A Rossetti fundoplication was performed in 22 patients. Sixty-eight percent became asymptomatic. Twenty-seven percent developed dysphagia or gas bloat. Thirty-five patients had a Nissen fundoplication. Ninety-one percent are asymptomatic. Eleven patients with severe abnormalities of esophageal peristalsis underwent a Guarner fundoplication with relief of symptoms in 82% of patients. No patients in the Nissen or Guarner group developed postoperative persistent dysphagia or gas bloat. A pyloromyotomy was performed in 3 patients because of severe delayed gastric emptying. CONCLUSIONS: Minimally invasive surgery for GERD gives good-to-excellent results even in patients with abnormal esophageal body function, provided that the operation is tailored to the individual patient based on the results of the preoperative function tests.

Adult↗

PubMed1994

Differences in outer membrane characteristics between gallstone-associated bacteria and normal bacterial flora.

Previous studies with scanning electron microscopy (SEM) have suggested that pigment gallstones contain bacteria. We set out to culture these bacteria and to study their membrane characteristics. We studied gallstones from 54 patients (36 men, 18 women; mean age 55.4 years) admitted consecutively to two hospitals for cholecystectomy. SEM detected bacteria in all of 14 brown pigment stones, 2 of 14 black pigment stones, and in the pigmented centres of 9 of 19 mixed cholesterol stones; no bacteria were detected in 14 pure cholesterol stones or within the cholesterol portions of mixed stones. We were able to culture bacteria from all gallstones with bacteria seen on SEM and for which sufficient material was available (n = 16). 20 bacterial species were recovered from these stones. Gallstones containing bacteria were associated with clinical sepsis and cholangitis. All bacteria obtained from gallstones agglutinated human O P1 erythrocytes, which reflects the presence of P1-specific fimbriae. 5 strains were positive for Forssman-antigen-specific fimbriae. None showed evidence of mannose-specific fimbriae. All of the organisms bound anti-Gal, a ubiquitous naturally occurring IgG specific for alpha-galactosyl residues. The presence of P1 fimbriae and alpha-galactosyl residues and the absence of mannose-specific fimbriae distinguish these organisms from gut flora. We postulate that possession of these unusual properties may enhance the ability of bacteria to colonise the biliary tree and initiate pigment gallstone formation.

Adolescent↗

PubMed1994

Carcinoma of the extrahepatic bile ducts. The University of California at San Francisco experience.

OBJECTIVE: The authors investigated the combined experience of a single institution in treating bile duct carcinoma during the modern era. SUMMARY BACKGROUND DATA: Bile duct carcinomas are notoriously difficult to cure, with locoregional recurrence the rule, even after radical resection. Adjuvant efforts have included various radiation modalities, with limited success. Recently, charged-particle radiotherapy has also been used in these patients. METHODS: The authors performed a retrospective chart analysis of 129 patients with bile duct adenocarcinomas treated between 1977 and 1987 through the University of California at San Francisco, including 22 patients treated at Lawrence Berkeley Laboratory with the charged particles helium and neon. The minimum follow-up was 5 years. Survival, outcome, and complication results were analyzed. RESULTS: Sixty-two patients were treated with surgery alone (S), 45 patients received conventional adjuvant x-ray radiotherapy (S + X), and 22 were treated with charged particles (S + CP). The median survival times were 6.5, 11, and 14 months, respectively, for the entire group, and 16, 16, and 23 months in patients treated with curative intent. There was a survival difference in patients undergoing total resection compared with debulking (p = 0.05) and minor resections (p = 0.0001). Patients with microscopic residual disease had increased median survival times when they were treated with adjuvant irradiation, most markedly after CP (p = 0.0005) but also with conventional X (p = 0.0109). Patients with gross residual disease had a less marked but still statistically significant extended survival (p = 0.05 for S + X and p = 0.0423 for S + CP) after irradiatio CONCLUSIONS: The mainstay of bile duct carcinoma management was maximal surgical resection in these patients. Postoperative radiotherapy gave patients with positive microscopic margins a significant survival advantage and may be of value in selected patients with gross disease.

Adenocarcinoma↗

PubMed1993

Laparoscopic jejunostomy using T-fasteners as retractors and anchors.

We developed a new technique for performing laparoscopic jejunostomies using T-fasteners to secure the jejunum to the abdominal wall. The proximal jejunum is identified with laparoscopy. Four T-fasteners are introduced percutaneously into the jejunal lumen for retraction, and an 8F catheter is inserted through a peel-away introducer via a J-wire. The jejunum is drawn up against the abdominal wall by pulling on the T-fasteners. Tube placement is checked with laparoscopy and roentgenography. We performed laparoscopic jejunostomies in five patients using this method, and the results were excellent. Jejunostomies can be performed safely, easily, and reliably this way.

Adult↗

PubMed1993

Diagnostic laparoscopy and laparoscopic cecostomy for colonic pseudo-obstruction.

Marked cecal dilatation due to colonic psuedo-obstruction (Ogilvie's syndrome) is most often treated by colonoscopic decompression. When this fails, cecostomy is usually indicated if the bowel is not infarcted. We describe a new technique of laparoscopy-guided percutaneous cecostomy using T-fasteners to retract and anchor the cecum to the anterior abdominal wall and using a Foley catheter as a cecostomy tube. We performed this procedure successfully in a patient with colonic pseudo-obstruction who had marked cecal dilatation that could not be decompressed by colonoscopy. Laparoscopic inspection showed that the cecum was viable, and a laparoscopic cecostomy was placed. This procedure can be performed easily and safely and with much less morbidity than laparotomy and open cecostomy.

Aged↗