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Biomedical subjects

M Gagner

Publications and source records attributed to M Gagner.

At least 19 recordsLinked to original sources

A porcine model for laparoscopic adrenalectomy.

Laparoscopic adrenalectomy has been successfully performed and described in humans. Though it is presently not widely employed it offers tremendous potential for adrenal surgery. It remains, however, an advanced technique requiring demonstration and practice. The aim of this study is to develop a porcine model of adrenalectomy for teaching and advancing the technique applicable to human surgery. Five female pigs weighing 10-20 kg underwent bilateral adrenalectomy by the lateral approach using endotracheal intubation. The left adrenal was resected with the pig in the right decubitus position. The animal was repositioned to left decubitus and the right adrenal was resected. In each case four 10-mm trochars were placed over the respective flanks. There was no need to mobilize the colon or liver (in the pig model). The peritoneum over each gland was incised and the gland dissected in a cephalocaudal manner. The vessels were ligated and divided particularly those from the vena cava. Upon completion blood loss (< 100 cc) and operating times (mean 60 min for the left and 90 min for the right) were assessed and the animal was sacrificed. The glands were weighed (mean 1.23 g R and 1.15 g L) and measured. Using this model, experience is gained in positioning the subject as well as trocars, in fine dissection in a lateral orientation, and in techniques of hemostasis. Although porcine and human adrenal anatomy differ in some details the pig constitutes an excellent model for the development of the technical experience required to perform adrenalectomy in humans.

Adrenalectomy

Percutaneous stent placement for treatment of stenosis of a portacaval H-graft shunt.

Surgical treatment of an occluded or stenotic portacaval shunt carries a high risk of mortality, but the rate of restenosis after transluminal angioplasty is also high. The authors report high-grade stricture of a portacaval H-graft shunt in a 51-year-old man, who presented with hematemesis and melena. The patient was treated with concomitant balloon angioplasty and placement of a metallic stent through a percutaneous venous approach. The procedure was tolerated well by the patient, and stenosis had not recurred at follow-up 1 year later.

Angioplasty, Balloon

A robotic camera for laparoscopic surgery: conception and experimental results.

The aim of this project was to replace the surgical assistant for common laparoscopic procedures with a robotic camera. The motions of the human camera operator were defined and expressed mathematically by a spherical displacement model. A revolving robotic arm with six degrees of freedom was employed in conjunction with this model as an automated camera in the performance of cholecystectomy, Taylor and Nissen procedures in animals, and cholecystectomy in humans. It represents a first step toward the introduction of robotic technology in laparoscopic surgery.

Animals

Laparoscopic adrenalectomy. The importance of a flank approach in the lateral decubitus position.

Adrenalectomy is usually performed via transabdominal or posterior approaches. Unfortunately, both approaches are associated with painful postoperative syndromes. Recently, laparoscopic surgery was applied to organ removal. During a period of 12 months, we performed a series of successful laparoscopic adrenalectomies (10 of the right and 11 of the left gland). The pathologies were medullary cyst (1), angiomyolipoma (1), DHEAS hyperplasia (1), primary aldosteronism (2), Cushing's adenoma (3), pheochromocytoma (4), Cushing's syndrome (4), and nonfunctional adenoma (5). A flank approach was taken with four 11-mm trocars. Electrocautery and blunt forceps were used for dissection. The vessels were secured with medium-large titanium clips, and the adrenal was removed in a sterile plastic bag. The average operating time was 2.3 h, and median postoperative stay was 4 days. Two patients required blood transfusion of 2 units postoperatively. We believe this technique is adequate for the surgical removal of adrenal tissue, resulting in less postoperative pain and in rapid recovery. It may also change the surgical management of asymptomatic adrenal lesions.

Adrenal Gland Diseases

Laparoscopic pylorus-preserving pancreatoduodenectomy.

A case of chronic pancreatitis localized in the head of the pancreas with pancreas divisum was treated by laparoscopic pylorus-preserving pancreatoduodenectomy. The laparoscopic technique of resection and reconstruction with a gastrojejunostomy, hepaticojejunostomy, and pancreaticojejunostomy is described. The postoperative period was complicated by a jejunal ulcer and delayed gastric emptying necessitating a prolonged hospitalization and intravenous hyperalimentation. No fistulas occurred, a follow-up CT scan revealed no pancreatic abnormalities, and the patient was discharged in good condition on the 30th postoperative day. Although technically feasible, the laparoscopic Whipple procedure may not improve the postoperative outcome or shorten the postoperative recovery period.

Adult

Malignant biliary obstruction: preliminary results of palliative treatment with hepaticogastrostomy under fluoroscopic, endoscopic, and laparoscopic guidance.

PURPOSE: To report a technique of peripheral biliary decompression by means of anastomosis of a bile duct in segment II of the liver to the lesser curvature of the stomach. MATERIALS AND METHODS: Seven patients with unresectable biliary neoplasm were treated. After transhepatic catheterization of a segment II bile duct, the left lobe of the liver and the lesser curvature of the stomach were perforated under fluoroscopic and laparoscopic guidance. Anastomosis between the biliary tree and the stomach was maintained with a gastrostomy tube placed across the tract. After 2 weeks, the tube was removed and patency of the tract was preserved with a metallic stent. RESULTS: Three patients died, at 3, 6, and 9 months, respectively, without reocclusion; the other four were alive at 5 months without jaundice. One patient had an episode of cholangitis, which was resolved with antibiotic therapy. CONCLUSION: This method yields a good patency rate with few problems. Further investigation is required to evaluate long-term patency and the necessity of laparoscopic guidance.

Aged

Effects of posture on the coordination of respiration and swallowing.

1. Although a pause in respiration during swallowing is a feature common to all mammals, inhibition usually occurs during expiration in adult humans and during inspiration in most other species. We tested the hypothesis that this difference is due, at least in part, to the position of the body while feeding. 2. The coordination of respiration and swallowing was studied in adult human subjects in two body positions; upright, which is typically human, and on hands and knees, which is similar to the feeding posture of most other animal species. 3. Our major finding was that the respiratory phase in which swallowing occurred was significantly related to posture. Swallows tended to occur late in the expiratory phase while feeding upright, but during early expiration while on all fours. 4. We speculate that the phase of respiration in which swallowing occurs changes with posture to compensate for the alterations in the mechanical properties of the upper body.

Animals

Diaphragmatic and abdominal muscle activity after endoscopic cholecystectomy.

We studied diaphragmatic and abdominal muscle activity immediately and 16 h after laparoscopic cholecystectomy (LAPC). Tidal volumes (VT), partitioning of VT between the rib cage and the abdomen, and esophageal, gastric, and transdiaphragmatic pressures were recorded for 5 min every 15 min up to 90 min after the end of anesthesia in 10 young patients submitted to an elective LAPC. All had chest radiographs in full inspiration and expiration as well as lung function tests (LFTs) before and 16 h after surgery. In 5 of the 10 patients, thoracoabdominal patterns of breathing were also measured before both LFTs. After LAPC, VT did not change. There was no significant shift from abdominal to thoracic respiration. No paradoxical respiration developed. Functional residual capacity (FRC) and residual volume (RV) remained normal. However, all measures of LFTs requiring maximum inspiratory effort decreased up to 20%. Tonic and phasic activity of the abdominal muscle appeared early in the recovery period and disappeared after 75 min. The diaphragm adjusted to this additional load so that VT remained constant. These results indicate that diaphragm function is intact during quiet breathing after LAPC, but slightly reduced when maximum effort is needed. However, this represents a net gain over the changes previously described after classic "open" cholecystectomy (OC).

Abdominal Muscles

[Variations of body composition by bioelectric impedancemetry after major surgery].

Body water variations are traditionally measured postoperatively by fluid balance and body weight. Bioelectrical impedance assessment permits the evaluation of body composition, i.e., lean body mass, body fat and total body water. We compared the traditional method (body weight and fluid balance) with bioelectrical impedance assessment while estimating body water. Body weight, fluid balance, resistance, reactance, lean body mass, body fat, total body water, triceps skinfold and total protein blood level were measured prospectively (preop, and on days 1, 3 and 5 postop) in 30 patients admitted for major surgery (thoracic, abdominal or vascular). The results suggest that body composition changed significantly with time (p < .05); in all 3 surgical groups. There was a low correlation between total body water measured by bioelectrical Impedance and fluid balance. Bioelectrical impedance assessment is sensitive to body water changes but appears to overestimate these variations compared to the traditional method.

Blood Proteins

Ultrasonic mucosectomy of the gallbladder. A histological analysis.

The Cavitron Ultrasonic Surgical Aspirator (CUSA) may be used to remove mucosa of organs of the gastro-intestinal tract. A histological analysis was performed on gallbladders treated with a CUSA-mucosectomy to assess the extent and degree of mucosectomy and to evaluate parietal damage. The histological studies performed on three specimens of chronic cholecystitis revealed a complete mucosectomy except in areas where Rokitansky-Aschof sinuses were present. There was no evidence of parietal damage. The CUSA may be used to remove the mucosa of gallbladders without injury to other layers, and may have a potential application in procedures such as mucosal cholecystectomy.

Cholecystitis

Routine operative cholangiography during laparoscopic cholecystectomy: feasibility and value in 107 patients.

OBJECTIVE: Laparoscopic cholecystectomy is becoming a popular alternative to open cholecystectomy. However, the technical aspects of this new procedure increase the risk of injuring the bile ducts. The purpose of this study was to determine the feasibility and value of performing cholangiography during laparoscopic cholecystectomy. MATERIALS AND METHODS: We retrospectively reviewed the clinical and operative cholangiographic findings of the first 107 patients undergoing laparoscopic cholecystectomy at Hôtel-Dieu de Montréal between August 1990 and August 1991. RESULTS: Operative cholangiography was attempted in 98% of patients; the success rate was 71%. Eight anatomic anomalies of the biliary tract that were of surgical importance were found as well as 10 cases of stones in the common bile duct, eight of which were unsuspected. No biliary tract injuries occurred. With experience, surgical cannulation of the cystic duct for injection of contrast material can be done quickly without major difficulty, and cholangiograms of excellent diagnostic quality can be obtained. CONCLUSION: Our results show that operative cholangiography is feasible and useful in patients undergoing laparoscopic cholecystectomy.

Bile Ducts

Early experience with laparoscopic approach for adrenalectomy.

BACKGROUND: Adrenalectomy performed by a posterior or transabdominal approach causes substantial postoperative pain. The purpose of this study was to evaluate laparoscopy as a potential approach for adrenalectomy. METHODS: We performed 25 consecutive laparoscopic adrenalectomies on 22 patients from April 1, 1992, to March 30, 1993. Laparoscopic surgery was performed by using a lateral decubitus flank approach with four 11 mm trocars. RESULTS: Twelve right and 13 left adrenal glands were removed in a mean time of 2.3 hours. Three patients underwent bilateral adrenalectomies in a mean time of 5.3 hours. The 15 women and 7 men range in age from 31 to 60 years (mean, 42 years). The adrenal gland diseases were nonfunctional adenoma (seven), pheochromocytoma (five), Cushing's disease (four), Cushing's adenoma (four), primary aldosteronism (two), dehydroepiandrostenedione sulfate hypersecretion (one), angiomyolipoma (one), and medullary cyst (one). Average tumor size was 4.1 cm (range, 1 to 15 cm). Laparoscopic adrenalectomy was successful in 96% of patients, with one patient requiring a laparotomy because of inadequate exposure. The median postoperative stay was 4 days (range, 2 to 19), with a mean of five narcotic injections. There were no deaths, and morbidity was minor. CONCLUSIONS: Laparoscopy can be used successfully for adrenalectomy. It produces less postoperative pain and rapid return to normal activity. It may be the preferred method for removing most adrenal gland lesions that require operation.

Adrenal Gland Diseases

Intra-abdominal sepsis and adrenergic receptor response.

This study measured the adrenergic receptor response of 13 patients with severe intra-abdominal sepsis, who required laparotomy and an open abdominal closure with Marlex mesh. The source of the sepsis was gram-negative organisms of intestinal origin. There were seven survivors and six nonsurvivors. When the patients were stratified into survivors and nonsurvivors, the Septic Severity Score, the APACHE II score, the Acute Physiological Score, and the Glasgow Coma Scale score results were not significantly different between groups. The alpha-2 and beta-1 adrenergic receptor responses were measured in the adipose tissue of the abdominal wall and the small bowel mesentery on day 1 of admission to the intensive care unit. The results demonstrated that the alpha-2 and beta-1 receptors of the nonsurvivors had a significantly decreased receptor response with desensitization and down regulation. The alpha-2 and beta-1 receptors of the survivors had an increased response with hypersensitization and up regulation. This study indicates that the adrenergic receptor pattern is distinctly different between survivors and nonsurvivors with severe abdominal gram-negative sepsis. The pattern differences occurred early (within 24 hours) when the patients had similar physiologic profiles. It is concluded that adrenergic receptor response may be a biologic indicator of the magnitude of the septic injury and a predictor of outcome.

Adipose Tissue

Pylorus-preserving pancreatoduodenectomy--technical aspects.

Pylorus-preserving pancreatododenectomy is the resection of choice for patients with carcinoma of the head of the pancreas and periampullary area and for certain patients with chronic pancreatitis. Preoperative preparation, operative technique, and results are discussed.

Duodenum

Hepatobiliary anomalies associated with polysplenia syndrome.

The report of a 29-year-old woman with polysplenia syndrome, Crohn's disease, and bilateral cataracts is presented. The patient was noted to have a right-sided stomach and small bowel, Crohn's ileitis, and a left-sided colon. Results of roentgenography of the chest and echocardiography were consistent with a diagnosis of hypoplasia of the inferior vena cava with azygos continuation. The patient underwent laparotomy with cholecystectomy, exploration of the common bile duct, and choledochoscopy for cholelithiasis, choledocholithiasis, and chronic cholecystitis. Laparotomy revealed a liver that had two lobes, each with the morphologic appearance of the left lobe. The gallbladder was centrally located. T-tube cholangiography revealed a quadruplication of the intrahepatic biliary ducts. To our knowledge, this patient is the only known adult with this syndrome in whom cholangiography demonstrated isomerism of the biliary tree. A review of the literature on this subject is given with emphasis on biliary anomalies.

Abnormalities, Multiple

Surgical management of nonparasitic cystic liver disease.

We report clinical features, surgical management, recurrences, and follow-up study of 12 patients with simple hepatic cyst, 11 patients with polycystic liver disease, and 19 patients with cystadenoma who were surgically treated over a 25-year period. The median age of patients was 48 years, and 37 women and 5 men were in the series. The most common presenting symptom and physical finding were chronic abdominal pain and tenderness in the right upper quadrant. The most commonly associated disease was polycystic kidney disease, which was an associated finding in 5 of the 11 patients with polycystic liver disease (45%). The most valuable diagnostic studies in all groups were computed tomography and ultrasonography. The location of the disease was bilobar in patients with polycystic liver disease, with a right lobe predominance in 18% of patients. The right lobe was also predominant in 83% of patients with simple hepatic cyst and 58% of patients with cystadenoma. Of all solitary cystic lesions in the left lobe, 75% of them were cystadenomas. Of the 66 surgical procedures performed, aspiration was associated with a failure rate of 100%; partial excision, a failure rate of 61%; and total excision and liver resection, a failure rate of 0%. Orthotopic liver transplantation was performed in three patients and was associated with two early deaths. Partial excision relieved symptoms in three patients (43%) with polycystic liver disease. Total excision, enucleation, or liver resection with cyst(s) is the treatment of choice for non-parasitic cystic lesions of the liver.

Adult