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Biomedical subjects

G Mentha

Publications and source records attributed to G Mentha.

At least 145 records · Page 8Linked to original sources

[Who are the candidates for liver transplantation?].

Over the past 12 years, new immunosuppressive agents, better knowledge of anesthesiology and postoperative reanimation as well as refinement in surgical technics modified the indications for and results of orthotopic liver transplantation (OLT). At the beginning of the OLT era, liver tumors that could only be removed by total hepatectomy were one of the most frequent indications. Nowadays, this indication is mostly abandoned in view of a high rate of recurrence and poor long-term results. In contrast, the prognosis of fulminant hepatic failure has been dramatically improved by OLT, once efficient organization systems allowed adequate organ supply and emergency transplantation within a few hours. Three main groups of diseases (cholestatic diseases, inborn errors of metabolism and parenchymal diseases) can be treated by OLT with excellent results (actuarial survivals of 80 to 90% have been reported at one and 2 years). Later graft dysfunction is rare except for virus B recurrence. Primary biliary cirrhosis and the group of inborn errors of metabolism are regarded as the optimal indications of OLT in adults and children respectively. Precocious evaluation of patients, before advanced stages of the disease associated with multiple complications, should prevent them from dying on a waiting list and decrease operative as well as early postoperative risks. Not only does OLT provide mere survival (among 5 patients with lethal hepatic disease, 4 are alive at 2 years from OLT), it also provides a regained quality of life with a virtually normal (for the price of a daily medication intake) family, professional and sportive life. Such achievements prompt us today to propose early transplantation to these patients.

Contraindications↗

[Impact of organ shortage on the transplantation program].

The purpose of the study was to evaluate the consequences of a recent progressive shortage of donor organs on our different transplant programs. Although the waiting time before transplantation remained in general relatively short (4.6 [mean], 0-3, 0-10 months for renal, liver and heart transplantation, respectively), patients started to accumulate on our waiting list during the last year (1990) of the study (kidney transplantation). Furthermore some patients clearly deteriorated, other died awaiting transplantation (18% and 15% of the patients listed for liver and heart transplantation, respectively). In emergency, organs were provided most often by neighbouring foreign centers. Given these facts adhesion to supranational donor networks should be considered.

Humans↗

[Orthotopic liver transplantation--indications and results].

Indications for and results of orthotopic liver transplantation (OLT) were modified over the past ten years by new immunosuppressive agents, earlier timing of transplantation and better knowledge of potential complications. In 1990, OLT appears justified in the treatment of all liver disease threatening life, in the absence of contraindications and other possible treatments. Between July 1987 and December 1990, 21 patients were transplanted at the Geneva University Hospital. Three children received part of an adult liver (two or three segments), using the reduced-size liver transplantation technique. Four OLTs had to be performed in an emergency situation. Two patients died within six months of transplantation, one after 7.5 months, and the last patient died after one year from cancer recurrence. 17 patients are presently alive (81%) at 4 to 39 months (median 14 months) following OLT. More than the mere survival, however, the quality of life regained after transplantation prompts us to consider transplantation early in the progress of the disease.

Adolescent↗

[Surgical treatment of hepatic hydatidosis].

Between January 1981 and December 1990, 41 patients were operated on for hepatic hydatid disease, representing 18% of the overall surgery for liver disease performed in our institution during the same period of time. The mean age of the patients was 39.5 years (range 17-71 years), 24 were females and 17 males. The most common clinical sign was abdominal pain (59%) with 3 patients jaundiced at the time of admission. 2 patients suffered from acute rightsided pneumonia, one of them with a very important productive cough due to bronchial perforation of the hydatid cyst of the liver. One patient was admitted due to anaphylactic shock with collapse. For 14 patients (34%) the discovery of the disease was casual, either by clinical hepatomegaly or by X-ray investigations performed for other reasons. We performed 18 pericystectomies, 4 subtotal pericystectomies and 16 liver resections. Only 3 patients were treated by partial cystectomy with removal of the prominent part of the cyst. Several other surgical procedures were performed concomitantly, including 2 pulmonary lobectomies, 1 cystojejunostomy, and pericystectomies for other hepatic or extrahepatic localizations of hydatid cysts. Rupture of the cyst into the bile duct was diagnosed in 13 patients. One patient presented with a peritoneal rupture of the cyst and 2 patients had a fistula through the diaphragm into the pleural cavity. Our postoperative morbidity is acceptable (10 patients, 25%). A bilioma and a biliary leak were successfully treated by percutaneous drainage, a postoperative hemorrhage required surgical treatment, four patients experienced pulmonary complications and the three others minor wound abscesses.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

[Ischemic colitis. Results of conservative treatment].

34 consecutive patients were admitted for ischemic colitis confirmed by colonoscopy, contrast enema, laparotomy, and/or post-mortem between 1984 and 1988. 13 underwent excisional surgery, usually at an early stage, because of acute abdomen. This study is devoted to the remaining 21 patients (62%), i.e. nearly two thirds of the whole series, who were treated conservatively (intravenous hydration and antibiotics). Our results suggest that (1) ischemic colitis usually affects elderly patients in whom an underlying cardiovascular disease is seldom found; (2) the right colon is infrequently involved, and (3) outcome is generally favorable in the absence of superimposed major pathology or of peritoneal signs which would require surgical exploration.

Adult↗

[Experience with a surgical mesh covering a hepatectomy incision].

A polyglycolic acid net (Vicryl) has been applied against the hepatectomy section of 27 patients (14% of all our liver resections) to complete its hemostasis. The indications for the use of this net were: the persistence of blood oozing and/or the necessity to shorten the operation. In one patient suffering from severe coagulopathy, active bleeding continued until the patient died; another patient bled until his blood dyscrasia was corrected. One case of abscess was encountered, and treated through a percutaneous approach. Although the achievement of perfect hemostasis is usual in surgical exeresis of the liver, a minority of patients can present with resistant bleeding of the resection slice, for which packing with a net may prove to be useful.

Adult↗

[Results of surgical treatment of ischemic colitis].

Between January 1984 and December 1989, 13 patients, aged 39 to 89 (median 63), underwent surgery for histologically proven ischemic colitis. Most suffered from pre-existing cardiovascular conditions (2 shortly after surgery for aortic aneurysm). One patient developed ischemia after the traumatic avulsion of the ileocolic artery and another after the spontaneous reduction of a strangled inguinal hernia. Diagnosis of ischemic colitis was made prior to operation in 4 instances only. The left colon was affected 5 times and the right colon 8 times (with the terminal coil of ileum 3 times). Treatment always consisted in segmental colectomy; laparotomy was used in 3 patients (2 to 7 reoperations). Colon anastomosis was performed directly 5 times, while 4 patients had secondary stomy closures; 2 patients still have their original stomy. Two patients died (15%), one of sepsis and the other following broncho-aspiration. The prognosis of ischemic colitis is rather favorable, even at the stage of transmural necrosis, provided all ischemic zones are resected. This is in contrast with the severe mortality of mesenteric infarcts, when extensive small bowel necrosis is found in association with colonic ischemia.

Colectomy↗

[Liver transplantation. Preliminary results in the district University Hospital of Geneva].

Between July 1987 and May 1989, 11 liver transplants were performed on 10 patients at the University Hospital of Geneva. Of 15 patients evaluated for elective transplantation, 10 were accepted and put on the waiting list. 5 patients were rejected because of a contraindication or because another treatment seemed preferable. 8 transplantations were eventually performed. Emergency transplantation was considered for 6 patients, but could be performed in only 3. Indications for transplantation were as follows: one hepatocellular carcinoma in a non-cirrhotic patient, 2 post-hepatitis cirrhoses (one B and one non-A-, non-B), 3 primary biliary cirrhoses, one autoimmune cirrhosis, one primary sclerosing cholangitis, one cirrhosis on alpha-1-antitrypsin deficiency, and one fulminant B-Delta hepatitis. Most of these patients had advanced liver disease and a limited life expectancy. 8 of the 10 patients transplanted are nevertheless alive and none is hospitalized at the present time. More than mere survival, however, quality of life regained after transplantation prompts us to consider transplantation early in the progress of the disease. Earlier evaluation of patients would make transplantation feasible soon after the first complication of the disease. This attitude would probably prevent patients from dying while on a waiting list and decrease operative as well as early postoperative risks. Better information and coordination regarding potential donors is necessary in Switzerland to obtain better results in organ transplantation.

Adult↗

[Results of biliary surgery in a teaching center].

The last few years have seen the introduction of new medical approaches to treatment of gallstone disease. To investigate whether this was the consequence of disappointing results following surgical treatment, we undertook a one-year prospective study at the Clinic of Digestive Surgery in Geneva, a training center with an unselected patient population. From October 1986 to September 1987, 306 biliary operations were performed for calculous disease by 20 surgeons, most of whom were under training. Juniors were supervised by senior surgeons. Operative indications and management were based on the strict criteria established at our center. Over half the patients had suffered one or more complications of gallstone disease. Overall mortality and morbidity were 0.3% and 11.7% respectively. In conclusion, gallstone surgery, which is a definitive treatment, has provided us with very acceptable results and therefore should not be a reason for encouraging other conservative approaches in the treatment of gallstone disease.

Adult↗

Dose requirements and plasma concentrations of pipecuronium during bilateral renal exclusion and orthotopic liver transplantation in pigs.

We have studied five pigs undergoing bilateral clamping of the renal pedicles, seven pigs undergoing orthotopic liver transplantation and three control animals without surgery in order to examine the roles of the kidney and liver in the plasma clearance of pipecuronium. An i.v. infusion of pipecuronium was controlled to maintain a constant 90-95% twitch depression throughout the investigation. The right sciatic nerve was stimulated continuously with supramaximal stimuli at 0.1 Hz and the force of the corresponding evoked isometric muscle contraction was recorded continuously. Control pigs needed an infusion rate of pipecuronium 8-10.7 micrograms kg-1 min-1. In the renal group, it was necessary to reduce the infusion rate of pipe-curonium by about 25% after clamping both renal vascular pedicles (P less than 0.05 compared with controls); in pigs undergoing liver transplantation, it was necessary to reduce the rate by approximately 80% after clamping hepatic vessels (P less than 0.05 compared with controls and from the period after clamping of renal vessels). After hepatic recirculation, the infusion rate of pipecuronium was increased progressively to a rate which corresponded to 50% of baseline values (P less than 0.05 compared with the anhepatic phase and from controls). Plasma concentrations of pipecuronium were comparable in the three animal groups and did not change significantly during the study. These data suggest that the liver plays a more important role than the kidney in the plasma clearance of pipecuronium in pigs.

Androstane-3,17-diol↗

Plasma concentrations of laudanosine, but not of atracurium, are increased during the anhepatic phase of orthotopic liver transplantation in pigs.

To quantify the changes in plasma concentrations of atracurium and laudanosine induced by the lack of hepatic function and circulation, the authors studied nine domestic pigs (22-25 kg) undergoing an orthotopic liver transplantation, and three control animals without surgery, using atracurium as the muscle relaxant. After intubation facilitated by isoflurane 2-3%, anesthesia was maintained with isoflurane (0.5% in oxygen) and fentanyl (4 micrograms.kg-1.hr-1). Ventilation was controlled to keep end-tidal CO2 at 35-40 mmHg, body temperature maintained at 35.5-37.5 degrees C, and arterial pH at 7.35-7.50. The right sciatic nerve was stimulated with a nerve stimulator delivering a single twitch at 0.1 Hz with 0.2-ms duration, at supramaximal stimulation. The force of the corresponding evoked isometric muscle contraction was continuously measured by a force-displacement transducer. A single iv bolus of atracurium (2 mg/kg) was given to obtain a 90-95% twitch depression, followed 5 min later by a constant-rate iv infusion of atracurium at 120 micrograms.kg-1.min-1 maintained during the entire investigation. Blood samples for plasma atracurium and laudanosine concentrations were drawn every 15 min. In the control group, plasma concentrations of atracurium remained stable between 6.5-8.0 micrograms/ml following initial bolus injection; plasma concentrations of laudanosine increased during the first 60 min, then remained stable between 0.69-0.74 micrograms/ml up to the end of the study. In animals undergoing transplantation, plasma concentrations of atracurium remained stable between 10-12 micrograms/ml, despite a 90-min duration of liver exclusion.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

Experimental porcine orthotopic liver transplantation: a training protocol for transplantation in humans.

The authors suggest that, prior to human liver transplantations, exhaustive training be undertaken on an animal model in order to acquire the expertise required for this delicate procedure. The pig has considerable anatomic similarities to man, as well as a comparable physiological and hemodynamic sensitivity, and has been used as a model by our experimental team to perfect our clinical liver transplantation technique. In particular, a surgical model representing the adult donor/child recipient situation has been developed. Anesthesia, extracorporeal bypass procedure and the full surgical protocol are described. This operative protocol was elaborated to mimic as closely as possible the clinical situation. Our model also allowed us to undertake several relevant physiological and pharmacological studies during the transplantation procedure.

Animals↗