Biomedical subjects

S Benoist

Publications and source records attributed to S Benoist.

At least 37 records · Page 2Linked to original sources

PubMed2001

Semiautomatic macroencapsulation of fresh or cryopreserved porcine hepatocytes maintain their ability for treatment of acute liver failure.

We have previously demonstrated that fresh or cryopreserved xenogeneic hepatocytes manually macroencapsulated in AN69 polymer and transplanted intraperitoneally in rats were able to improve the survival rate after 95% hepatectomy without immunosuppression. In addition, we developed a semiautomatic device where porcine hepatocytes were coextruded with AN69 hydrogel in order to macroencapsulate large amounts of cells. The purpose of the present study was to 1) test whether transplanted porcine hepatocytes macroencapsulated in this device remained functional as evaluated by their ability to prevent death from acute liver failure, and 2) compare the efficiency of cryopreserved or freshly isolated hepatocytes. Fresh or cryopreserved porcine hepatocytes were macroencapsulated in the semiautomatic device by coextrusion in AN69 polymer in 2-m minitubes containing 6 x 10(7) cells. Acute liver failure was induced in rats by two-step 95% hepatectomy. At the time of completion of liver resection, rats were either not transplanted with minitubes (control group I, n = 13), or were implanted with two minitubes containing culture medium (control group II, n = 11), hepatocytes killed by heat treatment (control group III, n = 10), coextruded fresh hepatocytes (group IV, n = 11), or coextruded cryopreserved hepatocytes (group V, n = 11), without immunosuppression. The survival rate at day 7 was between 0% and 31% in the three control groups. By contrast, coextruded fresh hepatocytes significantly improved the survival rate (group IV, 82%) as did cryopreserved cells (group V, 91% survival). In surviving rats, minitubes were explanted after 20 days; either fresh or cryopreserved hepatocytes appeared morphologically viable and their ultrastructure was preserved. Their detoxification capacities evaluated by the activity of the cyt P450 CYP3A4 were partly maintained. In conclusion, porcine hepatocytes macroencapsulated by coextrusion using a semiautomatic device and transplanted without immunosuppression were able to prevent death from acute liver failure in rats. Cryopreserved cells were as efficient as fresh hepatocytes.

Animals↗

PubMed2000

Transplanted cryopreserved encapsulated porcine hepatocytes are as effective as fresh hepatocytes in preventing death from acute liver failure in rats.

BACKGROUND: An implantable bioartificial liver (BAL) using xenogeneic isolated hepatocytes may be an alternative method to orthotopic liver transplantation for treatment of acute liver failure. The purpose of this study was to demonstrate that not only fresh but also cryopreserved porcine hepatocytes could be used in a BAL to prevent death after the onset of acute liver failure in rats. METHODS: Acute liver failure was induced by two-stage 95% hepatectomy. At the time of completion of liver resection, 100 rats were assigned to undergo or not undergo transplantation into the peritoneum of 4 meters of hollow fibers filled with 60 million either fresh or cryopreserved porcine hepatocytes, or syngeneic hepatocytes, or culture medium, or of 60 million nonencapsulated cryopreserved porcine hepatocytes without immunosuppressive therapy. Survival rates at 7 days were compared between the different groups. RESULTS: In the control groups of hepatectomized animals not receiving encapsulated hepatocytes, 69-79% of the rats died from acute liver failure. The mortality rate was reduced to 15% (2 of 13) in rats receiving fresh porcine hepatocytes (P<0.01), 25% (4 of 16) in rats transplanted with either cryopreserved or syngeneic hepatocytes (P<0.05). Survival rates were maintained when hollow fibers were explanted > or =4 days after hepatectomy. In surviving rats, the weight of the remnant native liver increased with time and returned to the initial weight after 1 month. CONCLUSIONS: The implantable BAL using xenogeneic porcine hepatocytes was able in preventing death from acute liver failure without immunosuppressive therapy. Encapsulated cryopreserved hepatocytes were as effective as fresh hepatocytes.

Animals↗

PubMed2000

Major liver resection for carcinoma in jaundiced patients without preoperative biliary drainage.

BACKGROUND: The role of preoperative biliary drainage (PBD) before liver resection in the presence of obstructive jaundice remains controversial. Our patients with proximal duct carcinoma undergo noninvasive assessment followed by rapid laparotomy without PBD if the lesion is deemed resectable. HYPOTHESIS: Our aim was to report operative outcome of these patients and to analyze their specific features by comparison with patients without biliary obstruction who underwent major liver resection. DESIGN: A case-comparison study. SETTING: A tertiary care university hospital in a metropolitan area. PATIENTS: Twenty consecutive jaundiced patients underwent major liver resection without PBD. The jaundiced patients were matched with 27 nonjaundiced patients with normal underlying liver selected from a computer bank of 261 patients undergoing liver resections and identical for age, tumor size, type of liver resection, and vascular occlusion. MAIN OUTCOME MEASURE: Postoperative course including mortality, morbidity, transfusion rates, and results of liver function tests. RESULTS: Seventeen jaundiced patients (85%) and 13 nonjaundiced patients (48%) received blood transfusions (P = .03). Morbidity was 50% in jaundiced and 15% in nonjaundiced patients (P = .006), mainly resulting from subphrenic collections and bile leaks occurring only in jaundiced patients. In contrast, there were no significant differences for mortality (5% vs 0%) and liver failure (5% vs 0%). Postoperative changes in liver function test results were comparable between groups. CONCLUSIONS: Major liver resections without PBD are safe in most patients with obstructive jaundice. Recovery of hepatic synthetic function is identical to that of nonjaundiced patients. Transfusion requirements and incidence of postoperative complications, especially bile leaks and subphrenic collections, are higher in jaundiced patients. Whether PBD could improve these results remains to be determined.

Adult↗

PubMed2000

A reversible model of acute hepatic failure by temporary hepatic ischemia in the pig.

BACKGROUND: To evaluate new therapies for human fulminant hepatic failure, a suitable large animal model is needed. The purpose of this study was to develop a reversible surgical model of acute hepatic liver failure by transient ischemia in pigs. MATERIALS AND METHODS: Under general anesthesia, an end-to-side portacaval shunt was performed in 17 pigs and tape was laid around the hepatoduodenal ligament. Two days after construction of the functional portacaval shunt, 13 ambulant pigs underwent transient total liver ischemia by tightening of the tape around the hepatoduodenal ligament for 5.5 h. During ischemia, 10% glucose was continuously infused intravenously to prevent hypoglycemia. RESULTS: Ten animals (77%) died with hepatic coma after a mean duration of 22.5 +/- 1.9 h. The 3 remaining animals survived more than 5 days and were sacrificed. In dying animals, encephalopathy was observed 14 +/- 1.7 h after the onset of ischemia. During ischemia, similar progressive decrease of fibrinogen, platelets, prothrombin time, and factors V and VII activities was observed in dying and surviving animals. Just before death, mean prothrombin and factors V and VII activities were respectively 22 +/- 2, 21 +/- 4.4, and 24 +/- 5%. At 22 h, plasma ammonia and lactate levels were respectively 705 +/- 93 micromol/L and 10.5 +/- 0.4 mmol/L in dying animals and 249 +/- 75 micromol/L and 2.9 +/- 0.1 mmol/L in surviving animals (P < 0.01). Estimation of the percentage liver cells necrosed was 74 +/- 4.7% in the survivors and 86 +/- 5.5% in animals who died of hepatic coma (NS). CONCLUSIONS: This model is reproducible and reversible and should allow the quantitative evaluation of new technologies, such as bioartificial liver, for the support of hepatic failure in humans.

Acute Disease↗

PubMed2000

Impact of obesity on surgical outcomes after colorectal resection.

BACKGROUND: As the impact of obesity on surgical outcomes after colorectal resection is not well known, this study was designed to compare the results of colorectal resection in obese and nonobese patients. METHODS: From 1990 to 1997, 584 consecutive patients underwent elective colorectal resection in our department. Of these, 158 (27%) were obese (body mass index >27). Obese and nonobese patients were well matched for demographic data and surgical procedures. RESULTS: After right or left colectomy, no difference was noted between obese and nonobese patients for overall mortality, morbidity, or leakage rates. However, after left colectomy, postoperative intra-abdominal collections requiring treatment were significantly more frequent in obese than in nonobese patients (10% versus 2%; P <0.05). After proctectomy, the mortality rate was 5% (3 of 61) among obese patients and 0.5% (1 of 185) among nonobese patients (P <0.02). The anastomotic leakage rate was 16% (5 of 58) for obese patients and 6% (11 of 169) for nonobese patients (P <0. 05), and the corresponding proportions of transfused patients were 43% and 19%, respectively (P <0.02). After proctectomy, multivariate analysis showed that for obese patients, diabetes mellitus (P <0.05) and American Society of Anesthesiologists (ASA) status >2 (P <0.05) were significant risk factors for anastomotic leakage; age >60 years (P <0.01) and ASA status >2 (P <0.05) were significant risk factors for perioperative blood transfusions. CONCLUSIONS: Our study suggested that, for obese patients, (1) right colectomy can be performed in the same manner as for nonobese patients; (2) after left colectomy, abdominal drainage may be indicated, and (3) after proctectomy, a defunctioning stoma should be recommended when diabetes mellitus or ASA status >2 is present, and an autologous blood transfusion could be discussed for patients >60 years old or with ASA status >2.

Aged↗

PubMed2000

[Median and long-term complications of splenectomy].

Splenectomy was one of the most common operations in abdominal surgery. During the past decade, an increased rate of late complications, especially septic and thromboembolic complications occurring after splenectomy, have been reported. The septic complications are well documented. The risk is related to the indication of splenectomy, and is less than 1% in adults without immunodeficiency. However, these overwhelming postsplenectomy infections are associated with a high mortality rate, about 50%. The best treatment of these infections is preventive measures which are based on vaccination and education of asplenic patients. The thromboembolic complications are rare, little studied, and specific preventive procedures have not been implemented.

Adult↗

PubMed2000

Semiautomatic macroencapsulation of large numbers of porcine hepatocytes by coextrusion with a solution of AN69 polymer.

We have previously demonstrated that allogenic and xenogenic hepatocytes macroencapsulated manually in AN-69 polymer and transplanted intra-peritoneally in rats remained viable for several weeks. However, this manual technique is inadequate to encapsulate several billions of hepatocytes which would be required to correct hepatic failure in big animals or humans. In the present study, we developed an original semiautomatic device in which isolated pig hepatocytes and the polymer solution containing 6% poly(acrylonitrile-sodium methallylsulfonate), 91% dimethylsulfoxide and 3% 0.9% NaCl solution were coextruded through a double-lumen spinneret. The extruded minitube (inner diameter: 1.8 mm, wall thickness: 0.07-0.1 mm) containing the encapsulated hepatocytes fell and coiled up in a 0.9% NaCl solution at 4 degrees C and was cut down in 4 m units containing about 120 million hepatocytes. This process allowed to encapsulate 50 million hepatocytes by minute with a preserved immediate cell viability (92 +/- 5%). To test prolonged cell viability after coextrusion, the minitubes were implanted intraperitoneally in rats. Three and seven days after implantation, they were explanted and analyzed. Cells were viable and well-preserved. Therefore, the semiautomatic device appears able to efficiently macroencapsulate in a limited time several billions of porcine hepatocytes which remain viable after transplantation in xenogenic conditions.

Acrylic Resins↗

PubMed2000

Seven hundred forty-seven hepatectomies in the 1990s: an update to evaluate the actual risk of liver resection.

BACKGROUND: Recent reports highlighting reduced mortality rates to less than 1% after hepatic resections have evaluated the management of selected patients. The current risk of liver resection in unselected patients needs to be more clearly defined to appreciate the actual risk of new indications. STUDY DESIGN: From 1990 to 1997, 747 consecutive patients, including 16 operated in emergency, underwent hepatic resection. Resection was indicated for malignancy in 473 patients (63%). Major resections were performed in 333 patients (45%). An underlying liver disease, including cirrhosis (n = 239) and obstructive jaundice (n = 4), was present in 253 patients (35%). Multivariate analysis of the risk factors for postoperative mortality, morbidity, and transfusion after stratifying patients for the circumstance of the operation and the pathological changes of the remnant liver was performed. RESULTS: There was no intraoperative death and the overall mortality rate was 4.4%. This rate was 25% after emergency liver resection and 3.9% after elective liver resection (p < 0.001). After elective resection, mortality was significantly higher in patients with cirrhosis (8.7%) or obstructive jaundice (21%) than in patients with a normal liver (1%; p < 0.001). Analysis of this subgroup of 478 patients with normal liver showed that the mortality rate was 0% in 220 patients operated for a benign disease and in 263 patients who underwent minor resections. All five deaths occurred in patients with a malignancy and resulted from extrahepatic complications. In patients with a malignancy, the only independent predictor of death was an associated extrahepatic procedure. The incidence of postoperative complications was 22% and was influenced by the American Society of Anaesthesiology (ASA) score, extent of resection, presence of a steatosis, and an associated extrahepatic procedure. The incidence of major complications was 8% and of reoperation 3%. Perioperative blood transfusion was required in 112 of 478 (23%) and was not associated with increased mortality. CONCLUSIONS: The 1% basic risk of elective liver resection on normal liver suggests that indications of resection for malignancy could be extended, unless an associated extrahepatic procedure is needed. Because of this low basic risk, future studies evaluating resection on normal liver should not consider in-hospital mortality as the only end point.

Adolescent↗

PubMed1999

Plain abdominal radiography as a routine procedure for acute abdominal pain of the right lower quadrant: prospective evaluation.

The aim of this prospective study was to determine whether plain abdominal radiographs (PAX) are helpful in the management of adult patients presenting with acute pain of the right lower quadrant (RLQ). A questionnaire was filled in for each patient admitted to our hospital for acute abdominal pain of the RLQ, before and after PAX were obtained. The initial questionnaire indicated the suspected diagnosis and a provisional therapeutic option. A total of 104 consecutive patients were included in this study, 76 of whom underwent surgery. The negative laparotomy rate was 22%. PAX changed the suspected diagnosis and management for six patients (6%), leading in one case to negative laparotomy. Of the remaining five patients, three were operated (two for acute appendicitis and one for small bowel obstruction), and two were treated conservatively for ureteral calculi. This prospective study seems to demonstrate that the indiscriminate use of PAX is not helpful for most patients with acute pain of the RLQ. However, it may be performed in selected patients with clinically suspected small bowel obstruction or urinary symptoms.

Abdomen, Acute↗

PubMed1999

Is there a role of preservation of the spleen in distal pancreatectomy?

BACKGROUND: The spleen may be preserved during distal pancreatectomy (DP) for benign disease. The aim of this retrospective study was to compare the postoperative course of DP with or without splenectomy. STUDY DESIGN: From June 1992 to June 1997, 40 adult patients without chronic pancreatitis underwent elective DP for benign lesions. Fifteen underwent spleen-preserving DP (Conservative Group) and 25 DP with splenectomy (Splenectomy Group). In spleen-preserving DP, we attempted to preserve the splenic artery and vein. RESULTS: Spleen-preserving DP was successfully performed in all 15 cases. Patient groups were comparable for clinical features, indication for DP, and surgical procedure. There were no postoperative deaths. The overall incidence of pancreatic fistula was 23%, but was significantly higher in the Conservative Group (40%) than in the Splenectomy Group (12%; p < 0.05). Subphrenic abscesses were more frequently observed in the Conservative Group than in the Splenectomy Group (p < 0.05). The mean duration of postoperative hospital stay was 19 days (range 6 to 46 days) in the Conservative Group and 12.5 days (range 7 to 45 days) in the Splenectomy Group (p < 0.05). At the end of mean followup of 30 months (range 8 to 40 months), no severe postsplenectomy sepsis was observed in the Splenectomy Group. CONCLUSIONS: In our experience, DP with splenectomy has a lower morbidity rate and we consider it to be the best procedure for benign pancreatic disease.

Adult↗

PubMed1999

Surgical treatment of anoperineal Crohn's disease: can abdominoperineal resection be predicted?

BACKGROUND: Anoperineal Crohn's disease (APCD) runs an unpredictable course. Although this course is relatively benign in most patients, some will eventually require abdominoperineal resection (APR). The aim of this study was to identify prognostic factors of longterm APR in patients with APCD. STUDY DESIGN: From 1980 to 1996, 119 patients were operated on for APCD (mean +/- SD age 30 +/- 13 years; range 11 to 96 years). Patients were divided into two groups: those undergoing APR and patients without APR at the end of followup. The following prognostic criteria were studied: (1) age at onset of Crohn's disease (CD) and at the first manifestation of APCD, gender, APCD as the first manifestation of CD, and interval between the onset of CD and the first manifestation of APCD; (2) for the first manifestation of APCD, the type and number of lesions and the results of surgical treatment; and (3) associated intestinal localizations of CD and the type and number of manifestations of APCD during followup. RESULTS: Mean followup from the first manifestation of APCD was 93 months (range 1 to 398 months). At the end of followup, 30 patients had undergone APR (25%). Logistic regression analysis showed that four criteria seemed to be associated with an increased risk of APR: age at first APCD (p < 0.02), fistula as the first manifestation of APCD (p < 0.04), more than three APCD lesions during followup (p < 0.01), and rectal involvement by CD (p < 0.000001). When, as in eight patients, these criteria were all present, APR was performed during followup in 100% of patients. In the absence of all four criteria (eight patients), APR was never performed. CONCLUSIONS: This study allowed us to identify patients with APCD at high risk of APR. For these patients, early prevention of CD recurrence should be attempted by aggressive medical therapy.

Adolescent↗

PubMed1999

Optimal duration of urinary drainage after rectal resection: a randomized controlled trial.

BACKGROUND: Voiding dysfunction is frequently observed after rectal resection and justifies urinary drainage. However, there is no agreement about the optimal duration of this postoperative drainage. The aim of this controlled trial was to compare 1 versus 5 days of transurethral catheterization after rectal resection, with special reference to urinary tract infection and bladder retention. METHODS: One hundred twenty-six patients undergoing rectal resection were included in a prospective randomized study designed to compare the results for patients undergoing 1 day of transurethral catheterization after rectal resection (1-day group) with those for patients undergoing 5 days' catheterization (5-day group). RESULTS: Patients were randomly assigned to the 1-day and 5-day groups (n = 64 and 62, respectively). Clinical findings and surgical procedures were comparable in both groups. Acute urinary retention occurred in 16 patients (25%) in the 1-day group versus 6 (10%) in the 5-day group (P < .05). Urinary tract infection was observed in 13 of 64 patients (20%) in the 1-day group versus 26 of 62 (42%) in the 5-day group (P < .01). Multivariate analysis revealed that after 1 day of catheterization carcinoma of the low rectum and lymph node metastasis were significant risk factors for acute urinary retention (P < .05 for both factors). After selection of patients without low rectum carcinoma, the acute urinary retention rate was comparable in both groups (14% in the 1-day group versus 7% in the 5-day group), but the urinary tract infection rate was significantly lower in the 1-day group versus the 5-day group (14% vs 40, P < .01). CONCLUSIONS: Our controlled study showed that after rectal resection 1 day of urinary drainage can be recommended for most patients. Five-day drainage should be reserved for patients with low rectal carcinoma.

Aged↗

PubMed1999

[Three cases of diverticular perforation of the caecum and ascending colon].

Perforation of the ascending colon secondary to diverticulitis is an uncommon surgical emergency. It is usually diagnosed during exploratory laparotomy for suspected appendicitis. We report three cases of cecal perforation due to diverticulitis. Imaging work-up, especially computed tomography can establish the preoperative diagnosis of cecal diverticulitis and guide its management.

Adult↗

PubMed1999

[What is new in the surgical treatment of rectal cancer?].

Rectal adenocarcinoma is a common cancer. Substantial advances in surgical technique and adjuvant treatments usually allow to preserve sphincter function, without overruling oncologic surgery standards. Sexual function is usually preserved, except in patients with locally advanced tumors. There is sound evidence that complete removal of the mesorectum and local radiation therapy decrease the rate of local recurrences. Quality of functional results after colorectal versus coloanal anastomosis is compared, and the contribution to patient comfort of construction of a reservoir is evaluated.

Adenocarcinoma↗

PubMed1998

New treatment for ileal pouch-anal or coloanal anastomotic stenosis.

Persistent anastomotic stricture following ileal pouch-anal or coloanal anastomoses can be treated by transanal resection using a stapler or a more complex procedure, such as transanal pouch advancement with neoanastomosis. We propose an easier and faster technique, which does not require any particular device. Its long-term functional results are satisfactory in most patients.

Adult↗

PubMed1998

Long-term results after curative resection for carcinoma of the gallbladder. French University Association for Surgical Research.

BACKGROUND: The surgical management of gallbladder carcinoma is controversial, especially as regards the indications for radical resection. The aim of this study was to evaluate the results of surgical treatment for gallbladder carcinoma with special reference to the extent of its histological spread. METHODS: Eighty-six patients from 25 French centers underwent resection for cure and were included in this study. They comprised 65 women and 21 men (mean age 65 +/- 21 years). Resection included radical resection in 21 patients (partial hepatectomy, regional lymphadenectomy, and common bile duct resection) and simple cholecystectomy in 65. RESULTS: There were 3 postoperative deaths (3.5%). The mean follow-up period was 25 +/- 24 months. The overall 5-year actuarial survival rate was 26%. The 5-year actuarial survival rate was 27% for patients who had radical resection. Eight patients with nodal metastasis had a 5-year survival rate of 0%, but the rate for 13 patients without such metastasis was 43% (P <0.05). For patients undergoing simple cholecystectomy, the 5-year actuarial survival rate was 44% for stage I disease, 22% for stage II, and 0% for stage III (P <0.05). CONCLUSIONS: In patients with stage I gallbladder carcinoma, outcome is good after cholecystectomy only. In stages II to IV, radical resection should only be considered in the absence of regional lymph node metastasis.

Adenocarcinoma↗

PubMed1997

Common bile duct stenosis caused by chronic pancreatitis after liver transplantation for alcoholic cirrhosis.

BACKGROUND: The prevalence of chronic pancreatitis in patients with alcoholic cirrhosis ranges from 7% to 11% and is not considered a contraindication for liver transplantation. METHODS: Among 59 liver transplant recipients grafted for alcoholic cirrhosis, we report two observations of common bile duct stenosis due to chronic pancreatitis. RESULTS: In both cases, pretransplant work-up disclosed no clinical or radiological evidence of chronic pancreatitis. The diagnosis of common bile duct stricture was made 6 and 60 months after liver transplantation. One patient was reoperated upon, and his choledochocholedochostomy was converted into a Rouxen-Y choledochojejunostomy. The second patient experienced metastatic laryngeal carcinoma and died before reoperation. CONCLUSIONS: These observations suggest that common bile duct stricture caused by chronic pancreatitis may occur after liver transplantation for alcoholic cirrhosis, even after a long-standing history of abstinence.

Adult↗

PubMed1997

Functional outcome after coloanal versus low colorectal anastomosis for rectal carcinoma.

BACKGROUND: The aim of this study was to compare retrospectively the longterm functional results of straight or J-pouch coloanal anastomosis and low colorectal anastomosis in patients operated for rectal carcinoma. STUDY DESIGN: Of the 260 patients who underwent rectal resection for carcinoma in our department during a 12-year period, 105 were included in this study. Of these, 37 had straight coloanal, 15 J-pouch coloanal, and 53 low colorectal anastomoses. RESULTS: At 1 year of followup, continence was significantly better after low colorectal than straight coloanal anastomosis (perfect continence: 81% versus 51%; p < 0.01). No significant difference was observed for continence after J-pouch coloanal and low colorectal anastomosis. Stool frequency during a 24-hour period was significantly higher after straight coloanal anastomosis than after either J-pouch coloanal (p < 0.05) or low colorectal anastomosis (p < 0.01). Night stools were significantly more frequent after straight than J-pouch coloanal anastomosis (p < 0.05). Three years after surgery, continence had improved in the three groups, as 70% of the straight coloanal group, 91% of the J-pouch coloanal group, and 94% of the colorectal anastomosis group had perfect continence (p < 0.02 versus straight coloanal anastomosis). No significant difference for continence was observed between the J-pouch coloanal and low colorectal anastomosis groups. Neither were significant differences observed among the three groups for urgency, gas/stool discrimination, stool frequency (including night stools), or the need for medication. CONCLUSIONS: The functional results of both J-pouch coloanal and low stapled colorectal anastomosis seem better than those of straight coloanal anastomosis. Both J-pouch and low-stapled procedures can safely be proposed for patients with rectal carcinoma requiring total mesorectal rectal excision; however, because low stapled colorectal anastomosis seems to us easier and faster to perform, we consider it the best option for rectal reconstruction after proctectomy for carcinoma, provided it is possible based on the level of the tumor.

Anal Canal↗