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Biomedical subjects

H Obertop

Publications and source records attributed to H Obertop.

At least 127 records · Page 7Linked to original sources
PubMed1997

No attenuation of ischemic and reperfusion injury in Kupffer cell-depleted, cold-preserved rat livers.

Activated Kupffer cells (KC) have been implicated in the damage sustained by preserved liver grafts during ischemia and reperfusion. The aim of this study was to compare ischemia/reperfusion injury in preserved, KC-depleted rat livers and preserved control livers, with special regard to sinusoidal endothelial cell (SEC) injury. Wistar rats were injected with liposome-encapsulated dichloromethylene diphosphonate, 48 hr before hepatectomy, to eliminate KC, or were withheld this pretreatment (controls). Livers were flushed with cold University of Wisconsin solution and after 0, 8, 16, or 24 hr of storage at 4 degrees C, were reperfused in a recirculation system with 200 ml of oxygenated Krebs-Henseleit solution at 37 degrees C for 90 min. Damage to SEC was measured by the uptake of hyaluronic acid (HA) from the perfusate and release of purine nucleoside phosphorylase (PNP). Perfusate samples were, furthermore, analyzed for aspartate aminotransferase (AST) and tumor necrosis factor-alpha. Carbon particles were infused in the perfusate to determine the phagocytotic capacity of KC. Biopsies were taken for histological examination and sections were stained with ED2 monoclonal antibodies to confirm the absence of KC. After 90 min of reperfusion, immediately after cold flush (t0), the uptake of HA was 72.2+/-2.3% and 69.3+/-1.3% in KC-depleted livers and in control livers, respectively (n.s.). After 8 hr of storage, HA uptake was 21.6+/-4.5% and 34.6+/-8.0%, respectively (n.s.). After 16 and 24 hr of storage and reperfusion, no uptake of HA was found in either KC-depleted or control livers, indicating abolished SEC function. PNP activities in the perfusate were higher in control livers (after 8 and 24 hr of storage), presumably due to release from damaged KC. No difference was found in AST and no tumor necrosis factor-alpha was measured in the perfusates of normal and KC-depleted livers. Electron microscopic studies showed that after 8 and 24 hr of storage and reperfusion, KC were activated and were able to phagocytose colloidal carbon. Our conclusion was that the elimination of Kupffer cells did not result in reduction of ischemic and reperfusion damage in livers preserved up to 24 hr, as assessed in vitro by SEC uptake of HA, PNP release, and AST release.

Animals↗
PubMed1997

Local resection or pancreaticoduodenectomy for villous adenoma of the ampulla of Vater diagnosed before operation.

BACKGROUND: Treatment of ampullary adenoma is complicated by difficult preoperative staging, malignant potential and a high recurrence rate. This study was designed to assess the accuracy of diagnosis and staging by endoscopic biopsy and endosonography, and to compare the results of local resection and pancreaticoduodenectomy (Whipple procedure). METHODS: All 23 patients, diagnosed by endoscopic biopsy and surgically treated by local resection (n = 12) or pancreaticoduodenectomy (n = 11) between 1984 and 1994, were analysed retrospectively. RESULTS: Pancreaticoduodenectomy was associated with more complications (seven of 11 patients versus three of 12) and a longer hospital stay (36 versus 18 days) than local resection. After local resection tumour excision was incomplete in half of the patients. One patient died after a Whipple procedure. Endoscopic biopsy did not identify infiltrating carcinoma in seven of the 23 patients. Endoscopic ultrasonography had a 44 per cent accuracy rate for tumour invasion and was false positive for lymph node metastases in five of 16 patients. After local resection one recurrence was observed during follow-up and one possibly died from tumour recurrence. CONCLUSION: Diagnosis and staging of ampullary adenomas by endoscopic biopsy and endosonography was unreliable. Local resection seems a viable alternative for patients whose general condition does not allow a Whipple procedure.

Adenoma, Villous↗
PubMed1997

Prospective study on the value of endosonographic follow-up after surgery for esophageal carcinoma.

BACKGROUND: Half of the patients who undergo surgery for cancer of the esophagus or gastric cardia present with recurrent disease within 2 years after the operation. We investigated the value of endosonography for the early detection of recurrent disease. METHODS: Forty-three patients entered a follow-up protocol in which endosonography was performed every 6 months within the first 2 years after resection. RESULTS: During 16 of a total of 66 examinations, suspicious abnormalities were found. In three patients free fluid was seen, but recurrence could not be confirmed during follow-up. In eight patients suspicious lymph nodes were seen; six died within 6 months, one was alive with a proven recurrence at 6 months, and one was alive without recurrence at 22 months. In five patients focal wall-thickening or a mass was seen; three died within 6 months, and two were alive with a proven recurrence at 2 and 5 months. After exclusion of free fluid, the positive predictive value of abnormalities on endoscopic ultrasonography (EUS) was 92%. CONCLUSIONS: Endosonography, performed at 6-month intervals after resection of cancer of the esophagus or gastric cardia, is accurate in the early detection of locoregional recurrent disease. Two thirds of the patients were still without symptoms when the recurrence was found.

Adenocarcinoma↗
PubMed1997

Incidence and clinical findings of benign, inflammatory disease in patients resected for presumed pancreatic head cancer.

BACKGROUND: The differentiation between cancer and benign disease in the pancreatic head is difficult. The aim of this study was to examine common features in a group of patients that had undergone pancreatoduodenectomy for a benign, inflammatory lesion misdiagnosed as pancreatic head cancer. METHODS: Among 220 pancreatoduodenectomies performed on the suspiscion of pancreatic head cancer, an inflammatory lesion in the pancreas or distal common bile duct was diagnosed in 14 patients (6%). Of these patients, all preoperative clinical information and radiologic images (ultrasound, endoscopic retrograde cholangio-pancreaticography [ERCP]) were critically reassessed. For each examination, the suspicion of cancer was scored on a 0/+/++ scale. RESULTS: Clinical presentation (pain, weight loss, jaundice) raised a suspicion of cancer in 12 patients. On ultrasound, a tumor (mean size: 2.8 cm) was found in the pancreatic head in 13 patients; 12 of 14 ultrasound examinations raised a suspicion of cancer. ERCP showed a distal common bile duct stenosis (length: 1 to 4 cm), stenosis of the pancreatic duct (length: 1 to 5 cm), or a "double duct" stenosis, suspicious for cancer in 13 evaluable patients. The overall index of suspicion was + in seven patients and ++ in seven patients, confirming the initial interpretation of preoperative data. CONCLUSION: When undertaking pancreatoduodenectomy for a suspicious lesion in the pancreatic head, it is necessary to expect at least a 5% chance of resecting a benign, inflammatory lesion masquerading as cancer.

Cholangiopancreatography, Endoscopic Retrograde↗
PubMed1997

Incidence, risk factors, and treatment of pancreatic leakage after pancreaticoduodenectomy: drainage versus resection of the pancreatic remnant.

BACKGROUND: Pancreatic leakage is a major cause of morbidity and mortality after pancreaticoduodenectomy, with incidences varying between 6-24% and a mortality rate up to 40%. Treatment is an issue of controversy. In this study we analyzed risk factors for pancreatic leakage and the results of early resection of the pancreatic remnant versus drainage procedures for leakage of the pancreaticojejunostomy. STUDY DESIGN: From 1983 to 1995, 269 patients underwent pancreaticoduodenectomy, with pancreaticojejunostomy. Patients with manifestations of pancreatic leakage were compared with nonleakage patients to evaluate risk factors. Patients with leakage were divided into two treatment groups. One group comprised patients undergoing percutaneous or surgical drainage procedures; the other had patients undergoing resection of the pancreatic remnant. RESULTS: Twenty-nine patients (11%) had clinical manifestations of pancreatic leakage, and the mortality in these patients was 28% (overall mortality: 3.7%). Leakage occurred after a median of 5 days (range 1-20). Age, preoperative bilirubin level, and albumin counts were not risk factors for pancreatic leakage. Small pancreatic duct size (< 2 mm) (p < 0.01) and ampullary carcinoma as histopathologic diagnosis (p < 0.05) were risk factors. The median number of relaparotomies was two (range 0-4) in the drainage group (n = 21), versus 1.5 (range 1-5) in patients who underwent resection (n = 8). The median hospital stay was 74 days (range 36-219), versus 55 days (range 22-107) for the drainage and resection groups, respectively (p < 0.05). Mortality was lower in patients who underwent resection, 38 versus 0% (p < 0.05). CONCLUSIONS: Leakage of the pancreatic anastomosis is a severe complication after pancreaticoduodenectomy and carries a high mortality rate (28%). Completion pancreatectomy could be performed without additional mortality. In patients with severe and persistent leakage of the anastomosis, early completion pancreatectomy is the treatment of choice.

Aged↗
PubMed1997

Delayed gastric emptying after standard pancreaticoduodenectomy versus pylorus-preserving pancreaticoduodenectomy: an analysis of 200 consecutive patients.

BACKGROUND: It has been suggested that pylorus-preserving pancreaticoduodenectomy (PPPD) is associated with a high incidence of delayed gastric emptying and consequently with a prolonged hospital stay compared with standard Whipple's resection. The aim of this prospective study was to evaluate whether the incidence of delayed postoperative gastric emptying was different after both procedures. STUDY DESIGN: From 1989 to 1996, 200 consecutive patients underwent pancreatic head resection (100 standard pancreaticoduodenectomy [PD]; 100 PPPD). The groups were compared with regard to patient characteristics, operative indices, postoperative morbidity, hospital stay, and mortality. Delayed gastric emptying was defined as nasogastric suction for > or = 10 days or delay of regular diet until > 14 days postoperatively. RESULTS: Operative time and blood loss were higher for PD: 6 versus 4.8 hours (p < 0.0001) and 1,580 versus 1,247 mL (p < 0.001), respectively. Postoperative morbidity was 48% after PD and 44% after PPPD (not significant [NS]). Hospital mortality was 6% and 1% after PD and PPPD, respectively (NS). Delayed gastric emptying occurred in 34 patients after PD and in 37 after PPPD (NS). Median days of gastric suction was 3 versus 6 days for PD and PPPD (p < 0.0001). A regular diet was tolerated after a median of 10 and 11 days for PD and PPPD, respectively (NS). Postoperative hospital stay was shorter for patients who underwent PPPD: 20 versus 18 days (p < 0.03). Patients with intraabdominal complications (n = 52) showed a higher incidence of delayed gastric emptying (p < 0.0001). CONCLUSIONS: Our results show that PPPD is a safe procedure associated with less operative time and blood loss than PD. After PPPD, patients require longer postoperative nasogastric intubation than after PD, suggesting some form of early postoperative gastric stasis. There is, however, no difference in the incidence of delayed gastric emptying or the first postoperative day on which a regular diet is tolerated between these surgical procedures. Intraabdominal complications are major risk factors for delayed gastric emptying.

Blood Loss, Surgical↗
PubMed1997

Prospective, randomized trial on the effect of cyclic versus continuous enteral nutrition on postoperative gastric function after pylorus-preserving pancreatoduodenectomy.

OBJECTIVE: The effect of a cyclic versus a continuous enteral feeding protocol on postoperative delayed gastric emptying, start of normal diet, and hospital stay was assessed in patients undergoing pylorus-preserving pancreatoduodenectomy (PPPD). SUMMARY BACKGROUND DATA: Delayed gastric emptying occurs in approximately 30% of patients after PPPD and causes prolonged hospital stay. Enteral nutrition through a catheter jejunostomy is used to provide postoperative nutritional support. Enteral infusion of fats and proteins activates neurohumoral feedback mechanisms and therefore can potentially impair gastric emptying and prolong postoperative gastroparesis. METHODS: From September 1995 to December 1996, 72 consecutive patients underwent PPPD at the Academic Medical Center, Amsterdam. Fifty-seven patients were included and randomized for either continuous (CON) jejunal nutrition (0-24 hr; 1500 kCal/24 hr) or cyclic (CYC) enteral nutrition (6-24 hr; 1125 kCal/18 hr). Both groups had an equal caloric load of 1 kCal/min. The following parameters were assessed: days of nasogastric intubation, days of enteral nutrition, days until normal diet was tolerated orally, and hospital stay. On postoperative day 10, plasma cholecystokinin (CCK) levels were measured during both feeding protocols. RESULTS: Nasogastric intubation was 9.1 days in the CON group (n = 30) and 6.7 days in the CYC group (n = 27) (not statistically significant). First day of normal diet was earlier for the CYC group (15.7 vs. 12.2 days, p < 0.05). Hospital stay was shorter in the CYC group (21.4 vs. 17.5 days, p < 0.05). CCK levels were lower in CYC patients, before and after feeding, compared with CON patients (p < 0.05). CONCLUSIONS: Cyclic enteral feeding after PPPD is associated with a shorter period of enteral nutrition, a faster return to a normal diet, and a shorter hospital stay. Continuously high CCK levels could be a cause of prolonged time until normal diet is tolerated in patients on continuous enteral nutrition. Cyclic enteral nutrition is therefore the feeding regimen of choice in patients after PPPD.

Adult↗
PubMed1997

Reproducibility of p53 and Ki-67 immunoquantitation in Barrett's esophagus.

OBJECTIVE: To test the reproducibility and time effectiveness of two immunoquantitation and sampling methods in Barrett's esophagus (BE) mucosa. STUDY DESIGN: Measurements were performed using image cytometry (CAS 200/486) with "at convenience" sampling and stereology (QPRODIT 5.2) with both at convenience and systematic random sampling. RESULTS: Quantitation of p53 immunohistochemistry (IHC) by CAS was very reproducible by the same observer (r = .99), but its interobserver reproducibility was lower, and the measurement was time consuming (r = .81, 35 minutes). Moreover, CAS also detected a "signal" in the absence of any visually observable brown stain, giving false positive results. Both intraobserver and interobserver reproducibility by QPRODIT 5.2 were good. With QPRODIT, using systematic random sampling, the measurements were more reproducible by different observers and faster (r = .96, 10 minutes) than with QPRODIT with at convenience sampling (r = .91, 20 minutes). Therefore, for assessment of the Ki-67 labelling index (LI) and area percentage (area%) of Ki-67-positive nuclei, we used only QPRODIT with systematic random sampling. While intraobserver reproducibility of both Ki-67 LI and area% was good (r = .96, r = .99), interobserver reproducibility of Ki-67 LI was poorer than area% (r = .72 vs. r = .97). The assessment of Ki-67 LI was time consuming, whereas the measurement of the area% of Ki-67-positive nuclei was very time effective (45 vs. 7 minutes). A strong correlation was found between Ki-67 LI and area% of Ki-67-positive nuclei (r = .92). CONCLUSION: Therefore, we conclude that quantitation of p53 and Ki-67 IHC in BE mucosa can be very reproducible and highly time effective by means of stereology with systematic random sampling.

Barrett Esophagus↗
PubMed1997

Outcome of palliative biliary and gastric bypass surgery for pancreatic head carcinoma in 126 patients.

BACKGROUND: Recent reports of decreased morbidity and mortality following palliative surgery for patients with irresectable pancreatic head carcinoma prompted a review of the results in 126 patients (median age 64 (range 39-90) years) who had undergone palliative biliary and gastric bypass surgery. METHODS: The indication for surgical palliation was the finding of an irresectable tumour at laparotomy (n = 44), failure of endoscopic treatment (n = 43), clinical symptoms of gastric outlet obstruction (n = 28) and miscellaneous (n = 11). Biliary and gastric bypass was performed in 118 patients, biliary bypass alone in six and gastrojejunostomy alone in two. The indication for gastrojejunostomy was symptoms in 28 patients (23 per cent) and prophylaxis in 92 patients (77 per cent). RESULTS: Postoperative local complications occurred in 17 per cent of patients, general complications in 10 per cent and delayed gastric emptying in 14 per cent of patients. The 30-day mortality rate was 1 per cent and overall hospital mortality rate 2 per cent. Median hospital stay was 17 (range 5-80) days. Median overall postoperative survival was 190 (range 14-830) days. Late obstructive gastrointestinal symptoms occurred in 14 patients (11 per cent) after a median of 141 (range 21-356) days. CONCLUSION: Roux-en-Y hepaticojejunostomy combined with gastrojejunostomy offers effective palliation for irresectable pancreatic head cancer and can be performed with low mortality and acceptable morbidity rates.

Adult↗
PubMed1996

[More recurrencies than expected following inguinal hernia surgery].

OBJECTIVE: To make an inventory of inguinal hernia repairs performed in one year, and to analyse the number of and origin of recurrent hernias. DESIGN: Retrospective. SETTING: Onze Lieve Vrouwe Gasthuis, Amsterdam, the Netherlands. METHOD: Analysis of all hernia operations performed in Amsterdam and Amstelveen in 1994 in male patients over 18 years of age. Request of national data, computer data from the hospitals, hand count of all operation reports and investigation of patient files. RESULTS: In 1994, 1108 patients were operated for inguinal hernia on one or two sides. In 216/1108 (19.5%) cases recurrent hernia was involved. According to national statistics this occurred in 175/1123 (15.6%). In the two University hospitals 25.7% of all repairs were for a recurrent hernia, in the two hospitals with a surgical training programme this proportion was 17.9% and in the five hospitals without a training programme it was 18.6%. Of the early recurrences (within two years) 82.5% (47/57) were reoperated in the same hospital as before but of the late recurrences (more than 10 years) this proportion was only 26.8%. Only 16.6% (36/216) of the patients with a recurrence were reoperated by the same surgeon who had performed the prior operation. Most popular method for repair was a Bassini (59%). In the training hospitals more early recurrences were repaired than in the non-training hospitals. CONCLUSION: The percentage of hernia repairs for recurrent hernia is higher than national statistics suggest and higher than expected. Surgeons have little insight into their performance as many recurrences are repaired by another surgeon and many recurrences occur after ten years. Better training and more use of modern techniques may improve results.

Academic Medical Centers↗
PubMed1996

Role of the Shouldice technique in inguinal hernia repair: a systematic review of controlled trials and a meta-analysis.

The Shouldice technique for inguinal hernia repair has been suggested by some authors as the best conventional method against which other methods using prostheses should be compared. The paper which follows is a systematic review involving a comprehensive search of the medical literature to identify all clinical trials (article or abstract) evaluating the Shouldice repair. After assessment of certain quality criteria, the best studies were pooled in a meta-analysis. Nine publications were found with 11 study arms. In ten studies the results of the Shouldice technique were better than the results of the control arm. Six studies could be pooled in a meta-analysis of 2500 patients; Shouldice was significantly better than control methods (relative risk 0.62 (95 per cent confidence interval 0.45-0.85)). In spite of possible bias caused by different variables (modifications in operative technique, suture material, level of surgeon, follow-up methods and outcome measurement), the results of this systematic review suggest that the Shouldice method is the best current conventional technique for inguinal hernia repair.

Controlled Clinical Trials as Topic↗
PubMed1996

Severe complications of perianal sepsis in patients with human immunodeficiency virus.

Fifty human immunodeficiency virus (HIV)-infected patients with perianal sepsis were studied. Seven (14 per cent) had serious septic complications, four patients with severe necrotizing gangrene, and three with abscesses in the mediastinum, liver and brain respectively. CD4+ lymphocyte counts were significantly lower in patients with severe septic complications as compared with those with uncomplicated perianal sepsis (P < 0.05). In patients with HIV presenting with rare (metastatic) abscesses, perianal sepsis must always be kept in mind as a possible focus. Although HIV-infected patients have a limited life expectancy perianal fistulas and abscesses should be aggressively treated, because of the high risk of severe complications.

AIDS-Related Opportunistic Infections↗