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Biomedical subjects

H Obertop

Publications and source records attributed to H Obertop.

At least 19 recordsLinked to original sources
PubMed1999

Extended lymph-node dissection for gastric cancer.

BACKGROUND: Curative resection is the treatment of choice for gastric cancer, but it is unclear whether this operation should include an extended (D2) lymph-node dissection, as recommended by the Japanese medical community, or a limited (D1) dissection. We conducted a randomized trial in 80 Dutch hospitals in which we compared D1 with D2 lymph-node dissection for gastric cancer in terms of morbidity, postoperative mortality, long-term survival, and cumulative risk of relapse after surgery. METHODS: Between August 1989 and July 1993, a total of 996 patients entered the study. Of these patients, 711 (380 in the D1 group and 331 in the D2 group) underwent the randomly assigned treatment with curative intent, and 285 received palliative treatment. The procedures for quality control included instruction and supervision in the operating room and monitoring of the pathological results. RESULTS: Patients in the D2 group had a significantly higher rate of complications than did those in the D1 group (43 percent vs. 25 percent, P<0.001), more postoperative deaths (10 percent vs. 4 percent, P= 0.004), and longer hospital stays (median, 16 vs. 14 days; P<0.001). Five-year survival rates were similar in the two groups: 45 percent for the D1 group and 47 percent for the D2 group (95 percent confidence interval for the difference, -9.6 percent to +5.6 percent). The patients who had R0 resections (i.e., who had no microscopical evidence of remaining disease), excluding those who died postoperatively, had cumulative risks of relapse at five years of 43 percent with D1 dissection and 37 percent with D2 dissection (95 percent confidence interval for the difference, -2.4 percent to +14.4 percent). CONCLUSIONS: Our results in Dutch patients do not support the routine use of D2 lymph-node dissection in patients with gastric cancer.

Aged↗
PubMed1999

[Bile duct injuries after a laparoscopic cholecystectomy].

Eight years after the introduction of laparoscopic cholecystectomy a decrease of the incidence of bile duct injuries is reported in the literature. The incidence of a bile duct injury after laparoscopic cholecystectomy is now slightly higher than after open cholecystectomy. A minority of these injuries are detected during surgery. Most patients have a delayed identification of the bile duct injury, even after discharge from the hospital. An early diagnostic work-up with ultrasound and endoscopic retrograde cholangiopancreatography (ERCP) is mandatory in every patient with persisting symptoms (more than 48 hours) after laparoscopic cholecystectomy. Still, one-third of the patients are subjected to a 'diagnostic' exploratory laparotomy without preoperative visualization of the biliary tract by ERCP or percutaneous transhepatic cholangiography. Minor lesions are mostly treated successfully by endoscopy with a stent. After transection of the bile duct surgical reconstruction by a hepaticojejunostomy has to be performed. A delayed elective reconstruction was associated with fewer complications than acute repair under suboptimal circumstances such as local inflammatory changes and bile leakage.

Adult↗
PubMed1999

[Prospective follow-up of patients with abdominal symptoms treated by emergency room physicians].

In order to evaluate the functioning of emergency room (ER) physicians, patients seen at the ER of the Onze Lieve Vrouwe Gasthuis. Amsterdam, the Netherlands, for abdominal symptoms without having been referred by the GP, were questioned by letter about the course of events two weeks after their visit. Of the 1853 patients with abdominal symptoms attending the ER in July-December 1997, 1221 had no referral letter; of these, 933 were treated independently by the ER physician. Of the latter, 814 were sent a letter, to which 663 of them responded. 307 of them had visited the GP and 48 an ER. Of these 48 patients, 17 had been admitted and 14 of them had been operated. In seven of the 17 patients, the condition had not been recognized by the ER physician at the first visit.

Abdominal Pain↗
PubMed1999

Microcirculatory perfusion of the canine esophagus before and after blind longitudinal dissection and thoracoscopic distal transsection.

In the treatment of distal esophageal pathology, surgical mobilization and exteriorization of the thoracic esophagus can be necessary. This may threaten its vascularization. We investigated the effect of longitudinal dissection and distal transsection on the microcirculatory perfusion of the canine esophagus. Esophageal perfusion and muscular oxygenation were investigated in 11 dogs using laser Doppler fluxmetry and oxygen pressure measurements before and up to 2 weeks after longitudinal dissection with and without distal thoracoscopic transsection. Histological examination was performed at the end of the follow-up period. Distal esophageal perfusion was higher than proximal. Longitudinal dissection caused an insignificant reduction, whereas additional transsection significantly lowered esophageal perfusion, which was restored only partially during follow-up. After transsection distal muscular oxygen pressure was also significantly lower than proximal. Histologically, no significant ischemic cell damage was observed. Laser Doppler perfusion measurement is a feasible technique to measure (changes in) microcirculatory circulation of the esophageal wall. This may be useful in clinical settings to monitor the viability of the esophagus after surgical interventions. Distal transsection substantially reduces esophageal perfusion without apparent short-term histological damage.

Animals↗
PubMed1999

Are there indications for palliative resection in pancreatic cancer?

Controversy exists about the indication for a palliative pancreatoduodenectomy. A palliative resection for patients with a pancreatic carcinoma can be performed safely nowadays with low mortality and acceptable morbidity in centers with experience. The early results in terms of mortality and morbidity are not different from resections with curative intent or even after bypass surgery. The procedure seems effective for controlling symptoms of the disease, and the quality of life after a palliative resection is acceptable and not worse than after bypass surgery. It is, however, still doubtful whether the incidence of symptom recurrence, such as jaundice, obstruction, and pain, is lower after resection than after bypass surgery. The longer survival after palliative resection could also be due to patient selection and postoperative treatment. There are no randomized trials to prove the superiority of palliative resection over bypass surgery. The safety of pancreatic resection for cancer has already changed the policy in centers with experience, and surgeons are more willing to perform a resection because the results are better or at least the same as after bypass surgery. There are, however, no results to confirm that a palliative resection should be performed routinely or to justify resection as a debulking procedure.

Gastric Outlet Obstruction↗
PubMed1999

Treatment with recombinant bactericidal/permeability-increasing protein to prevent endotoxin-induced mortality in bile duct-ligated rats.

BACKGROUND: Operation in patients with obstructive jaundice is associated with substantial morbidity because of increased susceptibility to endotoxin (lipopolysaccharide) and the inflammatory cascade. Different interventions to reduce endotoxemia and cytokine induction, and resulting complications, have been studied. Bactericidal/permeability-increasing protein (BPI) is a naturally occurring endotoxin-binding protein produced in neutrophils. It binds endotoxin, neutralizing the activity and inhibiting cytokine production by mononuclear cells. In experimental endotoxemia in animals and in healthy human volunteers, BPI has shown a protective effect. The aim of this study was to determine whether BPI could protect against increased endotoxin sensitivity in rats with obstructive jaundice and reduce endotoxin-induced mortality. STUDY DESIGN: Male Wistar rats were used. Intraperitoneal Escherichia coli 2mg/kg was given 1 week after sham operation or bile duct ligation (BDL). Three groups were studied: sham, BDL with placebo, and BDL with 5 mg/kg recombinant BPI21. RESULTS: BDL rats were jaundiced (mean bilirubin 186 micromol/L; no difference between BDL rats without or with BPI). Bilirubin remained less than 1 micromol/L in sham-operated rats (p = 0.002). Endotoxin levels were 3.4pg/mL in sham controls and 3.1 pg/mL in BDL rats before administration of lipopolysaccharide (p = NS). Two hours after administration, levels were 615.4ng/mL in placebo BDL rats and 10 times less in BPI-treated BDL rats, at 60.2ng/mL (p=0.03). The same trend was found at 6 hours. At 24 hours, mortality was 1 of 6 in sham-operated rats (15%) versus 8 of 11 in untreated BDL rats (75%). BPI intervention reduced the death rate to 1 of 12 BDL rats (8%) (p = 0.003). CONCLUSIONS: Intraperitoneal recombinant BPI21 in rats having BDL reduced endotoxin-induced mortality from 75% to 8%, a death rate comparable to that in nonjaundiced rats. BPI could be an interesting perioperative treatment in clinical obstructive jaundice.

Animals↗
PubMed1999

Diaphragmatic herniation following oesophagectomy.

BACKGROUND: Intrathoracic herniation of abdominal viscera is a potentially life-threatening condition, especially when diagnosis is delayed. The aim of this study was to estimate its incidence following oesophageal resection and to define contributing factors that might influence its occurrence. METHODS: All radiographic studies of the chest that were made during follow-up in a series of 218 patients who underwent oesophagectomy between 1993 and 1997 were reviewed. RESULTS: Herniation of bowel alongside the oesophageal substitute was detected in nine patients (4 per cent). Four hernias occurred within the first week after operation and five were detected at late follow-up. Surgical treatment was indicated in six patients. Analysis of predisposing factors revealed that extended incision and partial resection of the diaphragm were associated with an increased risk of postoperative hernia formation (four of 29 following extended enlargement versus five of 189 after routine opening of the oesophageal hiatus; P = 0.02). CONCLUSION: Diaphragmatic herniation was found in 4 per cent of patients after oesophagectomy. After extended iatrogenic disruption of the normal hiatal anatomy, narrowing of the diaphragmatic opening may be indicated to avoid postoperative herniation of bowel into the chest. Awareness of its possible occurrence may help prevent the development of intestinal obstruction and strangulation.

Adult↗
PubMed1999

Impaired healing of extraperitoneal intestinal anastomoses.

BACKGROUND: The extra-anatomical position of a cervical oesophagogastrostomy might be a reason for impaired anastomotic healing. METHODS: This hypothesis was tested in a rat model. Jejunal resection with an end-to-end jejunojejunostomy was placed intra-abdominally in group 1 (n = 24) and subcutaneously in group 2 (n = 30). Jejunum without anastomosis was placed subcutaneously in group 3 (n = 12). After 3, 7 or 14 days the rats were killed; the bursting pressure of the anastomosis or jejunum was measured and the hydroxyproline level was determined. RESULTS: Two of 24 rats in group 1 and eight of 30 in group 2 died following anastomotic leakage (P not significant) and were excluded from other measurements. Bursting pressure was decreased after 3 days in group 1 (mean(s.e.) 62(10) mmHg) and group 2 (57(10) mmHg) compared with that in group 3 (204(17) mmHg) (P < 0.001). After 7 days, it was in the normal range in group 1 (200(14) mmHg), but lower in group 2 (104(15) mmHg) compared with that in group 3 (230(8) mmHg) (P < 0.001). Differences in hydroxyproline levels were not statistically significant between the groups after 3, 7 and 14 days. CONCLUSION: Healing of jejunojejunostomies is impaired in an extraperitoneal position compared with an intra-abdominal position.

Anastomosis, Surgical↗
PubMed1999

Efficacy of monoclonal antibody 131I-B72.3 immunoscintigraphy of pancreatic adenocarcinoma xenografts in nude mice.

OBJECTIVE: To assess the efficacy of monoclonal antibody (MoAb) B72.3 for in vivo-immunoscintigraphy of pancreatic carcinoma in nude mice. DESIGN: Experimental controlled animal study. SETTING: University hospital, The Netherlands. SUBJECTS: 11 nude mice with subcutaneously xenografted human pancreatic carcinoma. INTERVENTIONS: Specific MoAb B72.3 and non-specific MoAb MOPC21 were iodinated with 131I and injected intraperitoneally in nude mice. Scintigrams were taken on days 1-10 and tumour:non-tumour ratios of the regions of interest (tumour, thorax, abdomen, background) were calculated. The mice were then killed for in vitro tissue counts. MAIN OUTCOME MEASURES: Tumour:non-tumour ratios in vivo and in vitro. RESULTS: Results of immunoscintigraphy on days 1, 2, and 6 were compared. In the B72.3-group all ratios were only moderately raised, the tumour:background ratio being the highest (2.35 (SD 0.67)) on day 6. There were no obvious differences between the ratios of the B72.3-group and the MOPC21-group. The results of tissue counts done at the end of the study, showed that tumour:non-tumour ratios were twice as high in the B72.3-group, suggesting some specificity of this MoAb. CONCLUSION: The results of our study suggest that MoAb B72.3 is not powerful enough for in vivo detection of pancreatic cancer as assessed in this xenograft model in nude mice.

Adenocarcinoma↗
PubMed1999

Disturbed enterogastric inhibitory reflex after esophageal resection and narrow gastric tube reconstruction.

BACKGROUND/AIMS: The gastric emptying pattern after esophageal resection and narrow gastric tube reconstruction is determined by multiple factors. One of the possible factors is a disruption in the neurohumoral enterogastric inhibitory reflex. The aim of the present study was to determine the possible alterations of this reflex after esophageal resection and narrow gastric tube reconstruction. METHODS: Nine patients each underwent two gastric tube emptying studies, one without and one with high caloric duodenal tube feeding. The dual isotope scintigraphic data were corrected for subject movement, radionuclide decay, downscatter and gamma-ray attenuation. RESULTS: The median gastric tube emptying rate of solid food was 57%/h (range 27-195). The median T(1/2) of liquid food was 67 (range 4->80) min. Both for solid and for liquid food, the gastric tube emptying patterns without and with duodenal tube feeding were not significantly different. CONCLUSION: The neurohumoral enterogastric inhibitory reflex is disrupted after esophageal resection and narrow gastric tube reconstruction, which may contribute to disturbed gastric emptying.

Adenocarcinoma↗
PubMed1999

A surgical and pathological based classification of resective treatment of pancreatic cancer. Summary of an international workshop on surgical procedures in pancreatic cancer.

BACKGROUND: The extent of pancreatic resection and lymphadenectomy, both for Kausch-Whipple pancreatoduodenectomy and for left pancreatectomy, is variable between surgeons, according to their training. METHODS: On May 30, 1998, a consensus conference on the surgical treatment of pancreatic cancer took place in Castelfranco Veneto, Italy. A group of 29 European surgeons and pathologists, recognized as international experts, analyzed the surgical and pathological procedures used in European countries to resect pancreatic cancer and examine the specimen. RESULTS: A general agreement was reached on the definitions of standard , 'radical and 'extended radical Kausch-Whipple pancreatoduodenectomy for carcinoma of the head of the pancreas, and standard and 'radical left pancreatectomy for carcinoma of the body and tail of the pancreas. Segmental venous resection, as well as adjacent organ resection, can be performed at the time of standard, radical or extended radical pancreatoduodenectomy or left pancreatectomy if required. The pylorus-preserving procedure is contraindicated only for carcinomas of the anteriorsuperior part of the head of the pancreas. Guidelines for a standardized pathological examination of the resected specimen were produced. CONCLUSION: Adoption of the recommended terminology will improve outcome comparisons between institutions performing the different procedures. Moreover, standardization of operations, terminology and pathological reporting is essential for prospective randomized trials comparing different operations either alone or within the context of adjuvant therapy studies.

Humans↗
PubMed1999

Laparoscopic staging of biliopancreatic malignancy.

The main benefit of laparoscopic staging (LLU) of (distal) bilio-pancreatic malignancy is the detection of small superficial metastases at the liver surface and peritoneum and local tumor ingrowth. The different aspects of laparoscopic staging have been described extensively in the literature and the benefit is generally expressed in terms of prevention of laparotomy. The impact of this final staging procedure on outcome for the patient in terms of the efficacy of the subsequent non-surgical palliative treatment have been analysed scarsely. In this review the results of laparoscopic staging of bilio-pancreatic tumors concerning the detection of metastases and tumor ingrowth as well as the results of long term follow up after subsequent non-surgical treatment and the preferred palliative treatment after laparoscopic staging are discussed.

Bile Duct Neoplasms↗
PubMed1999

Differential diagnosis of focal pancreatitis and pancreatic cancer.

UNLABELLED: The differentiation of focal, chronic pancreatitis (CP) and pancreatic cancer (PAC) poses a diagnostic dilemma. Both conditions may present with the same symptoms and signs. The complexity of differential diagnosis is enhanced because PAC is frequently associated with secondary inflammatory changes and CP may develop into PAC. The aim of this study was tot analyze two sets of patients (group A and B) who were misdiagnosed to have either CP or PAC. The clinical and radiographical features of these patients were reviewed. Group A consisted of 22 patients (median age 54.5 years) who were referred with PAC after a previous diagnosis of PC. Eleven patients had a history of CP of > 12 mths (mean 40.2 mths) whereas in 11 patients, PAC became apparent within 12 mths (mean 4.9 mths) after the diagnosis of CP was made. The etiology of CP was alcohol abuse in 9 patients, pancreas divisum in 3 patients and was undefined in the remaining 10 patients. Imaging studies showed features of CP (parenchymal calcifications, irregularities and stenoses of the pancreatic duct wall). Pseudocysts were present in 13 patients. A mass lesion was detected in 13 patients. At the time of diagnosis, 20 patients had unresectable tumors and 2 patients underwent a Whipple resection which proved non-radical. Group B consisted of 14 patients (median age 53 years) who underwent a Whipple resection for a presumed PAC that on histopathology of the lesion proved to be CP. These patients accounted for 6% of all 220 patients who had undergone resection for PAC in the same period. Reassessment of clinical presentation and all imaging studies confirmed a high index of suspicion on PAC in these patients. CONCLUSION: In patients known with CP, misdiagnosis of PAC is a potential pitfall leading to delay of treatment. For any lesion suspicious of PAC an aggressive surgical approach is justified lest a potentially curable lesion is missed. As a consequence, there is at least a 5% chance of resecting a lesion based on CP, mimicking PAC.

Cholangiopancreatography, Endoscopic Retrograde↗
PubMed1999

Essentials in biliopancreatic staging: a decision analysis.

Two possible strategies for diagnosis and staging of patients with suspected biliopancreatic cancer and obstructive jaundice were tested in a decision analysis. One strategy was called 'surgical' strategy and consisted of only Ultrasonography and (spiral) CT scan and exploratory laparotomy in all patients without irresectable disease or distant metastases according to this work-up. The other strategy was called 'non-surgical' strategy and consisted of the above strategy, but also included ERCP and endoscopic internal drainage (stent) and diagnostic laparoscopy and laparoscopic ultrasound. In the decision analysis incidences of the outcomes after the two strategies were estimated based on the literature and our own experience, and a utility (0-1) was attributed to each separate outcome, according to the expected quality of life as judged by the team. Total utility of each strategy was calculated. It could be concluded that a non-surgical strategy would lead to a somewhat higher total utility in case the yield (i.e. prevention of unnecessary laparotomies) could be high and supposed that a beneficial effect of pre-operative internal biliary drainage was present. In case of low yield of diagnostic laparoscopy the superiority of the 'non-surgical' strategy is doubtful.

Biliary Tract Neoplasms↗
PubMed1999

Local resection of biliopancreatic cancer.

Biliopancreatic tumors that are potentially amenable to local resection include proximal bile duct tumors (Klatskin tumors), mid-choledochal duct tumors and tumors arising from the papilla of Vater. This paper reviews our experience in the AMC, with local resection of these conditions. From 1983-1997, 112 patients underwent surgical resection of a carcinoma of the hepatic duct confluence (Klatskin tumor). Local resection was undertaken in 80 patients (52 patients with type I and II tumors, and 28 patients with type III tumors) whereas in 32 patients with type III tumors, hilar resection was performed with liver resection. Negative surgical margins were achieved in 10 patients after local resection of type I and II tumors (19.2%), in 1 patient after local resection of a type III tumor (3.6%), and in 5 patients after hilar resection and liver resection (15.6%). Middle-third carcinomas of the extra-hepatic biliary tract are less common than proximal or distal bile duct tumors. From 1993-1998, 12 patients underwent resection of a mid-choledochal duct carcinoma. In 8 patients, local resection was performed and in 4 patients, subtotal pancreatoduodenectomy (PPPD) because of the close relationship of the tumor and the pancreas. Four patients had negative surgical margins, 2 after local resection (25%) and 2 after PPPD (50%). Although accepted for villous adenomas located in the ampulla, local resection for ampullary carcinoma is controversial. Nine patients underwent local resection of a presumed adenoma that proved to be an ampullary carcinoma. In 4 patients with T1 tumors, resection of the carcinoma was locally complete (44%). Additional PPPD was performed in 6 patients, including the 4 patients with complete local resections, showing no residual tumor at the previous site of excision, but, lymphnode metastases in two resection specimens (both of patients with presumed T1 tumors). Hence, local resection of a T1 ampullary carcinoma might result in tumor free margins, but does not deal with (usually retropancreatic) lymphnode metastases. In conclusion, local resection is applicable to Klatskin type I and II tumors. Local resection may be considered in the proximally located, mid-choledochal duct carcinomas but, when located closer to the pancreas, PPPD is the preferred treatment. For ampullary adenomas, local resection is feasible unless frozen section examination raises suspicion on a malignancy. Local resection of even limited ampullary carcinomas is not advisable because of lymphatic dissemination of the tumor and consequently, inadequate clearance.

Adolescent↗
PubMed1999

Complications after resection of biliopancreatic cancer.

During the past decade the mortality after pancreaticoduodenectomy decreased to 0-4% in centers with experience. The morbidity however remains high although a decrease has also been demonstrated. Leakage of the pancreatic anastomosis is the most severe complication associated with a high mortality reported between 8-40%. Resection of the pancreatic remnant is the most radical treatment but unfortunately associated with insulin dependent diabetes. Subtotal resection of the pancreas tail seems an alternative. The incidence of postoperative bleeding is decreasing in particular bleeding from ulcers. Bleeding from a pseudoaneurysm (2%) is leading to a high mortality up to 50% and early aggressive intervention is mandatory. Delayed gastric emptying is reported between 20-30%, the pathophysiology is still unknown but postoperative intra-abdominal complications proved to be a risk factor. It is now evident that mortality is strongly related with hospital experience and regionalization reduced overall mortality. These findings are arguments to favour centralization of surgery for biliopancreatic cancer.

Anastomosis, Surgical↗