Hans U. Baer
University of Bern
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Diseases of The Colon & Rectum | 1992
Philippe Gertsch; Hans U. Baer; Rainer Kraft; Guy J. Maddern; Hans Jörg Altermatt
Anastomotic recurrence after resection of colorectal carcinoma has been attributed to insufficient clearance, migration of tumor cells into lymphatics, or implantation of exfoliated malignant cells during anastomosis. We studied 10 patients submitting to low anterior resection for cancer 6 to 16 cm (mean, 12.6 cm) from the anal verge. The anastomosis was performed with a circular stapler introduced transanally into the rectum using the established technique. No lavage of the rectal stump with a cytotoxic agent was conducted before the anastomosis was performed. Having completed the anastomosis, the stapler and the doughnuts were washed with saline, which was collected for cytologic examination. The doughnuts were then examined histologically; all were tumor free. In 9 of the 10 cases, malignant cells were identified in the centrifuged saline. It may be that malignant cells collected by the stapler are implanted during anastomosis and cause subsequent anastomotic recurrence.
Surgery | 1998
Kaspar Z'graggen; Stefan Birrer; Christoph A. Maurer; Heinz Wehrli; Christian Klaiber; Hans U. Baer
BACKGROUND We sought to determine the incidence of recurrence of carcinoma at the port site and the outcome of patients with such recurrences after exploratory laparoscopy/laparoscopic cholecystectomy for unsuspected gallbladder carcinoma and analyzed aspects of the laparoscopic procedure associated with recurrences at the port site. METHODS Thirty-seven patients with preoperatively unknown adenocarcinoma of the gallbladder were analyzed. The patients were part of a large prospective study of the Swiss Association of Laparoscopic and Thoracoscopic Surgery including 10,925 patients undergoing laparoscopic cholecystectomy. RESULTS Preoperatively undiagnosed adenocarcinoma of the gallbladder is rarely encountered in patients undergoing laparoscopic cholecystectomy (0.34%). The incidence of recurrence of carcinoma at the port site in these patients is 14% (5 of 37) and is similar whether the primary tumor is confined to the gallbladder (T1/T2) or locally advanced (T3/T4). The recurrences at the port site were diagnosed within 6 to 16 months (median 10 months) after the operation. Patients with an intraoperative perforation of the gallbladder had a higher incidence of recurrences at the port site (40%) than had patients without perforation (9%; P = .13). All patients with recurrences at the port site had distant metastases and all died of the disease 12 to 35 months (median 19 months) after cholecystectomy; all patients with such recurrences and stage T1/T2 tumors subsequently had peritoneal metastases. CONCLUSIONS Patients with a preoperatively undiagnosed adenocarcinoma of the gallbladder undergoing laparoscopy or laparoscopic cholecystectomy have a high incidence of recurrences at the port site, and the incidence increases when a gallbladder perforation occurs during the operation. All patients with such recurrences died of the disease. The diagnosis of an isolated recurrence at the port site may therefore be an indicator of disseminated disease in most cases.
Annals of Surgery | 1993
Hans U. Baer; Steven C. Stain; Ashley R. Dennison; Bernard Eggers; Leslie H. Blumgart
The operative management of hilar Cholangiocarcinoma has evolved because of advances in diagnostic imaging that have permitted improved patient selection, and refinements in operative techniques that have lowered operative mortality rates. Over a 4-year period, 48 patients with hilar Cholangiocarcinoma were managed. Twenty-seven patients were treated by palliative measures. Preoperative investigation identified 29 patients who were judged fit for operation without proven irresectability by radiologic studies, and 21 of the 29 patients had tumor removal (72%). Twenty-three operative procedures were performed: local excision (n = 12) (two had subsequent hepatic resection), and hepatic resection primarily (n = 9). Eight patients had complications (35%), and one patient died (4.3%). The mean actuarial survival after local excision is 36 months, and after hepatic resection, 32 months. Palliation as assessed by personal interview was excellent for more than 75% of the months of survival. A combination of careful patient selection and complete radiologic assessment will allow an increased proportion of patients to be resected by complex operative procedures with low mortality rate, acceptable morbidity rate, and an increase in survival with an improved quality of life.
Journal of The American College of Surgeons | 1998
Helmut Friess; Jörg Kleeff; Juan Carlos Silva; Charlotte Sadowski; Hans U. Baer; Markus W. Büchler
BACKGROUND The role of diagnostic laparoscopy before laparotomy in patients with pancreatic or periampullary malignancies remains controversial. We analyzed the value of using diagnostic laparoscopy to avoid laparotomy in these patients. STUDY DESIGN Between November 1993 and December 1996, 254 patients with pancreatic or periampullary malignancies were treated. In 74 patients, multiple distant metastases precluded further surgical treatment. In all, 180 patients underwent laparotomy for pancreatic cancer (119 patients) or periampullary cancer (61 patients). Preoperatively, all patients underwent computed tomography for staging and to assess resectability of the tumor. Based on the results of the imaging procedure, the patients were scheduled for either tumor resection or a palliative operation. RESULTS Twenty-one of 180 patients (12%) with pancreatic or periampullary malignancies were scheduled preoperatively for nonresectional operations because of distant metastasis or retroperitoneal tumor infiltration. In none of these patients was the operative strategy changed. In 159 of 180 patients (88%), a pancreatic resection was planned preoperatively; 119 patients underwent pancreatic resection. In the remaining 40 patients preoperatively scheduled for tumor resection, removal of the tumor was not possible. In 24, this resulted from tumor infiltration into the retropancreatic vessels, and in 16 it resulted from liver or peritoneal metastasis detected for the first time intraoperatively. These 16 patients (10%) could have benefited from diagnostic laparoscopy. Similar results were found in the subgroup of 119 patients with pancreatic cancer, of whom 102 were planned for tumor resection and 17 for palliative operation. Of the 102 patients planned preoperatively for tumor resection, 71 patients (70%) underwent pancreatic resection. In the remaining 31 patients scheduled for tumor resection, removal of the tumor was not possible: in 17 because of tumor infiltration into the retropancreatic vessels and in 14 because of liver or peritoneal metastasis detected for the first time intraoperatively. These 14 patients (14%) also would have benefited from laparoscopy. CONCLUSIONS Preoperative computed tomography is a reliable technique to detect tumor metastasis in patients with pancreatic or periampullary cancer. Unlike other investigators, we found that only 10% of patients with periampullary or pancreatic cancer and 14% of patients with pancreatic cancer might profit from laparoscopy. Because of this low number, laparoscopy cannot generally be recommended for patients with pancreatic or periampullary cancer before laparotomy.
American Journal of Surgery | 1999
Mohamed Abou-Shady; Hans U. Baer; Helmut Friess; Pascal O. Berberat; Arthur Zimmermann; Hans U. Graber; Leslie I. Gold; Murray Korc; Markus W. Büchler
BACKGROUND Transforming growth factor betas (TGF-betas) are multifunctional polypeptides that have been suggested to influence tumor growth. They mediate their functions via specific cell surface receptors (type I ALK5 and type II TGF-beta receptors). The aim of this study was to analyze the roles of the three TGF-betas and their signaling receptors in human hepatocellular carcinoma (HCC). METHODS HCC tissue samples were obtained from 18 patients undergoing partial liver resection. Normal liver tissues from 7 females and 3 males served as controls. The tissues for histological analysis were fixed in Bouins solution and paraffin embedded. For RNA analysis, freshly obtained tissue samples were snap frozen in liquid nitrogen and stored at -80 degrees C until used. Northern blot analysis was used in normal liver and HCC to examine the expression of TGF-beta1, -beta2, -beta3 and their receptors: type I ALK5 (TbetaR-I ALK5), type II (TbetaR-II), and type III (TbetaR-III). Immunohistochemistry was performed to localize the corresponding proteins. RESULTS All three TGF-betas demonstrated a marked mRNA overexpression in HCC in comparison with normal controls, whereas the levels of all three TGF-beta receptors showed no significant changes. Intense TGF-beta1, TGF-beta2, and TGF-beta3 immunostaining was found in hepatocellular carcinoma cells and in the perineoplastic stroma with immunohistochemistry, whereas no or mild immunostaining was present in the normal liver. For TbetaR-I ALK5 and TbetaR-II, the immunostaining in both HCC and normal liver was mild to moderate, with a slightly higher intensity in the normal tissues. CONCLUSION The upregulation of TGF-betas in HCC suggests an important role for these isoforms in hepatic carcinogenesis and tumor progression. Moreover, the localization of the immunoreactivity in both malignant hepatocytes and stromal cells suggests that TGF-betas act via autocrine and paracrine pathways in this neoplasm.
Journal of The American College of Surgeons | 1998
Peter U. Reber; Hans U. Baer; Ameet G. Patel; Stephan Wildi; Jürgen Triller; Markus W. Büchler
BACKGROUND Only a few isolated case reports of extrahepatic pseudoaneurysms of the hepatic arteries have been published. We present the first documented series of patients with extrahepatic pseudoaneurysms treated at a single institution, and discuss the etiology and management of this condition. STUDY DESIGN A retrospective review of all cases of extrahepatic pseudoaneurysms of the hepatic arteries between 1989 and 1997. RESULTS A total of seven patients with extrahepatic pseudoaneurysms of the hepatic arteries all had upper abdominal pain; five patients were also in shock secondary to a gastrointestinal bleeding from ruptured pseudoaneurysms. The most common factor of the pseudoaneurysms was previous pancreatobiliary surgery in five patients with blunt truncal trauma and chronic pancreatitis in the remaining two patients. Initial endoscopy and ultrasonography were unrevealing, whereas dynamic computed tomography (CT) scan and angiography were diagnostic. The median size of the pseudoaneurysms was 3.6 cm (range 2.1-5.7). Treatment consisted of superselective transcatheter microcoil embolization in five hemodynamically unstable patients and surgical resection of the pseudoaneurysms with vascular reconstruction in the two stable patients. Mortality and morbidity were 0% and 43%, respectively. In a median followup of 35 months (range 2-96), no recurrence of pseudoaneurysm has been found. CONCLUSIONS A high index of suspicion combined with appropriate diagnostic modalities are required for the diagnosis of extrahepatic pseudoaneurysms. In high-risk patients, superselective transcatheter microcoil embolization should be considered the treatment of choice.
Surgery | 1997
Claudio A. Redaelli; Markus W. Büchler; Martin K. Schilling; L. Krähenbühl; Charles Ruchti; L. H. Blumgart; Hans U. Baer
BACKGROUND Mirizzi syndrome is a rare complication of long-standing cholelithiasis. It is defined as obstructive jaundice caused by external compression of the common hepatic duct by an impacted stone in the gallbladder neck. Gallstone disease and cholelithiasis-associated chronic biliary inflammation may play a causative role in the pathogenesis of gallbladder carcinoma. The purpose of this study was to investigate the coincidence of gallbladder carcinoma associated with Mirizzi syndrome. Furthermore, the diagnostic value of elevated CA 19-9 levels as indicator for a coincidental gallbladder carcinoma in this syndrome was studied. METHODS Patient demographics, clinical findings, laboratory data, results of diagnostic studies, pathologic reports, and intraoperative findings of 1579 patients undergoing cholecystectomy were obtained from patient records and were retrospectively studied. Only patients with proven Mirizzi syndrome (i.e., extrinsic mechanical compression of the common hepatic duct by impacted gallstones, associated chronic cholecystitis, and a history of jaundice) were included in this study. RESULTS Eighteen cases of Mirizzi syndrome (1.0%) out of 1759 cholecystectomies performed between January 1986 and March 1995 were identified. The seven male patients and 11 female patients had an average age of 74.8 years (range, 32 to 87 years). In five of these patients (27.8%) coincidental cases of gallbladder carcinoma were detected. The incidence of unsuspected malignancies in long-standing gallstone disease was 36 (2%) of 1759 and was statistically significantly different (p < 0.001) from the incidence in patients with Mirizzi syndrome (27.8%, 5 of 18). No significant difference was noted in age, gender, duration of jaundice, and type of lesions between these two groups. Tumor-associated antigen CA 19-9 level was elevated in 12 patients with Mirizzi syndrome, but it was significantly higher (p < 0.0001) in all five patients with coincidental gallbladder neoplasm and peaked at 1000 units/ml. All patients diagnosed with gallbladder carcinoma died within 18 months after operation. CONCLUSIONS There is high association of gallbladder cancer in Mirizzi syndrome. Elevated CA 19-9 levels in this syndrome are indicative of a coincidental gallbladder malignancy. Because of this high coincidence of Mirizzi syndrome and gallbladder cancer we recommend an intraoperative frozen section of the gallbladder in all patients presenting with Mirizzi syndrome.
European Journal of Cancer | 1998
J.M Läuffer; Hans U. Baer; Christoph A. Maurer; Ch. Stoupis; A Zimmerman; Markus W. Büchler
We report on a patient with biliary cystadenocarcinoma and review 112 previously published cases of this rare cystic hepatic neoplasm. This tumour mainly occurs in women at a ratio of 62% (female) to 38% (male), and at an average age of 56.2 years (range 18-88 years). The origin of these neoplasms is intrahepatic in 97% of cases and extrahepatic in the remaining 3%. The clinical symptoms are nonspecific and are not distinctive from benign cystic liver lesions unless invasive growth of the tumour occurs or distant metastases are present. Sonography and computed tomography (CT), as well as magnetic resonance imaging (MRI) demonstrate the multilocular nature of the tumour with septal or mural nodules. Discrete soft tissue masses, thick and coarse calcifications and varying density on CT or intensity on MRI within the loculi are additional non-specific imaging findings. The best therapeutic result with a 5-year survival rate of 100% and a recurrence rate of only 13% was achieved by complete excision (n = 16). Surgical removal of the tumour by complete excision is, therefore, the treatment of choice for biliary cystadenocarcinomas.
Annals of Surgery | 1992
Hans U. Baer; Ashley R. Dennison; W Mouton; Steven C. Stain; Arthur Zimmermann; Leslie H. Blumgart
Cavernous hemangiomas arc the most common benign tumors of the liver. Giant cavernous hemangiomas, defined as those larger than 4 cm in diameter, can reach enormous proportions. Newer imaging modalities, although often demonstrating characteristic features that strongly suggest the diagnosis, should not be augmented by biopsy because of the risk of hemorrhage. Elective surgical resection may be indicated for symptomatic giant lesions and for those with an atypical appearance where the diagnosis is in doubt. Between October 1986 and May 1991, we treated 10 patients with giant hemangiomas by enuclcation or enuclcation plus resection. Median operative blood loss was 800 mL (range, 200 to 3000 mL). One patient required reoperatin for control of postoperative hemorrhage. Detailed pathologic examination has demonstrated an interface between hemangiomas and the normal liver tissue that allows enucleation. Enucleation is an underused procedure that if carefully performed allows resection of giant hcmangiomas with a reduced blood loss and the preservation of virtually all normal hepatic parenchyma.
Hpb Surgery | 1993
Hans U. Baer; Steven C. Stain; T. Guastella; Guy J. Maddern; L. H. Blumgart
The mortality and morbidity in major hepatic resection is often related to hemorrhage. A high pressure, high velocity water jet has been developed and has been utilized to assist in hepatic parenchymal transection. Sixty-seven major hepatic resections were performed for solid hepatic tumors. The tissue fracture technique was used in 51 patients (76%), and the water jet dissector was used predominantly in 16 patients (24%). The extent of hepatic resection using each technique was similar. The results showed no difference in operative duration (p = .499). The mean estimated blood loss using the water jet was 1386 ml, and tissue fracture technique 2450 ml (p = .217). Transfusion requirements were less in the water jet group (mean 2.0 units) compared to the tissue fracture group (mean 5.2 units); (p = .023). Results obtained with the new water dissector are encouraging. The preliminary results suggest that blood loss may be diminished.