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Charles M Vollmer

Publications and source records attributed to Charles M Vollmer.

13 recordsLinked to original sources
PubMed2007

Chemotherapy for colorectal cancer prior to liver resection for colorectal cancer hepatic metastases does not adversely affect peri-operative outcomes.

BACKGROUND: Systemic chemotherapy is being used increasingly in patients with colorectal cancer. The effects of prior systemic adjuvant or palliative chemotherapy on morbidity following hepatic resection for metastases are not well defined. OBJECTIVES: To assess the peri-operative impact of systemic chemotherapy on liver resection for colorectal cancer hepatic metastases. METHODS: Ninety-six resections for colorectal cancer hepatic metastases performed from July 2001 to July 2003 (93% > or =2 segments) were reviewed. Pre-operative demographics, peri-operative features, and post-operative outcomes were collected prospectively. Type of chemotherapy and the temporal relationship of chemotherapy to the liver resection were analyzed. RESULTS: Fifty-three of 96 patients (55%) received a mean of 5.7 cycles (6.1 months) of systemic chemotherapy prior to hepatic resection, with a median interval of 12 months from end of chemotherapy to liver resection (range 1-75 months). Thirty-five received 5-fluorouracil/leucovorin (5-FU/LV) alone, nine had irinotecan (CPT-11) in addition to 5-FU/LV, and nine were not specified. Pre-operative age, sex, co-morbidities, ASA score, biochemical and liver enzyme profiles, tumor number, and extent and technique of hepatic resection were the same in the chemotherapy and non-chemotherapy cohorts. Mean tumor size was smaller (4.5 cm vs. 5.8 cm) and synchronous metastases were half as common (25% vs. 49%) in the chemotherapy group. Liver resection operative time was equivalent (270 min) in the two groups. Higher estimated blood loss (EBL) (1,000 ml vs. 850 ml), but fewer transfusions (23% vs. 15%) were associated with the chemotherapy group. Although not statistically significant, post-operative liver enzyme peaks were higher in the chemotherapy group (AST = 402 U/L vs. 302 U/L, P = 0.09 and ALT = 433 U/L vs. 312 U/L, P = 0.1). Peak changes in INR and serum bilirubin did not differ. Complications and length of stay (LOS) did not differ between the groups. The only post-operative death was in the non-chemotherapy group. Interestingly, hepatic steatosis was present in 28% of the non-chemotherapy cases and 57% of the chemotherapy resection specimens (P = 0.005) and was marked (>30%) in 7% and 10%, respectively. Further analysis of the chemotherapy group based on the interval between completion of chemotherapy and the hepatic resection (<6 months, 7-12 months, 1-2 years, and >2 years) revealed a trend towards worse outcomes in most categories for those in the >2 years cohort. When comparing the 5-FU/LV alone, to the CPT-11 group there were no significant differences except higher intra-operative blood loss in the group receiving 5-FU/LV alone (1,295 ml vs. 756 ml, P = 0.01). CONCLUSION: Despite variations in biochemical function and hepatic steatosis, short-term clinical outcomes are not affected by the administration of chemotherapy prior to hepatic resection. Furthermore, there is no detrimental effect of close timing of chemotherapy prior to resection, and there are no appreciable differences between irinotecan containing regimes and more traditional 5-FU-only based therapies, although the subset sample sizes were small in this study.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed2007

Impact of regional lymph node evaluation in staging patients with periampullary tumors.

BACKGROUND: Two distinct lymph nodes reproducibly assessed by computed tomography for the evaluation of periampullary tumors are the common bile duct (CBD) node and the gastroduodenal artery (GDA) node. We examined whether radiographical enlargement of either lymph node predicts tumor resectability, nodal metastasis, or patient survival. METHODS: Ninety-four consecutive patients underwent attempted curative resection of periampullary tumors between September 2001 and June 2003. A single radiologist recorded in a retrospective, blinded fashion the short- and long-axis measurements of the CBD and GDA nodes. RESULTS: Sixty-one percent (n = 57) of tumors were resectable by pancreaticoduodenectomy. Overall, actual 6-, 12-, and 18-month survival was 87%, 68%, and 63%, respectively. Enlarged radiographical nodal size by either axis was not associated with the presence of metastasis to these lymph nodes or with reduced overall patient survival. Only a CBD node short-axis size >10 mm predicted unresectability (odds ratio, 3.2; P = .036). Liver metastasis and/or carcinomatosis were present in 43% of unresectable patients, and this was associated with decreased survival at both 1 year (25% vs. 77%; P < .001) and 18 months (19% vs. 72%; P <.001). A pathologic diagnosis of metastasis to the GDA node, but not the CBD node, was associated with a similarly decreased survival (1 year: 33% vs. 78%, P = .028; 18 months: 22% vs. 70%, P = .023). CONCLUSIONS: For presumed periampullary malignancy, a CBD node short-axis size >10 mm predicts tumor unresectability. Metastatic disease to the GDA node, particularly for pancreatic adenocarcinoma, portends a poor prognosis equivalent to that of hepatic or peritoneal spread. Given these findings, radiographical CBD lymph node measurements may guide selection for performing laparoscopic staging with or without ultrasonography in conjunction with GDA nodal biopsy in patients with periampullary malignancy.

Abdomen↗
PubMed2005

Factors associated with early recurrence after resection for hepatocellular carcinoma and outcomes.

BACKGROUND: Early recurrence (ER) (<1 year) after liver resection is one of the most important factors that impact the prognosis of patients with hepatocellular carcinoma (HCC). We sought to determine factors associated with ER of HCC and examine the outcomes thereafter. STUDY DESIGN: From March 2001 to June 2003, 56 patients underwent hepatic resection for HCC at University of Toronto and were prospectively followed with median followup of 24 months. Patients with ER were compared with those who remained disease free for more than 1 year. Patient characteristics, tumor stage, and operative procedures were evaluated for their prognostic significance by univariate and multivariable analysis. Time to recurrence and time to death were analyzed using Kaplan-Meier survival curves and compared using log-rank analysis. RESULTS: The initial procedure in all patients was surgical hepatectomy. ER occurred in 21 patients (38%), 31 (55%) remained disease free for more than 1 year, and 4 (7%) were omitted from evaluation because of early (<30 days) death. Median survival after initial hepatic resection for those with ER was 27 months, and 2-year survival was 54%. There were no deaths in the group that remained disease free for more than 1 year (100% 2-year survival, p < 0.05). By multivariate analysis, vascular invasion and positive microscopic margins were significant predictors when all 4 variables were considered in the model (p < 0.05). After ER, 11 of 21 patients (52%) underwent additional therapy with significant improvement in median survival (33 months) compared with those not eligible for conventional therapy (18 months, p = 0.05). CONCLUSIONS: ER after liver resection for HCC is the leading cause of death during the first 2 years after potentially curative resection. ER will develop in approximately 75% of patients with either vascular invasion or positive margins. For patients with these predictive factors additional treatment might be advised.

Adult↗
PubMed2005

Predominant Bcl-XL knockdown disables antiapoptotic mechanisms: tumor necrosis factor-related apoptosis-inducing ligand-based triple chemotherapy overcomes chemoresistance in pancreatic cancer cells in vitro.

Pancreatic cancer is lethal because of its invasiveness, rapid progression, and profound resistance to chemotherapy and radiation therapy. To identify the molecular mechanisms underlying this, we have examined the expression and potency of three major death receptors: tumor necrosis factor receptor (TNF-R), TNF-related apoptosis-inducing ligand receptor (TRAIL-R), and Fas in mediating cytotoxicity in four invasive pancreatic cancer cell lines. We have analyzed the expression of major antiapoptotic factors, cell cycle regulators and death receptor decoys (DcR) in comparison with normal pancreas tissues and five other human malignant tumor cell lines. We have found that different pancreatic cancer cell lines coexpress high-level TRAIL-R, Fas, and TNF-R1 but are strongly resistant to apoptosis triggered by the death receptors. DcR2 and DcR3 overexpression may partly contribute to the resistance of pancreatic cancer cells to TRAIL-R- and Fas-mediated cytotoxicity. Bcl-XL and Bcl-2 are predominantly overexpressed in pancreatic cancer cell lines, respectively. Bcl-XL is also predominantly overexpressed in prostate, colorectal, and intestinal cancer cells. The knockdown of the predominant Bcl-XL overexpression significantly reduces the viability of pancreatic cancer cells to TNFalpha- and TRAIL-mediated apoptosis by sublethal-dose single and combined antitumor drugs, including geldanamycin, PS-341, Trichostatin A, and doxorubicine. Geldanamyin and PS-341 synergistically block NFkappaB activation, suppress Akt/PKB pathway, and down-regulate Bcl-XL, Bcl-2, cIAP-1, and cyclin D1 expression. This combined regimen dramatically enhances TRAIL cytotoxic effects and breaks through chemoresistance. Bcl-XL plays a vital role in pancreatic cancer chemoresistance. Geldanamycin, PS-341, and TRAIL triple combination may be a novel therapeutic strategy for pancreatic cancer.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed2005

Transduodenal resection of peri-ampullary lesions.

Transduodenal resection (TDR) of lesions near the ampulla of Vater is an alternative to the Whipple pancreaticoduodenectomy. A retrospective analysis was performed to determine the long-term outcome and the utility of intraoperative frozen section examinations in aiding operative decision making in patients undergoing TDR. From 1992 to 2002, 19 patients with an average age of 64.2 years (range: 33-84 years) underwent a transduodenal resection of a peri-ampullary lesion; median follow-up was 47 months (range: 2-100 months). Pathology of the lesions was as follows: 11 with benign ampullary adenomas, including 4 with familial adenomatous polyposis (FAP); 7 with peri-ampullary adenocarcinomas; and 1 with a benign stricture. Survival for the entire cohort is 100%. In 12 cases an intraoperative frozen section was performed. The specificity and positive predictive value of the intraoperative histology were both 100%, and the sensitivity and negative predictive value were 57% and 38%, respectively. Three of the 4 patients with FAP have recurrent adenomatous change; 2 of the 7 with carcinoma have metastatic adenocarcinoma. Transduodenal resection of peri-ampullary lesions appears to be a safe alternative to radical resection for benign adenomas and selected carcinoma. Intraoperative frozen section assessment is recommended in cases of potential adenocarcinoma.

Adenocarcinoma↗
PubMed2005

Vascular occlusion to decrease blood loss during hepatic resection.

BACKGROUND: Historically, the primary hazard with liver surgery has been intraoperative blood loss. This led to the refinement of inflow and outflow occlusive techniques. The utility of the different methods of inflow and outflow techniques for hepatic surgery were reviewed. METHODS: A search of the English literature (Medline, Embase, Cochrane library, Cochrane clinical trials registry, hand searches, and bibliographic reviews) using the terms "liver," "hepatic," "Pringle," "total vascular exclusion," "ischemia," "reperfusion," "inflow," and "outflow occlusion" was performed. RESULTS: A multitude of techniques to minimize blood loss during hepatic resection have been studied. The evidence suggests that inflow occlusion techniques are generally well tolerated. These should be used with caution in patients with cirrhosis, fibrosis, steatosis, cholestasis, and recent chemotherapy, and for prolonged time intervals. CONCLUSIONS: Harmful effects of intraoperative blood loss and transfusion occur during hepatic resection. Portal triad clamping (PTC) is associated with less blood loss compared with no clamping. In procedures with ischemic times <1 hour in length, PTC-C (continuous) is likely equal to PTC-I (intermittent). In patients with chronic liver disease or undergoing lengthy operations, PTC-I is likely superior to PTC-C. PTC is superior to total vascular exclusion except in patients with tumors that are large and deep seated, hypervascular, and/or abutting the hepatic veins or vena cava and in patients with increased right-sided heart pressures.

Blood Loss, Surgical↗
PubMed2005

Training, practice, and referral patterns in hepatobiliary and pancreatic surgery: survey of general surgeons.

Subspecialization has changed the way that general surgery is practiced. Hepatobiliary and pancreatic surgery (HPB) is maturing as a subspecialty. The objective of this study was to identify the current levels of practice, self-assessments of adequacy of training, referral patterns, and perceptions regarding regionalization of HPB care to high-volume centers. A total of 240 nonstratified general surgeons from across Canada were randomly selected to receive a survey developed by an expert work group. A reference group of 10 HPB specialists were also polled for a total of 250 respondents. The overall response rate was 73% (182 responders). Subspecialty training had been completed by 65% of respondents. This included surgical oncology (15%), HPB (15%), HPB and transplant (8%), laparoscopy (7%), liver transplantation (5%), and other (50%). This training was obtained in Canada (51%), the United States (35%), Europe (11%), and Australia (3%). Ninety-five percent of responders believed that some HPB services should be regionalized. Similarly, most responders thought that they were not adequately trained to perform these procedures. The following were especially considered subspecialty procedures: major hepatectomy (93%), pancreaticoduodenectomy (90%), and biliary reconstruction (79%). The majority of non-HPB surgeons do not consider themselves adequately trained to perform complex HPB procedures. Furthermore, most surgeons think that major hepatectomy, pancreaticoduodenectomy, and biliary reconstruction should be referred to HPB specialists at high-volume centers.

Adult↗
PubMed2005

An aggressive surgical approach leads to improved survival in patients with gallbladder cancer: a 12-year study at a North American Center.

OBJECTIVE: To determine if an aggressive surgical approach, with an increase in R0 resections, has resulted in improved survival for patients with gallbladder cancer. SUMMARY BACKGROUND DATA: Many physicians express a relatively nihilistic approach to the treatment of gallbladder cancer; consensus among surgeons regarding the indications for a radical surgical approach has not been reached. METHODS: A retrospective review of all patients with gallbladder cancer admitted during the past 12 years was conducted. Ninety-nine patients were identified. Cases treated during the 12-year period 1990 to 2002 were divided into 2 time-period (TP) cohorts, those treated in the first 6 years (TP1, N = 35) and those treated in the last 6 years (TP2, N = 64). RESULTS: Disease stratification by stage and other demographic features were similar in the 2 time periods. An operation with curative intent was performed on 38 patients. Nine (26%) R0 resections were performed in TP1 and 24 (38%) in TP2. The number of liver resections, as well as the frequency of extrahepatic biliary resections, was greater in TP2 (P < 0.04). In both time periods, an R0 resection was associated with improved survival (P < 0.02 TP1, P < 0.0001 TP2). Overall survival of all patients in TP2 was significantly greater than in TP1 (P < 0.03), with a median survival of 9 months in TP1 and 17 months in TP2. The median 5-year survival in TP1 was 7%, and 35% in TP2. The surgical mortality rate for the entire cohort was 2%, with a 49% morbidity rate. CONCLUSIONS: A margin-negative, R0 resection leads to improved survival in patients with gallbladder cancer.

Adult↗
PubMed2004

Multipurpose extended subcostal incision for hepatobiliary surgery.

Exposure is especially important for procedures performed on the liver and biliary tract where careful, precise anatomic dissection of vascular and biliary structures is required. We describe a modified subcostal incision that provides both safe exposure and versatility for most hepatobiliary procedures.

Biliary Tract Surgical Procedures↗
PubMed2004

Living-donor right hepatectomy with or without inclusion of middle hepatic vein: comparison of morbidity and outcome in 56 patients.

Venous congestion of segments V and VIII is observed frequently in living-donor right lobe liver transplants without middle hepatic vein (MHV) drainage, and can be a cause of graft dysfunction and failure. Inclusion of the MHV with the graft is controversial, however, because of the perceived potential for increased donor morbidity. We compared the outcome of living liver donors in whom the MHV was either left intact in the donor (group 1; n = 28) or was removed with the graft (group 2; n = 28). All prospective donors completed an extensive multidisciplinary evaluation to determine suitability for surgery and to ensure that the MHV could be removed safely without compromising venous outflow from the remaining liver. Patient demographics including age, weight, body-mass index, and liver volumetry as determined by computerized tomography were similar in both groups. Operative time in group 2 was significantly shorter than in group 1. There was no difference in estimated blood loss, transfusion requirements, peak serum liver tests, time interval from surgery to complete normalization of liver tests, complications, and length of hospitalization. We conclude that including the MHV with living-donor right lobe grafts can be performed safely in most donors.

Adult↗
PubMed2002

Utility of staging laparoscopy in subsets of peripancreatic and biliary malignancies.

OBJECTIVE: To determine the relative benefit of staging laparoscopy in peripancreatic and biliary malignancies. SUMMARY BACKGROUND DATA: Staging laparoscopy has been used in a variety of peripancreatic and biliary malignancies. The utility of the technique in subsets of these types of cancer has not been systematically compared. METHODS: One hundred fifty-seven patients underwent laparoscopy after conventional tumor staging; 89 were also staged with laparoscopic ultrasonography. Diagnostic categories were cancer of the pancreatic head and uncinate process, cancer of the body and tail of pancreas, cancer of the extrahepatic bile duct, cancer of the gallbladder, and cancer of the ampulla of Vater/duodenum. RESULTS: In patients with cancer of the head of the pancreas, metastatic disease or vascular invasion was discovered frequently by laparoscopy (31%), whereas in ampullary/duodenal cancer it was never found. The laparoscopic findings in cancer of the head of the pancreas had an important influence on treatment decisions, whereas in cancer of the ampulla/duodenum, laparoscopy had no effect on clinical decisions. Laparoscopy also substantially influenced the treatment of gallbladder cancer; in other tumor types, results were intermediate. Laparoscopic ultrasonography was valuable in cancer of the head of the pancreas. CONCLUSIONS: The utility of staging laparoscopy depends on diagnosis. It is recommended for continued use in pancreatic head and gallbladder cancers but not in ampullary malignancies.

Adult↗