Risk Factors and Clinical Outcome for Anastomotic Leakage After Total Mesorectal Excision for Rectal Cancer

BACKGROUND: Anastomosis leakage is a major complication of rectal surgery. The aim of this study was to identify risk factors for anastomotic leakage after low anterior resection (LAR) in rectal cancer patients and study its impact on long-term prognosis and disease-free survival and overall survival in rectal cancer patients. METHODS: Consecutive patients who underwent rectal resection with primary anastomosis below the pelvic peritoneal reflexion for rectal cancer between October 1996 to February 2006 were included. RESULTS: Anastomosis leakage after LAR occurred in 51 patients (4.0%). The median time to leakage was 4 days (range = 2-30 days). In univariate analysis, gender, level of anastomosis less than 4 cm, preoperative concomitant chemoradiation (CCRT), and length of operation greater than 120 min were significantly associated with anastomosis leakage. In a multivariate analysis, gender (p = 0.041; relative risk = 2.007; 95% CI = 1.030-3.912) and preoperative CCRT (p = 0.003; relative risk = 2.861; 95% CI = 1.417-5.778) were identified as independent prognostic factors. The overall survival of the nonleakage group and the leakage group was 80.2% and 64.9%, respectively (p = 0.170). The 5-year disease-free survival rates were not significantly different between the nonleakage and leakage groups (78.1% vs. 65.9%, p = 0.166). CONCLUSIONS: The incidence of anastomotic leakage after low anterior resection is relatively low. Male gender and preoperative CCRT were associated with increased risk for anastomotic leakage after rectal cancer surgery. No effect of anastomosis leakage on local recurrence was found in this series.     

Laparoscopic-Assisted Combined Colon and Liver Resection for Primary Colorectal Cancer with Synchronous Liver Metastases: Initial Experience

BACKGROUND: Laparoscopic approaches have become increasingly used in selected patients with either colorectal or liver cancer. However, the feasibility of laparoscopic-assisted combined colon and liver resection in primary colorectal cancer with synchronous liver metastases remains unknown. The aim of the present study was to determine the feasibility of laparoscopic-assisted combined colon and liver resection for primary colorectal cancer with synchronous liver metastases. METHODS: Laparoscopic surgery involving intestinal anastomosis was performed for primary colorectal cancer. The liver was then mobilized with the assistance of a hand inserted through the upper midline incision. For minor resections, the parenchymal transection was performed laparoscopically. For major resection involving a hilar dissection, transection was performed according to the standard open techniques under direct vision through the incision. Resected specimens were retrieved directly through the midline incision. RESULTS: Ten patients with primary colorectal cancer and synchronous liver metastases underwent the above procedure between September 2006 and April 2007. Surgical procedures for colorectal cancer included 5 low anterior resections, 3 anterior resections, 1 right hemicolectomy, and 1 subtotal colectomy. Combined hepatic surgery included 6 major hepatectomies, 3 segmentectomies, and 1 tumorectomy. All procedures were successful, with no conversions to open surgery required. The median operation time was 439 min (range: 210-690 min), and the median estimated blood loss was 350 ml (range: 300-1,200 ml). There was no surgical mortality or major morbidity, except in one patient in whom postoperative bleeding at the site of para-aortic node dissection was promptly controlled. CONCLUSIONS: Laparoscopic-assisted combined colon and liver resection is a feasible and safe procedure for the treatment of primary colorectal cancer with synchronous liver metastases.     

Proteomic analysis to identify biomarker proteins in pancreatic ductal adenocarcinoma

Background: Pancreatic ductal adenocarcinoma (PDAC) is the fifth most common cause of death from cancer in Korea. PDAC is difficult to diagnose at an early stage and even more difficult to cure. Thus, there is an urgent need to identify molecular targets for early diagnosis and effective treatment. The objectives of this study were to identify differentially expressed biomarker proteins of PDAC using proteomic analysis, to validate the identified biomarker proteins associated with carcinogenesis using western blot analysis and to evaluate clinical factors influencing expression of candidate biomarker proteins. Methods: In the present study, we carried out proteomic analysis in 10 pairs of PDAC specimens with matching adjacent normal tissues to clarify the different patterns of protein expression. The proteins were separated by high‐resolution 2‐D polyacrylamide gel electrophoresis (2D PAGE) and the differentially expressed proteins were identified by matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry (MALDI‐TOF MS). Differential expression of candidate biomarker proteins associated with carcinogenesis was further validated using western blot analysis. Standard statistical analysis was carried out in an attempt to establish a correlation between clinical variables and expression of candidate biomarker proteins. Results: Analysis of PDAC and the adjacent normal tissues showed reproducibly similar proteomic patterns for each group. Approximately 700 spots each were seen by silver‐stained gels from both PDAC and normal tissues. Differentially expressed protein spots were gel digested and identified by MALDI‐TOF MS. Twenty‐five proteins were identified, of which five proteins (galectin‐1, enolase‐2, α‐1‐antitrypsin, N‐myc interactor, peroxiredoxin‐4) were previously reported as being differentially expressed either at the mRNA level or protein level in human cancer. The five proteins were selected for candidate biomarker proteins related to carcinogenesis. These proteins were further validated by western blot analysis. Among the candidate biomarker proteins, galectin‐1 expression was highly correlated to histology (P = 0.019), T stage (P = 0.047), N stage (P = 0.033) and American Joint Committee on Cancer stage (P = 0.011). Conclusion: Differentially expressed 25 proteins in PDAC were identified using proteomic analysis and five proteins related to carcinogenesis were validated by western blot analysis. galectin‐1 expression was highly correlated to tumour histology and stage.     

Treatment Guidelines for Branch Duct Type Intraductal Papillary Mucinous Neoplasms of the Pancreas: When Can We Operate or Observe?

Background The objectives of this study were to investigate the clinicopathological features of branch intraductal papillary mucinous neoplasm (IPMN) and to determine safe criteria for its observation. Most clinicians agree that surgical resection is required to treat main duct-type IPMN because of its high malignancy rate. However, no definite treatment guideline (with respect to surgery or observation) has been issued on the management of branch duct type IPMN. Methods We retrospectively reviewed the clinicopathological data of 138 patients who underwent operations for IPMN between 1993 and 2006 at five institutes in Korea. Results Of 138 patients (mean age, 60.6 years; 87 men, 51 women), 76 underwent pancreatoduodenectomy, 39 distal pancreatectomy, 4 total pancreatectomy, and 20 limited pancreatic resection. There were 112 benign cases: 47 adenoma, 63 borderline cases, and 26 malignant cases, with 9 of these being noninvasive and 17 invasive. By univariate analysis, tumor size and the presence of a mural nodule were identified as meaningful predictors of malignancy. By receiver operating characteristic curve analysis, a tumor size of >2 cm was found to be the most valuable predictor of malignancy. When cases were classified according to tumor size and the presence of a mural nodule, the malignancy rate for a tumor ≤2 cm without a mural nodule was 9.2%, for a tumor of ≤2 cm plus a mural nodule was 25%, and for other conditions such as tumor >2 cm, >25%. Conclusions Many branch duct IPMNs are malignant. Surgical treatment is recommended, except in cases that are strongly suspected to be benign or cases that present a high operative risk. Observation is only recommended in patients with a tumor size of ≤2 cm without a mural nodule.     

Feasibility of Single-Stage Laparoscopic Resection After Placement of a Self-Expandable Metallic Stent for Obstructive Left Colorectal Cancer

BACKGROUND: The present study investigated the feasibility of a single-stage operation consisting of self-expandable metallic stent (SEMS) placement followed by laparoscopic surgery for obstructive left colorectal cancer. METHODS: From July 2002 to March 2007, 17 consecutive patients with primary obstructive left colorectal cancer underwent SEMS placement followed by laparoscopic surgery. Data were collected retrospectively regarding clinicopathological findings, SEMS placement, operative procedures, and perioperative outcomes. Technical success was defined as successful stent deployment across the obstructive lesion, and clinical success as the possibility of performing a single-stage operation without creating a stoma. RESULTS: In the laparoscopic group, the technical success rate was 100% (17/17) and there was no morbidity associated with SEMS placement. The median interval to laparoscopic surgery was 7 (range, 2-11) days, and the procedures included 11 anterior resections, 3 left hemicolectomies, 2 Hartmann's procedures, and 1 subtotal colectomy. All procedures were completed laparoscopically without conversion to open surgery. The median operating time was 178 (range, 93-377) minutes, and the median estimated blood loss was 100 (range, 50-400) ml with no cases requiring intraoperative transfusions. The clinical success rate was 82.4% (14/17), and there was no surgical morbidity other than two patients in whom chyloperitoneum and ileus were controlled by using conservative management. The median postoperative hospital stay was 9 (range, 7-49) days. CONCLUSIONS: A single-stage operation consisting of SEMS placement followed by laparoscopic surgery seems to be a feasible and safe treatment option for obstructive left colorectal cancer.     

Low-pressure laparoscopy may ameliorate intracranial hypertension and renal hypoperfusion

BACKGROUND: Increased abdominal pressure is associated with elevations in the intracranial pressure (ICP) and impaired renal function. These adverse effects are potentially important in clinical situations such as severe abdominal trauma and laparoscopic donor nephrectomy. It was hypothesized that the secondary elevation of ICP leads to release of vasoconstrictors, which may affect renal function by decreasing the renal blood flow (RBF). We investigated the effect of laparoscopy on ICP and renal blood flow in a porcine model. MATERIALS AND METHODS: The abdominal pressure of swine (N = 5; 20-25 kg) was gradually increased from baseline to 5, 15, and 25 mm Hg by insufflation of nitrogen into the abdominal cavity. The ICP was measured using a Camino monitor, and RBF was simultaneously measured using a Transonic Doppler probe placed on the renal artery. Results were analyzed using repeated measures ANOVA and the paired t-test. RESULTS: No significant change from baseline was observed in ICP and RBF when the abdominal pressure was 5 mm Hg. However, both ICP and RBF were affected by increasing the abdominal pressure to 15 and 25 mm Hg (P = 0.035 and 0.04 for ICP and P = 0.074 and 0.034 for RBF, respectively). CONCLUSIONS: Low-pressure laparoscopy may reduce the adverse effects of pneumoperitoneum on ICP and RBF. It may be advisable to use low pressures in laparoscopic surgery, especially when changes in ICP or renal perfusion may have significant clinical implications.     

Transduodenal local resection for low-risk group ampulla of vater carcinoma

BACKGROUND: Carcinoma of the ampulla of Vater has a more favorable prognosis, compared to other malignant tumors of the periampullary region, because it usually presents with symptoms in the early stage. However, treatment by local resection only of the ampullary carcinoma remains controversial. The aim of this study was to evaluate the treatment results of the ampulla of Vater carcinoma according to different types of operation in low-risk-group patients. METHODS: We retrospectively reviewed the medical records of 17 low-risk-group patients among a total of 102 patients with ampulla of Vater carcinoma who had underwent curative surgery from 1992 to 2002. All specimens were critically reviewed by a single expert pathologist, and the relationship between surgical outcomes and operation type was assessed. RESULTS: The low-risk group was comprised of 10 men and 7 women with a median age of 57.8 years. Thirteen of 17 patients underwent a pancreaticoduodenectomy (PD) or a pylorus preserving pancreaticoduodenectomy (PPPD), while 4 patients underwent a transduodenal local resection (TDLR). The operation time was significantly shorter in the TDLR group, compared to the PD or PPPD groups. Among the 17 patients, there was only 1 case of recurrence in the inguinal area 33 months after the pancreaticoduodenectomy. CONCLUSIONS: Transduodenal local resection is a comparable mode of operation for low-risk-group patients with Ampulla of Vater carcinoma. In particular, it is essential to evaluate the invasion depth in preoperative endoscopic ultrasonography, cell differentiation in preoperative biopsy, and positivity of resection margin accurately by using frozen section during the operation.