Hidenobu Masui

Male sexual function after autonomic nerve-preserving operation for rectal cancer

PURPOSE: Sexual dysfunction after surgery of the rectum is a serious complication to male patients. Autonomic nerve-preserving operation for rectal cancer has been performed within the recent ten years to maintain urinary and male sexual functions without spoiling of therapeutic radicality. To clarify male sexual function as the degree of autonomic nerve-preserving operation, the function was outlined through clinical interview. METHOD: In a series of 134 male patients who were undergoing autonomic nerve-preserving operation for rectal cancer, a detailed history of postoperative sexual function was obtained by interviews. RESULTS: In 87.7 and 66.9 percent of patients, erectile and ejaculatory potencies were maintained, respectively, which were higher rates than those after extended and conventional pelvic dissections. According to the preserving extent of autonomic nerve, patients undergoing complete preserving operations showed higher rates of maintained erectile (92.9 percent) and ejaculatory functions (82.5 percent), sexual intercourse (89.9 percent), and orgasm (93.9 percent) compared with those undergoing hemilateral autonomic nerve-preserving (82.3, 47.1, 52.9, 64.7 percent) or partial pelvic plexus-preserving operation (61.1, 0, 26.3, 22.2 percent). CONCLUSION: Pelvic plexus preservation is necessary to maintain erectile potency, and both hypogastric nerve and pelvic plexus preservation are necessary to maintain ejaculate function and orgasm. To maintain satisfactory sexual function, complete autonomic nerve-preserving operation is suitable.

DETECTION OF REGIONAL LYMPH NODE METASTASES IN COLON CANCER BY USING RT-PCR FOR MATRIX METALLOPROTEINASE 7, MATRILYSIN

Lymph node metastasis is the most important prognostic factor in colon cancer. However, more accurate screening for metastasis than that afforded by conventional pathology remains elusive. We have employed a reverse transcriptase-polymerase chain reaction (RT-PCR) assay for a matrix metalloproteinase (MMP), ‘matrilysin’, because this gene is epithelial-specific and consistently expressed in colorectal cancer cells. The sensitivity of this assay was examined with the matrilysin-producing rectal cancer cell line ‘CaR-1’. Matrilysin mRNA was detected in this system when more than 10 matrilysin-positive cells existed in a lymph node of ordinary size. Fourteen of 15 (93%) primary colon cancers and none of the surrounding normal tissues expressed matrilysin. All 10 histologically-positive lymph nodes were positive for matrilysin, while of 60 histologically-negative lymph nodes, eight were positive for matrilysin. When the additional sequential sectioning and histological re-examinati on was performed on five of these eight ‘matrilysin-positive, but histologically-negative’ lymph nodes, micrometastases were detected in three. Only one of the lymph nodes that were histologically-positive, but negative by matrilysin assay was from a patient with colon cancer in which matrilysin was not detected. In conclusion, RT-PCR assay for matrilysin is a sensitive method for detecting occult metastases in patients with colon cancer, and may complement histologic examination.

Results of surgical treatment for multiple (≥5 nodules) bi-lobar hepatic metastases from colorectal cancer

BackgroundThe surgery for the treatment of multiple (≥5) bi-lobar hepatic metastases from colorectal cancer is controversial. This retrospective study presents our experience in an attempt to develop reasonable treatment guidelines.MethodOne hundred sixty-one consecutive patients who underwent liver resection with curative intent were classified into three groups: H1 (unilateral), H2 (bilateral, ≤4 nodules), or H3 (bilateral, ≥5 nodules).ResultsThe overall cumulative 5-year survival rate was 46.7%. Survival was similar among patients with H1, H2, and H3 disease. Thirty-two patients with H3 disease underwent hepatectomy: straightforward hepatectomy in 12, portal vein embolization (PVE) prior to hepatectomy in eight, two-stage hepatectomy in two, and two-stage hepatectomy combined with PVE in ten. Two-stage hepatectomy with or without PVE was the standard approach in patients with synchronous liver metastases. The operating mortality in hepatectomy for H3 disease was 0%, and the morbidity was 15.2%. The overall response rate to neoadjuvant chemotherapy (NAC) was 41.7% (5/12). Patients who responded to NAC (n=5) had a better prognosis than non-responders (n=7) (P<0.05).ConclusionsExtended hepatectomy, including preoperative PVE and multi-step hepatectomy, combined with NAC, may result in a favourable prognosis, especially in patients who respond to NAC, but further studies with more patients are needed to confirm this.

Treatment strategies for hepatic metastasis from colorectal cancer

Hepatic micrometastases of the parenchyma adjacent to a macroscopic lesion were detected in 17 of 31 resected liver metastases. Fifty-nine micrometastatic lesions were detected in total; 26 lesions were situated in the portal vein (PV), 22 in the central vein (CV), 5 in the bile duct (BD), and 6 in the sinusoid (SS). A histological study confirmed the direct invasion of the macrometastatic cancer cells into the adjacent PV, CV, BD, and SS. According to the tumor doubling time, the mean diameter of the macrometastases in 19 remnant livers was calculated to have been 0.57±0.87 cm at the time of the primary resection. The calculated diameter of 3 of these 19 macrometastases was found to be less than 0.01 cm, the minimum implantable size, indicating that the cancer recurrence in these specimens may have developed from macroscopic metastatic lesions as a satellite, and not from the primary tumor. In 13 patients who received doses of 5250 mg or more of 5 fluorouracil (FU) via the hepatic artery, the cumulative disease-free rate 2 years postoperatively was 100%; this value was 47.6% in 11 patients who received less than 5250 mg of 5 FU via the hepatic artery, and 0% in 39 patients who received no chemotherapy (P<0.005). These results suggest that anatomical hepatic resection for satellite lesions, combined with prophylactic hepatic arterial chemotherapy for micrometastases, decreases the recurrence rate of hepatic metastases in the remnant liver.

A case of lymphoepithelioma-like carcinoma of the colon with ulcerative colitis

Follow-up colonoscopy of a 25-year-old Japanese man with ulcerative colitis (UC) who had undergone endoscopic mucosal resection twice for early colon cancers revealed the presence of a new 1.5-cm-diameter tumor in the sigmoid colon. It was diagnosed by preoperative biopsy as a poorly differentiated adenocarcinoma. Sigmoidectomy was performed, and the pathological findings revealed lymphoepithelioma-like carcinoma (LEC). In situ hybridization to detect Epstein-Barr virus (EBV)-encoded small RNAs showed positive signals in stromal lymphocytes, but weak signals in the tumor cells. The association between EBV and LEC was obscure in this case. Unlike typical UC-mediated colon cancers, the lesion was poorly differentiated, and negative for p53 signals immunohistochemically. These findings may hint at a novel mechanism of carcinogenesis in UC-mediated colorectal cancer.

Caudate Lobectomy Combined with Resection of the Inferior Vena cava and Its Reconstruction by a Pericardial Autograft Patch

A 53-year-old woman with remnant liver metastasis originating from colon cancer was referred to our department. She underwent successful caudate lobectomy combined with resection of the inferior vena cava (IVC), including reconstruction with a pericardial autograft patch. IVC clamping was performed between the IVC below the confluence of the left hepatic vein and the infrahepatic IVC in order to preserve the hepatic circulation. After 18 months, the graft was patent and there was no sign of recurrence. A part of the pericardium used as an autograft for patch repair of the defect of the IVC was very useful because it was easily available, required only division of the diaphragm, and was of sufficient length and width.

Real-Time Indocyanine Green Fluorescence Imaging-Guided Complete Mesocolic Excision in Laparoscopic Flexural Colon Cancer Surgery.

INTRODUCTION: Laparoscopic surgery for colon cancer located in the hepatic flexure or splenic flexure is not standardized, because lymphatic drainage at this site may vary and the precise site of lymphatic dissection is uncertain. TECHNIQUE: Indocyanine green was injected into the submucosal layer around the tumor at 2 points with a 23-gauge localized injection before lymph node dissection and the lymph flow was observed using a near-infrared camera system 30 minutes after injection. In addition, a complete mesocolic excision with central vascular ligation guided the region where the lymph flow was fluorescently observed. RESULTS: A total of 20 consecutive patients (hepatic flexure, 10 patients; splenic flexure, 10 patients) were enrolled in this study. All of the procedures were safely performed without any complications. The lymph flow was visualized in 19 patients (95%) intraoperatively. Modification of the operative methods was required for 5 patients (modification in the separation line of the mesocolon and vessel selection for central vascular ligation) because the area of lymph flow observed during surgery differed from that of the preoperative diagnosis. CONCLUSION: Intraoperative real-time visualization of the lymph flow using indocyanine green fluorescence imaging during laparoscopic colon cancer surgery, especially flexural colon cancer surgery, is feasible and a helpful technique for identifying appropriate central vessels to be dissected and for determining an appropriate separation line of the mesentery.

Clinicopathological and Prognostic Evaluations of Mixed Adenoneuroendocrine Carcinoma of the Colon and Rectum: A Case-Matched Study

BACKGROUND: Mixed adenoneuroendocrine carcinoma of the colon and rectum is a very rare type of tumor. OBJECTIVE: The aim of the present study was to evaluate the clinicopathological characteristics and prognosis of mixed adenoneuroendocrine carcinomas of the colon and rectum. DESIGN: This was a retrospective case-matched analysis (from March 2007 to December 2013). SETTINGS: This study was conducted at Yokosuka Kyosai Hospital. PATIENTS: One thousand three hundred six consecutive patients with a preoperative diagnosis of colorectal cancer and who underwent tumor resection were enrolled in the present study. Each patient diagnosed with mixed adenoneuroendocrine carcinoma was 1:2 matched with 2 counterparts who had been diagnosed with adenocarcinoma. INTERVENTION: Immunohistochemical staining for neuroendocrine markers (chromogranin A, synaptophysin, and CD56) was performed. Cases in which the neuroendocrine component accounted for >30% of the tumor were diagnosed as mixed adenoneuroendocrine carcinomas. RESULTS: Among 1306 patients, 42 patients (3.2%) were diagnosed with mixed adenoneuroendocrine carcinoma and were compared with 84 patients with adenocarcinoma who had been randomly case matched. The average Ki-67–labeling index value was 78.0% (range, 30.0%–99.0%). Chromogranin A, synaptophysin, and CD56 positivity were observed in 42.9% (18/42), 81.0% (34/42), and 33.3% (14/42) of the tumors. Both the disease-free survival and overall survival were significantly worse for mixed adenoneuroendocrine carcinoma than for adenocarcinoma. Ten patients underwent treatment with oxaliplatin-based chemotherapy. The response rate was 40.0%; the median progression-free survival and overall survival were 6.3 months and 18.1 months. LIMITATIONS: This was a retrospective single-institution study that included a limited number of cases. The treatment regimens used included different types of oxaliplatin-based chemotherapy. CONCLUSION: Mixed adenoneuroendocrine carcinoma of the colon and rectum has a poor prognosis after curative resection and should be distinguished from adenocarcinoma.

Right hepatic lobectomy and removal of inferior vena caval tumor embolus in a patient with hepatocellular carcinoma, using veno-venous bypass while preserving perfusion in the remnant liver: A case report

We describe a successful hepatectomy and the removal of a tumor embolus in a 43-year-old woman with hepatocellular carcinoma occupying the right lobe extending to the right branch of the portal vein and the inferior vena cava (IVC). Intraoperative echography revealed the tumor embolus in the IVC to originate from the main tumor via the right inferior hepatic vein, which extended cephalad from the confluence of the right hepatic vein to the IVC. Right hepatc lobectomy was performed via the anterior approach. Using femoro-axillary veno-venous bypass, we opened the IVC at the root of the inferior right hepatic vein to remove the tumor embolus after oblique clamping of the IVC between the right and middle hepatic veins was carried out to preserve perfusion in the remnant liver. Preserving perfusion in the remmant liver in radical hepatectomy for hepatocellular carcinoma with tumor embolism in the IVC appears to be a safe and advantageous technique in patients with poor liver reserve.

Single-Incision Laparoscopic Anterior Resection Using a Curved Stapler.

INTRODUCTION:Single-incision laparoscopic colectomy is technically limited because of such factors as instrument crowding, in-line viewing, and insufficient countertraction. In particular, it is technically difficult to cut the distal rectum from the umbilicus using an articulating linear stapler in single-incision laparoscopic anterior resection. TECHNIQUE:After treating the mesorectum, the 5-mm trocar is replaced with a 12-mm trocar. The cartridge of the curved stapler is mounted while the shaft of the stapler is inserted into the 12-mm port extracorporeally. The curved stapler is inserted through the umbilical incision with the cartridge. A multichannel port is then mounted, and the abdominal cavity is reinsufflated. The curved stapler can then be operated intracorporeally. This procedure facilitates the vertical dissection of the rectum from the umbilicus. RESULTS:A total of 27 consecutive patients were analyzed in this study. All the procedures were safely performed without any complications. The median distance from the peritoneal reflection to the transection point of the distal bowel in single-incision laparoscopic anterior resection was 5.0 cm (range, –2.0 to 15.0). One stapler firing was required to achieve distal bowel division in 26 patients (96.3 %), whereas 2 firings were required in 1 patient (3.7 %). The median distal margin was 7.0 cm (range, 3.0–13.0). The time from the insertion of the stapler to transection was 180 seconds (range, 100–420). There were no cases of anastomotic leakage. CONCLUSIONS:In single-incision laparoscopic anterior resection, it is feasible to perform rectal transection from the umbilicus by using a curved stapler. This technique may allow for the omission of 1 trocar from the operation.