Takaaki Matsudo

Deregulation of miR-92a expression is implicated in hepatocellular carcinoma development

MicroRNAs (miRNAs) belong to a class of the endogenously expressed non‐coding small RNAs which primarily function as gene regulators. Growing evidence suggests that miRNAs have a significant role in tumor development and may constitute robust biomarkers for cancer diagnosis and prognosis. The miR‐17‐92 cluster especially is markedly overexpressed in several cancers, and is associated with the cancer development and progression. In this study, we have demonstrated that miR‐92a is highly expressed in hepatocellular carcinoma (HCC). In addition, the proliferation of HCC‐derived cell lines was enhanced by miR‐92a and inhibited by the anti‐miR‐92a antagomir. On the other hand, we have found that the relative amount of miR‐92a in the plasmas from HCC patients is decreased compared with that from the healthy donors. Interestingly, the amount of miR‐92a was elevated after surgical treatment. Thus, although the physiological significance of the decrease of miR‐92a in plasma is still unknown, deregulation of miR‐92 expression in cells and plasma should be implicated in the development of HCC.

Bacterial contamination in ascitic fluid is associated with the development of clinically relevant pancreatic fistula after pancreatoduodenectomy.

Objectives Clinically relevant postoperative pancreatic fistula (POPF) after pancreatoduodenectomy is often accompanied by bacterial infection. To elucidate the mechanism of bacterial infection associated with POPF, we investigated the relationship between POPF and bacteria isolated from ascitic fluid and removed drains. Methods Subjects were 101 patients who had undergone pancreatoduodenectomy. Microbial culture was performed using ascitic fluid obtained from drains. We also compared the isolated bacteria from removed drains on postoperative day (POD) 4 and after POD 7. Results In 23 patients (22.8%), microbial cultures were already positive on POD 1, although purulent discharge was not observed. Among patients with grade B/C POPF, bacteria were detected on POD 1 in 53.8%; these isolated bacteria were the same as those isolated after POPF formation. In contrast, only 7.7% of patients with grade A POPF were positive on POD 1. The number of bacteria isolated from drains removed after POD 7 significantly increased compared with those isolated from drains removed on POD 4. Conclusions Bacterial contamination in ascitic fluid may be an initiating event that leads to the development of clinically relevant POPF. Therefore, it is important to perform both the administration of the appropriate antibiotics and early drain removal.

p53 gene mutation and p53 protein overexpression in a patient with simultaneous double cancer of the gallbladder and bile duct associated with pancreaticobiliary maljunction

Pancreaticobiliary maljunction (PBM) is associated with the occurrence of biliary cancer due to pancreatobiliary reflux. We present a case of simultaneous double cancer of the gallbladder and bile duct. A 77-year-old woman who had jaundice, intra- and extra-hepatic biliary ductal dilatation and a space-occupying lesion in the gallbladder and lower bile duct underwent pancreatoduodenectomy. The gallbladder cancer showed papillary carcinoma without mutation of the K-ras gene and with p53 non-sense mutation of CCA (Pro) to CA (Stop) on codon 301 in exon 8. The bile duct cancer revealed a well-differentiated adenocarcinoma without mutation of the K-ras gene and with p53 miss-sense mutation of GTG (Val) to GAG (Glu) on codon 272 in exon 8. There were no mutations of either the K-ras or p53 gene in non-cancerous epithelia. In contrast, only the mucosa of the common channel had p53 protein accumulation and high cell proliferation activity. Therefore, the genetic pathway might be the same in both the gallbladder and bile duct cancer, and a high potential for carcinogenesis might be present in the epithelium of the common channel in patients with PBM.

The VIO soft-coagulation system can prevent pancreatic fistula following pancreatectomy

BACKGROUND/PURPOSE The VIO soft-coagulation system (SC) is a new device for tissue coagulation. We hypothesized that this device would be an effective tool for sealing small pancreatic ducts, thus reducing pancreatic fistula following pancreatectomy. METHODS To confirm whether the SC could be used to seal small pancreatic ducts, we measured the burst pressure in sealed ducts in mongrel dogs. Eight dogs underwent distal pancreatectomy, with the remnant stump coagulated by using the SC. The animals were necropsied on postoperative day 10. In a clinical trial, 11 patients who underwent pancreatoduodenectomy with SC treatment (SC group), and 24 patients who underwent pancreatoduodenectomy without SC treatment (non-SC group) were compared. RESULTS In the experimental study, the burst-pressure test revealed that the SC had efficiently sealed the small pancreatic ducts. Histological examination revealed completely obstructed pancreatic ductal structures, ranging from large pancreatic ducts (diameter, 500 microm) to microscopic ducts. No pancreatic leakage was observed following distal pancreatectomy without main pancreatic duct (MPD) suturing in dogs that had an MPD diameter of less than 500 microm. In the clinical trial, pancreatic fistula developed in only one patient (9.1%) in the SC group, but a pancreatic fistula developed in five patients (20.8%) in the non-SC group. CONCLUSIONS This novel technique using the SC is an effective procedure for preventing the development of pancreatic fistula following pancreatectomy.

Complete laparoscopic resection of the rectum using natural orifice specimen extraction

AIM To investigate how complete laparoscopic anterior resection with natural orifice specimen extraction (NOSE), as a novel minimally invasive surgery, compares to conventional laparoscopic surgery. METHODS Twenty patients who underwent complete laparoscopic anterior resection with NOSE and 50 patients who underwent laparoscopic assisted anterior resection by the conventional method between 2011 and 2012 were studied. Selection for complete laparoscopic anterior resection with NOSE was decided on the basis of tumor size, localization of the tumor, and body mass index. Outcomes related to surgery, including operation time, postoperative wound pain, hospital stay after surgery, the number of totally dissected lymph nodes, postoperative complications (suture failure and wound infection), and anal function, were reviewed retrospectively. Anal function was assessed at 3 and 6 mo after surgery using the Wexner fecal incontinence scoring system. RESULTS Complete laparoscopic resection with NOSE was performed to completion in all 20 patients. There was no patient emergency that required conversion to conventional laparoscopic surgery or open surgery. The comparison between complete laparoscopic resection with NOSE and conventional laparoscopic surgery showed no significant differences in the maximal diameter of the tumor, number of totally dissected lymph nodes, bleeding volume, mean operation time, time to start of oral ingestion, postoperative hospital stay, and postoperative complications. On the other hand, with regard to pain after epidural anesthesia, the total usage of analgesia in this novel surgical technique was 1.85 ± 1.8 times, whereas it was 5.89 ± 2.86 in conventional laparoscopic surgery (P < 0.001). The postoperative pain period was 1.9 ± 1.9 d in this novel surgical technique, whereas it was 3.43 ± 1.41 d in conventional laparoscopic surgery (P < 0.004). In complete laparoscopic surgery with NOSE, the mean postoperative follow-up period was 20 mo (range: 12-30 mo). Neither local recurrence nor remote metastasis was observed during the follow-up period. CONCLUSION Complete laparoscopic anterior resection using NOSE does not require any incision and has excellent cosmetic properties, with mitigated postoperative pain.

Reconsideration of Laparoscopic Cholecystectomy

We describe the surgical method of cases showing a distended gallbladder. Because the most important thing does not cause biliary tract injury, it is to find orientation carefully. The frequency of incidental gallbladder cancer was in 7 (0.7%) of the 983. Only cholecystectomy is necessary to be performed for Tis or T1 cancer, and surgery has to be changed to radical surgery for T2 cancer or deeper invasion. Laparoscopic cholecystectomy is already an established standard operation. In the presence of acute or severe chronic inflammation, special attention should be paid to these points.

Successful laparoscopic resection of a retroperitoneal schwannoma arising from the femoral nerve: A case report

We report on a 45‐year‐old man who presented with pain in the left leg, which he had had for 2 months. A contrast‐enhanced CT scan displayed a 25‐mm tumor in the lateral side of the left psoas muscle. For this suspected retroperitoneal tumor, we performed laparoscopic resection of the tumor, which was encapsulated by the funicular femoral nerve, using surgical scissors rather than a surgical energy device and preserved the normal fascicles wherever possible. Pathological examination indicated a benign ancient schwannoma arising from the femoral nerve. The patient was able to return to his job 3 weeks after surgery, and he has shown no evidence of recurrence. This was thought to be because of the use of surgical scissors, rather than a surgical energy device, combined with visual magnification. Therefore, the laparoscopic approach is an effective and minimally invasive option for the resection of femoral nerve schwannoma.

Preoperative evaluation of blood vessel anatomy using three-dimensional computed tomography for laparoscopic surgery of transverse colon cancer

This study describes the efficacy of the evaluation of blood vessel anatomy by 3-dimensional computed tomography (3D-CT) for laparoscopic surgery for transverse colon cancer (TCC). A total of 102 p...

Comparison of preoperative images with gross and histopathological findings of liver slices in patients with liver metastases from colorectal cancer after chemotherapy.

BACKGROUND/AIMS Since there is a difference in the slice thickness between preoperative images of liver metastases (1-3mm slices) and surgical liver pathology specimens (5mm slices), micrometastases may not be detected in these specimens. In addition, the accuracy of preoperative imaging for the detection of metastases degenerated by chemotherapy is unclear. METHODOLOGY Five patients with liver metastases from colorectal cancer who had received adjuvant chemotherapy and undergone hepatectomy were included. The whole resected liver was sliced at approximately 1mm intervals and the slices were examined carefully for gross lesions. The preoperative CT and EOB-MRI findings of each lesion were compared with gross and histopathological findings. RESULTS The accuracy of EOB-MRI was higher than that of CT for the detection of liver metastases. The number of lesions detected on EOB-MRI was in agreement with that of histopathologically proven liver metastases in 4 of the 5 patients. All lesions that were grossly identified but turned out to be non-neoplastic were regenerative nodules associated with drug-induced liver injury or lobular nodules associated with marked fatty change, measuring about 1mm in diameter. CONCLUSIONS EOB-MRI was the most accurate method for the preoperative detection of liver metastases, enabling the visualization of almost all liver metastases.