Kabuto Takano

Left Posterior Approach to the Superior Mesenteric Vascular Pedicle in Pancreaticoduodenectomy for Cancer of the Pancreatic Head

CONTEXT Dissection of the superior mesenteric artery is the most important part of a pancreaticoduodenectomy for pancreatic cancer. Since 2005, we have used the left posterior approach for superior mesenteric vascular pedicle dissection, in which the superior mesenteric artery and the superior mesenteric vein are dissected first in a clockwise fashion. OBJECTIVE This article presents the technique of a left posterior approach and the clinical outcome. PATIENTS Forty patients underwent a left posterior approach and were compared to 35 patients treated with a conventional dissection. MAIN OUTCOME MEASURES The differences in surgical technique between the left posterior approach and the conventional method were described, and the short- and long-term surgical results compared patients who underwent the left posterior approach to those who were treated with the conventional method. INTERVENTION The superior mesenteric vascular pedicle was first dissected from the left lateral border of the superior mesenteric artery. The superior mesenteric vein was also dissected from the left side. Then, the uncinate process and perivascular soft tissue were separated en bloc from the vasculature. RESULTS No life-threatening complications occurred after the pancreaticoduodenectomies using a left posterior approach. Diarrhea requiring the administration of antidiarrheal agents occurred in 65% of patients; however, planned adjuvant chemotherapy was completed in all patients who did not have an early tumor recurrence. Survival rate was 52.8% at 3 years after surgery. CONCLUSION After a pancreaticoduodenectomy with a left posterior approach, most patients had various degrees of diarrhea, but the adjuvant chemotherapy was able to be continued with close monitoring. The left posterior approach facilitates understanding of the topographic anatomy in the superior mesenteric vascular pedicle.

Intrahepatic cholangiocarcinoma arising 34 years after excision of a type IV-A congenital choledochal cyst: Report of a case

We report a rare case of intrahepatic cholangiocarcinoma (IHCC) arising many years after excision of a type IV-A congenital choledochal cyst. A 44-year-old man was transferred to our hospital with acute cholangitis more than 34 years after several operations for congenital biliary dilatation. Imaging showed a huge tumor in the left medial section of the liver, extending to the porta hepatis. Although he had no jaundice, the intrahepatic bile ducts showed cylinder-like dilatation with narrowing of the hilar bile duct. At surgery, the tumor was found to arise from the dilated intrahepatic bile duct just above the narrow portion. He underwent a left hepatic trisectionectomy with a vascular procedure. Microscopically, the tumor was confirmed to be moderate-to-well-differentiated tubular adenocarcinoma. Thus, when the narrow segment is left untouched, careful long-term follow-up is important to detect new lesions at an early stage.

Immunohistochemical staining for P1 and P2 promoter‐driven hepatocyte nuclear factor‐4α may complement mucin phenotype of differentiated‐type early gastric carcinoma

Hepatocyte nuclear factor 4α (HNF4α) isoforms in the human stomach have not been fully investigated. The purpose of the present study was to evaluate the expression of P1 and P2 promoter‐driven HNF4α (P1 and P2‐HNF4α) in differentiated‐type early gastric carcinomas (DEGC). P1‐ and P2‐HNF4α expression was examined immunohistochemically both in non‐neoplastic mucosa and carcinoma from surgical specimens. In all samples of non‐neoplastic mucosa, foveolar, cardiac, fundic and pyloric gland epithelium was negative for P1‐HNF4α, but was positive for P2‐HNF4α. Intestinal metaplasia was positive for P1 and P2‐HNF4α in all cases. Gastric carcinomas were classified into four mucin phenotypes based on the pattern of mucin expression: gastric, intestinal, mixed and null type. DEGC showed striking differences in the staining pattern for P1‐HNF4α according to the mucin phenotype. Gastric carcinomas of intestinal, mixed and null type showed high positivity for P1‐HNF4α, but the gastric type was negative for P1‐HNF4α in all but one tumor. In contrast, P2‐HNF4α was expressed in all tumors regardless of the mucin phenotype. Negative expression of P1‐HNF4α was indicated as one of the useful immunohistochemical markers in the classification of mucin phenotype of both non‐neoplastic mucosa and cancers of gastric phenotype.

The Role of Wide Excision of Occult Cancer Tissue Harbored Posteriorly to the Superior Mesenteric Artery

We would like to thank Drs. Dumitrascu and Popescu for their letter. A major point of comment regarding our article is the question that “the surgical outcome was improved but status of positive surgical margin was not changed”. As shown in our article [1], postoperative survival after a pancreaticoduodenectomy using left posterior approach was improved as compared with that after a pancreaticoduodenectomy using conventional methods in “univariate analysis”, but the difference was not shown in “multivariate analysis”. It is well known the nerve bundle arising from the celiac ganglia forms the superior mesenteric plexus and then ramifies into the secondary plexus consisting of pancreatic branches and intestinal branches. The superior mesenteric plexus is thin and located in the innermost layer. Although the excision of the superior mesenteric plexus or the intestinal branches causes severe diarrhea after surgery, excision of the pancreatic branches alone does not influence intestinal motility. Regardless of the dissection techniques, the principal variable affecting postoperative intestinal motility is whether or not dissection of the superior mesenteric plexus was performed, and whether the dissection was performed partially or extensively. In the control group of our study [1], the right half of the superior mesenteric plexus was resected. Accordingly, it is thought that the incidence of diarrhea did not differ significantly between the two groups. From the point of view of the pathological examination, the resected margin of the plexus showed a complicated and irregular shape in the left posterior approach rather than in the conventional dissection (dissection on the right side of the superior mesenteric artery). Considering the mode of tumor extension involved in perineural invasion, the cancer cells spread continuously along the perineural space as reported previously by Nagakawa et al. [2]. However, on the mapping of the tumor extension in our study (Figure 3) [1], the deposit of the perineural invasion was far from the main tumor in some cases. The continuity of the perineural spread of the tumor was divided by the dissection of the plexus. In addition, the resected plexus was sampled and underwent intraoperative frozen section examination in some cases. Accordingly, the identification of the true surgical margins, especially the medial margin, may sometimes be difficult. The method of pathologically examining the evaluation of the status of the medial margin was altered gradually during the study period. In our study, the plexus invasion-positive case was taken as the margin-positive case [1]. The more detailed pathology examination was conducted in the left posterior approach group as compared to the control group. It may be one of the possible reasons that the positive rate in medial margin status did not decrease. However, we believe that the occult cancer tissue which was harbored posteriorly to the superior mesenteric artery was widely excised using the left posterior approach, and that local recurrence around the artery was reduced. Nowadays, gemcitabine-based chemotherapy is the most popular therapy in a postoperative adjuvant setting. The preoperative imaging diagnosis for patient selection and postoperative management, including adjuvant chemotherapy, have improved rapidly. Liver perfusion chemotherapy [3] was performed more frequently in the left posterior approach group as compared to the control group [1], although its Received August 9, 2011