Takahide Yokoyama

Preoperative diagnosis of strangulated Obturator hernia using ultrasonography

BACKGROUND Obturator hernia is rarely recognized before surgical intervention, since it is relatively infrequent and its definitive diagnosis is difficult. To change this situation, we introduced ultrasound examination in 1993 for differential diagnosis of strangulated obturator hernia among patients with bowel obstruction of unknown cause. PATIENTS AND METHODS Between 1993 and 1995, we encountered 15 patients with suspected obturator hernia based on the presence of bowel obstruction of unknown cause and so-called predisposing factors. These patients underwent ultrasound examinations. RESULTS The 4 patients with bowel obstruction caused by strangulated obturator hernia were all correctly diagnosed preoperatively by ultrasonography and were successfully cured by surgery. The time required for diagnosis was shorter than reported previously (average 16.5 h). CONCLUSIONS Ultrasonography is useful and reliable for the diagnosis of strangulated obturator hernia and can decrease the morbidity and mortality associated with delayed diagnosis.

Multicenter comparative study of laparoscopic and open distal pancreatectomy using propensity score-matching

Laparoscopic distal pancreatectomy has been shown to be associated with favorable postoperative outcomes using meta‐analysis. However, there have been no randomized controlled studies yet. This study aimed to compare laparoscopic and open distal pancreatectomy using propensity score‐matching.

Acute Colorectal Obstruction Treated by Means of Transanal Drainage Tube: Effectiveness Before Surgery and Stenting

OBJECTIVES: The aim of this study was to clarify the usefulness of the management of acute colorectal obstruction using a transanal drainage tube before surgery or stenting.METHODS:Fifty-four patients (34 males and 20 females, aged 46–94 yr, mean = 69.7) treated between May 1998 and March 2004 for acute colorectal obstruction were identified in a colorectal obstruction database, and their clinical and radiological features were reviewed. Based on abdominal computed tomography findings, urgent colonoscopy was performed. Subsequently, endoscopic decompression using a Dennis® Colorectal Tube (DCT) was attempted.RESULTS:Endoscopic decompression using the DCT was technically successful in 52 of 54 patients (96.3%). The site of obstruction was the cecum in 4, the ascending colon in 2, the transverse colon in 7, the descending colon in 11, the sigmoid colon in 18, and the rectum in 12. The etiology of obstruction was primary colorectal carcinoma in 45, non-colonic metastatic carcinoma in 4, postoperative obstruction in 4, and retrograde intussusception in 1. Following adequate cleansing of the colon, 44 patients underwent a one-stage surgery after 7 ± 3 days (SD; range, 4–10 days). Stenting was successfully used as the final palliative treatment in 4. The use of the DCT alone relieved postoperative stenosis (3 patients) and retrograde intussusception (Prognosis in patients with obstructing colorectal carcinoma. Am J Surg 1982;143:742–7). During these treatments, perforation occurred in one patient with postoperative stenosis of the cecum.CONCLUSIONS:Management of acute colorectal obstruction using the DCT was found to be effective and safe, irrespective of the site or etiology of the obstruction. Therefore, this procedure should be considered as a primary method for decompression of the obstructed colon before considering surgery or stenting.

Transabdominal Preperitoneal Repair for Obturator Hernia

BackgroundA laparoscopic surgical approach for obturator hernia (OH) repair is uncommon. The aim of the present study was to assess the effectiveness of laparoscopic transabdominal preperitoneal (TAPP) repair for OH.MethodsFrom 2001 to May 2010, 659 patients with inguinal hernia underwent TAPP repair at in our institutes. Among these, the eight patients with OH were the subjects of this study.ResultsThree of the eight patients were diagnosed as having occult OH, and the other five were diagnosed preoperatively, by ultrasonography and/or computed tomography, as having strangulated OH. Bilateral OH was found in five patients (63%), and combined groin hernias, either unilaterally or bilaterally, were observed in seven patients (88%), all of whom had femoral hernia. Of the five patients with bowel obstruction at presentation, four were determined not to require resection after assessment of the intestinal viability by laparoscopy. There was one case of conversion to a two-stage hernia repair performed to avoid mesh contamination: addition of mini-laparotomy, followed by extraction of the gangrenous intestine for resection and anastomosis with simple peritoneal closure of the hernia defect in the first stage, and a Kugel hernia repair in the second stage. There was no incidence of postoperative morbidity, mortality, or recurrence.ConclusionsBecause TAPP allows assessment of not only the entire groin area bilaterally but also simultaneous assessment of the viability of the incarcerated intestine with a minimum abdominal wall defect, we believe that it is an adequate approach to the treatment of both occult and acutely incarcerated OH. Two-stage hernia repair is technically feasible in patients requiring resection of the incarcerated intestine.

A case of well-differentiated cholangiolocellular carcinoma visualized with contrast-enhanced ultrasonography using Sonazoid

We here report the first case of cholangiolocellular carcinoma (CoCC) visualized with contrast‐enhanced ultrasonography (CEUS) using a second‐generation contrast agent, Sonazoid. A 76‐year‐old man was admitted to our hospital for evaluation of a hepatic tumor. The tumor was described as having hyper‐enhancement in the early phase and persistent enhancement in the late phase by contrast‐enhanced computed tomography (CT) and magnetic resonance imaging (MRI), as well as hypervascularity by angiography. CEUS assessment of the nodule showed diffuse and homogeneous enhancement in the pure arterial phase, which became progressively hypoechoic relative to the adjacent liver parenchyma during the portal vein and late phases (mixed vascular phase), and showed a contrast defect with an unclear border in the Kupffer phase. Histologically we diagnosed this hepatic tumor as CoCC. In light of the above findings and the rarity of CoCC, it is helpful to incorporate the results of several imagings, such as CT, MRI, angiography and CEUS with a second‐generation contrast agent when clinically diagnosing CoCC.

Role of bone marrow cells in the development of pancreatic fibrosis in a rat model of pancreatitis induced by a choline-deficient/ethionine-supplemented diet

Bone marrow cell (BMC)-derived myofibroblast-like cells have been reported in various organs, including the pancreas. However, the contribution of these cells to pancreatic fibrosis has not been fully discussed. The present study examined the possible involvement of pancreatic stellate cells (PSCs) originating from BMCs in the development of pancreatic fibrosis in a clinically relevant rat model of acute pancreatitis induced by a choline-deficient/ethionine-supplemented (CDE) diet. BMCs from female transgenic mice ubiquitously expressing green fluorescent protein (GFP) were transplanted into lethally irradiated male rats. Once chimerism was established, acute pancreatitis was induced by a CDE diet. Chronological changes in the number of PSCs originating from the donor BMCs were examined using double immunofluorescence for GFP and markers for PSCs, such as desmin and alpha smooth muscle actin (αSMA), 1, 3 and 8 weeks after the initiation of CDE feeding. We also used immunohistochemical staining to evaluate whether the PSCs from the BMCs produce growth factors, such as platelet-derived growth factor (PDGF) and transforming growth factor (TGF) β1. The percentage of BMC-derived activated PSCs increased significantly, peaking after 1 week of CDE treatment (accounting for 23.3±0.9% of the total population of activated PSCs) and then decreasing. These cells produced both PDGF and TGFβ1 during the early stage of pancreatic fibrosis. Our results suggest that PSCs originating from BMCs contribute mainly to the early stage of pancreatic injury, at least in part, by producing growth factors in a rat CDE diet-induced pancreatitis model.

Impact of advanced age on the short- and long-term outcomes in patients undergoing hepatectomy for hepatocellular carcinoma: a single-center analysis over a 20-year period

BACKGROUND The purpose of this study was to analyze the influence of age on both the risk of hepatectomy and the prognosis in patients with hepatocellular carcinoma (HCC). METHODS Patients undergoing an initial hepatectomy for HCC were classified into 2 age groups: 75 years or over (n = 113) and less than 75 years (n = 499). RESULTS A zero 90-day mortality was achieved in the elderly. Although the recurrence rate and recurrence sites were almost similar between the 2 groups, the 5-year survival rate in the elderly patients was significantly lower than that in the younger patients (46.0% vs 57.6%; P = .018), possibly because of the higher incidence of deaths from other causes (26.8% vs 10.4%; P = .011) in the elderly. CONCLUSION Selected elderly HCC patients can undergo a hepatectomy safely and can benefit from long-term HCC control comparable with that of their younger counterparts.

Hepatectomy preserving drainage veins of the posterior section for liver malignancy invading the right hepatic vein: an alternative to right hepatectomy.

BACKGROUND Although a right hepatectomy (RH) traditionally has been performed for liver tumors infiltrating the main trunk of the right hepatic vein (RHV), the presence of drainage veins of the posterior section (DVPS) beside the RHV provides a chance to preserve their draining area even if the main trunk of the RHV is removed. METHODS Since 2005, we systematically have performed DVPS-preserving hepatectomies whenever possible. In the present study, we describe our experience treating 12 consecutive patients who underwent this procedure. RESULTS We performed the following types of liver resections concomitant with the main trunk of the RHV without packed red cell transfusion, liver failure, or 90-day mortality: extended right anterior sectionectomy in 2 patients, extended segmentectomy 7 in 3, extended segmentectomy 8 in 2, and partial resection of segment 7 in 2 and segment 8 in 3. Postoperative morbidity was observed in 4 (33%) cases, all of which had pleural effusion requiring a tap. A free resection margin was obtained in all patients. CONCLUSIONS This procedure could be a useful alternative to RH, providing a chance for radical liver resection with minimal parenchymal sacrifice in selected patients with DVPS.

Biliary tract variations of the left liver with special reference to the left medial sectional bile duct in 500 patients

BACKGROUND Among the intrahepatic bile ducts, the biliary system of the left medial sectional bile duct (B4) is known to have relatively complex patterns. METHODS The records of 500 patients who had been diagnosed as having hepato-pancreatico-biliary disease were retrospectively studied for anatomical biliary variations of the left liver with special reference to the drainage system of B4 using magnetic resonance images. RESULTS The left hepatic duct was present in 494 patients (98.8%), whereas it was lacking in 6 patients (1.2%), and these patients exhibited the following B4 confluence patterns: B4 drained into the common hepatic duct in 2 patients (.4%), the right anterior sectional bile duct in 3 patients (.6%), and the right posterior sectional bile duct in 1 patient (.2%). The left hepatic duct was absent more frequently in patients with portal venous variations than in patients with a common branching pattern (8.2% vs .4%, P = .0011). CONCLUSION The presently reported data are useful for obtaining a better understanding of the surgical anatomy of the biliary system of the left liver.

Survival pathway of cholangiocarcinoma via AKT/mTOR signaling to escape RAF/MEK/ERKpathway inhibition by sorafenib

Cholangiocarcinoma (CCC) is a strongly aggressive malignancy for which surgical resection is the only potential curative therapy. Sorafenib, a multikinase inhibitor of the RAF/MEK/ERK pathway, is a molecular-targeted drug that is approved for hepatocellular carcinoma (HCC) but not for CCC. The differences in signaling pathway characteristics under sorafenib treatment between HCC (HLF, Huh7, PLC/PRF/5) and CCC (RBE, YSCCC, Huh28) cell lines were therefore investigated using cell proliferation, western blotting, and apoptosis analyses. Sorafenib inhibited cell growth significantly less in CCC cells than in HCC cells, with lower suppression of ERK phosphorylation. Significantly decreased AKT Ser473 phosphorylation in HCC cells, and conversely enhanced phosphorylation of AKT Ser473 and mTORC2 in CCC cells, were observed with sorafenib treatment. Disassembly of the mTORC2 complex in RBE cells with siRNA targeting Rictor resulted in the downregulation of AKT Ser473 phosphorylation and enhanced apoptosis presumably via increased FOXO1, which consequently suppressed RBE cell proliferation. Phosphorylation of mTORC1 and autophagy were not influenced by sorafenib in CCC cells. Simultaneous administration of everolimus to suppress activated mTORC1 in RBE cells revealed that combined everolimus and sorafenib treatment under mTORC2 disassembly could enhance growth inhibition through the suppression of both sorafenib- and everolimus-dependent AKT Ser473 phosphorylation in addition to the inhibition of mTORC1 phosphorylation. Prevention of escape by AKT/mTOR signaling from the RAF/MEK/ERK pathway in sorafenib treatment by suppressing mTORC2 activity may lead to promising new approaches in CCC therapy.