Kanehisa Fukumoto

Radixin deficiency causes conjugated hyperbilirubinemia with loss of Mrp2 from bile canalicular membranes

The ezrin-radixin-moesin (ERM) family of proteins crosslink actin filaments and integral membrane proteins. Radixin (encoded by Rdx) is the dominant ERM protein in the liver of wildtype mice and is concentrated at bile canalicular membranes (BCMs). Here we show that Rdx−/− mice are normal at birth, but their serum concentrations of conjugated bilirubin begin to increase gradually around 4 weeks, and they show mild liver injury after 8 weeks. This phenotype is similar to human conjugated hyperbilirubinemia in Dubin-Johnson syndrome, which is caused by mutations in the multidrug resistance protein 2 (MRP2, gene symbol ABCC2), although this syndrome is not associated with overt liver injury. In wildtype mice, Mrp2 concentrates at BCMs to secrete conjugated bilirubin into bile. In the BCMs of Rdx−/− mice, Mrp2 is decreased compared with other BCM proteins such as dipeptidyl peptidase IV (CD26) and P-glycoproteins. In vitro binding studies show that radixin associates directly with the carboxy-terminal cytoplasmic domain of human MRP2. These findings indicate that radixin is required for secretion of conjugated bilirubin through its support of Mrp2 localization at BCMs.

Radixin deficiency causes deafness associated with progressive degeneration of cochlear stereocilia

Ezrin/radixin/moesin (ERM) proteins cross-link actin filaments to plasma membranes to integrate the function of cortical layers, especially microvilli. We found that in cochlear and vestibular sensory hair cells of adult wild-type mice, radixin was specifically enriched in stereocilia, specially developed giant microvilli, and that radixin-deficient (Rdx − / −) adult mice exhibited deafness but no obvious vestibular dysfunction. Before the age of hearing onset (∼2 wk), in the cochlea and vestibule of Rdx − / − mice, stereocilia developed normally in which ezrin was concentrated. As these Rdx − / − mice grew, ezrin-based cochlear stereocilia progressively degenerated, causing deafness, whereas ezrin-based vestibular stereocilia were maintained normally in adult Rdx − / − mice. Thus, we concluded that radixin is indispensable for the hearing ability in mice through the maintenance of cochlear stereocilia, once developed. In Rdx − / − mice, ezrin appeared to compensate for radixin deficiency in terms of the development of cochlear stereocilia and the development/maintenance of vestibular stereocilia. These findings indicated the existence of complicate functional redundancy in situ among ERM proteins.

Hemobilia and cystic artery stump pseudoaneurysm associated with liver abscess after a laparoscopic cholecystectomy: report of a case.

A 63-year-old woman was admitted for cholecystitis and underwent a laparoscopic cholecystectomy (LC). She experienced abdominal pain and hemobilia 11 days after the LC. Angiography was performed but it did not show any source of bleeding. Thereafter, at 27 days after LC, a repeat angiogram was performed which revealed a pseudoaneurysm (PA) arising from a cystic artery stump and an embolized PA sack. However, another PA arising from near the embolized PA and liver abscess was observed 4 days after embolization. The arterial collateral flow was evaluated by endovascular balloon occlusion of the right hepatic artery and it was embolized proximal and distal to the bleeding point. The embolization of the partial hepatic artery was effective for PA when packing the PA sack proved to be insufficient. In patients with liver cirrhosis or liver abscess who require an adequate arterial liver flow, it is important to evaluate the collateral arterial flow before hepatic artery embolization.

Efficacy of the modified anvil grasper for laparoscopic intra-corporeal circular stapled anastomosis

The traditional anvil grasper may be difficult to use for connecting the stem of an anvil with the centre rod of a circular stapler because the grasper holds the anvil completely still. In addition, the head angle is fixed and cannot handle the anvil head delicately in a tight pelvic space. Many surgeons use a grasper designed for holding the bowel or a dissector for holding the anvil during intra-corporeal circular stapled anastomosis during low anterior resection, sigmoidectomy, left hemi colectomy and know that it is difficult to connect segments with these instruments due to slipping. A new modified anvil grasper was developed with curved blades that can easily grasp the stem of an anvil and smoothly connect it with the centre rod of the circular stapler. This grasper should be useful for surgeons performing laparoscopic intra-corporeal circular stapled anastomoses, which are the most challenging part of laparoscopic colorectal surgery.

Massive chronic irreducible rectal prolapse successfully treated with Altemeier’s procedure

Abstract The guideline for the treatment of rectal prolapse recommends that surgeons select appropriate surgical procedures individually based on each patient’s overall status. However, in cases of irreducible or incarcerated rectal prolapse, surgical options are quite limited. Here we present a case of an elderly woman with massive chronic irreducible rectal prolapse. An 87-year-old woman presented to our hospital with a complaint of massive rectal prolapse. The prolapsed rectum was over 20 cm long, and completely irreducible. She underwent perineal rectosigmoidectomy with levatorplasty known as Altemeier’s procedure. More than 30 cm of rectosigmoid colon was resected. After the operation, rectal prolapse was resolved completely. Her postoperative course was uneventful, and her quality of life and bowel movements improved. She has since been healthy without recurrence for over 2 years. Altemeier’s procedure is applicable even in cases of irreducible rectal prolapse and features acceptable safety and a satisfactory outcome.

Is Single-incision Laparoscopic Cholecystectomy Feasible for Acute Cholecystitis? A Consecutive Study of 60 Cases

The feasibility of single-incision laparoscopic cholecystectomy (SIL-C) for patients with acute cholecystitis were evaluated based on the timing of operation after onset of symptoms. Sixty patients with acute cholecystitis who underwent SIL-C were divided into 2 groups according to the timing of operation: group E included 23 patients who underwent SIL-C within 72 hours, and group O included 37 patients who underwent SIL-C later. There were no statistical differences between group E and group O in clinicopathologic characteristics. Group E demonstrated significantly shorter operating time and less blood loss than group O. Although the incidences of additional port(s) requirements were not significantly different, 8 patients in group O required open conversion, indicating significantly higher rate. As group E demonstrated favorable surgical outcomes compared with group O, SIL-C for acute cholecystitis seems to be a feasible therapeutic procedure when performed within 72 hours as updated Tokyo Guidelines recommended.

Single-Incision Laparoscopic Surgery for Undiagnosed Small Bowel Obstruction in a Patient without a History of Abdominal Surgery

We herein report a 66-year-old female patient who developed an undiagnosed small bowel obstruction without a history of prior abdominal surgery and was successfully treated by single-incision laparoscopic surgery. A small bowel obstruction with unknown cause typically requires some sort of surgical treatment in parallel with a definitive diagnosis. Although open abdominal surgery has been generally performed for the treatment of small bowel obstructions, laparoscopic surgery for small bowel obstructions has been increasing in popularity due to its less invasiveness, including fewer postoperative complications and a shorter hospital stay. As a much less invasive therapeutic strategy, we have performed single-incision laparoscopic surgery for the treatment of an undiagnosed small bowel obstruction. We were able to make a definitive diagnosis after sufficient intra-abdominal inspection and to perform enterotomy through a small umbilical incision. Single-incision laparoscopic surgery appears to be comparable to conventional laparoscopic surgery and provides improved cosmesis, although it is an optional strategy only applicable to selected patients.

Usefulness of the novel evolutional anvil grasper for laparoendoscopic surgery for intracorporeal circular stapled anastomosis during laparoscopic colorectal surgery.

Traditional anvil graspers cannot delicately handle the anvil head as a result of their unique jaw shape that enhances grip force, and they are not suitable for confined pelvic space. With a manufacturing company, we developed a novel anvil grasper, the evolutional anvil grasper for laparoendoscopic surgery (EAGLE), to ensure more precise and safer anastomosis procedures. The EAGLE has curved blades that create a 6‐mm grasping surface that is the same diameter as the anvil stem and is covered with tungsten carbide tips. When using the EAGLE, a surgeon grasps the anvil stem slightly and easily, handles the anvil head and proximal colon, and smoothly sets the anvil to the center rod of the circular stapler. A surgeon can also securely grasp the stem of the anvil, push it into the center rod of the circular stapler and then perform a sequence of actions in anastomosis procedures smoothly and safely.