Patient-specific hemodynamic analysis of small internal carotid artery-ophthalmic artery aneurysms

BackgroundProphylactic treatment of unruptured small brain aneurysms is still controversial due to the low risk of rupture. Distinguishing which small aneurysms are at risk for rupture has become important for treatment. Previous studies have indicated a variety of hemodynamic properties that may influence aneurysm rupture. This study uses hemodynamic principles to evaluate these in the context of ruptured and unruptured small aneurysms in a single location.MethodsEight small internal carotid artery-ophthalmic artery (ICA-Oph) aneurysms (<10 mm) were selected from the University of California, Los Angeles, database. We analyzed rupture-related hemodynamic characteristics including flow patterns, wall shear stress (WSS), and flow impingement using previously developed patient-specific computational fluid dynamics software.ResultsMost ruptured aneurysms had complicated flow patterns in the aneurysm domes, but all of the unruptured cases showed a simple vortex. A reduction in flow velocity between the parent artery and the aneurysm sac was found in all the cases. Inside the aneurysms, the highest flow velocities were found either at the apex or neck. We also observed a trend of higher and more inhomogeneous WSS distribution within ruptured aneurysms (10.66 ± 5.99 Pa) in comparison with the unruptured ones (6.31 ± 6.47 Pa) (P < .01).ConclusionA comparison of hemodynamic properties between ruptured and unruptured small ICA-Oph aneurysms found that some hemodynamic properties vary between small aneurysms although they are similar in size and share the same anatomical location. In particular, WSS may be a useful hemodynamic factor for studying small aneurysm rupture.     

Surgical Resection of Hypopharynx and Cervical Esophageal Cancer with a History of Esophagectomy for Thoracic Esophageal Cancer

Background

Cancer of the hypopharynx and cervical esophagus (PhCe cancer) frequently develops synchronously or metachronously with esophageal cancer. The surgical approach is usually difficult, especially in metachronous PhCe cancer after esophagectomy. The purpose of this study was to clarify the treatment outcomes of patients with metachronous PhCe cancer with a history of esophagectomy.

Methods

The subjects evaluated in this study were 14 patients with metachronous PhCe cancer who underwent pharyngo-laryngo-esophagectomy after subtotal esophagectomy and gastric tube pull-up for primary esophageal cancer.

Results

Definitive chemoradiotherapy (CRT; radiation dose >50 Gy) was performed for primary laryngeal (n = 1), pharyngeal (n = 2), esophageal (n = 1), and recurrent esophageal cancer (n = 2). For seven patients with metachronous PhCe cancer, induction CRT (radiation dose <40 Gy) was performed. In all 14 patients, pharyngo-laryngo-esophagectomy was followed by free jejunal graft interposition with reconstruction of the jejunal vessels. Although postoperative complications developed in four patients, no perioperative death or necrosis of the reconstructed free jejunum occurred. The 2- and 5-year overall survival rates were 84 and 50 %, respectively.

Conclusions

Pharyngo-laryngo-esophagectomy with free jejunal transfer is considered to be safe for metachronous PhCe cancer, even in patients with a history of CRT and esophagectomy.     

Solid-pseudopapillary pancreatic tumor, mimicking submucosal tumor of the stomach: A case report

Solid-pseudopapillary tumors of the pancreas(SPTs) are comparatively rare and have low malignancy,with a predilection for young women.Diagnosis is difficult when a SPT develops in a boundary region with other organs.Here,we report a 42-year old woman with a SPT of the pancreas mimicking a submucosal tumor of the stomach on imaging.She was admitted to our hospital complaining of abdominal pain.We suspected a submucosal tumor of the stomach from the f indings of endoscopy,endoscopic ultrasonography and abdominal computed tomography.However,angiography showed that some of the tumor vessels arose from the pancreas.Intraoperative f indings revealed the tumor originated from the pancreas.Therefore,distal pancreatectomy was performed.The pathological diagnosis was SPT of the pancreas.     

Giant Cystic Lymphangioma of the Small Bowel Mesentery: Report of a Case

We herein describe the case of a 48-year-old man who presented to our hospital with abdominal distension and pain. Preoperative studies including abdominal ultrasonography and computed tomography failed to determine the cause of the pain. At laparotomy, a giant cystic tumor of the small bowel mesentery was found. Histologically, the tumor was diagnosed as a cystic lymphangioma. Although mesenteric lymphangiomas are rare, especially in adults, they should be considered as a possible cause of acute abdomen. Received: August 8, 2001 / Accepted: January 8, 2002     

Laparoscopic Versus Open Multivisceral Resection for Primary Colorectal Cancer: Comparison of Perioperative Outcomes

Background

The role of laparoscopic surgery for locally advanced colorectal cancer invading or adhering to neighboring organs is controversial. This study evaluated the safety and feasibility of laparoscopic multivisceral resection for colorectal cancer.

Methods

This study included 126 patients who underwent multivisceral resection for primary colorectal cancer invading or adhering to neighboring organs or structures between July 2005 and November 2012 at our institution. Perioperative outcomes were compared between laparoscopic and open resections.

Results

Laparoscopic and open multivisceral resections were performed in 60 and 66 patients, respectively. Conversion to open surgery occurred in 6.7 % of patients. The median operative time was significantly longer (271 vs. 227 min), but the median blood loss was significantly less (40 vs. 205 mL), in the laparoscopic compared with the open group. The R0 resection rate of the primary tumor (95 vs. 98.5 %), number of lymph nodes harvested (18 vs. 18), and postoperative complications (28 vs. 24 %) were comparable between the groups. The median length of hospital stay was significantly shorter (13.5 vs. 18 days) in the laparoscopic compared with the open group.

Conclusions

Laparoscopic multivisceral resection for colorectal cancer invading or adhering to neighboring organs is safe and feasible in selected patients.     

Navigator-echo-based MR provides high-resolution images and precise volumetry of swine livers without breath holding or injection of contrast media.

The accurate calculation of hepatic volume by computed tomography (CT) or magnetic resonance (MR) is complicated by the need for breath holding and the injection of contrast media. These are often contraindicated in patients with liver failure, and we examined the ability of unenhanced 3-dimensional (3-D) navigator-echo-based MR (NE-MR) to accurately image livers and measure volumes without breath holding compared to unenhanced (plain) or gadolinium-diethylene triamine pentaacetic acid enhanced MR (Gd-MR) in miniature swine (n = 8). Without breath holding, diaphragm movement monitoring with NE-MR reduced motion artifacts in hepatic images compared with the other modalities. Without the injection of contrast media, the signal-to-noise ratios of the images obtained using NE-MR were significantly higher than those from plain MR; Gd-MR was superior to NE-MR, however (79.5 +/- 7.5 vs. 63.2 +/- 6.0 or 97.8 +/- 8.1, respectively; P < 0.01 for each). Overall, NE-MR produced improved high-resolution liver images. Consequently, liver volumes calculated based on NE-MR images were more highly correlated with actual liver weights compared to plain or Gd-MR in the whole livers (n = 8; r = 0.937 vs. 0.835 or 0.904, respectively). Also, NE-MR demonstrated significantly strong correlation between actual weights and volumetry-calculated volumes in regenerative livers 7 days after massive hepatectomy (n = 10, r = 0.989, P < 0.01). In conclusion, our results indicate that without breath holding or the injection of contrast media, 3-D NE-MR can provide both high-resolution liver images and precise hepatic volumes in patients with liver failure due to liver surgery (massive hepatectomy and living donor liver transplantation) or fulminant hepatic failure.     

Hilar cholangiocarcinoma—surgical anatomy and curative resection

We have studied the surgical anatomy of the intrahepatic bile duct, hepatic hilus, and caudate lobe based on intraoperative findings and selective cholangiography of surgical patients and resected specimens, and have established the cholangiographic anatomy of the intrahepatic subsegmental bile duct. Thorough knowledge of the three-dimensional anatomy of the subsegmental bile duct, hepatic hilus, and caudate lobe is indispensable for curative surgery of hilar cholangiocarcinoma. We designed and actually performed 15 kinds of hepatic segmentectomies with caudate lobectomy and extrahepatic bile buct resection in 100 consecutive patients, with curative resection being possible in 82 patients. Postoperative survival after curative resection of hilar cholangiocarcinoma was better than expected, and the 5-year survival rates for all 82 patients with curative resection and for 55 patients with curative surgery without portal vein resection were 31% and 43%, respectively. Hepatic segmentectomy with caudate lobectomy and extrahepatic bile duct resection should be designed not only in accordance with the preoperative diagnosis of tumor extension into the intrahepatic bile ducts but also so that curative surgery for advanced hilar cholangiocarcinoma can be performed.     

Risk factors of liver dysfunction after extended hepatic resection in biliary tract malignancies

Background

Postoperative hepatic insufficiency is a critical complication after extended hepatic resection in patients with biliary tract malignancies, the majority of whom suffer from obstructive jaundice. The aim of this study was to assess clinical parameters linked to this type of liver dysfunction.

Methods

A total of 111 patients were retrospectively reviewed. Patient background, pre- and intraoperative parameters, and a ratio of remnant liver volume/entire liver volume (RLV/ELV) as a volumetric parameter were compared between patients with and without postoperative hyperbilirubinemia and subsequent fatal outcome.

Results

Logistic regression indicated that only RLV/ELV ratio was an independent factor influencing postoperative hyperbilirubinemia, and RLV/ELV ratio and indocyanine green retention rate at 15 minutes (ICG-R15) were factors affecting survival. Patients with RLV/ELV less than 40% had 7.6 times the risk of postoperative hyperbilirubinemia, while no patients with RLV/ELV greater than 40% and ICG-R15 less than 25% died of liver failure.

Conclusions

The RLV/ELV ratio was the factor with the greatest impact on liver dysfunction after extended hepatectomy in patients with biliary tract malignancies.