Segmental Anatomy (segmental + anatomy)

Distribution by Scientific Domains


Selected Abstracts


Preoperative biliary drainage before resection for cholangiocarcinoma (Pro)

HPB, Issue 2 2008
Y. NIMURA
Abstract Three types of preoperative biliary drainage (BD): percutaneous transhepatic (PTBD), endoscopic (EBD), and endoscopic nasobiliary (ENBD) can be indicated before resection of cholangiocarcinoma. However, three randomized controlled trials (RCTs) have revealed that preoperative PTBD does not improve perioperative results. Other RCTs have revealed that preoperative EBD for malignant obstructive jaundice has no demonstrable benefit and after EBD for hilar cholangiocarcinoma there are highly developed infectious complications. Most patients with distal cholangiocarcinoma undergo pancreatoduodenectomy (PD) without preoperative BD. However, no RCTs have been performed to clarify the safety of major hepatectomy without preoperative BD for cholestatic patients with hilar cholangiocarcinoma. Furthermore, preoperative intrahepatic segmental cholangitis is a prognostic factor in the outcome of major hepatectomy for biliary cancer. Preoperative BD has another purpose in the preoperative management of patients with hilar cholangiocarcinoma. Selective cholangiography via ENBD and/or PTBD catheters provides precise information about the complicated segmental anatomy of the intrahepatic bile ducts and extent of cancer along the separated segmental bile ducts, which contributes toward designing a type of resective procedure. RCTs in biliary cancer patients undergoing major hepatectomy have revealed that bile replacement during external biliary drainage and perioperative synbiotic treatment can prevent postoperative infectious complications. Although preoperative EBD increases the risk of cholangitis, major hepatectomy combined with preoperative biliary drainage, preferably PTBD and/or ENBD, followed by portal vein embolization has been established as a safer management strategy for perihilar cholangiocarcinoma. [source]


Current techniques of liver transection

HPB, Issue 3 2007
RONNIE T.P. POON
The operative mortality rate of liver resection has decreased from 10% to 20% before the 1980s to <5% in most specialized hepatobiliary centers nowadays. The most important factor for better outcome is reduced blood loss due to improvement in surgical techniques. Liver transection is the most challenging part of liver resection, associated with a risk of massive hemorrhage. Understanding the segmental anatomy of the liver and delineation of the proper transection plane using intraoperative ultrasound are prerequisites to safe liver transection. Clamp crushing and ultrasonic dissection are the two most widely used transection techniques. In recent years, new instruments using different types of energy for coagulation or sealing of vessels have been developed for liver transection. These include radiofrequency devices, Harmonic Scalpel, Ligasure and TissueLink dissecting sealer. Whether these new instruments, used alone or in combination with clamp crushing or ultrasonic dissection, improve the safety of liver transection has not been clearly demonstrated. The use of the vascular stapler for transection of major intrahepatic vascular trunks is also gaining popularity. These new instruments are particularly useful in liver transection during laparoscopic liver resection. Adjunctive measures such as intermittent Pringle maneuver and low central venous pressure anesthesia are also useful measures to reduce the risk of hemorrhage. This article reviews the safety and efficacy of different techniques of liver transection, with particular attention to evidence from randomized controlled trials available in the literature. [source]


Effect of slice thickness on liver lesion detection and characterisation by multidetector CT

JOURNAL OF MEDICAL IMAGING AND RADIATION ONCOLOGY, Issue 3 2010
JT Smith
Summary The purpose of our study was to compare the effectiveness of 3.2 mm, 5 mm and 7.5 mm slice thicknesses in the detection and characterisation of liver lesions found on CT in patients with known or suspected malignant disease. 110 patients underwent portal phase imaging using four-slice MDCT. Two blinded observers independently read hard copy images at each slice thickness. The size and location of each lesion detected was recorded by each observer on a diagram of liver segmental anatomy. Each lesion was characterised as benign, malignant or indeterminate in nature. A diagnostic confidence score was allocated for each lesion on a scale of 1,4. The pathology or behaviour of lesions was assessed using surgery with intra-operative ultrasound (IOUS) and histology, or interval imaging with MRI, CT, or sonography. 294 lesions were detected, 64 (22%) of which were malignant. Both observers detected significantly more lesions on the 3.2 mm versus 7.5 mm slice thickness (p < 0.0001). Both observers detected more malignant lesions on 3.2 mm and 5 mm slice thicknesses versus 7.5 mm. As slice thickness decreased there was a significant increase in the sensitivity of malignant lesion detection for observer 1 (p < 0.001) and borderline significance for observer 2 (p = 0.07). As slice thickness decreased the proportion of lesions characterised as indeterminate by both observers fell. With thinner slices, both detection and characterisation of liver lesions were improved. A slice thickness no greater than 5 mm should be used to maximise both detection and correct characterisation of liver lesions. [source]


Segmental nature of the porcine liver and its potential as a model for experimental partial hepatectomy,

BRITISH JOURNAL OF SURGERY (NOW INCLUDES EUROPEAN JOURNAL OF SURGERY), Issue 4 2003
F. G. Court
Background: In-depth knowledge of pig liver anatomy allows potential research into segmental liver resections and hepatic regeneration, as well as liver transplantation techniques. The segmental anatomy, however, remains largely unknown. This study aimed to delineate the segmental anatomy of the porcine liver in comparison with that of the human. Methods: The segmental anatomy of the porcine liver was determined using acrylic injection casting of ex vivo pig livers, allowing the arterial, venous and biliary supply to be visualized directly. This was correlated using multi-slice computed tomography (CT) and three-dimensional reconstructions. Results: Although the external morphology of the porcine liver differs from that of the human, the segmental anatomy is remarkably similar in term of its vascularity and biliary tree. Conclusion: Acrylic casting of the porcine liver accurately delineates the vascular and biliary anatomy, and is a useful tool for performing experimental liver surgery. The similarities between porcine and human segmental anatomy allow domestic swine to be used as a comparable model. Three-dimensional CT reconstructions can also accurately visualize the anatomy and may be used to perform virtual surgery, or to assess segmental volumes. Copyright © 2003 British Journal of Surgery Society Ltd. Published by John Wiley & Sons, Ltd. [source]