The ischemic preconditioning paradox in deceased donor liver transplantation-evidence from a prospective randomized single blind clinical trial.

While animal studies show that ischemic preconditioning (IPC) is beneficial in liver transplantation (LT), evidence from few smaller clinical trials is conflicting. From October 2003 to July 2006, 101 deceased donors (DD) were randomized to 10 min IPC (n = 50) or No IPC (n = 51). Primary objective was efficacy of IPC to decrease reperfusion (RP) injury. Both groups had similar donor risk index (DRI) (1.54 vs. 1.57). Aminotransferases on days 1 and 2 were significantly greater (p < 0.05) in IPC recipients. In multivariate analyses, IPC had an independent effect only on day 2 aspartate transferase. Prothrombin time, bilirubin and histological injury were similar in both groups. IPC had no significant effect on plasma TNF-alpha, IL-6 and IL-10 in the donor and TNF-alpha and IL-6 in the recipient. In contrast, IPC recipients had a significant rise in systemic IL-10 levels after RP (p < 0.05) and had fewer moderate/severe rejections within 30 days (p = 0.09). Hospital stay was similar in both groups. One-year patient and graft survival in IPC versus No IPC were 88% versus 78% (p = 0.1) and 86 versus 76% (p = 0.25), respectively. IPC increases RP injury after DDLT, an 'IPC paradox'. Other potential benefits of IPC are limited. IPC may be more effective in combination with other preconditioning regimens.

Pitfalls in the CT diagnosis of appendicitis.

CT evaluation of appendicitis represents an increasingly common emergency room request. While the overall accuracy of CT is high, numerous pitfalls exist which may deceive radiologists, resulting in a missed diagnosis of appendicitis. The inflamed appendix may be unusual in its location, or may appear normal if only a small portion of the distal appendix is involved (tip appendicitis). In a patient with a history of appendectomy, inflammation of the appendiceal stump may be easily missed. Appendicitis may closely mimic small bowel obstruction, or gynaecological disease, especially after perforation has occurred. Even a misleading clinical history may lead the radiologist's eye astray. This pictorial review demonstrates these and other potential radiological pitfalls, and includes important points for the accurate diagnosis of appendicitis.

Respiratory variation of the diameter of the pancreatic duct on sonography.

OBJECTIVE: The objective of this study was to assess the prevalence of a 1-mm or greater increase in the diameter of the pancreatic duct during deep inspiration in patients without pancreatic disease. MATERIALS AND METHODS: A retrospective review was performed of normal findings on pancreatic sonograms of 25 consecutive lean patients without pancreatic disease who were capable of taking deep breaths. The anteroposterior diameter of the pancreatic duct in the body of the gland was measured at end-expiration and end-inspiration. A significant change was defined as a 1-mm or greater difference between the end-inspiratory and end-expiratory diameters for at least two of three consecutive breaths. RESULTS: Seven patients (28%) had a significant increase in the diameter of the pancreatic duct at end-inspiration. These included four patients (16%) in whom the diameter of the duct was less than or equal to 2.5 mm (i.e., normal) at end-inspiration and three patients (12%) in whom the diameter of the duct was greater than 2.5 mm at end-inspiration. CONCLUSION: The diameter of the pancreatic duct can increase during deep inspiration in some adults without pancreatic disease. This finding should be borne in mind as a potential pitfall during pancreatic sonography.

Transjugular intrahepatic portosystemic shunt for the treatment of intractable ascites in a patient with polycystic liver disease.

Though polycystic liver disease (PCLD) has historically been considered a contraindication to TIPS, we present a case where technically successful shunt creation was achieved without the need for modification of the standard TIPS procedure, as was required in a previous report.

Non-Asian hepatocellular carcinoma: correlation between histologic features and echogenicity.

Studies of hepatocellular carcinoma in Asia have revealed a correlation between lesion hyperechogenicity and five histologic features: nonliquefied necrosis, sinusoidal dilatation, hemorrhage, fatty metamorphosis, and fibrosis. However, this correlation has not been investigated for non-Asian hepatocellular carcinoma, despite substantial differences between the Asian and non-Asian forms of this carcinoma. We retrospectively reviewed records of 29 patients seen at one United States institution who had hepatocellular carcinoma lesions that were either completely hyperechoic or completely hypoechoic. Tissue specimens obtained surgically (n = 7) or percutaneously (n = 22) were evaluated microscopically for the presence of nonliquefied necrosis, sinusoidal dilatation, hemorrhage, fatty metamorphosis, and fibrosis. A statistically significant correlation was identified between the number of histologic features identified and lesion diameter (P = 0.04) but not between the number of histologic features identified and the likelihood of hyperechogenicity (P = 0.11). Two lesions (50%) with three histologic features, four lesions (40%) with two histologic features, and six lesions (55%) with one histologic feature were hypoechoic. The echogenicity of non-Asian hepatocellular carcinoma lesions cannot be attributed to the histologic features that are believed to underlie echogenicity of the Asian type of hepatocellular carcinoma.

Narrowing of the upper abdominal inferior vena cava in patients with elevated intraabdominal pressure: sonographic observations.

Focal narrowing of the upper intrahepatic inferior vena cava on computed tomography performed in patients with elevated intraabdominal pressure has been reported recently. The purpose of this study was to assess this phenomenon further with gray scale and duplex Doppler sonography. Seven patients with elevated intraabdominal pressure due to massive ascites in whom computed tomography showed narrowing of the intrahepatic inferior vena cava were studied. Sonography confirmed focal narrowing of the intrahepatic inferior vena cava that persisted throughout the respiratory and cardiac cycles. The narrowed inferior vena cava segment had a characteristic slitlike appearance on transverse images, slightly oblique to the sagittal plane. A focal flow jet typical of stenosis was observed in the three patients in whom Doppler sonography technically was feasible. In three of four patients who were able to sit or to turn into the left lateral decubitus position, the narrowing immediately resolved after the positional change but promptly recurred upon return to the supine position. In patients with elevated intraabdominal pressure, focal slitlike narrowing of the intrahepatic inferior vena cava is an anticipated finding that should not be misinterpreted as evidence of stenosis of the inferior vena cava or of a juxtacaval liver lesion.

Duplex Doppler sonography of small (<3 cm diameter) liver tumours: intralesional arterial flow does not exclude cavernous haemangioma.

In small liver lesions (<3 cm diameter), detection of internal arterial flow with duplex Doppler sonography is thought to virtually exclude the diagnosis of cavernous haemangioma. We retrospectively reviewed 114 consecutive small lesions confirmed or suspected to be haemangiomas. Doppler sonography revealed intralesional arterial flow in four lesions for which correlative imaging studies were diagnostic of haemangioma, and for which stability was documented with follow-up sonography. We conclude that intralesional arterial flow should not be interpreted as conclusive evidence that a small liver lesion is not a haemangioma. If the presence of arterial flow within a small liver lesion prompts concern that the lesion is not a haemangioma, our findings suggest that a correlative imaging study should be considered before percutaneous biopsy is performed.

Unilateral absence of ureteral jets in the third trimester of pregnancy: pitfall in color Doppler US diagnosis of urinary obstruction.

Among 23 asymptomatic pregnant women with ureteral jets noted at color Doppler ultrasonography, jets were detected at only one ureteral orifice in three (13%) during the third trimester. In each such case, normal jets were detected from the suspicious ureter after the patient turned to the contralateral decubitus position. A unilaterally absent jet noted in the third trimester of pregnancy should not be interpreted as a sign of ureteral obstruction unless the finding persists in the contralateral decubitus position.

Echogenic peritoneal fluid as an isolated sonographic finding: significance in patients at risk of ectopic pregnancy.

Echogenic intraperitoneal fluid in any quantity noted on sonography is thought to indicate a very high likelihood of ectopic pregnancy (EP) in patients at risk. We retrospectively reviewed 12 consecutive symptomatic patients with a positive pregnancy test in whom sonography revealed echogenic fluid as an isolated finding without evidence of intrauterine pregnancy and in whom follow-up was available. Final diagnoses were EP in seven patients (58%) and spontaneous abortion in five (42%). EP was diagnosed in all four patients with a large amount of echogenic fluid, but in only three (38%) of eight patients with a small-to-moderate amount of echogenic fluid. We conclude that a small-to-moderate amount of echogenic fluid noted as an isolated finding may not be highly predictive of EP.

Sonographic endometrial three-layer pattern in symptomatic first-trimester pregnancy: not diagnostic of ectopic pregnancy.

PURPOSE: We evaluated a recent report that suggested that a "3-layer" appearance of the endometrium on sonography is diagnostic of ectopic pregnancy in symptomatic pregnant patients. METHODS: We reviewed the log of pelvic sonograms performed to rule out ectopic pregnancy in women presenting with first-trimester bleeding and/or pain during a 29-month period. Medical records and sonograms of patients without sonographic evidence of intrauterine pregnancy were reviewed to determine final diagnoses and whether the 3-layer pattern was present. RESULTS: One hundred twenty patients with available follow-up had no sonographic evidence of intrauterine pregnancy. Fifty-nine (49%) had ectopic pregnancy. An endometrial 3-layer pattern was noted sonographically in 15 patients (13%), of whom 6 (40%) had ectopic pregnancy. As a diagnostic sign of ectopic pregnancy, the endometrial 3-layer pattern had a sensitivity of 10.2%, specificity of 85.2%, positive predictive value of 40%, negative predictive value of 50.5%, and accuracy of 49.2%. CONCLUSIONS: The endometrial 3-layer pattern is neither sensitive nor specific for the diagnosis of ectopic pregnancy.

Sonographic versus endoscopic retrograde cholangiographic measurements of the bile duct revisited: importance of the transverse diameter.

OBJECTIVE: The purpose of this study was to investigate how frequently the cross section of the bile duct is oval versus round on sonography and whether the transverse diameter of the bile duct (DTRV) on sonography corresponds better than the conventional anteroposterior diameter (DAP) to measurements on endoscopic retrograde cholangiography (ERC). SUBJECTS AND METHODS: In 44 consecutive patients with a DAP greater than or equal to 8 mm, DTRV was measured on short-axis sonograms. Diameter of the bile duct measured on ERC (DERC) was compared with DAP and DTRV in patients who underwent ERC shortly after sonography. RESULTS: The cross section of the bile duct was oval in 31 patients (70%). In 20 patients who underwent ERC after sonography, mean DERC was statistically indistinguishable from mean DTRV but statistically different from mean DAP. Comparing both DAP and DTRV with DERC in each patient, we found no statistically significant difference between DERC and DTRV, but we did find a statistically significant difference between DERC and DAP. CONCLUSION: An oval cross section is common in bile ducts with a DAP greater than or equal to 8 mm. The discrepancy between measurements of the bile duct made sonographically and those made on ERC is largely attributable to different cross-sectional diameters. Because DTRV correlates better than conventional DAP with DERC, measurement of DTRV can be helpful in confirming or excluding true biliary dilatation in patients with a DAP larger than normal.

Narrowing of the upper abdominal inferior vena cava in patients with elevated intraabdominal pressure.

BACKGROUND: Previous investigators have suggested that narrowing of the suprahepatic inferior vena cava (IVC) occurs in patients with increased intraabdominal pressure (IAP). SUBJECTS AND METHODS: We retrospectively reviewed 59 contrast-enhanced computed tomographic (CT) scans performed over a 2-year period in patients with evidence of increased IAP. We also reviewed CT scans performed in a control group of 30 normal patients. The intrahepatic and suprahepatic IVC segments were assessed for narrowing. RESULTS: Narrowing of the suprahepatic IVC was never observed in the patients with elevated IAP. Slit-like narrowing of the upper intrahepatic IVC was noted in 11 (44%) of 25 patients; the intrahepatic IVC was not evaluated in 34 other patients with liver abnormalities or unsatisfactory opacification of the intrahepatic IVC. In control subjects, narrowing was not observed in either the intrahepatic or suprahepatic IVC. CONCLUSION: Narrowing of the upper intrahepatic IVC can be seen in some patients with increased IAP. The cause and significance of this phenomenon remain to be determined.

Retroperitoneal edema: sonographic mimic of retroperitoneal fluid collection.

BACKGROUND: The sonographic finding of an anechoic retroperitoneal abnormality suggests a fluid collection (e.g., abscess, urinoma, hematoma). Our study was performed to evaluate cases in which this sonographic finding appeared to be a manifestation of systemic edema. SUBJECTS AND METHODS: Inpatient sonograms performed over a 40-month period were reviewed for the presence of anechoic areas suggestive of fluid collection in the retroperitoneum of the flank. Records of patients with such findings were reviewed for evidence of retroperitoneal abscess, urinoma, or hemorrhage, as well as for the presence and cause(s) of peripheral edema. RESULTS: Of the 29 patients identified with sonographic findings suspicious for retroperitoneal fluid collection, 13 (45%) had no cause for and no clinical evidence of focal retroperitoneal collection. All 13 patients had peripheral edema attributable to hypoalbuminemia, congestive heart failure, overhydration, cirrhosis, and/or the systemic inflammatory response (multiple organ failure) syndrome. Resolution of the retroperitoneal abnormality following therapy for congestive heart failure was documented in one case, and CT scan confirmed retroperitoneal edema in another. CONCLUSION: Anechoic regions that represent edema can be seen on sonograms of the retroperitoneum in patients with conditions that cause edema in other regions. The possibility of edema mimicking a fluid collection should be particularly considered prior to invasive procedures in the retroperitoneum.

Dilatation of the inferior vena cava in patients with cirrhotic portal hypertension. Causes and imaging findings.

Dilatation of the inferior vena cava is a frequent finding in patients with cirrhosis and portal hypertension, and may be produced by various mechanisms. In this article we illustrate the spectrum of causes and appearances of inferior vena caval dilatation in patients with cirrhosis and portal hypertension.

Cholangiographic demonstration of the cholecystohepatic duct of Luschka.

The cholecystohepatic duct of Luschka is demonstrated. This anomaly directly connects the gallbladder to the bile ducts, draining a portion of the right lobe of the liver. The pertinent embryology is reviewed. When accidentally severed, it may cause a bile leak leading to biloma formation. It should be recognized before surgery to alert the surgeon.

Echogenicity of hepatic versus portal vein walls revisited with histologic correlation.

The portal vein wall typically is hyperechoic over a wide range of beam-vessel angles, whereas the hepatic vein wall is hyperechoic only when the incident beam and the vessel are perpendicular. This has been attributed to marked discrepancies in mural thickness, collagen content, or perivascular fat between portal and hepatic veins. We evaluated histologically the walls of portal and hepatic veins using three cadaveric livers. For vessels with luminal diameter above 2 to 3 mm, hepatic vein and portal vein wall thicknesses were similar such that portal vein walls were not more than 50% thicker than those of hepatic veins of comparable size. Hepatic vein walls were mostly composed of parallel, tightly packed collagen fibers. In contrast, portal vein walls were composed of loosely arrayed, nonparallel connective tissue fibers which were separated by multiple intervening spaces and only a minority of which were collagenous. Perivascular fat was not identified adjacent to intrahepatic vessels beyond the liver hilus. The marked differences in echogenicity between portal vein and hepatic vein walls typically observed at ultrasonography thus cannot be attributed to differences in mural thickness, collagen content, or perivascular fat between these vessels. Rather, the distinct composition of the hepatic vein wall renders it a specular reflector, which is hyperechoic only when the angle between the ultrasound beam and the vessel wall is close to 90 degrees, whereas the composition of the portal vein wall enables it to appear hyperechoic at a wide range of beam-vessel angles.

CT evaluation of pararectal varices.

PURPOSE: This study was undertaken to determine the prevalence of pararectal varices on CT scan in patients with portal hypertension and to see if dilatation of the inferior mesenteric vein (IMV) or the presence of pararectal varices on CT correlates with rectal varices noted on colonoscopy. METHOD: We reviewed 83 consecutive CT scans of the abdomen and pelvis performed in patients with portal hypertension. The size and prevalence of pararectal varices were determined. Correlation with colonoscopic and endoscopic reports was performed. The diameter of the IMV was compared in those patients with pararectal varices with that in those patients without, as was the presence of esophageal varices. RESULTS: Twenty patients (24%) had CT evidence of pararectal varices, ranging from 5 to 11 mm in diameter (mean 7.8 mm). Colonoscopic correlation was available in 30 patients. Of these, 6 of 30 (20%) had pararectal varices on CT and no rectal varices on colonoscopy, 3 of 30 (10%) had pararectal varices on CT and rectal varices on colonoscopy, and 3 of 30 (10%) had no pararectal varices on CT but did have rectal varices on colonoscopy. Endoscopic correlation (available in 48 patients) demonstrated esophageal varices in 88% of patients with rectal or pararectal varices and in 66% of patients without rectal or pararectal varices (p = 0.170). The IMV was significantly larger in patients with pararectal varices (mean diameter 7.5 mm, SD 2.3) as compared with those without (mean diameter 5.8 mm, SD 2.0) (p = 0.014). However, in patients with colonoscopically proven rectal varices, only two of six (33%) had an IMV diameter of > or = 7 mm. CONCLUSION: Inclusion of the pelvis on CT scans of patients with portal hypertension can yield further information about the presence and extent of pararectal venous collaterals, which may be of particular importance in those patients requiring pelvic surgery. The presence of pararectal varices on CT and the diameter of the IMV do not correlate with the presence of rectal varices on colonoscopy. Decompression of portal hypertension by rectal and pararectal varices does not result in a decreased incidence of esophageal varices.