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Biomedical subjects

W D Warren

Publications and source records attributed to W D Warren.

At least 91 records · Page 5Linked to original sources

A noninvasive method for measuring portal venous/total hepatic blood flow by hepatosplenic radionuclide angiography.

Radionuclide angiography was used to generate first-pass radioactivity vs. time curves for the left heart, right hepatic lobe, right lung, spleen, and both kidneys following rapid intravenous injection of 20 mCi (740 MBq) of 99mTc-pertechnetate. Seven normal subjects were examined as well as 57 cirrhotic patients, who also underwent angiographic grading of portal venous perfusion. For analysis, two time points were identified: (a) t0, when 99mTc first entered the liver (the initial rise of either curve); and (b)tc, when 99mTc was maximal in abdominal organs (the renal peak). Analysis was based on the slopes of the two phases of the hepatic curves t0 + 7 seconds and Tc + 7 seconds; this time selection permitted analysis of all curves. The hepatic perfusion index (HPI) = slope (tc + 7 secs)/slope (t0 + 7 secs) + slope (tc + 7 secs). The mean HPI for the normal subjects was 66% +/- 7; for the cirrhotic patients with angiographic Grades I, II, III, and IV, the HPI was 52% +/- 9, 37% +/- 6, 15% +/- 7, and 3% +/- 4, respectively. Correlation between HPI and angiography was significant (p less than 0.001). This method offers a readily available, rapid, relatively inexpensive, and quantitative method of grading the ratio of portal venous to total hepatic blood flow.

Adult↗

Infected Dacron mesorenal portosystemic shunt.

A serious septicemia developed in a patient two years after placement of a Dacron mesorenal shung for bleeding esophageal varices. The source of the sepsis remained unknown for 13 months and was refractory to antibiotic therapy. Roentgenographic studies showed the shunt to be patent and without intralumenal thrombus. At operation, the shung was being contaminated by a hole in the proximal jejunum and the patient has been cured of sepsis by removing the shunt. In contrast to the presentation of infected prosthesis used in the arterial system, infectious complications of prosthesis used in the portal systemic venous system occur without thrombosis of the shunt, aneurysm formation, or intraintestinal bleeding thus making operative evaluation the only means of diagnosis.

Blood Vessel Prosthesis↗

Dacron interposition shunts for portal hypertension. An analysis of morbidity correlates.

Analysis of 79 Dacron interposition shunts performed at Emory University from 1971 to 1977 identified a number of preoperative characteristics that correlate with short-term and long-term morbidity. Initial hospital mortality was related to the degree of elevation of the bilirubin and serum glutamic oxaloacetic transaminase (SGOT), to the presence of encephalopathy and to the urgency of the shunt procedure. Cumulative survival correlated best with the preoperative SGOT and bilirubin values, but other variables, including the Child's classification, preoperative encephalopathy, serum albumin, and the age of the patient at the time of operation, also exhibited significant associations. The hospital mortality of 13% and cumulative mortality of 48% in this series are in substantial agreement with similar reports in the literature. This experience differs widely from that described by most authors, however, in two other important respects: 1) significant hepatic encephalopathy has been observed in 45% of these hospital survivors, and 2) almost one-quarter of these patients have experienced spontaneous shunt closure. Thus, major shunt related complications have occurred in 70% of the patients to date. This incidence of undesirable consequences raises a serious question concerning the continued use of the Dacron interposition shunt for elective portal decompression.

Adult↗

Noncirrhotic portal vein thrombosis. Physiology before and after shunts.

Controversy exists concerning the proper therapy for bleeding gastroesophageal varices secondary to noncirrhotic portal vein thrombosis. Disparity of opinion exists regarding the significance of hepatic portal blood flow and the consequences of total portal-systemic shunts in this condition. One patient is presented who developed severe, crippling encephalopathy 20 years after a central splenorenal shunt. This was associated with loss of portal flow to the liver and marked nitrogen intolerance. Closure of the shunt resulted in restoration of hepatic portal flow via collateral veins (HPI 0.36), clearance of encephalopathy and return to near normal protein tolerance. An additional patient was studied with hyperammonemia and early suggestive signs of encephalopathy eight years following a mesocaval shunt. Four patients were evaluated before and after selective distal splenorenal shunts. All had "cavernous transformation" of the portal vein with angiographic evidence of portal flow to the liver. Postoperative angiograms revealed continued hepatic portal perfusion and a patent shunt in each patient. Radionuclide imaging postoperatively gave an estimated portal fraction of total hepatic blood flow (HPI) of .39 and .60 in two of the four patients. We conclude that 1) there is significant hepatic portal perfusion in noncirrhotic portal vein thrombosis (cavernous transformation), 2) loss of this hepatic portal flow following total shunts can lead to severe encephalopathy, 3) the selective distal splenorenal shunt maintains hepatic portal perfusion and is the procedure of choice when there is a patent splenic vein and surgical intervention is indicated.

Adolescent↗

The relationship between conventional liver tests, quantitative function tests, and histopathology in cirrhosis.

Thirty patients with cirrhosis were evaluated with the 2-hr [14C]aminopyrine breath test (score) and with conventional liver tests. Of the 30 patients, 24 also had current liver biopsies. There was a good correlation between necroinflammatory activity in the 24 cirrhotic liver biopsies and the 2-hr aminopyrine scores. All five patients who had at least grade 2 necroinflammatory activity on their biopsy had an abnormal prothrombin time (greater than 3.5 sec above control) and their aminopyrine score was less than 2%. The correlation was good between the 2-hr aminopyrine score and the prothrombin time (seconds over control). No correlation was found between the 2-hr aminopyrine score and either the serum aspartate aminotransferase (SGOT) or any other liver test except for the prothrombin time. It seems that the 2-hr aminopyrine score and prothrombin time are more likely to give a quantitative estimate of total functioning parenchymal mass which is left unaffected by hepatocellular disease in cirrhosis, than the other commonly used liver tests.

Aminopyrine↗

Portal pseudoperfusion: an angiographic illusion.

Much confusion regarding the hemodynamics following interposition mesosystemic shunts prevails. Many authorities have claimed that portal venous perfusion continues following interposition mesocaval shunts. In 1971, a prospective, randomized trial comparing the distal splenorenal shunt with a variety of interposition mesosystemic shunts (primarily mesocaval or mesorenal) was begun. Visceral angiography was utilized to assess the early and late postoperative hemodynamic changes following both selective and nonselective shunts. None of the patients with patent interposition shunts retained portal perfusion present preoperatively. Searching for an explanation for this hemodynamic discrepancy, we examined two patients of the randomized trial angiographically. Both patients had excellent portal perfusion preoperatively, yet following interposition shunting (one mesocaval and one splenocaval), neither maintained portal perfusion of the liver. Celiac artery injections produced opacification of the entire splenoportal axis; however, it is shown that such portal venous opacification occurred in a retrograde direction by selective hepatic arterial injections demonstrating hepatofugal portal venous flow. Additionally, two nonrandomized patients received interposition mesorenal shunts and exemplify this phenomenon, entitled "portal pseudoperfusion". The explanation for conflicting literature reports lies in the misinterpretation of venous phase celiac and non-selective SMA arteriography in determining the direction of portal flow. A narrative of preoperative and postoperative angiograms of four patients will clarify the mechanism of "portal pseudoperfusion" and demonstrate that interposition shunts totally siphon portal venous perfusion. Clues to the detection and techniques to avoid this phenomenon will be presented.

Adult↗

The mortality of bleeding esophageal varices in a private university hospital.

The mortality of patients with bleeding esophageal varices was studied in a private hospital where the modalities of treatment are considered optimal. Of the sixty-two patients in the study, twenty (32 per cent) died. Mortality was higher (p is less than 0.02) for those who had ascites or bilirubin more than 5 mg/dl, albumin less than 3 gm/dl, prothrombin time more than 4 seconds of control, or blood transfusions of more than 5 liters. The lower mortality in this study as compared with other studies among indigent population is the result of either private patients having less severe liver disease or having more effective care of both.

Adolescent↗

Splenic artery ligation in distal splenorenal shunts.

Splenic artery ligation, a simple surgical procedure expected to decrease splenic flow and portal pressure in patients with cirrhosis of the liver, was performed concomitantly with a distal splenorenal shunt procedure in six patients and as the main surgical procedure in two patients. Immediate cessation of bleeding was achieved in the four patients in whom the splenic artery was ligated to reduce intraoperative bleeding. However, three of the seven patients with previous gastroesophageal hemorrhage rebled from various postoperatively. Symptoms of splenic infarction were observed in six patients, resulting in thrombosis of the splenic vein and/or of the distal splenorenal shunt in four patients and necessitating splenectomy in one. This incidence of thrombosis of the distal splenorenal shunt is much higher than the overall incidence of 5 per cent observed at our institution. It is thus concluded that the splenic artery should not be ligated in cirrhotic patients with patent distal splenorenal shunts, since splenic arterial collateral vessels have already been reduced by the gastric devascularization, an integral component of the distal splenorenal shunt.

Adolescent↗

A randomized, controlled trial of the distal splenorenal shunt.

In 1971 a prospective, randomized trial was initiated to determine efficacy of the distal splenorenal shunt in the management of cirrhotic patients who had previously bled from esophageal varices. When entry into the trial was terminated in 1976, 26 patients had received the distal splenorenal shunt (selective) and 29 had undergone a nonselective shunting procedure (18 interposition mesorenal, six interposition mesocaval, and five other nonselective shunts). Three operative deaths occurred in each group. Early postoperative angiography revealed preservation of hepatic portal perfusion in 14 of 16 selective patients (88%), but in only one of 20 nonselective patients (5%; p < .001). Quantitative measures of hepatic function (maximal rate of urea synthesis or MRUS and Child's score) were similar to preoperative values in the selective group but were significantly decreased in nonselective patients on the first postoperative evaluation (p < .001 for MRUS; p < .05 for Child's score). Eighty-seven per cent of selective and 81% of nonselective patients have now been followed for three to six years since surgery. Late postoperative evaluation of 29 survivors (12 selective, 17 nonselective) still shows an advantage to the selective group with respect to MRUS, Child's score, and incidence of hepatopetal portal blood flow, but differences are no longer statistically significant. However, if the seven patients with portal flow (five selective; two nonselective) are compared to the 20 with absent portal flow (seven selective; 13 nonselective), the former group has significantly higher values for MRUS (p < .05) and Child's score (p < .025). No patient with continuing portal perfusion has developed encephalopathy as compared to a 45% incidence of this complication in individuals without portal flow (p < .05). No significant differences between selective and nonselective groups have appeared with respect to total cumulative mortality (ten selective; 38%; eight nonselective, 28%), shunt occlusion (two selective, 10%; five nonselective, 18%), or recurrent variceal hemorrhage (one selective, 4%; two nonselective, 8%). Overall, significantly fewer selective patients have developed postoperative encephalopathy (three selective, 12%; 15 nonselective, 52%; p < .001). Therefore, we conclude that the distal splenorenal shunt, especially when its objective of maintaining hepatic portal perfusion is achieved, results in significantly less morbidity than nonselective shunting procedures.

Alcoholism↗

Evaluation of the left renal vein in candidates for splenorenal shunts.

The authors describe 4 patients who had functioning distal splenorenal shunts despite obstruction of the left renal vein at its insertion into the inferior vena cava. The angiographic technique and findings of left renal vein evaluation in 40 shunted patients are reviewed. There were two important findings. First, no correlation existed between the degree of portal hypertension and the degree of filling of collateral tributaries of renal veins. Second, obstruction of the left renal vein does not impair a splenorenal shunt if good collateral pathways are present.

Angiography↗