W. Dean Warren

Maximal Rates of Excretion and Synthesis of Urea in Normal and Cirrhotic Subjects

When normal individuals eat 0.33 g protein N/kg body weight (BW)((3/4)) per day, they excrete 10-15 mg urea N/h per kg BW((3/4)). If they now ingest (at 0 h) 0.27 (dose A), 0.40 (dose B), 0.53 (dose C), 0.94 (dose D), or 1.33 (dose E) g protein N/kg BW((3/4)) (in the form of casein, ovalbumin, or lactalbumin), the rate of urea N excretion accelerates within 4 h. At dose C a maximal rate of urinary urea N excretion (MRUE) is reached, which averages 55 mg urea N/h per kg BW((3/4)) and which persists for 16 h. Higher doses of protein do not further accelerate urea excretion, but prolong the duration of MRUE to 28 h (after dose E). Blood urea N (BUN) rises by 7-20 mg/100 ml during the first 8 h after dose C to E, and remains stable within +/-5 mg/100 ml during the ensuing 8-28 h of MRUE. Each increment of protein above dose C causes a further increment in plasma alpha-amino N. During infusion of free amino acids at a rate of 110 or 165 mg amino acid N/h per kg BW((3/4)) for 12 h, rate of urea excretion increases to the MRUE value produced by dose C-E of oral protein.These findings indicate that MRUE corresponds to a period of maximal rate of urea synthesis (MRUS). MRUS is greater than MRUE because one fraction of newly formed urea is hydrolyzed in the gastrointestinal tract, and another fraction may accumulate temporarily in body water during the MRUE period. Oral neomycin reduces the proportion of urea hydrolyzed in the gut to less than 20%; its extent is measured by recovery in the urine of a tracer dose of [(14)C]urea injected intramuscularly during determination of MRUE. Accumulation of urea in body water is estimated from increment in BUN during the period of MRUE measurement (8-24 h after dose E of casein) and from body water measured with (3)H(2)O. Then MRUS is calculated as: ([mg urea N excreted between 8 and 24 h after dose E] + [BUN at 24 h - BUN at 8 h] x [body water]) x (100/% recovery [(14)C]urea) x (1/kg BW((3/4))) x (1/16 h).MRUS in 10 normal subjects averaged 65 mg urea N/h per kg BW((3/4)) (range 55-76), and in 34 cirrhotics 27 mg urea N/h per kg BW((3/4)) (range 6-64). Among 19 cirrhotic patients fed 40, 60, 80, or 100 g protein daily for successive 10 day periods, the occurrences of hyperammonemia, hyperaminoacidemia, and encephalopathy at each level of protein intake were inversely related to MRUS value.

Ten Years Portal Hypertensive Surgery at Emory: Results and New Perspectives

Five hundred four shunt procedures have been done at Emory University Hospitals between 1971 and 1981 to decompress bleeding esophageal varices. This paper reviews how far the experiences of a prospective randomized study (55 patients) of distal splenorenal shunts against total shunts is supported by the nonrandomized experience (449 patients), and outlines our current methods of management dictated by this experience. The overall operative mortality for 348 selective shunts is 4.1%, and for 156 nonselective shunts, 14.1%. The five-year survival following selective shunt is 59%, and following nonselective shunt is 49%: more than half the selective shunt patients are alive, in contrast to the median survival of 44.5 months for patients having nonselective shunts. Following selective shunt, the survival in nonalcoholic patients is significantly better than the median survival of alcoholic patients of 57 months. Encephalopathy, reported at three years after surgery in the randomized patients was significantly (p < 0.001) lower after selective shunt (12%) compared to nonselective shunt (52%): in the same population at seven years, all patients with patent nonselective shunts have clinical or subclinical encephalopathy, but only 30% of the selective shunt patients have subclinical encephalopathy. Shunt patency, immediately after surgery, is 93% following selective shunt, with only two documented late thromboses: nine of nine patients, at a mean of seven years, retain patency in the randomized study. Shunt occlusion increases with time after interposition nonselective shunts: seven of 13 are occluded at a mean follow-up of seven years in the randomized study. Portal venous perfusion is retained in 93% of patients seven to ten days after selective shunt, but in no patient with a patent nonselective shunt. Late portal perfusion is maintained in nine of the eleven patients in the randomized group studied at a mean of seven years after selective shunt. Restoration of portal perfusion has led to clearing of encephalopathy and improvement in hepatic function in six patients. The following conclusions are made; (1) selective shunts can be done with low operative mortality, and long-term patency with excellent control of bleeding; (2) hepatic portal venous perfusion has been maintained after selective shunt for ten years, and this is vital for preventing encephalopathy and maintaining hepatic function; (3) long-term survival after selective shunt is better than any reported series for nonselective shunt; and (4) selective shunts are the operative procedure of choice for variceal decompression and nonselective shunts should rarely be performed for elective decompression.

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 non-selective patients (5%; p <.001). Quantitative measures of hepatic function (maximal rate of urea synthesis or MRUS and Childs 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 Childs 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 non-selective) still shows an advantage to the selective group with respect to MRUS, Childs 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 Childs 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 non-selective, 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.

Endoscopic Variceal Sclerosis Compared with Distal Splenorenal Shunt To Prevent Recurrent Variceal Bleeding in Cirrhosis: A Prospective, Randomized Trial

STUDY OBJECTIVE To define the roles of endoscopic variceal sclerosis and distal splenorenal shunt in the prevention of recurrent variceal bleeding in patients with cirrhosis. DESIGN A prospective, randomized clinical trial with crossover for those failing therapy. The median follow-up was 61 months. SETTING A private, tertiary-referral university hospital. PATIENTS Seventy-two patients fulfilling inclusion criteria were drawn from a total of 420 patients treated during a 4.5-year interval. TREATMENTS Endoscopic variceal sclerosis or distal splenorenal shunt. MEASUREMENTS AND MAIN RESULTS Survival was significantly (P = 0.02) improved in patients randomly assigned to receive sclerotherapy: 13 of these 37 (35%) patients failed sclerotherapy and required surgical rescue. A survival advantage (P = 0.01) was seen in patients with alcoholic cirrhosis who had this combined therapy; however, in patients with nonalcoholic cirrhosis, survival for those receiving sclerotherapy and surgical rescue was not significantly (P = 0.36) different from that of patients receiving distal splenorenal shunt. Control of variceal bleeding was significantly (P less than 0.001) better in the distal splenorenal shunt group (34 of 35 [97%] compared with 15 of 37 [41%] in the sclerotherapy group). Using death, uncontrolled rebleeding, or shunt thrombosis as the endpoints resulted in no significant difference between treatment groups. Hepatocyte function and portal perfusion were significantly better maintained in patients with alcoholic cirrhosis who were managed by sclerotherapy rather than shunt (P = 0.01 and P = 0.001, respectively). CONCLUSIONS Endoscopic sclerotherapy with surgical rescue for uncontrolled bleeding is the optimum therapy for patients with alcoholic cirrhosis and variceal bleeding. Survival is similar in nonalcoholic patients treated with either distal splenorenal shunt or endoscopic sclerotherapy, but shunting provides better control of variceal bleeding.

Surgical options, hematologic evaluation, and pathologic changes in Budd-Chiari syndrome

This article presents a scheme of management for Budd-Chiari syndrome based on experience with 33 patients. Therapy in acute Budd-Chiari syndrome is dictated by the liver biopsy, with hepatocyte necrosis indicating the need for placement of a decompressive shunt. The type of shunt was determined by intrahepatic vena cava obstruction; a higher morbidity rate was associated with the mesoatrial shunt in 11 patients than with a portacaval shunt in 10 patients. Successful shunt placement allowed stabilization of the liver biopsy and maintenance of good hepatocyte function [galactose elimination capacity (preoperative: 349 +/- 40 mg/minute; 20 months: 344 +/- 60 mg/minute)]. Severe fibrosis and reduced galactose elimination capacity (264 +/- 43 mg/minute) indicated advanced disease--chronic Budd-Chiari syndrome--and were indications for liver transplant. Hematologic evaluation documented a myeloproliferative disorder in 8 of the last 13 patients evaluated; perioperative and late anticoagulation and/or chemotherapy reduced recurrent thrombosis. We conclude that the Budd-Chiari syndrome requires different therapies depending on the stage of disease. If no hepatocyte injury is present on biopsy, therapy may not be needed. Acute, reversible injury can be managed by placement of a decompressive shunt. Irreversible damage requires transplantation. Selection of the right therapy requires a complete evaluation.

Selective and total shunts in the treatment of bleeding varices. A randomized controlled trial.

Two types of surgical therapy of bleeding esophageal varices were evaluated in 48 patients by a randomized controlled trial: 24 were randomized for a total shunt and 24 for the selective shunt. In two of the latter, a total shunt had to be performed for technical reasons. The fatality rates (six in the 24 total, and six in 22 selective [performed], and seven in 24 selective [randomized]), the frequency of shunt occlusion (two in each group), and of recurrent gastronintestinal bleeding (three in each group) were similar. Encephalopathy developed more often after a total shunt -- 10 of 24, or one per 58 patient-months -- than after selective (performed) -- one of 22, or one per 593 patient-months (P less than 0.005). Total shunts consistently diverted the hepatopetal mesenteric-portal flow from the liver. Deterioration of hepatic function (maximum rate of urea synthesis) was greater after total than selective shunt (P less than 0.05).

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 encepha-lopathy and to the urgency of the shunt procedure. Cumulative survival correlated best with the preoperative SGOT and bilirubin values, but other variables, including the Childs 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.

Reversal of hepatic encephalopathy after occlusion of total portasystemic shunts

Abstract In conclusion, therefore, we recommend selective distal splenorenal shunt for patients with hepatopetal flow and nonselective total portasystemic shunt for most patients with hepatofugal flow in order to minimize the incidence of postshunt encephalopathy. Patients with hepatopetal flow who are treated by a nonselective shunt and develop chronic, refractory encephalopathy are candidates for shunt ligation if they have good liver function.

The Rate of Synthesis of Glycosaminoglycans and Collagen by Fibroblasts Cultured from Adult Human Liver Biopsies

Adult human liver biopsies were cultured from normal, alcoholic hepatitis, chronic active hepatitis, fibrosis plus alcoholic hepatitis (active cirrhosis), inactive cirrhosis, and drug hepatitis. The synthesis of collagen was estimated in cultures from 58 livers by measuring the conversion of [(14)C]proline to the [(14)C]hydroxyproline of collagen; that of glycosaminoglycans in cultures from 57 livers by the incorporation of [(3)H]acetate and (35)SO(4) into glycosaminoglycans (GAG). The synthesis of procollagen was increased only in cultures from alcoholic hepatitis, both in the pulse medium (P < 0.05) and in the chase medium (P < 0.02). The synthesis of insoluble collagen was increased in cultures from chronic (active) hepatitis (P < 0.01), fibrosis plus alcoholic hepatitis (active cirrhosis) (P < 0.001), and inactive cirrhosis (P < 0.05). Essentially all radioactive GAG was soluble in culture media. The predominant GAG were chondroitin-4 or -6-SO(4). The synthesis of GAG was increased only in cultures from fibrosis plus alcoholic hepatitis (active cirrhosis) both in the pulse medium (P < 0.01) and chase medium (P < 0.001). The data indicate that in the absence of immuno-competent cells or their secretory products, tissue cultures from livers showing biopsy evidence of active fibrosis in vivo may demonstrate increased synthesis of collagen and GAG in vitro. Increased (soluble) procollagen synthesis in cultures from alcoholic hepatitis was not associated with histologically demonstrable overt hepatic fibrosis in vivo, nor was it associated with increased GAG synthesis in vitro. No significant difference was demonstrable in collagen or GAG synthesis in paired cultures which contained either 300 mg/dl ethanol or 3.75 mg/dl methylprednisolone compared to their respective controls.

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 (>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.