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.

The delayed onset of anuria/oliguria in acute tubular necrosis has been theorized to represent a complicating compartment syndrome, i.e., parenchymal swelling within an unyielding capsule. To test this proposition, 12 monkeys had suprarenal aortic cross-clamping, followed by unilateral renal decapsulation to create an experimental as well as a control kidney unit in the same animal. Histologic examination uniformly confirmed tubular necrosis at death or sacrifice. Subsequent split renal function studies (creatinine, urea, and free water clearances) indicated significantly greater maintenance of renal function by the decapsulated kidney than by its paired control. Clinical evaluation in 21 hemorrhagic shock patients, with the capsule of one kidney stripped, revealed on follow-up that 15 developed a renal failure consistent with acute tubular necrosis. Although three patients with polyuric failure died before split studies could be run and two others have been too recent for computer analysis to have been completed, nine of the remaining ten had significantly greater renal plasma flows (194 versus 121 ml/min M(2), p < .01) and significantly greater urine flows (.99 versus .18 ml/min M(2), p < .01) on the decapsulated side than on the control, as determined by differential renal scans. No significant difference in these same lateralized renal functions was noted in the tenth patient with renal failure and in the six survivors without renal failure. Renal decapsulation as prophylaxis reduced the anticipated incidence of oliguria/anuria from an expected 75% to 7% (p < .01) in these 21 shock patients. Such data suggest that delayed renal ischemia, possibly based on a compartment syndrome, may be the cause for a progression of acute tubular necrosis from polyuria to oliguria and then to anuria.

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.

A B S T R A C T Hypertyraminemia is common in hepatic cirrhosis and correlates in severity with encephalopathy. The mechanism of cirrhotic hypertyraminemia has not been established. The alternative possibilities are increased production from tyrosine and impaired degradation by monoamine oxidase. This investigation determined the pharmacokinetics of tyramine after an intravenous bolus injection of [3H]-tyramine uCi,12 Ci/mmol sp act) in 13 cirrhotics and 9 controls. In normals, [3H]tyramine levels initially declined rapidly (a-phase) followed by a slower decline (,8-phase) with an average t1/2 of20.8 min. Average normal metabolic clearance rate and production rate were 13.2 liters/min and 15.4 ,ug/min, respectively.In cirrhotic patients, the plasma disappearance curve for [3H]tyramine was qualitatively similar to that of the control subjects with no apparent difference in _3-t1/2 (17.2 min). The hypertyraminemia of cirrhosis resulted primarily from overproduction of tyramine, as the production rate (32.0 ,Lg/min) in these patients was significantly greater (P < 0.05) than in controls, whereas the metabolic clearance rate remained normal (average 12.2 liters/min). A difference in ratio of tyramine metabolic products was noted as well. Cirrhotics had a high ratio of plasma 4-hydroxyphenylethanol:4-hydroxyphenylacetic acid (60:40 vs. 30:70) fects on circulatory and neurologic functions, which are often disturbed in cirrhotics (1-5). An understanding of the mechanism of the hypertyraminemia of cirrhotic patients is therefore desirable. The accumulation of tyramine in plasma could result from increased production, decreased degradation, or a combination of both effects.Tyramine is produced by decarboxylation of tyrosine (Fig. 1). Plasma tyrosine is elevated in cirrhotics (6-8), and tyrosine tolerance is impaired (9), therefore more tyrosine is available for tyramine formation than in normals. Tyramine is also produced in the gastrointestinal tract by bacterial decarboxylation of tyrosine and may enter the systemic circulation via portasystemic shunts.Tyramine is degraded by monoamine oxidase, of which the major proportion is located in the liver. Accordingly, tyramine degradation could be delayed in cirrhosis because ofhepatocellular disease, diminished hepatic blood flow, or both.In this study, we have measured the production rate and metabolic clearance rate of plasma tyramine in normals and in cirrhotics with a pharmacokinetic technique. The kinetics of tyramine were correlated with the clinical status of the liver patients, the fasting plasma tyrosine, and the tyrosine tolerance. A hypothesis relating hypertyraminemia and hypertyrosinemia was developed from the results. METHODS Materials[3H]Tyramine (11.6 Ci/mmol sp act) was obtained from New England Nuclear (Boston, Mass.). Radiochemical purity, evaluated by analytic thin-layer chromatography with three different solvent systems (10) SubjectsThe control group consisted of 11 healthy adult volunteers, 9 males and 2 females, with no history of hepatobiliary d...