Robert B. Smith

Nonoperative management of visceral aneurysmsand pseudoaneurysms

During the period from 1975 to 1991, 41 patients with 60 visceral artery aneurysms were treated at the Affiliated Hospitals of Emory University. The total included 13 patients in whom 16 aneurysms were treated primarily by transarterial embolization. There were seven hepatic artery aneurysms, three splenic artery aneurysms, three gastroduodenal artery aneurysms, two left gastric artery aneurysms, and one right gastroepiploic artery aneurysm. Average age of these patients was 50 years; there were eight males and five females. Seven patients presented with gastrointestinal bleeding, and two patients presented with abdominal pain. In four patients, the aneurysm was an incidental finding. Etiology of the true or false aneurysms consisted of pancreatitis in two patients, trauma in three patients, connective tissue disease in one, and was unknown in the remainder. Embolization was performed in seven cases with Gianturco coils and Gelfoam, with coils alone in four, with Gelfoam alone in four, and with detachable balloons in one instance. Complete occlusion was achieved initially in 13 cases. Recanalization occurred in two patients over a mean follow-up period of 8.6 months, requiring re-embolization in one patient, whereas the other patient was managed expectantly. In three cases, embolization was unsuccessful: two cases required surgical correction, and one case was managed expectantly. Only one complication was related to the embolization procedure, which was a common hepatic arterial dissection that proceeded to the formation of a false aneurysm. Embolization as the primary treatment modality for visceral artery aneurysms should be considered in patients with the following diagnoses: pseudoaneurysms associated with pancreatitis, intrahepatic aneurysms, most splenic artery aneurysms, and gastric, gastroduodenal, and gastroepiploic aneurysms. The procedure has a low risk and may obviate a difficult surgical procedure, but it does not preclude surgical intervention should the need arise.

Postcatheterization vascular complications associated with percutaneous transluminal coronary angioplasty.

The threat of a vascular complication exists in association with any percutaneous arterial catheterization, but is greater in the more complex interventional techniques. During a 3 1/2-year period from January 1985 through June 1988, 4988 percutaneous transluminal coronary angioplasty procedures were performed at Emory University Hospital. All patients were given heparin during the cardiac intervention, and all had a catheter introducer left in place for several hours after completion of the procedure. Fifty-five iatrogenic vascular complications developed in 52 patients (1%), resulting in 54 corrective operations. Pseudoaneurysm, the most frequent complication, was seen in 35 patients (64%). This was followed by arteriovenous fistula in eight (15%), uncontrolled hemorrhage in six (11%), arterial thrombosis in three (6%), peripheral embolization in two (4%), and bowel ischemia in one patient. The outcome of surgical therapy in the entire group was quite acceptable with no operative mortality, no extremity amputation, and a 7.4% complication rate. Variables that correlated with an increased risk of peripheral vascular problems after percutaneous transluminal coronary angioplasty included advanced age, female gender, thrombolytic therapy, and postprocedural anticoagulation. Variables that did not appear to correlate were hypertension, diabetes, prior percutaneous transluminal coronary angioplasty, antiplatelet therapy, or the size of the guiding catheter used.

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.

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.

Physiologic considerations in major hepatic resections

Abstract An experience with thirty-eight hepatic resections has demonstrated a direct relationship between the per cent of liver excised and the magnitude of derangements in metabolic and physiologic functions. Except in patients with cirrhosis, transient depressions of the coagulation mechanism do not cause bleeding difficulties unless avascular liver parenchyma is retained. Jaundice is brief; seldom does the serum bilirubin exceed 6 mg. per cent. Bile production gradually improves to near normal levels within ten days. By four months a noncirrhotic liver remnant has regenerated to preoperative size. Bile peritonitis can be averted by tube decompression of the common duct. Massive resections produce splanchnic sequestrations of blood volume (due to an interruption of major draining channels of the portal venous bed); systemic “hypovolemic” shock develops and must be corrected by volume replacement according to the central venous pressure. Blood sugar should be supported by a constant infusion of glucose, although hourly gastrostomy feedings will provide sufficient carbohydrates after the second postoperative week. The serum albumin must be maintained at normal to supranormal levels to preserve an effective oncotic pressure.

Paraanastomotic aneurysms of the abdominal aorta.

PURPOSE Aneurysm formation after abdominal aortic bypass reconstruction is an infrequent but underestimated complication. Aneurysms may occur after aortic prosthetic reconstruction for both occlusive and aneurysmal disease, may occur early or late, and may be classified as a pseudoaneurysm or true aneurysm. METHODS Thirty-one cases in 29 patients treated at a tertiary referral center from 1980 to 1992 were retrospectively reviewed. Iliac and femoral aneurysms were excluded. The indication for initial abdominal aortic grafting had been aneurysmal disease in 19 patient and occlusive disease in 10 patients. RESULTS There were 25 pseudoaneurysms and six true aneurysms, the latter followed grafting for aneurysmal disease. The current aneurysm (mean size 7.1 cm) was at the proximal aortic anastomosis in 27 cases and at the distal aortic anastomosis in two cases. Symptoms at presentation included abdominal pain (14), mass (12), claudication (9), back pain (6), and gastrointestinal bleeding (3). Surgical management included interposition tube grafting (16), aortoiliofemoral bypass (9), and graft removal with extraanatomic bypass (3). The overall operative morbidity rate was 73%, and mortality rate was 21%. CONCLUSIONS Paraanastomotic aortic aneurysms are being increasingly recognized and are associated with high morbidity and mortality rates. Patients should be periodically studied after aortic grafting with abdominal ultrasonography for early detection of this potentially serious complication. Elective surgical repair is advocated in the effort to minimize morbidity rates.

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.

The natural history of carotid fibromuscular dysplasia

Although graduated internal dilatation has proved to be an effective, safe, and durable operation for the treatment of symptomatic patients with fibromuscular dysplasia of the extracranial internal carotid artery, the role of surgical treatment in this entity remains unclear because the natural history is not well defined. Forty-nine patients, aged 29 to 82 years (mean, 58.5 years), with angiographically proven fibromuscular dysplasia of 88 internal carotid arteries have been evaluated since 1969. Twenty patients showed symptoms of focal cerebral or retinal ischemia, 10 patients had nonlateralizing neurologic symptoms, three patients sustained intracerebral hemorrhage, five patients complained of nonischemic symptoms, and 11 patients were asymptomatic. The three patients with intracranial hemorrhage and one person who suffered a massive stroke after angiography died within weeks of admission; no surgical therapy was performed. Initial management of the other patients included four internal carotid endarterectomies in four patients for associated atherosclerosis, one with simultaneous graduated internal dilatation; seven graduated internal dilatations in five patients; and one extracranial-to-intracranial bypass in a patient with occlusion occurring after graduated internal dilatation. Seventy-three nondilated arteries in 42 patients have been followed for up to 16 years (mean, 6.8 years). During this time only three patients have undergone surgical therapy; one carotid endarterectomy was done for an asymptomatic atherosclerotic lesion and two graduated internal dilatations in patients with nonfocal ischemia. Through follow-up of all 49 patients, none has had a new neurologic deficit. Fourteen patients who initially presented with focal ischemia were not treated surgically and all but one are now asymptomatic.(ABSTRACT TRUNCATED AT 250 WORDS)

Morbidity and Mortality Associated With Carotid Endarterectomy: Effect of Adjunctive Coronary Revascularization

The occurrence of significant carotid disease in patients requiring coronary revascularization results in the dilemma of whether simultaneous or staged operations should be performed. To determine appropriate therapy we reviewed this experience at Emory University Hospital. During a 10-year period from 1983 to 1992, 110 patients underwent carotid endarterectomy during the same hospitalization or simultaneously with coronary artery bypass; 907 patients underwent carotid endarterectomy alone during the same period. The combined 30-day postoperative stroke and death rate was 18.2% for the 110 patients undergoing concomitant procedures. When comparing morbidity and mortality rates for those having simultaneous carotid endarterectomy and coronary artery bypass with those having delayed coronary artery bypass, the latter group was found to have a 6.6% combined risk of postoperative stroke or death within 30 days, whereas those undergoing simultaneous procedures had a 26.2% rate. In the control group of 907 patients undergoing carotid endarterectomy alone during the same period, the combined 30-day mortality and stroke morbidity rate was 2.1%. Although the patient population undergoing simultaneous carotid and coronary revascularization may have more severe disease, we believe that combining the procedures during the same operative setting results in an increased perioperative stroke and death rate. Consequently only extremely high-risk patients are selected for simultaneous procedures; otherwise our experience suggests that delaying coronary artery bypass by several days will reduce overall postoperative mortality and stroke morbidity.