Atef A. Salam

Rupture rate of large abdominal aortic aneurysms in patients refusing or unfit for elective repair

CONTEXT Among patients with abdominal aortic aneurysm (AAA) who have high operative risk, repair is usually deferred until the AAA reaches a diameter at which rupture risk is thought to outweigh operative risk, but few data exist on rupture risk of large AAA. OBJECTIVE To determine the incidence of rupture in patients with large AAA. DESIGN AND SETTING Prospective cohort study in 47 Veterans Affairs medical centers. PATIENTS Veterans (n = 198) with AAA of at least 5.5 cm for whom elective AAA repair was not planned because of medical contraindication or patient refusal. Patients were enrolled between April 1995 and April 2000 and followed up through July 2000 (mean, 1.52 years). MAIN OUTCOME MEASURE Incidence of AAA rupture by strata of initial and attained diameter. RESULTS Outcome ascertainment was complete for all patients. There were 112 deaths (57%) and the autopsy rate was 46%. Forty-five patients had probable AAA rupture. The 1-year incidence of probable rupture by initial AAA diameter was 9.4% for AAA of 5.5 to 5.9 cm, 10.2% for AAA of 6.0 to 6.9 cm (19.1% for the subgroup of 6.5-6.9 cm), and 32.5% for AAA of 7.0 cm or more. Much of the increased risk of rupture associated with initial AAA diameters of 6.5-7.9 cm was related to the likelihood that the AAA diameter would reach 8.0 cm during follow-up, after which 25.7% ruptured within 6 months. CONCLUSION The rupture rate is substantial in high-operative-risk patients with AAA of at least 5.5 cm in diameter and increases with larger diameter.

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.

Distal splenorenal shunt versus endoscopic sclerotherapy for long-term management of variceal bleeding. Preliminary report of a prospective, randomized trial.

This paper reports the preliminary results of a prospective randomized trial comparing endoscopic variceal sclerosis and distal splenorenal shunt (DSRS) in the management of patients with cirrhosis and variceal bleeding. Seventy-one patients have been entered; 36 have received sclerosis and 35 DSRS. Randomization of the study population was stratified on Childs A/B (56%) and Childs C (44%). Sixty-one per cent had alcoholic and 39% nonalcoholic cirrhosis. No patients have been lost to follow-up, which currently stands at a median of 26 months. Rebleeding occurred significantly (p < 0.05) more frequently in patients in the sclerosis group (19 of 36: 53%) compared to DSRS (1 of 35: 3%), but only 11 of 36 (31%) were not controlled by further sclerosis and failed that therapy. Patients in whom sclerosis failed underwent surgery. Survival was significantly (p < 0.01) improved in the sclerosis group (+ surgery in 31%), with an 84% 2-year survival compared to a 59% 2-year survival in the DSRS group. Portal perfusion was significantly (p < 0.05) better maintained in the sclerosis (95%) compared to the DSRS (53%) group. Galactose elimination capacity improved significantly (p < 0.05) in 21 patients successfully managed by sclerosis at 1 year and was significantly (p < 0.01) better maintained in the sclerosis compared to DSRS group. The authors conclude that endoscopic sclerosis: (1) has a higher rebleeding rate than DSRS, with one third of patients failing therapy from rebleeding; (2) allows significant improvement in liver function when successful; and (3) gives significantly improved survival in the management of variceal bleeding when backed up by surgical therapy for patients with uncontrolled rebleeding.

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.

Surgical treatment of chronic mesenteric arterial insufficiency.

The treatment of 41 patients with chronic mesenteric insufficiency is reviewed: 20 men and 21 women with a mean age of 59 years were treated and observed for an average of 42 months. Thirty-one patients had symptoms of intestinal angina whereas 10 patients underwent prophylactic revascularization during other aortic operations. All but one patient had revascularization of the superior mesenteric artery, alone or in combination with another revascularization. Various surgical techniques were used, including retrograde bypass in 24 patients, antegrade bypass in 11 patients, and endarterectomy in the remaining six patients. Seven patients had acute abdominal symptoms and required emergency operation while in the hospital awaiting elective revascularization. There were two deaths in the perioperative period (4.9%), both caused by bowel necrosis. Six patients are known to have had late revascularization failure, resulting in recurrent symptoms in three patients and two subsequent deaths. All patients who remained asymptomatic after late graft failure had undergone multiple vessel revascularization; no patient revascularized prophylactically had symptoms of intestinal angina during the follow-up period. Early mesenteric revascularization is a safe and effective method of relieving the symptoms of chronic visceral ischemia and may prevent the development of fatal bowel necrosis.

Acute mesenteric ischemia after cardiopulmonary bypass

Acute mesenteric ischemia is an uncommon but catastrophic event after cardiopulmonary bypass. From 1980 to 1990, 16,951 cardiac procedures requiring cardiopulmonary bypass were performed at Emory University Hospital in Atlanta, Ga. Eighteen patients (0.1%) had acute mesenteric ischemia that resulted in intestinal infarction. Emergency cardiac surgery had been performed in 16 of the 18 patients, and all 18 patients were vasopressor dependent for hemodynamic support after surgery. Diagnostic difficulties resulted in the diagnosis of intestinal infarction an average of 9 1/2 days after cardiopulmonary bypass. Nonocclusive mesenteric arterial ischemia was the determined cause in all cases. Statistically significant risk factors associated with acute mesenteric ischemia after cardiopulmonary bypass surgery included (1) emergency cardiac surgery (p less than 0.0001), (2) the use of an intraaortic balloon pump (p less than 0.0001), (3) failed angioplasty requiring emergency surgery (p = 0.0074), (4) prolonged pump time (p = 0.0093), and (5) advanced age (p = 0.0016). A high index of suspicion for mesenteric ischemia after cardiopulmonary bypass in patients with identified risk factors may decrease the diagnostic delay and lead to an improvement in the 67% mortality rate seen in this series.

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).

Frailty increases the risk of 30-day mortality, morbidity, and failure to rescue after elective abdominal aortic aneurysm repair independent of age and comorbidities

BACKGROUND Frailty, defined as a biologic syndrome of decreased reserve and resistance to stressors, has been linked to adverse outcomes after surgery. We evaluated the effect of frailty on 30-day mortality, morbidity, and failure to rescue (FTR) in patients undergoing elective abdominal aortic aneurysm (AAA) repair. METHODS Patients undergoing elective endovascular AAA repair (EVAR) or open AAA repair (OAR) were identified in the National Surgical Quality Improvement Program database for the years 2005 to 2012. Frailty was assessed using the modified frailty index (mFI) derived from the Canadian Study of Health and Aging (CSHA). The primary outcome was 30-day mortality, and secondary outcomes included 30-day morbidity and FTR. The effect of frailty on outcomes was assessed by multivariate regression analysis, adjusted for age, American Society of Anesthesiology (ASA) class, and significant comorbidities. RESULTS Of 23,207 patients, 339 (1.5% overall; 1.0% EVAR and 3.0% OAR) died ≤30 days of repair. One or more complications occurred in 2567 patients (11.2% overall; 7.8% EVAR and 22.1% OAR). Odds ratios (ORs) for mortality adjusted for age, ASA class, and other comorbidities in the group with the highest frailty score were 1.9 (95% confidence interval [CI], 1.2-3.0) after EVAR and 2.3 (95% CI, 1.4-3.7) after OAR. Similarly, compared with the least frail, the most frail patients were significantly more likely to experience severe (Clavien-Dindo class IV) complications after EVAR (OR, 1.7; 95% CI, 1.3-2.1) and OAR (OR, 1.8; 95%, CI, 1.5-2.1). There was also a higher FTR rate among frail patients, with 1.7-fold higher risk odds of mortality (95% CI, 1.2-2.5) in the highest tertile of frailty compared with the lowest when postoperative complications occurred. CONCLUSIONS Higher mFI, independent of other risk factors, is associated with higher mortality and morbidity in patients undergoing elective EVAR and OAR. The mortality in frail patients is further driven by FTR from postoperative complications. Preoperative recognition of frailty may serve as a useful adjunct for risk assessment.

Splenopancreatic disconnection. Improved selectivity of distal splenorenal shunt.

Distal splenorenal shunt (DSRS) improves survival from variceal bleeding in nonalcoholic cirrhotics but not in alcoholic subjects. The metabolic response after DSRS is also different in alcoholic and nonalcoholic cirrhotics. Portal perfusion, quality of blood perfusing the liver, cardiac output, and liver blood flow do not change in nonalcoholics. In alcoholics, portal perfusion is frequently lost (60%), quality of blood perfusing the liver decreases, and cardiac output and liver blood flow increase. It is proposed that portal flow is lost in alcoholics via pancreatic and colonic collaterals after surgery. Elimination of this sump by adding complete dissection of the splenic vein and division of the splenocolic ligament to DSRS (splenopancreatic disconnection, SPD) could preserve portal perfusion, decrease shunt loss of hepatotrophic factor, and improve survival in alcoholic cirrhotics. This report compares data 1 year after surgery in two groups of cirrhotics: group I (8 nonalcoholic; 16 alcoholic) had DSRS without SPD; group II (17 nonalcoholic; 11 alcoholic) received DSRS + SPD. Methods: Portal perfusion grade, cardiac output (CO), liver blood flow (f), hepatic function (GEC), and hepatic volume (vol) were measured before and 1 year after surgery. Shunt loss of hepatotrophic factor was estimated by insulin response (change in plasma concentration over 10 minutes: AUC) after arginine stimulation. Results: Groups I and II were similar before surgery. Metabolically, nonalcoholics remained stable after both DSRS and DSRS + SPD. After standard DSRS, alcoholics lost portal perfusion (75%, p < 0.05), CO, and f increased (p < 0.05), and quality of blood perfusing the liver was decreased (GEC/f: p < 0.05). DSRS + SPD preserved portal perfusion better (p < 0.05) in alcoholic cirrhotics than did DSRS alone. After DSRS + SPD, the metabolic response in alcoholics resembled that of nonalcoholics. CO, f, and GEC/f remained stable. These data show: (1) DSRS + SPD preserves postoperative portal perfusion in alcoholic cirrhotics better than DSRS alone. (2) Metabolic response to DSRS + SPD is similar in alcoholic and nonalcoholic cirrhotics. (3) Because portal perfusion and metabolic integrity.