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Reduced aortic cross-clamp time in high-risk patients with abdominal aortic aneurysm

1986; Elsevier BV; Volume: 3; Issue: 5 Linguagem: Inglês

10.1016/0741-5214(86)90049-2

1097-6809

RICHARD T. PURDY, Frederick C. Beyer, William D. McCann, Ian Darian Smith, Richard H. Mann,

Aortic aneurysm repair treatments

Cardiac complications are the major cause of morbidity and death in patients undergoing elective resection of abdominal aortic aneurysm.1Brown OW Hollier LH Pairolero PC Kazmier FJ McCready RA Abdominal aortic aneurysm and coronary artery disease.Arch Surg. 1981; 116: 1484-1488Crossref PubMed Scopus (153) Google Scholar, 2Bush Jr, HL LoGerfo FW Weisel RD Mannick JA Hechtman HB Assessment of myocardial performance and optimal volume loading during elective abdominal aortic aneurysm resection.Arch Surg. 1977; 112: 1301-1305Crossref PubMed Scopus (75) Google Scholar, 3Cooperman M Pflug B Martin EW Evans EE Cardiovascular risk factors in patients with peripheral vascular disease.Surgery. 1978; 84: 505-509PubMed Google Scholar, 4Crawford ES Saleh SA Babb III, JW Glaeser DH Vaccaro PS Silvers A Infrarenal abdominal aortic aneurysm: Factors influencing survival after operation performed over a 25-year period.Ann Surg. 1981; 193: 699-709Crossref PubMed Scopus (376) Google Scholar, 5Diehl JT Cali RF Hertzer NR Beven EG Complications of abdominal aortic reconstruction. An analysis of perioperative risk factors in 557 patients.Ann Surg. 1983; 197: 49-56PubMed Google Scholar, 6Dunn E Prager RL Fry W Kirsh MM The effect of abdominal aortic cross-clamping on myocardial function.J Surg Res. 1977; 22: 463-468Abstract Full Text PDF PubMed Scopus (68) Google Scholar Most studies relate these untoward events to aortic cross-clamping (ACC).6Dunn E Prager RL Fry W Kirsh MM The effect of abdominal aortic cross-clamping on myocardial function.J Surg Res. 1977; 22: 463-468Abstract Full Text PDF PubMed Scopus (68) Google Scholar, 7Falk JL Rackow EC Blumenberg R Gelfand M Fein IA Hemodynamic and metabolic effects of abdominal aortic cross clamping.Am J Surg. 1981; 142: 174-177Abstract Full Text PDF PubMed Scopus (43) Google Scholar Recent attempts to reduce cardiac complications have focused on the management of the adverse physiologic effects of cross-clamping.7Falk JL Rackow EC Blumenberg R Gelfand M Fein IA Hemodynamic and metabolic effects of abdominal aortic cross clamping.Am J Surg. 1981; 142: 174-177Abstract Full Text PDF PubMed Scopus (43) Google Scholar, 8Nicholas GG Martin DE Osbakken MD Cardiovascular monitoring during elective aortic surgery.Arch Surg. 1983; 118: 1256-1258Crossref PubMed Scopus (4) Google Scholar, 9Whittemore AD Clowes AW Hechtman HB Mannick JA Aortic aneurysm repair: Reduced operative mortality associated with maintenance of optimal cardiac performance.Ann Surg. 1980; 192: 414-421Crossref PubMed Scopus (180) Google Scholar In this study an attempt was made to protect the high-risk patient by reducing the ACC time. The high-risk patient was categorized by use of radionuclide angiography (multigated acquisition radionuclide ventriculography [MUGA] scan). A surgical technique was used in those patients with a systolic ejection fraction of less than 50% in which the ACC time was significantly shortened; this involved the insertion of a Y graft in reverse fashion.10Clauss RH Redisch W. Remedial arterial disease.in: Grune & Stratton, Inc, New York1971: 117-121Google Scholar This is a prospective study of 40 consecutive patients who had elective resection of an abdominal aortic aneurysm from November 1983 through April 1985. All patients with aneurysms of 5 cm in diameter or greater were offered and accepted surgery. Four patients had aneurysms of less than 5 cm and were operated on because of the need for bypass surgery. The average aneurysm size was 6.3 cm (range, 3 to 12 cm). The patients ranged in age from 44 to 91 years (mean, 68 years) (Table I).Table IPreoperative medical status (N = 40)No. of patients%Previous myocardial infarct1025Hypertension1742History of congestive heart failure820Previous coronary artery bypass graft410Atrial fibrillation410 Open table in a new tab Ten had an old myocardial infarction. Seventeen were hypertensive. Eight had a history of congestive heart failure. Three patients had a previous coronary artery bypass graft. Four had significant chronic obstructive pulmonary disease. Twenty-seven were diagnosed as having arteriosclerotic heart disease. Only five patients appeared to be free of cardiac disease. Six patients were older than 80 years of age. MUGA scans were performed on all patients as part of their preoperative evaluation. The left ventricular systolic ejection fraction was obtained with a Technicare 420 mobile scintillation camera. The agent employed was in vivo 99mTc-labeled red blood cells. Ejection fraction was calculated by the area counts technique in systole and diastole. All of the ejection fractions quoted are values obtained at rest. The systolic ejection fraction obtained by this means was used to categorize the level of cardiac risk.11Pasternack PF Imparato AM Bear G Riles TS Baumann FG Benjamin D Sanger J Kramer E Wood RP The value of radionuclide angiography as a predictor of perioperative myocardial infarction in patients undergoing abdominal aortic aneurysm resection.J Vasc Surg. 1984; 1: 320-325PubMed Scopus (107) Google Scholar Those with ejection fraction of less than 50% were considered to be high risk (group I). Those with an ejection fraction of 50% or more were placed in the low-risk category (group II). Ten patients in group I had an average ejection fraction of 38% (range, 16% to 49%) (Table II).Table IIMedical and physiologic data for group ICardiac index (L/m2)AgeSexSystolic ejection fraction (%)Preoperative medical statusAortic cross-clamp time (min)PreclampClampPostclampPostopComplicationsOutcome91M30CHF, AF, ASHD, Cr 2.0142.31.41.92.9Rapid AFSurvived74F49CABG 1981, HBP, ASHD, Cr 2.1102.7Prolonged ileusSurvived76M33HBP153.12.13.24.2Survived44M42HBP, Cr 4.0126.0Survived76M43MI 1969, CHF, HBP, ASHD112.32.32.93.8VPC with VTSurvived78M40ASHD121.91.82.1Survived77M41HBP, Cr 1.9152.31.62.82.8Survived74F16CHF, hypothyroid131.51.21.5DiedBleeding diathesesDied83M39ASHD, old MI241.31.12.13.1SVTSurvived82M48Angina, old MI, ASHD152.51.92.03.3SurvivedCHF = congestive heart failure; AF = atrial fibrillation; ASHD = arteriosclerotic heart disease; Cr = creatinine mg/dl; HBP = hypertension; MI = myocardial infarct; VPC = ventricular premature contractions, VT = ventricular tachycardia; SVT = supraventricular tachycardia. Open table in a new tab The remaining 30 patients (group II) had ejection fractions of 50% to 86% (average, 67.6%). The evening before operation the patient was given Ringer's lactate solution intravenously at 100 ml/hr until the time of operation. A Swan-Ganz catheter was placed in the pulmonary artery immediately before operation with the use of fluoroscopy. An arterial line was placed in the radial artery. The catheters were multiple-lumen balloon-type pulmonary artery catheters (7 Fr.) with distal thermistor. Cardiac indices were obtained on the patients during anesthesia: before ACC, during ACC and after ACC, as well as within 24 hours after operation. CHF = congestive heart failure; AF = atrial fibrillation; ASHD = arteriosclerotic heart disease; Cr = creatinine mg/dl; HBP = hypertension; MI = myocardial infarct; VPC = ventricular premature contractions, VT = ventricular tachycardia; SVT = supraventricular tachycardia. In group I all grafts were knitted Dacron Y grafts implanted in retrograde fashion (Fig. 1).After the graft was preclotted and the patient heparinized, the left common or external iliac artery was clamped and an end-to-side anastomosis carried out with the left limb of the Y graft. During this time flow was maintained through the right iliac artery. ACC was then undertaken and the proximal anastomosis completed. This procedure represented the duration of ACC. Flow was then maintained in the left iliac artery as the right iliac artery anastomosis was accomplished. In group II a variety of procedures were employed. In addition, three patients had aortorenal bypasses done concomitantly. One patient had the inferior mesenteric artery reimplanted into the graft. In group I the average ACC time used in the performance of a retrograde Y graft was 14 minutes (range, 10 to 24 minutes) (Table III). In group II there were 11 tube grafts with a mean ACC time of 28 minutes; five antegrade Y grafts with a mean ACC time of 39 minutes; and 14 retrograde Y grafts with a mean ACC time of 20 minutes. The implantation of the Y graft in retrograde sequence added little to the overall time of surgery.Table IIIMortality and morbidity rates (N = 40)MortalityMorbidityNo. of patients%No. of patients%Bleeding diathesis12.5—Myocardial infarction—25Arrhythmias—615Postoperative bleeding—37.5 Open table in a new tab Retrograde Y grafts required 2 hours and 40 minutes, antegrade Y grafts 2 hours and 35 minutes, and tube grafts 1 hour and 53 minutes. The cardiac indices were determined in group 1 after 5 minutes of cross-clamping. The average fall was 0.46 L/m2 and all recovered to preclamp levels during anesthesia and to preoperative or normal levels within 24 hours. The fall of the cardiac indices in group II was less and averaged 0.37 L/m2 with return to preclamp levels. At 24 hours all had returned to preoperative or normal levels of cardiac index (Fig. 2). No deaths from cardiac causes occurred. There were two myocardial infarctions in group II patients (Table III). One death occurred in a 76-year-old female hypothyroid patient with a 16% systolic ejection fraction as a result of a bleeding diathesis.12Ladenson PW Levin AA Ridgway EC Daniels GH Complications of surgery in hypothyroid patients.Am J Med. 1984; 77: 261-266Abstract Full Text PDF PubMed Scopus (126) Google Scholar After a retrograde Y graft was completed, bleeding through the interstices of the left limb of the graft was noted. The graft limb was packed with Avitene and Surgicel until the bleeding appeared to have stopped. In the recovery department the patient began to bleed heavily again and was returned to the operating room. Massive bleeding through the interstices of the entire graft was seen. This graft was removed and replaced with a woven Dacron graft. Bleeding continued postoperatively and the patient died. Two additional patients were returned to the operating room to control postoperative bleeding; one had an injury to the spleen and another showed oozing from the retroperitoneum. The patient whose spleen was removed had an uneventful postoperative course. The second patient later had some lateral T wave changes as seen on ECG and had cardiac enzyme studies done that showed positive traces of the CK-MB isoenzyme. He was diagnosed as having a subendocardial infarct but remained in hemodynamically stable condition. The other myocardial infarction was in a patient who appeared to have stable vital signs. The ECG did not show an infarct. Cardiac enzyme studies showed a rise in creatine kinase to 655 μmol/L; the CK-MB isoenzyme was trace positive. Six additional cardiac events occurred, three in group I and three in group II. Four had frequent premature ventricular beats; two of these had runs of ventricular tachycardia. Two patients had transient atrial fibrillation. All six cases were successfully treated with cardiac medications. All of these patients remained in hemodynamically stable condition. In the past two decades the mortality rate for operation of abdominal aortic aneurysm has declined to 5%; some centers have reported 2% or less.9Whittemore AD Clowes AW Hechtman HB Mannick JA Aortic aneurysm repair: Reduced operative mortality associated with maintenance of optimal cardiac performance.Ann Surg. 1980; 192: 414-421Crossref PubMed Scopus (180) Google Scholar Advances in diagnostic technology and aggressive cardiac therapy including coronary artery bypass grafting have contributed to this improvement. High-risk patients are often selected for coronary operation before referral and subsequently tolerate aneurysm particularly well.13Hertzer NR Young JR Kramer JR Phillips DF deWolfe VG Ruschhaupt WF Beven EG Routine coronary angiography prior to elective aortic reconstruction: Results of selective myocardial revascularization in patients with peripheral vascular disease.Arch Surg. 1979; 114: 1336-1344Crossref PubMed Scopus (181) Google Scholar Pasternak et al.11Pasternack PF Imparato AM Bear G Riles TS Baumann FG Benjamin D Sanger J Kramer E Wood RP The value of radionuclide angiography as a predictor of perioperative myocardial infarction in patients undergoing abdominal aortic aneurysm resection.J Vasc Surg. 1984; 1: 320-325PubMed Scopus (107) Google Scholar have categorized cardiac risk with the use of MUGA scanning. They showed the systolic ejection fraction to be a very sensitive indicator of the heart's ability to tolerate operation of abdominal aortic aneurysm. The adverse effects of ACC are well described. Rise in capillary wedge pressure because of increase in afterload with a fall in cardiac index are the dominant manifestations occurring within minutes of the application of the aortic clamp.14Attia RR Murphy JD Snider M Lappas DG Darling RC Lowenstein E Myocardial ischemia due to infrarenal aortic cross-clamping during aortic surgery in patients with severe coronary artery disease.Circulation. 1976; 53: 961-965Crossref PubMed Scopus (170) Google Scholar The well heart tolerates this, even for prolonged periods of time; it is the diseased heart that is most vulnerable. Sophisticated monitoring techniques with Swan-Ganz catheters and arterial lines permit some control of these events with appropriate volume loading and the use of vasodilators.9Whittemore AD Clowes AW Hechtman HB Mannick JA Aortic aneurysm repair: Reduced operative mortality associated with maintenance of optimal cardiac performance.Ann Surg. 1980; 192: 414-421Crossref PubMed Scopus (180) Google Scholar, 15Grindlinger GA Vegas AM Manny J Bush HL Mannick JA Hechtman HB Volume loading and vasodilators in abdominal aortic aneurysmectomy.Am J Surg. 1980; 139: 480-486Abstract Full Text PDF PubMed Scopus (54) Google Scholar Surprisingly little consideration is given in the literature to the actual duration of ACC time. It would appear that most authors consider this to be at an irreducible minimum or simply of no consequence, given the current ability to control the physiologic consequences. The present study is concerned with the adverse effects of ACC in the high-risk patient. In addition to intensive monitoring and precise physiologic control, we attempted to further reduce the risk by significantly reducing the ACC time. This was accomplished in that the ACC time in the high-risk patient was kept to an average of 14 minutes. The innovation in technique employed was simple and did not require any increase in skill level on the part of the operating surgeons. We thought that the outcome in these group I patients was remarkable in that they remained hemodynamically stable throughout their postoperative course. No clinically evident myocardial infarctions occurred in group I. We conclude that a shortened ACC time does contribute substantially to a hemodynamically stable course in high-risk patients.