Results of lower extremity amputations patients with end-stage renal disease

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1 Results of lower extremity amputations patients with end-stage renal disease in Christos D. Dossa, MD, Alexander D. Shepard, MD, Aaron M. Amos, MD, Warren L. Kupin, MD, Daniel J. Reddy, MD, Joseph P. Elliott, MD, Judith M. Wilczewski, RN, and Calvin B. Ernst, MD, Detroit, Mich. Purpose: The purpose of this study was to determine the impact of end-stage renal disease (ESRD) on the outcome of patients undergoing lower extremity (LE) amputation. Methods: Hospital charts and vascular surgery registry data were reviewed for all patients who underwent LE amputation over a consecutive 56-month period. The results of 84 patients with ESRD (137 amputations) were compared with 375 patients (442 amputations) without ESRD. Results: Hospital mortality rate was significantly greater in patients with ESRD than patients without ESRD, 24% versus 7% (p = 0.001). Patients with ESRD undergoing minor amputations had mortality rates three times greater than patients without ESRD undergoing major LE amputations. In patients with ESRD requiring bilateral or unilateral above-knee amputation hospital mortality rates were 43% and 38%, respectively. In addition, patients with ESRD were seven times more likely to undergo bilateral amputation than patients without ESRD over a mean follow-up period of 17 months. No kidney transplant patients died after amputation. Conclusion: ESRD has a profound negative impact on morbidity, mortality, and survival rates after LE amputation. Attempts at prevention of amputation with aggressive foot care and patient education in this high-risk group should be the focus of therapy. (J VASe SURG 1994;20:14-9.) Because of the aging population, the widespread availability of dialysis, liberal acceptance criteria for dialysis, and improved survival of kidney transplant recipients, the number of patients with end-stage renal disease (ESRD) is steadily expanding. The United States Renal Data System ~ estimated the number of patients with ESRD including those with functioning kidney transplants in 1989 to be greater than 200,000. l Because of the high incidence of peripheral arterial occlusive disease in these patients, the vascular surgeon is frequently consulted for the management of complications of lower extremity ischemia. Unfortunately, the results of peripheral arterial reconstructive procedures performed on this From the Department of Surgery, Division of Vascular Surgery, and Department of Nephrology (Dr. Kupin), Henry Ford Hospital, Detroit. Presented at the Sixteenth Annual Meeting of the Midwestern Vascular Surgical Society, Cleveland, Ohio, September 11-12, Reprint requests: Alexander D. Shepard, MD, Division of Vascular Surgery, Henry Ford Hospital, 2799 W. Grand Blvd., Detroit, MI Copyright 1994 by The Society for Vascular Surgery and International Society for Cardiovascular Surgery, North American Chapter /94/$ /1/ population have been discouraging. 24 Such poor results have led some authors to suggest temporizing endovascular revascularization techniques in patients with ESRD, 2 whereas others recommend primary amputation for patients with ESRD with large ischemic foot ulcers. 4 However, the impact of ESRD on the results of primary lower extremity amputations has not been studied. Therefore a retrospective review of patients with ESRD requiring lower extremity amputation for nonreconstructible arterial occlusive disease and advanced ischemia was undertaken. PATIENTS AND METHODS From January 1987 through August 1991, 85 patients with ESRD underwent 137 lower extremity amputations on the Vascular Surgery Service of the Henry Ford Hospital. Data from hospital records and the Vascular Surgery Registry were evaluated. There were 47 (55%) men and 38 (45%) women, with an age range from 28 to 94 years (mean 62 years). Seventy-four (87%) patients required longterm maintenance dialysis, and 11 (13%) had functioning kidney transplants, including three with functioning pancreas transplants. Among patients

2 Volume 20, Number 1 Dossa et al. 15 Table I. Patients with ESRD: demographics Category Dialysis (n = 74) Transplant (n = 11) p Value Mean age Male/Female 38/46 9/2 NS Hypertension 97% 100% NS Diabetes 85% 100% NS CAD* 82% 45% Heart failure 59% 27% NS CBVD~- 36% 9% NS Tobacco use 42% 36% NS *Coronary artery disease (defined as history of angina and/or myocardial infarction). -~Cerebrovascular disease (defined as history of transient ischemic attack or stroke). undergoing dialysis, 64 (86%) required hemodialysis, and 10 (14%) required peritoneal dialysis. The mean duration of dialysis before amputation was 36 months (median 21 months; range 3 days to 20 years). Comorbidities included hypertension (98%), diabetes (87%), coronary artery disease (78%), heart failure (55%), cerebrovascular disease (33%), and history of tobacco use (40%) (Table I). Nine patients (10%) had previously undergone a major lower extremity amputation. Two patients had patent infrainguinal bypass grafts with persistent limb ischemia/sepsis, and seven others had occluded infrainguinal bypass grafts. Indications for amputation were gangrene in 78% of patients, ischemic ulceration in 18%, and ischemic rest pain in 4%. Unsuitability for revascularization was determined by arteriography in 31 patients (36%) and by clinical assessment in 54 (64%). The latter group was deemed unsalvageable for a variety of reasons, including advanced infection, extensive tissue loss, failure to heal despite a patent graft, and chronic bedridden state. Amputation levels were dictated by the proximal extent of sepsis and assessment of operative bleeding, with an attempt to preserve the knee joint in all patients deemed to be candidates for rehabilitation. For purposes of statistical analysis the highest level amputation performed during the first hospitalization of the study period was used in calculating morbidity, mortality, and survival rates. Thus each patient was counted only once regardless of the number of procedures performed. A foot amputation was defined as either a ray or transmetatarsal amputation. Patients undergoing only phalangeal amputation during the study period were excluded. A failed amputation was defined as any amputation, excluding the guillotine type, that required revision to a level above the next proximal joint within 6 months of the original procedure. For above-knee amputations (AKAs) any proximal revision within 6 months was considered a failure. Survival rates were determined by Kaplan-Meier survival estimates. Survival comparisons were made with use of the log rank test for censored survival data. During the study interval 375 patients without ESRD underwent 442 AKA or below-knee amputations (BKAs) and served as a control group. This group was comprised of 204 (54%) men and 173 (46%) women with an age range from 24 to 97 years (mean 70 years). Risk factors included hypertension (56%), diabetes (51%), coronary artery disease (42%), cerebrovascular disease (20%), and history of tobacco use (38%). Over the same 56-month period, 509 patients underwent 693 arterial reconstructions for limb salvage. RESULTS ESRD group. Comparison of the transplant and dialysis subgroups of patients with ESRD revealed significant demographic differences. Transplant patients were younger (p = 0.001) and had a lower incidence of coronary artery disease (p = 0.013) (Table I). Of the 137 amputations performed on patients with ESRD there were 39 (29%) AKAs, 63 (46%) BKAs, 17 (12%) supramalleolar guillotine amputations, and 18 (13%) foot amputations. Excluding the guillotine amputations, 18 (15%) amputations required revision to a higher level. The revision rates were 3% (1 of 39) for AKAs, 14% (9 of 63) for BKAs, and 44% (8/18) for foot amputations. Twenty patients required a major (below- or aboveknee) amputation of the contralateral lower extremity at a mean interval of 16 months after their first amputation (range 1 to 58 months), resulting in 35% of patients undergoing bilateral amputations. Adjunctive revascularization procedures to aid amputation healing were performed on three patients and

3 16 Dossa et al. luly 1994 Table II. Operative morbidity in patients with ESRD Complication Dialysis (n = 74) Transplant (n = 11) Total (n = 85) Cardiac Arrhythmia (25%) Cardiac failure (18%) Myocardial infarction (5%) Pulmonary Pleural effusion (7%) Pneumonia (7%) Respiratory arrest (1%) Stroke (2%) DVT (upper extremity) (1%) Gastrointestinal bleeding (5%) Pulmonary embolism (2%) Pseudomembranous colitis (2%) Seizure (5%) Sepsis (6%) Urinary tract infection (15%) Arteriovenous graft thrombosis 12 NA 15/55 (22%)* DVT, Deep vein thrombosis. *Only 55 of the 74 patients undergoing dialysis had arteriovenous grafts. included one femorotibial bypass, one profundaplasty, and one tibial artery angioplasty. Hospital mortality rate, defned as death within 30 days of the amputation or during the same hospitalization, was 24%. Causes of death were cardiac arrhythmia (12), cessation of dialysis caused by clinical deterioration and unlikely survival (3), myocardial infarction (2), and pneumonia (2). Of the 12 fatal cardiac arrhythmias, nine were documented and three were presumed. Five of the nine patients with documented fatal arrhythmias had premonitory rhythm disturbances. The three patients with presumed arrhythmias had sudden cardiac death without any associated symptoms. Within the dialysis subgroup, hospital death was age related; patients less than or equal to 65 years of age had a mortality rate of 18% (6/33), whereas those older than 65 had a 34% (14/41) mortality rate. Postoperative morbidity unrelated to the amputation site occurred in 46 of 85 patients (54%) (Table II). The most common complications were cardiac, respiratory, and urinary. Perioperative vascular access thrombosis requiring thrombectomy or revision developed in 12 of 55 (22%) patients undergoing hemodialysis. Patients undergoing dialysis had significantly more complications than transplant patients, 61% versus 9% (p = 0.002). Patients undergoing dialysis also had greater mortality rate than transplant patients, 27% versus 0% (p = 0.06) (Table III). Transplant patients survived significantly longer than patients undergoing dialysis at 1 and 2 years, 82% versus 38% (p = 0.002) and 61% versus 20% (p = 0.002), and had survival rates slightly better than patients without ESRD undergoing amputation. Patients with ESRD with above-knee and bilateral amputations had the greatest mortality and worst overall survival rates, probably a reflection of their more advanced arterial occlusive disease (Table IV). Patients undergoing unilateral BKAs had a 50% lower mortality rate and two times greater survival rate than those requiring unilateral AKAs. Patients with ESRD undergoing foot amputations had mortality rates and survival characteristics similar to those undergoing major limb amputations (Table IV). Although the number of patients in the foot amputation subgroup are too small and the standard error is too great to make statistically valid comparisons, the associated hospital mortality and poor survival rates seem excessive given the magnitude of the operations. Of the 65 surviving patients with ESRD, 34 (62%) were rehabilitated to independent ambulation, six with unilateral AKAs, 25 with unilateral BKAs, one with bilateral BKAs, and four with unilateral foot amputations. Thirteen (24%) patients with ESRD required wheelchairs, and 11 (17%) were confined to bed. Follow-up data were lacking in seven. Non-ESRD group. Three hundred seventy-five patients without ESRD underwent 442 major limb amputations during the study period, 206 (47%) were AKAs and 236 (53%) BKAs. Seventeen patients required major amputation of the contralateral lower extremity at a mean interval of 17 months after their initial amputations (range 0 to 67 months);

4 Volume 20, Number 1 Dossa et al. 17 Table III. Mortality and survival rates among patients undergoing dialysis, transplantation, and patients without ESRD Survival ~ Group No. of patients Mortality rate 1-year 2-years Transplant 11 0% 82% ± 4% 61% - 16% Dialysis 74 27% 38% -+ 6% 20% + 6% Total ESRD 85 24% 44% _+ 6% 27% + 6% Total nonesrd 375 7% 79% ± 3% 68% + 3% ~Kaplan-Meier survival estimates with standard error. Table IV. Outcome by level of amputation in patients with ESRD S~trvival ~ Amputation No. of patients Mortality rate I-year 2-years AKA 21 38% 26% + 10% 13% + 8% BKA 40 18% 54% -+ 8% 29% + 9% Bilateral 7 43% 38% -+ 20% 6 mo NE AKA/BKA with history of 8 0% 63% + 17% 47% _+ 19% prior amputation Foot 9 22% 56% + 17% 42% + 18% NE, Not evaluable because of small number of patients. *Kaplan-Meier survival estimates with standard error. resulting in 5% of patients undergoing bilateral amputations. Significant differences were noted between the ESRD and the nonesrd groups (Table V). The ESRD group was younger (p = 0.001) but had a higher incidence of hypertension (p = 0.001), diabetes (p = 0.001), coronary artery disease (p = 0.001), and cerebrovascular disease (p = 0.01). The mortality rate for the nonesrd group was 7%, three times lower than the ESRD group (p = 0.001) (Table III). One- and two-year survival rates were significantly greater in the nonesrd than the ESRD group (p = 0.001) (Table III). Mortality rates for AKAs and BKAs in the patients without ESRD were 7% and 5%, respectively. Patients who required bilateral amputations or those who underwent a major amputation after previous contralateral major amputation had the greatest mortality and worst survival rates (Table VI). DISCUSSION Despite advances in lower extremity arterial reconstruction, amputation remains a commonly performed procedure. More than 69,000 major lower extremity amputations for ischemia were performed in the United States in s The operative mortality rate for lower extremity amputation is directly related to the level of amputation; the higher the amputation the higher the mortality rate. 6s Contemporary studies document operative mortality rates of 2% for BKAs and 9% for AKAs. These differences probably reflect the more advanced degree of atherosclerosis, the greater severity of ischemia, and the poorer clinical condition of patients requiring more proximal amputations. The incidence of lower extremity amputation among patients undergoing hemodialysis has been estimated to be 2.9% for unilateral amputation and 1% for bilateral amputations. 9 The influence of ESRD on the outcome of lower extremity amputations has not previously been studied. Our data suggest that ESRD has a significant adverse impact on hospital mortality and long-term survival rates after amputation. Among patients with ESRD, the hospital mortality rate was 24% and the 1- and 2-year survival rates were 44% and 27%, respectively. Patients without ESRD had a hospital mortality rate of only 7% and 1- and 2-year survival rates of 79% and 68%, respectively. Reports of lower extremity revascularization in patients in ESRD suggest no difference in outcome between patients undergoing dialysis and transplant patients, s,~,l However, after amputation there appears to be a significant difference. In this series there were no operative or hospital deaths and only a 9% morbidity rate in the transplant group, whereas the mortality rate was 27% and the morbidity rate was 61% in the dialysis group. Moreover, transplant

5 18 Dossa eta/. luly 1994 Table V. Patients with ESRD versus patients without ESRD: demographics Category ESRD (n = 85) NonESRD (n = 375) p Values Mean age Male/Female 47/38 204/173 NS Hypertension 98% 56% Diabetes 87% 51% CAD 78% 42% Heart failure 55% NA CBVD 33% 20% Tobacco use 40% 38% NS CAD, Coronary artery disease; NA, not available; CBVD, cerebrovascular disease. Table VI. Outcome by level of amputation in patients without ESRD Survival ~ Operauve Amputation No. of patients mortality rate I-year 2-years AKA 154 7% 79% +- 4% 62% --- 6% BKA 176 5% 85% _+ 3% 77% -+ 4% Bilateral 17 18% 24% -+ 14% NE AKA/BKA with 28 21% 63% -+ 10% 63% _+ 10% h/o prior amp NE, Not evaluable because of small sample size. *Kaplan-Meier survival estimates with standard error. patients had at least a two times better long-term survival rate than patients undergoing dialysis. These differences are not surprising considering the selection bias favoring transplant patients; they are younger and have less coronary artery disease than patients undergoing long-term dialysis. After the initiation of dialysis, 1- and 2-year survival rates have been reported to be 77% and 54%, respectively, n Elderly patients and those with diabetes mellitus form the highest risk groups in large reported series of patients with ESRD. lla2 In addition age and frequency of diabetes have been increasing in the ESRD population over recent years. 12 Among patients with ESRD over 60 years of age with diabetes, 1- and 2-year survival rates after 36 months initiation of dialysis have been reported at 36% and 27%, respectively, u Considering that the mean duration of dialysis in this series of patients with ESRD undergoing amputation was 36 months, their poor long-term survival rates correspond to what would be expected in the general ESRD population. Viewed from this perspective, the poor outcome of patients with ESRD undergoing amputation is a direct reflection of the predictable diminished life expectancy of elderly patients with diabetes and ESRD. The most common cause of death among patients with ESRD undergoing amputation in this series was a cardiac event. This finding is not unanticipated given the high incidence of clinically evident coronary artery disease present in this population compared with patients without ESRD (78% vs 42%). Heart disease is the most common cause of death in the general ESRD population, estimated to cause approximately 59.2 deaths per 1000 patient-years) The high incidence of fatal cardiac arrhythmias in this study is unexplained. Only one patient had a documented electrolyte imbalance as a presumed cause. In none of the 11 others was the arrhythmia associated with dialysis. As described previously, five of these patients did have premonitory rhythm disturbances before their fatal events. Six of these deaths occurred more than a week after operation, three after discharge from the hospital, suggesting that operative stress had less to do with their occurrence than did the patients' underlying heart disease. Because results after amputation or revascularization are discouragingly poor among patients with ESRD, more attention probably should be focused on patient education and optimal hygiene of ischemic lower extremities. A recent prospective randomized study documented a threefold decrease in amputation rates in patients with diabetes who participated in an education program on diabetic foot care. is Institution of such an education program in the nephrology clinic or the dialysis unit may prevent infectious complications of ischemia and reduce the need for amputation in this high-risk group of patients.

6 Volume 20, Number 1 Dossa et al. 19 REFERENCES 1. U.S. Renal Data System, USRDS 1991 Annual Data Report. Bethesda, Md.: The National Institutes of Health, National Institute of Diabetes and Digestive and Kidney Diseases; Whittemore AD, Donaldson MC, Mannick JA. Infrainguinal reconstruction for patients with chronic renal insufficiency. J VASC SURG 1993;17: Sanchez LA, Goldsmith J, Rivel~ SP, Panetta TF, Wengerter KI~, Veith FJ. Limb salvage surgery in end stage renal disease: Is it worthwhile? J Cardiovasc Surg 1992;33: Edwards JM, Taylor LM, Jr, Porter JM. Limb salvage in end-stage renal disease (ESRD). Arch Surg 1988;116: Graves EJ. Detailed diagnoses and procedures, National Hospital Discharge Survey, Vital Health Star [13] 1991;(108): Rush DS, Huston CC, Bivins BA, Hyde GL. Operative and late mortality rates of above-knee and below-knee amputations. Am Surg 1981;47: Huston CC, Bivins BA, Ernst CB, Griffen WO, Jr. Morbid implications of above-knee amputations. Arch Surg 1980; 115: Kald A, Carlsson R, Nilsson E. Major amputation in a defined population: incidence, mortality and results of treatment. Br J Surg 1989;76: Greenspun B, Harmon RL. Rehabilitation of patients with end-stage renal failure after lower extremity amputation. Arch Phys Med Rehabil 1986;67: Chang BB, Paty PSK, Shah DM, Kaufman JL, Leather RP. Results of infrainguinal bypass for limb salvage in patients with end-stage renal disease. Surgery 1990;108: Hellerstedt WL, Johnson WJ, Ascher N, et al. Survival rates of 2,728 patients with end-stage renal disease. Mayo Clin Proc 1984;59: Mailloux LU, Bellucci AG, Mossey RT, et al. Predictors of survival in patients undergoing dialysis. Am J Med 1988;84: Malone JM, Snyder M, Anderson G, Bernhard VM, Holloway GA, Bunt TJ. Prevention of amputation by diabetic education. Am J Surg 1989;158: Submitted Aug. 17, 1993; accepted Dec. 7, BOUND VOLUMES AVAILABLE TO SUBSCRIBERS Bound volumes of the JOURNAL OF VASCULAR SURGERY for 1994 are available to subscribers only. They may be purchased from the publisher at a cost of $76.00 for domestic, $97.32 for Canadian, and $92.00 for international subscribers for Vol. 19 (January to June) and Vol. 20 (July to December). Price includes shipping charges. Each bound volume contains a subject and author index, and all advertising is removed. Copies are shipped within 60 days after publication of the last issue in the volume. The binding is durable buckram with the journal name, volume number, and year stamped in gold on the spine. Payment must accompany all orders. Contact Subscription Services, Mosby-Year Book, Inc., Westline Industrial Dr., St. Louis, MO , USA. In the United States call toll free (800) , ext In Missouri or foreign countries call (314) Subscriptions must be in force to qualify. Bound volumes are not available in place of a regular JOURNAL subscription.