Limb salvage in diabetic foot syndrome with pedal bypass using the in-situ technique

INTRODUCTION: Treatment of the ischemic diabetic foot syndrome still represents a medical and economic challenge. Contrary to the aims of the Saint Vincent declaration a dramatic reduction of major amputations in Germany was not noted, although in the diabetic patients the predominant type of tibial artery occlusion allows construction of pedal bypasses for limb salvage. METHOD: In patients with ischemic diabetic foot syndrome following angiographic evaluation of the ischemic limb, the indication for surgical revascularisation of patent pedal arteries was established. The in-situ technique was preferred in the presence of a suitable ipsilateral greater saphenous vein whenever possible. Revascularisation was followed by treatment of foot ulcerations or, if necessary, minor amputations. Patients were followed by clinical examination and duplex scan investigation of the bypass in regular intervals. RESULTS: From 01/89 to 12/01 in 79 patients (59 men and 20 women) with non healing ulcerations or established gangrene from a total of 175 pedal bypasses 84 pedal bypass operations in 84 limbs were performed using the in-situ technique. All patients were diabetic and in addition 13.9% were dependent on hemodialysis for end stage renal disease. 59.5% of the bypasses originated from the popliteal artery (distal origin bypass). The dorsalis pedis artery was chosen for the distal anastomosis in 83% and the posterior tibial artery in 17%. Two patients (2.4%) died postoperatively from cardiac events. Early bypass occlusion occurred in 8.4% resulting in a major amputation rate of 6%. After 60 months primary, primary assisted and secondary patency was 67.7%, 71.5% and 75.3% respectively with a limb salvage rate of 78%. CONCLUSION: Pedal bypass using the in-situ technique provides excellent long term limb salvage rates in a disease with a generally unjustified bad prognosis with respect to limb salvage.     

Sequelae of limited amputation

Ninety patients underwent toe amputations because of vascular disease; 21% required higher amputation and 21% healed without further surgery (i.e., revascularization). Of 60 patients who required bypass surgery, 52 underwent successful first amputations and eight required higher amputations. No difference was seen between diabetic and nondiabetic patients in eventual limb salvage; however, men fared better than women. Without bypass surgery, 11 of 30 patients required a higher level of amputation. No patient's toe amputation site healed with an ankle-to-brachial index of less than 0.35. The judicious use of toe amputation remains an important tool in the surgeon's quest for limb salvage.     

Limb loss with patent infra-inguinal bypasses

To determine systemic and local risk factors that contribute to limb loss despite a patent infra-inguinal bypass graft and how to prevent it, we reviewed 987 patients who underwent infra-inguinal bypasses at our institution. Seventy-five (7.6%) patent grafts failed to achieve a healed foot despite exhaustive attempts to do so and these patients underwent major amputation either above the knee (AKA) or below the knee (BKA). In 525 femoro-popliteal bypasses, there were 38 major amputations (29 BKA; 9 AKA) with a patent graft; in 462 femoro-distal bypasses, there were 37 amputations (22 BKA; 15 AKA) with a patent graft. The remaining 912 patients with limb salvage as well as all the patients with limb loss were evaluated with regard to systemic risk factors, quality of the run-off from the popliteal artery, continuity of the tibial artery into the arch as demonstrated on arteriography, the haemodynamic improvement obtained postoperatively, and the presence and extent of necrosis in the foot. The presence of diabetes, extensive pedal necrosis and advanced infection predispose to limb loss despite a patent lower extremity bypass graft. Patients who lost their limbs despite a functioning bypass to an isolated popliteal segment had significantly less pronounced haemodynamic improvement postoperatively. An early graft extension to a reconstituted tibial or peroneal artery or a direct bypass to a distal tibial or peroneal artery may reduce the incidence of limb loss in this setting. When a patent bypass to an isolated tibial or peroneal artery segment failed to relieve foot ischaemia, limb salvage was achieved by a distal extension to plantar arteries.     

Limb salvage surgery in end stage renal disease: is it worthwhile?

The role of limb salvage surgery in patients with end stage renal disease (ESRD) is controversial. In view of this debate, we reviewed our experience with 54 primary and 15 secondary revascularizations for limb salvage in patients with ESRD over the past decade. Thirty-seven patients required dialysis and 10 had functioning renal transplants. Severe limb threatening ischemia was the indication for all revascularizations. The 2-year cumulative secondary graft patency rate was 56.2% with an associated limb salvage rate of 71.4%. There was no significant difference in graft patency or limb salvage rates between patients requiring dialysis and those with functioning renal allografts (p = 0.5). The 30-day operative mortality for the 99 surgical procedures (69 arterial bypasses and 30 additional operations) was 13% and the 2-year patient survival was 45.6%. Six of the 15 amputations were performed despite a patent graft on limbs which had extensive infection and gangrene. We conclude that limb salvage surgery should only be undertaken with recognition of these risks in patients with ESRD or functioning renal transplants. Surgery should be performed before gangrene and infection become extensive. Patients with unrelenting infection or mid-forefoot gangrene should be considered for primary amputation.     

Limb salvage vs amputation for critical ischemia. The role of vascular surgery

Since 1980, 498 patients with 627 critically ischemic legs (rest pain, gangrene, ischemic ulcer, and ankle-brachial pressure index less than 0.40) were treated with revascularization regardless of operative risk or anticipated operative difficulty. Primary amputation was performed only when no graftable distal vessels were present (14 primary amputations [2.8%]) or in neurologically impaired, hopelessly nonambulatory patients. The mortality for revascularization was 2.3%, and the median hospital stay was 11 days. During follow-up, 41 limbs (7%) required amputation, 31 after failure of revascularization and 10 despite patent revascularizations. Renal failure had an adverse influence on limb salvage (67%) because of a significantly increased requirement for amputation despite patent revascularizations. We conclude aggressive limb revascularization in patients with critical lower-extremity ischemia results in low operative morbidity and mortality and excellent long-term limb salvage. Patients with critical leg ischemia and renal failure are at higher risk for limb loss than patients without renal failure.     

Amputations in diabetic patients: a plea for footsparing surgery

The authors observed a rather high rate of primary major amputation (above-knee or below-knee) performed for diabetic foot problems as well as an important revision rate for minor amputations (forefoot or toe) in diabetics. They reviewed their experience in order to compare it with more recent data from the literature, pleading for foot-sparing surgery. From 1993 to 1998, 186 amputations were performed on 146 diabetic patients. The cause of foot ulcers was neuropathy in 43 of them (51 episodes of diabetic foot problems) while in the remaining 103 patients (135 episodes of diabetic foot problems), diabetic macroangiopathy (absent ankle pulses) was on cause. For neuropathic foot problems, amputations were almost minor, resulting in a limb salvage rate of 90%. Only five of these patients (12%) had primary major limb amputation versus 43 of the dysvascular patients (42%). The reasons for major amputation by first intention were extensive tissue loss, intractable infection or non-reconstructible occlusive vessel disease, as judged by the surgeon. A foot-sparing surgery was attempted in 92 dysvascular cases. In only 44 of them, a preliminary vascular repair was performed. Twenty eight percent of the primary toe amputations and 24% of the forefoot amputations required secondary revision to a more proximal level. Minor amputations in case of diabetic neuropathy were characterized by a more favourable outcome: only 14% of the toe and 9% of the forefoot amputations failed. During follow-up, only 63% of the major amputations regained an autonomic walking capability with their prosthesis. Wound healing problems in diabetic foot are mainly due to infection and poor tissue perfusion. An aggressive control of the infection and distal revascularization of calf- or foot arteries, whenever possible, could improve the results of diabetic foot surgery. The poor functional recovery after major amputation (only 63% autonomic gait with limb prosthesis) argues for foot-sparing surgery whenever possible.     

Pedal reconstructions for limb salvage.

If only one pedal artery is patent the vascular surgeon has to decide between primary amputation and a bypass. Between 1980 and 1990, 460 femoro-distal bypasses were performed in our clinic and 8% (39 cases) of these received a pedal reconstruction. At discharge from the hospital 85% of these grafts were patent. The primary goal of treatment, to maintain life and salvage the limb on the basis of a functioning bypass, was obtained in 82% of patients. After 1 year the secondary patency of our pedal reconstructions was 68%. Taking the mortality of amputations into account, vascular surgery to the foot arteries is preferable to amputation, whenever possible.     

Infrainguinal bypass grafting in patients with end-stage renal disease: improving outcomes?

OBJECTIVE: This study was undertaken to examine recent trends in the outcomes of patients with end-stage renal disease (ESRD) undergoing infrainguinal bypass grafting (IBG) with autogenous vein. METHODS: A retrospective analysis of all IBGs performed on patients with ESRD at a single tertiary care institution during the interval 1993 to 1999 was undertaken. The comparison groups consisted of concurrent series of patients with elevated creatinine (creatinine level > 1.2 mg/dL) and patients with normal renal function undergoing IBG. Procedural variables, angiographic runoff scores, and extent of tissue necrosis at presentation were correlated with outcome. Categoric parameters were compared with chi(2) analysis; rates were computed with life-table analysis. RESULTS: Of an overall cohort of 622 IBGs performed during this interval, 78 IBGs (12.5%) were performed on 60 patients with ESRD, with a perioperative mortality rate of 1.3% that was comparable to controls. All reconstructions in the ESRD cohort were for limb salvage indications. Four-year survival, primary, assisted primary, and secondary patency rates for the ESRD group were 51% +/- 9%, 60% +/- 11%, 86% +/- 5%, and 86% +/- 5%, respectively; these were not statistically different from the control groups. Limb salvage in the ESRD group was 77% +/- 6% at 4 years and was significantly less then either the elevated creatinine (92% +/- 4%; P <.02) or the normal renal function group (90% +/- 2%: P <.02). Of 16 amputations in the ESRD group, nine were performed in limbs with patent grafts. The only absolute predictor of limb loss despite a patent graft was the presence of a heel ulcer more than 4 cm in diameter. Age, runoff score of the International Society for Cardiovascular Surgery/Society for Vascular Surgery, isolated tibial bypass graft, and location of distal anastomosis were not predictive of hemodynamic failure. CONCLUSIONS: Patients with ESRD constitute an increasing proportion of patients undergoing IBG in a tertiary care setting. Four-year survival, perioperative mortality, and graft patency rates are similar to patients with normal renal function and support an aggressive approach to this population. Major limb amputation despite a patent graft remains a problem of unique frequency in patients with ESRD. Adequate predictors of hemodynamic failure of IBG in this group do not exist, although a heel ulcer more than 4 cm may indicate an unsalvageable foot.     

Functional failure of patent femorodistal in situ grafts

We have treated several patients who required major, proximal extremity amputations despite a patent infrainguinal in situ saphenous vein bypass graft. To determine those factors predisposing to such paradoxical limb loss, we studied a group of 45 patients who underwent 48 in situ, femorodistal bypass grafts for tissue necrosis and who maintained a patent graft throughout the perioperative period. Within this cohort, we compared two distinct subgroups: Group I, whose limbs (n = 8) ultimately required a major proximal amputation; Group II, whose limbs (n = 40) emerged with a viable foot and did not require a major amputation. There was no significant difference in the incidence of diabetes, renal failure, smoking, or postoperative ankle/brachial index between the two groups. The presence of gangrene (88% vs 45%), invasive sepsis (63% vs 23%), and combined gangrene and sepsis (63% vs 18%) was significantly (p less than 0.05) more prevalent in Group I versus Group II. Forty-three percent of patients with both gangrene and foot sepsis required a major proximal amputation despite a patent graft. Such patients are at high risk for limb loss even if they undergo successful revascularization.     

Arterial reconstruction of vessels in the foot and ankle.

OBJECTIVE: This study demonstrated that arterial reconstruction of vessels of the foot and ankle can preserve the majority of ischemic extremities with extensive tibial and peroneal occlusive disease and patent pedal arteries. SUMMARY BACKGROUND DATA: There are successful reports of bypass procedures to the ankle and foot, but despite this, these procedures have not gained widespread acceptance among surgeons performing infra-inguinal revascularization. Primary amputation is often offered for such patients. For this reason, the authors have reviewed their experience with bypasses to the foot and ankle. METHODS: A retrospective review was done of 75 arterial bypasses (5 bilateral), done since 1985, to the ankle and foot in 70 patients (38 males and 32 females). Fifty-four (77%) of the patients were diabetic. The age ranged from 55 to 95 years. Twenty-six (37%) were older than 80 years. The patients were selected for operative intervention because of severe tibioperoneal occlusive disease with ischemic rest pain or gangrene of the foot. Digital subtraction arteriography facilitated visualization of distal vessels. Operative principles included regional anesthesia, autogenous graft material, short bypass, non-traumatic vessel occlusion, selective operative arteriography, tension free ankle and foot skin closure, and concomitant conservative debridement of infected devitalized tissue. Incomplete pedal arch did not influence decision for operation. Indications for operation were: gangrene, 42 (56%); non-healing ulcer, 21 (28%); and rest pain, 12 (16%). Graft material was in situ greater saphenous vein, 40 (53%); translocated greater saphenous vein, 19 (25%); reversed greater saphenous vein, 11 (15%); and arm vein, lesser saphenous vein or vein patch, 5 (7%). Donor artery was popliteal, 30 (41%); common femoral, 26 (35%); and superficial femoral, 17 (23%). Recipient vessel was dorsalis pedis, 43 (57%); posterior tibial, 18 (24%); distal anterior tibial, 9 (12%); and distal peroneal, plantar or tibial endarterectomy, 5 (7%). RESULTS: There were four (5.7%) deaths and three (4.2%) graft failures within 30 days. Early graft failure led to transmetatarsal amputation (1), below knee amputation (1), and conversion of graft to femoral (1), popliteal bypass graft with limb salvage (1). In one patient, significant tissue necrosis with infection necessitated a below knee amputation within 30 days, despite a patent graft. Long-term follow-up revealed 10 graft failures, 4 major amputations, 3 graft revisions, and 15 deaths. Cumulative primary and secondary patency was 79.0% and 81.6% at 36 months. Limb salvage was 87.5% at 36 months. CONCLUSIONS: These results support an aggressive approach to limb salvage in patients with threatened limb loss, unreconstructable tibio-peroneal occlusive disease, and patent pedal arteries. Bypasses to the ankle and foot will maintain a functional extremity in the majority of these patients.     

Realistic expectations for pedal bypass grafts in patients with end-stage renal disease

Purpose: Limb-threatening ischemia in patients with end-stage renal disease (ESRD) represents a challenging clinical problem. Multiple series have shown the inferior limb salvage rate for femoropopliteal or femorotibial bypass grafts in this group. This outcome study is restricted to those patients with ESRD who require pedal bypass grafts for attempted limb salvage. Methods: Between December 1, 1990, and December 31, 1997, 34 patients with ESRD underwent pedal bypass grafting on 41 limbs. This review explores the patient and bypass graft outcomes and their relationships to typical risk factors. Results: The average age in the study was 64 years (range, 39 to 85 years). Twenty patients (59%) were men, 31 (91%) had diabetes, 32 (94%) were hypertensive, and 28 (82%) had coronary artery disease, but only 10 patients (29%) were smokers. All the patients were undergoing dialysis except 2 patients with functioning renal transplants. All bypass grafting procedures were performed for limb salvage. The follow-up periods ranged from 1 to 84 months (average, 13.5 months). With life-table analysis, the cumulative assisted primary patency rate was 62% at 1 year and 62% at 2 years. The limb salvage rate was 56% and 50% at 1 and 2 years, respectively. All the patients who were seen with heel gangrene had early limb loss or died. Seven of the 16 amputations (44%) were performed despite patent bypass grafts. Ten of the 16 amputations (63%) occurred within 3 months of the surgery. The survival rate was 64% at 1 year and 52% at 2 years. After the bypass graft procedure, the mean ankle brachial index and the toe pressure rose from 0.48 to 1.05 and 18 to 86, respectively. Conclusion: Modest success can be expected with pedal bypass grafts in patients with ESRD, with most failures occurring in the first 3 months. Limb salvage rates lag behind graft patency rates because of progressive necrosis despite a hemodynamically functioning bypass graft. Heel gangrene is a strong predictor for a negative outcome. Lastly, overall patient survival rates are poor but comparable with the rates of other patients with ESRD. (J Vasc Surg 1998;28:976-83.)     

Results of infrainguinal bypass for limb salvage in patients with end-stage renal disease

Limb salvage in patients with end-stage renal disease (ESRD) is complicated by the diffuse, obstructive, calcific arteriopathy that makes anastomotic technique especially critical. Furthermore, decreased resistance to infection and impaired wound healing produced by host-factor deficiencies such as diabetes mellitus, hypoalbuminemia, uremia, and immunosuppression produce additional obstacles to successful limb salvage. This report summarizes our experience with distal arterial bypass procedures in these patients. A total of 32 bypass procedures were performed for limb salvage in 24 patients (17 diabetic) during a period of 5 years. The operative mortality rate was 6%. During the same period, 635 infrainguinal bypass procedures were performed by the in situ technique in patients without ESRD. Primary bypass patency was comparable in both groups at 24 months (92% vs 90%). In the group with ESRD, overall limb salvage was 83% at 2 years. Life-table analysis of bypass patency and limb salvage was thought not to be appropriate in the population with ESRD beyond 2 years because of the increased mortality rate (38%; 9/24) during this interval. It is important that limb salvage was achieved in diabetic patients with ESRD in the presence of extensive foot gangrene or ischemic ulceration. Revascularization should be considered strongly for limb salvage in all patients in this difficult population.     

Isolated profundaplasty for limb salvage

Fifty-four patients underwent 56 profundaplasties for limb salvage. All had stenosis greater than 50% in diameter of the deep femoral artery and associated superficial femoral artery occlusive disease. After profundaplasty, ischemic ulcers healed in 9 of 17 (53%) patients. Rest pain was relieved in 6 of 19 (32%) and areas of ischemic necrosis healed in 7 of 20 (35%). Cumulative patency of the deep femoral artery was 49% at 3 years but fell to 21% at 5 years, whereas cumulative limb salvage was 49% and 36%, respectively. Eleven of the required 28 amputations were performed in the immediate postoperative period. Profundaplasty was used to lower the amputation level and preserve the knee joint in six patients. The other five early amputations occurred in severely ischemic limbs without distal vessels suitable for bypass. The profundaplasty remained patent in all 19 patients who underwent below-knee amputation and 16 (84%) became ambulatory with a prosthesis. Hemodynamic data provided by determination of the profundapopliteal collateral index predicted limb salvage in 10 of 11 (91%) of limbs when the index value was less than or equal to 0.19. Other clinical criteria, such as preoperative ankle-brachial index and the presence of diabetes mellitus, had no predictive value. Isolated profundaplasty for limb salvage is an effective first procedure for selected patients and provides a reasonable alternative to primary amputation or high-risk distal bypass. When amputation is inevitable, effective perfusion of the profunda femoris artery is essential for preservation of the knee joint and results in a high degree of functional rehabilitation.     

Influence of transmetatarsal amputation in patients requiring lower extremity distal revascularization

When a transmetatarsal amputation (TMA) is required, successful long-term limb salvage is questioned. We evaluated the influence of TMA on limb salvage in patients undergoing lower extremity revascularization. Patients who had distal bypasses extending to the infrapopliteal arterial tree and adjunctive TMA were retrospectively reviewed. Limb salvage was determined with life-table analysis. Twenty-four patients (29 limbs) were evaluated: 15 male and 9 female. Average age was 64.2 years old. Gangrene was the indication for bypass and TMA in 25 (86.2%) patients. Seven limbs were lost to follow-up. Nine of the remaining 22 limbs required below-knee (8) or above-knee (1) amputations, seven limbs within the first 3 months. In the group of patients who had major amputations within the first 3 months, graft thrombosis was the cause of leg amputation in six (85.7%) cases. No significant predictors of early major amputation were identified. Limb salvage was 62 per cent at 1 year in the TMA group. In comparison, among historical controls requiring distal revascularization and no adjunctive toe or foot amputations, limb salvage was 76.5 per cent (P = NS). Long-term limb salvage is dependent on successful lower extremity revascularization. Requirement for TMA should not influence the decision for limb salvage.     

Limb salvage after successful pedal bypass grafting is associated with improved long-term survival

OBJECTIVES: Assessments of outcome after reconstruction for critical limb ischemia frequently ignore functional result and long-term morbidity and mortality. This study was undertaken to identify factors affecting long-term clinical outcome and survival after pedal bypass grafting. METHODS: The clinical data of 256 consecutive patients who underwent pedal bypass grafting for critical limb ischemia over a 12-year period were retrospectively analyzed. RESULTS: A total of 174 men and 82 women (median age, 70 years; range, 30-91 years) underwent 280 pedal bypass graft placements with autologous vein. Seventy-five percent of the patients were diabetic, and 20% had renal insufficiency (serum creatinine level > 2 mg/dL). The in-hospital mortality rate was 1.6% (4/256). The mean follow-up was 2.7 years (range, 0.1-10.1 years). Rates of primary and secondary patency, limb salvage, and survival at 5 years were 58%, 71%, 78%, 60%, respectively. A total of 160 limbs (57%) required additional interventions. Nineteen early graft thrombectomies/revisions and nine early amputations were performed. One hundred thirty-eight late interventions included 31 graft salvage procedures, 27 wound debridements, and 34 minor and 42 major amputations. At last follow-up or death, 219 (78%) limbs were being used for ambulation. End-stage renal disease (ESRD) and composite vein grafts predicted limb loss (P <.001, P <.001, respectively). Overall survival at 5 years was 60%. Survival after amputation was 79%, 53%, and 26% at 1, 3, and 5 years. Amputation and ESRD predicted higher mortality (P =.014, P =.0001, respectively). CONCLUSIONS: Pedal bypass grafting resulted in good functional limb salvage, but at the expense of multiple interventions in more than half the cases. ESRD and composite vein graft were associated with poor long-term limb salvage. Amputation after bypass grafting was associated with significantly worse long-term survival.     

Multilevel occlusive vascular disease presenting with gangrene

The medical records of all patients subjected to lower extremity amputations during a 3-year period were reviewed. It was shown that advanced age and the presence of multiple medical problems do not predispose to higher levels of limb loss. Although diabetic patients more frequently undergo amputation because of sepsis than their nondiabetic counterparts, the diabetic state was not found to be associated with a greater likelihood of above knee (AK) procedures. Prior arterial surgery was not shown to make AK amputation more likely, but it was disconcerting to note that limb salvage was not achieved in many individuals despite patent proximal inflow revascularization procedures. This initial study showed that several presumed risk factors were not predictors of amputation level. Those patients requiring AK amputations had a greater frequency of combined segment (aortoiliac and femoropopliteal) occlusive disease than those who had successful amputations at more distal levels. A follow-up study of 41 consecutive patients presenting with tissue loss due to combined segment occlusive disease was performed. Eighteen (Group I) underwent inflow procedures only, while 23 (Group II) also underwent distal revascularization. The groups were similar with respect to age, risk factors, extent of tissue loss and sepsis. At 1 year 10 (56%) Group I and only 3 (13%) Group II patients required major amputation (P = 0.01). Distal bypass, in addition to an inflow procedure, is recommended for those who present with tissue loss due to multilevel arterial occlusion.     

Femoral-tibial bypass for calcific arterial disease

Overt calcification of the recipient artery and outflow bed has been regarded as a poor prognostic factor for femoral-distal arterial bypass patency and subsequent wound healing. In order to determine the short- and long-term limb salvage and graft patency rates achieved in these patients, the records of 35 patients undergoing 38 attempted femoral-tibial bypasses to a calcified recipient artery were reviewed. Two patients were unreconstructable at the time of surgery. Thirty-one of the 36 operations (86 percent) were performed using in situ saphenous vein bypass techniques, 3 were performed with polytetrafluoroethylene (PTFE), 1 with a composite sequential, and 1 with a composite vein graft. Immediate limb salvage was achieved in 31 of 36 limbs (86 percent). Five early below-knee amputations (14 percent) were required, two due to graft thromboses and three due to progressive foot necrosis despite patent grafts. One patient (3 percent) died secondary to sepsis. Three-year primary graft patency and limb salvage rates did not differ significantly from bypasses to noncalcified vessels. Femoral-distal bypass in the presence of overt calcific arterial disease may be successfully accomplished and offers an excellent prognosis for long-term graft patency and limb salvage.     

Ultimate salvage for the patient with limb-threatening ischemia. Realistic goals and surgical considerations

Ultimate salvage for the patient with a severely ischemic lower limb should be the preservation of bipedal gait. Arterial reconstructions which will sustain the limb by restoring circulation will accomplish this objective if the limb is functional. However, major amputations of the leg performed for ischemia are increasing yearly despite the proliferation of “salvage” bypass procedures. Evaluation of large experiences in revascularizations performed to popliteal or distal arteries for limb salvage reveal: (1) mortality 4 per cent; (2) early graft failure 20 to 35 per cent, late failure (2 years) 30 to 50 per cent; (3) amputation despite patent graft 7 to 10 per cent; and (4) factual palliation (2 years) less than 50 per cent. To these must be added the number of patients who required an above-knee amputation after their revascularization attempt failed, in whom a primary below-knee amputation would have healed.Primary healing has been achieved at the below-knee level in 80 per cent of such patients, most of whom are successfully returned to ambulatory status. Since the rehabilitation time is doubled and the attainment of independent bipedal gait halved with an above-knee amputation, the importance of the knee joint for ambulation cannot be overemphasized. In view of these observations, the wisdom of proceeding with a tenuous arterial reconstruction for treatment of patients with advanced limb ischemia is questioned. Primary below-knee amputations should be used more often in this setting. Appropriate therapy should not interfere with the dysvascular patient attaining the ultimate goal: social and economic independence through the preservation of bipedal gait.     

Midfoot Amputations Expand Limb Salvage Rates for Diabetic Foot Infections

The persistent high incidence of limb loss resulting from advanced forefoot tissue loss and infection in diabetic patients prompted an evaluation of transmetatarsal (TMA) and transtarsal/midfoot amputations in achieving foot salvage at our tertiary vascular practice. Over the last 8 years, 74 diabetic patients required 77 TMAs for tissue loss and/or infection. Twelve (16%) of the patients had a contralateral below-knee amputation (BKA) and 26% (n = 20) had dialysis-dependent renal failure. Thirty-five (45%) limbs had concomitant revascularization (bypass grafting or percutaneous transluminal angioplasty), 32 (42%) had arterial occlusive disease by noninvasive testing and/or arteriography but were not or could not be revascularized, and seven (13%) had normal hemodynamics. Patient factors, arterial testing, operative complications, operative mortality (<60 days), wound healing (at 90 days), limb salvage, functional status, and survival were evaluated during a mean follow-up of 20 months (range 3-48). Operative mortality was 5% (n = 4) after TMA and/or midfoot amputation. Although 32 TMAs initially healed (44%), six BKAs were required 5-38 months later. Of the 41 nonhealing TMAs (56%), progressive infection/tissue loss necessitated major amputation of nine limbs. Chopart (n = 22) or Lisfranc (n = 10) midfoot amputations were done in the remaining 32 nonhealing TMAs. Despite additional wound revisions in 14 patients (44%), major amputation was needed in six limbs. However, functional ambulation was achieved in 23 of 25 (92%) limbs with healed midfoot amputations, and foot salvage was possible in 61% (25/41) of nonhealing TMAs. Overall limb salvage for TMA/midfoot procedures was estimated from Kaplain-Meier life tables to be 73%, 68%, and 62% at 1, 3, and 5 years, respectively, with only 50% of dialysis patients avoiding major amputation. Ankle pressure >100 mm Hg and a biphasic pedal waveform had a positive predictive value (PPV) of 79%, and toe pressure >50 mm Hg had a PPV of 91% for determining healing of TMA/midfoot amputations. One- and 3-year survival rates were only 72% and 69% for the entire cohort from life table estimates. Aggressive attempts at foot salvage are justified in diabetic patients with advanced forefoot tissue loss/infection after assuring adequate arterial perfusion. Transtarsal amputations salvaged over half of nonhealing TMAs with excellent functional results. Presented at the Fifteenth Annual Winter Meeting of the Peripheral Vascular Surgery Society, Steamboat Springs, CO, January 28-30, 2005.     

The dorsalis pedis bypass--moderate success in difficult situations.

Recent reports have documented excellent results for inframalleolar reconstructions. We reviewed our outcomes for dorsalis pedis bypass and report a more modest rate of success. We analyzed reasons for failure. Sixty-nine patients underwent 73 dorsalis pedis bypass procedures between 1984 and 1991. Seventy-eight percent of the patients were diabetics. Inflow was from the external iliac in 1, femoral in 35, popliteal in 34, and tibial in 3. The operative indication was gangrene in 57%, ulcer in 22%, and rest pain in 21%. Forty-six percent of limbs had foot infection, with six requiring minor amputation before the bypass and 24 requiring minor amputation after bypass. There was one perioperative death. Twenty-nine grafts failed over the course of the series. The primary patency rate at 2 years was 59.2%. The limb salvage rate was 73.5%. Of the 10 perioperative failures, four were due to continued foot infection, four to marginal vein quality, and two to skin necrosis of the bypass incisions. Graft failure occurred at 3 to 30 months in 10 of 14 patients who had deficient anterior arches, with segmental occlusion of the dorsalis pedis or its branches. Six of the 14 patients with extensive infections of the forefoot or extensive heel ulcers required amputation with patent bypasses. In dorsalis pedis bypass, failure to achieve limb salvage was more likely in patients with marginal vein quality, deficient anterior pedal arches, and extensive foot infection. In patients where the chance of failure appears to be unacceptably high, primary amputation should be considered.