Minor amputations on the feet after revascularization for gangrene. A consecutive series of 95 limbs

Minor amputation after revascularization in chronic limb-threatening ischemia: What is the optimal timing?

OBJECTIVES

Patients with chronic limb-threatening ischemia (CLTI) have a high risk of lower limb amputation and loss of walking independence. Minor amputations play a key role in ensuring walking independence and they represent a challenge in terms of timing and level for vascular surgeons. A major cause of re-amputation is a defect in wound healing and a possible predictor of re-amputation for non-healing wounds could be the incorrect timing of minor amputation after revascularization. The lack of evidence in the literature leads to a wide variability of choices in clinical practice. The purpose of this study was to try to find the optimal timing analysing the risk of re-amputation in CLTI patients who have undergone successful revascularization and minor amputation focussing on timing of minor amputation.

METHODS

We conducted a single centre retrospective analysis on a cohort of 151 patients consecutively admitted to our hospital for CLTI (Rutherford 5) between January 2014 and April 2022. All the enrolled patients underwent successful revascularization of lower limbs and a minor amputation for dry acral necrosis. The characteristics of the patients and the revascularization procedures were collected and analysed. Patients were divided into two groups based on the timing of minor amputation performed before (group 1) or after the day (group 2) that best predicts the risk of re-amputation according to a Receiver Operating Characteristic (ROC) curve analysis. The primary outcome of this study was the risk of re-amputation during the first 60 days of follow-up after a primary minor amputation, with revascularization still effective. The impact of the timing of minor amputation after revascularization, the type of revascularization and the presence of risk factors known to prolong the wound healing process were evaluated in a uni- and multi-variable logistic regression model.

RESULTS

Systemic hypertension, and type of revascularization (i.e. open vs endovascular) were independent predictors of the risk of re-amputation at 60 days (HR 4.26, 95% CI 1.30-14.04, p = .017 and HR 2.35, 95% CI 1.16-4.78, p = .018, respectively). Moreover, time ≤14 days between revascularization and first amputation was associate with a clear, albeit not statistically significant, trend toward increased risk of re-amputation (HR 2.09, 95% CI 0.97-4.51, p = .06).

CONCLUSIONS

In a cohort of patients who underwent a successful revascularization for CLTI and a minor amputation for dry gangrene in the first 14 days after revascularization, a higher -although not significant-risk of re-amputation was reported. In this cohort of patients, a delayed demolitive procedure should be considered to allow better tissue perfusion and to reduce the risk of re-amputation.

Racial and ethnic amputation level disparities in veterans undergoing incident dysvascular lower extremity amputation

BACKGROUND

The choice of incident amputation level can have a profound effect on clinical outcomes. Amputations at the transmetatarsal (TM) or transtibial (TT) levels result in greater preservation of function and mobility, whereas transfemoral (TF) amputations typically result in a greater adverse impact. Prior investigations have explored racial/ethnic and regional variation in incident amputation level. This study overcomes some of the methodological limitations seen in prior research through the use of a large national, multiyear veteran sample and by including only those who have undergone an incident amputation.

OBJECTIVES

(1) Determine if there are national/regional differences in the frequency of incident TF amputation compared with TM and TT amputation, (2) Determine if race/ethnicity and geographic region are associated with incident TF amputation level, and (3) Determine if racial/ethnic disparities of incident TF amputation differ by the presence of diabetes or prior revascularization.

DESIGN

Retrospective cohort study of veterans undergoing an incident dysvascular lower extremity amputation.

SETTING

One hundred ten Veterans Affairs (VA) Medical Centers.

PARTICIPANTS

Seven thousand two hundred ninety-six Veterans undergoing incident unilateral dysvascular lower extremity amputation identified in the Veterans Affairs Surgical Quality Improvement Program (VASQIP) database (2005-2014).

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURE

Incident amputation level.

RESULTS

The White, Black, and Hispanic risk for an incident TF amputation was 31% (n = 1356), 35% (n = 810), and 46% (n = 293), respectively. In the Continental region, Blacks who had not had a prior revascularization were more likely to undergo a TF amputation compared to Whites both with and without diabetes (odds ratio [OR] = 1.4; 95% confidence interval [CI], 1.1, 1.9 and OR = 1.5; 95% CI, 1.1, 2.1, respectively). In the Southeast region, Hispanics compared with Whites were at increased odds of undergoing a TF amputation, irrespective of a diabetes or a prior revascularization (ORs ≥ 2.9).

CONCLUSIONS

Racial and ethnic disparities exist in choice of proximal compared with distal amputation in specific VA geographic regions.

The Effects of Endovascular Timing and In-line Flow on the Success of Pedal Amputations

There has been a growing trend toward endovascular intervention to improve peripheral flow in patients with peripheral arterial disease. To date, there is no clear consensus regarding timing of lower-extremity amputations after revascularization. The purpose of this study was to evaluate the effects of timing between endovascular intervention and minor lower-extremity amputations and its influence on wound healing and limb loss within 1 year. A secondary purpose was to evaluate the impact of restoring in-line flow on healing rates. A total of 310 patients who underwent endovascular intervention and a minor lower-extremity amputation within 90 days were included in the study. Healing rates were defined as optimal, delayed, or failure. There was a statistically significant difference between patients with optimal healing to delayed healing and amputation ≥30 days after endovascular intervention (p = .037). We found no difference in healing rates in regard to amputation timing when examining patients who ultimately healed versus patients who failed to heal (p = .6717). Absence of in-line flow (p = .0177), male sex (p = .0090) and diabetes mellitus (p = .0076) were statistically significant factors for failing to heal. Presence of infection (p ≤ .0001) and wound dehiscence (p ≤ .001) were also associated with a failure to heal. End-stage renal disease trended toward significance for failing to heal (p = .065). Amputation-free survival at 1 year after endovascular intervention and pedal amputation was 76.8% (n = 238). Our findings suggest that in the absence of infection, performing minor lower-extremity amputations 15 to 60 days after endovascular intervention may allow for improved healing. Absence of in-line flow, male sex, diabetes mellitus, postoperative infection, and wound dehiscence are significant factors for failure.

Anatomic Limitations of the Transmetatarsal Amputation With Consideration of the Deep Plantar Perforating Branch of the Dorsalis Pedis Artery

The transmetatarsal amputation is considered a durable procedure with respect to limb salvage when managing the consequences of diabetic foot disease. The success of the procedure is, in part, determined by the preoperative appreciation of arterial and functional status. The objectives of the present investigation were to determine the length of the remaining first metatarsal required during transmetatarsal amputation to preserve the anastomotic connection of the deep plantar perforating artery and subsequent "vascular arch" of the foot and the insertion of the tibialis anterior tendon. The primary outcome measure of our investigation was a measurement of the distance between the first metatarsal-medial cuneiform articulation and the distal extent of the deep plantar perforating artery in 85 embalmed lower limbs. As a secondary outcome measure, the insertion of the tibialis anterior tendon was evaluated relative to the deep plantar perforating artery. The most distal extent of the deep plantar perforating artery was observed at a mean ± standard deviation of 15.62 ± 3.74 (range 6.0 to 28.28) mm from the first metatarsal-medial cuneiform articulation. Most (89.41%) of the arteries were found within 20 mm of the first metatarsal-medial cuneiform articulation. The insertion of the tibialis anterior tendon was found to be proximal to the deep plantar perforating artery in all specimens (100.0%). In conclusion, 2.0 cm of remnant first metatarsal might represent an anatomic definition of how "short" a transmetatarsal amputation can safely be performed in most patients when considering the vascular and biomechanical anatomy.

Primary closure of elective toe amputations in the diabetic foot--is it safe?

BACKGROUND

Toe amputation is the most common partial foot amputation. Controversy exists regarding whether to primarily close toe amputations or to leave them open for secondary healing. The purpose of this study was to evaluate the results of closed toe amputations in diabetic patients, with respect to wound healing, complications, and the need for further higher level amputation.

METHODS

We retrospectively reviewed the results of 40 elective or semi-elective toe amputations with primary closure performed in 35 patients treated in a specialized diabetic foot unit. Patients with abscesses or necrotizing fasciitis were treated emergently and were excluded. Patients in whom clean margins could not be achieved due to extensive cellulitis or tenosynovitis and patients requiring vascular intervention were excluded as well. Outcome endpoints included wound healing at 3 weeks, delayed wound healing, or subsequent higher level amputation.

RESULTS

Out of 40 amputations, 38 healed well. Thirty amputations healed by the time of stitch removal at 3 weeks and eight had delayed healing. In two patients the wounds did not heal and subsequent higher level amputation was eventually required.

CONCLUSIONS

In carefully selected diabetic foot patients, primary closure of toe amputations is a safe surgical option. We do not recommend primary closure when infection control is not achieved or in patients requiring vascular reconstruction. Careful patient selection, skillful assessment of debridement margins and meticulous technique are required and may be offered by experienced designated surgeons in a specialized diabetic foot unit.

[Minor amputations: a maxi task : Part 2: From transmetatarsal amputation to hindfoot amputation]

The definitive aim of a minor amputation is limited resection with retention of feet and legs resulting in a completely loadable extremity, in contrast to the lower leg stump. A shift in the amputation level in the sense of a shortening is inevitably accompanied by a reduction in the stand area, an increase in axial pressure and a disruption of muscle equilibrium in the extent of movement of the rest of the foot. This knowledge forms the central issue for further treatment of minor amputations in addition to the subtle treatment of the skin of the sole for coverage of a tension-free tip of the stump. Advantageous are longitudinal partial amputations of the forefoot and midfoot.

[Minor amputations - a maxi task. Part 1: From the principles to transmetatarsal amputation]

A threatening major amputation represents a fateful turning point for diabetics. This occurs in 50% of cases of amputations in diabetics. This increases the demand for another therapeutic route not only because of the limitations in quality of life but also due to substantially higher mortality. Even if an osteomyelitic ischemic situation is often present specialized centers have succeeded in substantially reducing the rate of major amputations in such patients. The term "minor amputation" commonly used in vascular surgery is not uniformly understood. Following the "vascular surgery working model" developed by Rümenapf, the significance of "minor amputations" for retention of extremities and the associated controversies have been shown. "Minor amputations" therefore represent a maxi-task if patients undergoing such a procedure are to be timely and competently treated. The necessary interdisciplinary cooperation with other specialists should in the future also include orthopedic surgeons.

Minor amputation in patients with diabetes mellitus and severe foot ulcers achieves good outcomes

OBJECTIVE

To analyse the outcome of minor amputations (through, or distal to, the ankle joint) in patients with diabetes.

METHOD

All diabetic patients in a defined population undergoing one or more minor amputation between 1982 and 2006 were investigated according to a standardised protocol and were followed until final outcome (healing or death). A total of 410 consecutive amputations in 309 patients with a median age of 73 (32-93) years were identified.

RESULTS

In 94% of amputations, deep infection (39%) and/or gangrene (55%) was present. Severe peripheral vascular disease or critical limb ischaemia was present in 61% of amputations. 261/410 (64%) of the amputations healed at a level below the ankle joint; 69/410 (17%) healed after a re-amputation above the ankle joint; in 76/410 of amputations (19%), the patient died before healing could occur. In surviving patients, 79% of the amputations healed below the ankle. Median healing time for amputations that healed below the ankle was 26 (2-250) weeks; 21% of amputations required a re-amputation above the ankle. None of the analysed parameters excluded the possibility of healing below the ankle.

CONCLUSION

In this population-based survey, the goal of avoiding major amputation was achieved in almost two thirds of minor amputations, but at the price of long healing times. In almost all amputations, the patient had deep infection and/or gangrene. In spite of this, 64% of all amputations, and 79% of amputations in surviving patients, healed at a level below the ankle. This indicates that minor amputations in these patients are worthwhile.

DECLARATION OF INTEREST

None.

[Minor amputations for diabetic foot syndrome]

Minor amputations are frequently performed for neuroischemic or neuropathic lesions of the diabetic foot. Depending on the definition used, minor amputations can range from toe to Syme amputations. Minor amputations are often combined with necrosectomy and débridement. For early and optimal rehabilitation, as much vital tissue as possible should be conserved, especially considering the skeletal structures of the foot (borderline amputation). Minor amputations are of utmost importance for the prevention of ascending infections and reduce the duration of clinical and outpatient treatment. Minor amputations should be performed only by experienced surgeons and only if arterial perfusion is sufficient. They should be as tissue-conserving as possible and structured interdisciplinary postoperative care is mandatory. Metabolic control should be optimized. Controversial opinions exist with respect to the use of tourniquets, conservation or resection of cartilage and sesamoid bones, open amputation or primary closure of the wound, interdigital spacer function of toes, aseptic proximal transection of tendons, postoperative wound care, negative-pressure wound treatment and antibiotic therapy. In view of these controversies the most important minor amputation techniques are described and discussed.

Forefoot amputation with limb revascularization: the effects of amputation, timing, and wound closure on the peripheral vascular bypass graft site

BACKGROUND

Much has been written about the effects of successful arterial bypass on forefoot surgery for ulceration and gangrene. This study examined the effects of the amputation site and timing on the arterial bypass graft site.

METHODS

We reviewed the records of all patients who had successful vascular bypass graft surgery and amputation at our institution, between October, 1995 and May, 2002. Thirty-eight procedures in 35 patients fit the criteria and were included in the study.

RESULTS

Thirty-five patients had successful vascular bypass graft surgery and forefoot amputation for gangrene or nonhealing ulceration. Three of these patients developed gangrene on the contralateral side and received similar treatment for that side. All of the wounds eventually healed. Healing time, rate of graft infection, and rate of wound dehiscence did not differ noticeably between patients with amputation immediately after arterial bypass and patients with amputation one or more days after arterial bypass. Infection at the bypass site occurred in two patients; their amputation sites were closed primarily. Wound dehiscence developed at the bypass site in one patient whose amputation site was closed by secondary intention. Although not statistically significant, the median healing time in patients treated with primary closure (37 days) was less than that in patients treated with closure by secondary intention (61 days; p = 0.09), and rates of graft infection and wound dehiscence did not differ between these two groups of patients.

CONCLUSIONS

Amputation site wound closure may adversely affect the bypass graft, but results were not statistically significant. Treatment requires a closely coordinated team approach between the vascular surgeon and the orthopedic surgeon.

The positive experience of using a growth-factor product on deep wounds with exposed bone

Trafermin, a form of basic fibroblast growth factor, has been used in Japan since 2001. This study investigates whether it can facilitate closure in wounds with deep soft-tissue defects and exposed bone, where surgical closure is not possible.

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.