Toe amputation: a predictor of future limb loss?

Salami-Tactics: when is it time for a major cut after multiple minor amputations?

INTRODUCTION

Repetitive minor amputations carry the concomitant risks of multiple surgical procedures, major amputations have physical and economical major drawbacks. The aim of this study was to evaluate whether there is a distinct number of minor amputations predicting a major amputation in the same leg and to determine risk factors for major amputation in multiple minor amputations.

MATERIALS AND METHODS

A retrospective chart review including 429 patients with 534 index minor amputations between 07/1984 and 06/2019 was conducted. Patient demographics and clinical data including number and level of re-amputations were extracted from medical records and statistically analyzed.

RESULTS

290 legs (54.3%) had one or multiple re-amputations after index minor amputation. 89 (16.7%) legs needed major amputation during follow up. Major amputation was performed at a mean of 32.5 (range 0 - 275.2) months after index minor amputation. No particular re-amputation demonstrated statistically significant elevated odds ratio (a.) to be a major amputation compared to the preceding amputation and (b.) to lead to a major amputation at any point during follow up. Stepwise multivariate Cox regression analysis revealed minor re-amputation within 90 days (HR 3.8, 95% CI 2.0-7.3, p <0.001) as the only risk factor for major amputation if at least one re-amputation had to be performed.

CONCLUSIONS

There is no distinct number of prior minor amputations in one leg that would justify a major amputation on its own. If a re-amputation has to be done, the timepoint needs to be considered as re-amputations within 90 days carry a fourfold risk for major amputation.

LEVEL OF EVIDENCE

Retrospective comparative study (Level III).

Phase I/IIa Feasibility Trial of Autologous Quality- and Quantity-Cultured Peripheral Blood Mononuclear Cell Therapy for Non-Healing Extremity Ulcers

Non-healing wounds are among the main causes of morbidity and mortality. We recently described a novel, serum-free ex vivo expansion system, the quantity and quality culture system (QQc), which uses peripheral blood mononuclear cells (PBMNCs) for effective and noninvasive regeneration of tissue and vasculature in murine and porcine models. In this prospective clinical study, we investigated the safety and efficacy of QQ-cultured peripheral blood mononuclear cell (MNC-QQ) therapy for chronic non-healing ischemic extremity wounds. Peripheral blood was collected from 9 patients with 10 chronic (>1 month) non-healing wounds (8 males, 1 female; 64-74 years) corresponding to ischemic extremity ulcers. PBMNCs were isolated and cultured using QQc. Within a 20-cm area surrounding the ulcer, 2 × 107 cells were injected under local anesthesia. Wound healing was monitored photometrically every 2 weeks. The primary endpoint was safety, whereas the secondary endpoint was efficacy at 12-week post-injection. All patients remained ambulant, and no deaths, other serious adverse events, or major amputations were observed for 12 weeks after cell transplantation. Six of the 10 cases showed complete wound closure with an average wound closure rate of 73.2% ± 40.1% at 12 weeks. MNC-QQ therapy increased vascular perfusion, skin perfusion pressure, and decreased pain intensity in all patients. These results indicate the feasibility and safety of MNC-QQ therapy in patients with chronic non-healing ischemic extremity wounds. As the therapy involves transplanting highly vasculogenic cells obtained from a small blood sample, it may be an effective and highly vasculogenic strategy for limb salvage.

Etiology and outcomes of amputation in patients with peripheral artery disease in the EUCLID trial

OBJECTIVE

Amputation remains a frequent and feared outcome in patients with peripheral artery disease (PAD). Although typically characterized as major or minor on the extent of tissue loss, the etiologies and outcomes after amputation by extent are not well-understood. In addition, emerging data suggest that the drivers and outcomes of amputation in patients with PAD may differ in those with and without diabetes mellitus (DM).

METHODS

The EUCLID trial randomized 13,885 patients with symptomatic PAD, including 5345 with concomitant diabetes, to ticagrelor or clopidogrel and followed them for long-term outcomes. Amputations were prospectively reported by trial investigators. Their primary and contributing drivers were adjudicated using safety data, including infection, ischemia, or multifactorial etiologies. Outcomes following major and minor amputations were analyzed, including recurrent amputation, major adverse limb events, adverse cardiovascular events, and mortality. Multivariable logistic regression models were used to identify independent predictors of minor amputations. Analyses were performed overall and stratified by the presence or absence of DM at baseline.

RESULTS

Of the patients randomized, 398 (2.9%) underwent at least one lower extremity nontraumatic amputation, for a total of 511 amputations (255 major and 256 minor) over a median of 30 months. A history of minor amputation was the strongest independent predictor for a subsequent minor amputation (odds ratio, 7.29; 95% confidence interval, 5.17-10.30; P < .001) followed by comorbid DM (odds ratio, 4.60; 95% confidence interval, 3.16-6.69; P < .001). Compared with patients who had a major amputation, those with a minor amputation had similar rates of subsequent major amputation (12.2% vs 13.6%), major adverse limb events (15.1% vs 14.9%), and major adverse cardiovascular events (17.6% vs 16.3%). Ischemia alone was the primary driver of amputation (51%), followed by infection alone (27%), and multifactorial etiologies (22%); however, infection was the most frequent driver in those with DM (58%) but not in those without DM (15%).

CONCLUSIONS

Outcomes after amputation remain poor regardless of whether they are categorized as major or minor. The pattern of amputation drivers in PAD differs by history of DM, with infection being the dominant etiology in those with DM and ischemia in those without DM. Greater focus is needed on the prognostic importance of minor amputation and of the multifactorial etiologies of amputation in PAD. Nomenclature with anatomical description of amputations and eliminating terms "major" or "minor" would seem appropriate.

A meta-analysis of mortality after minor amputation among patients with diabetes and/or peripheral vascular disease

OBJECTIVE

Foot complications in patients with diabetes or peripheral artery disease (PAD) are serious events in the life of these patients that often lead to amputations and mortality. No evidence synthesis has been reported on the mortality rates after minor lower extremity amputation; thus, a quantitative evidence synthesis was needed.

METHODS

A systematic literature search was performed to identify studies that had reported the survival or mortality rates after a minor LEA. The studies were required to include one or more of the following primary outcomes: mortality rate at 30 days, 1 year, 3 years, 5 years, 6 to 7 years, or 8 to 9 years. The secondary outcomes were the mortality rates according to the anatomic location of the amputation in the foot and the independent risk factors for mortality.

RESULTS

A total of 28 studies with 17,325 subjects fulfilled the inclusion criteria. The meta-analytical results of the mortality rates were as follows: 3.5% at 1 month, 20% at 1 year, 28% at 3 years, 44.1% at 5 years, 51.3% at 6 to 7 years, and 58.5% at 8 to 9 years. From these studies of diabetic patients, age was the most consistent independent risk factor, followed by chronic kidney disease, PAD, and coronary artery disease. One study of patients with PAD had reported diabetes as an independent risk factor for mortality. The subgroup analysis of the four studies reporting the outcomes of patients with PAD showed greater 3- and 5-year mortality rates compared with the overall and "diabetic" results.

CONCLUSIONS

Mortality after minor amputation for patients with diabetes and/or PAD was found to be very high. Compared with the reported cancer data, survival was worse than that for many cancers. Just as in the case of major amputations, minor amputations should be considered a pivotal event in the life of these patients.

Risk of Ipsilateral Reamputation Following an Incident Toe Amputation Among U.S. Military Veterans With Diabetes, 2005-2016

OBJECTIVE

To assess whether the risk of subsequent lower-limb amputations and death following an initial toe amputation among individuals with diabetes has changed over time and varies by demographic characteristics and geographic region.

RESEARCH DESIGN AND METHODS

Using Veterans Health Administration (VHA) electronic medical records from 1 October 2004 to 30 September 2016, we determined risk of subsequent ipsilateral minor and major amputation within 1 year after an initial toe/ray amputation among veterans with diabetes. To assess changes in the annual rate of subsequent amputation over time, we estimated age-adjusted incidence of minor and major subsequent ipsilateral amputation for each year, separately for African Americans (AAs) and whites. Geographic variation was assessed across VHA markets (n = 89) using log-linear Poisson regression models adjusting for age and ethnoracial category.

RESULTS

Among 17,786 individuals who had an initial toe amputation, 34% had another amputation on the same limb within 1 year, including 10% who had a major ipsilateral amputation. Median time to subsequent ipsilateral amputation (minor or major) was 36 days. One-year risk of subsequent major amputation decreased over time, but risk of subsequent minor amputation did not. Risk of subsequent major ipsilateral amputation was higher in AAs than whites. After adjusting for age and ethnoracial category, 1-year risk of major subsequent amputation varied fivefold across VHA markets.

CONCLUSIONS

Nearly one-third of individuals require reamputation following an initial toe amputation, although risks of subsequent major ipsilateral amputation have decreased over time. Nevertheless, risks remain particularly high for AAs and vary substantially geographically.

Do toe blood pressures predict healing after minor lower limb amputation in people with diabetes? A systematic review and meta-analysis

PURPOSE OF STUDY

To investigate toe systolic blood pressure and/or toe-brachial pressure index in predicting healing post minor diabetic foot amputations.

KEY METHODS

A systematic search of EMBASE and PubMed (including Medline and The Cochrane Library) was conducted from database inception to 9 March 2020. Two authors independently reviewed and selected relevant studies. Quality was assessed with a modified Critical Appraisal Skill Programme checklist.

MAIN RESULTS

Ten studies met the inclusion criteria. Nine studies investigating toe systolic blood pressure reported healing occurred at mean toe systolic blood pressure values ⩾30 mmHg, ranging between 30 and 83.6 mmHg. The meta-analysis (four studies) found toe systolic blood pressure <30 mmHg had 2.09 times the relative risk of non-healing post amputation, compared to toe systolic blood pressure ⩾30 mmHg (relative risk = 2.09, 95% confidence interval: 1.37-3.20, p = 0.001). Two studies investigating toe-brachial pressure index report successful healing where toe-brachial pressure index >0.2, with one study reporting a higher value of 0.8.

MAIN CONCLUSIONS

Successful post-amputation healing outcomes were reported at mean toe systolic blood pressure ⩾30 mmHg, and the results varied considerably between the studies. Further research should identify whether variables, including amputation level, method of wound closure and length of post-operative follow-up periods, affect the values of toe systolic blood pressure and toe-brachial pressure index observed in this review.

Rates and timing of subsequent amputation after initial minor amputation

OBJECTIVE

Studies evaluating major amputation after initial minor amputation are few with rates of subsequent major amputation ranging from 14% to 35% with limited understanding of associated comorbidities and time to limb loss. The aim of this study is to determine the major amputation rates for patients who had already undergone an initial minor amputation and determine which factors are associated with the need for subsequent major amputation.

METHODS

Using statewide data between 2005 and 2013, patients with peripheral artery disease (PAD), diabetes mellitus (DM), and combined PAD/DM who had a lower extremity ulcer and who had also undergone a minor amputation were identified. These patients were evaluated for the rate of subsequent major amputation and competing risk Cox proportional hazards modeling was used to study which factors were associated with the risk of subsequent limb loss.

RESULTS

The cohort consisted of 11,597 patients (DM, n = 4254; PAD, n = 2142; PAD/DM, n = 5201) with lower extremity ulcers who underwent an initial minor amputation. The rate of any subsequent amputation was highest in patients with PAD/DM (23% vs DM = 17%, PAD = 17%; P = not statistically significant). The rate of subsequent minor amputation was 16% in the PAD/DM versus 15.2% in PAD and 12.2% in patients with DM (P < .001). Patients with PAD/DM had the highest rate of subsequent major amputation (6.3% vs DM = 5.2%, PAD = 2.1%; P < .001). There was no statistically significant difference in the median time to major amputation among the three groups (PAD/DM, 13 months; DM, 14 months; PAD, 8.6 months; P = NS). Patients who were revascularized before a repeat minor amputation had a decreased risk of a major amputation compared with those who were intervened on after a repeat minor amputation (hazard ratio, 0.002; 95% confidence interval, 0-0.22). Patients treated completely in the outpatient setting were also less likely to undergo subsequent major amputation (hazard ratio, 0.7; 95% confidence interval, 0.5-0.98) compared with those who required hospitalization or presented to the emergency room.

CONCLUSIONS

Patients with ulcers and combined PAD and DM have a higher risk for secondary major and minor amputation than patients with either disease alone with half of the limb loss occurring at approximately 1 year after the initial minor amputation. Additionally, early diagnosis and appropriate referral may result in decreased limb loss for these patients.

Toe Pressures are Superior to Duplex Parameters in Predicting Wound Healing following Toe and Foot Amputations

BACKGROUND

No criteria, including preamputation vascular diagnostic thresholds, have been established to reliably predict healing versus nonhealing following minor lower extremity amputations. Thus, the goal of our study was to identify clinical factors, including noninvasive vascular laboratory measures, associated with wound healing following toe, forefoot, and midfoot amputations.

METHODS

We retrospectively examined records of patients receiving elective toe, forefoot, or midfoot amputation at our institution over a 5-year span (2010-2015). A total of 333 amputations received noninvasive vascular assessment of the lower extremity preamputation and follow-up at 90 days postamputation. Multivariate binomial logistic regression was used to identify variables predicting wound healing as defined as the absence of reamputation due to wound breakdown.

RESULTS

Wound healing occurred in 81% of amputations. A total of 23 (7%) patients required revisions of the foot while 39 (12%) patients required major amputations by 90 days. Chi-squared analysis found that toe pressure at or above the value of 47 mm Hg (P = 0.04), bi/triphasic anterior tibial (P = 0.01), and posterior tibial artery (P = 0.01) waveforms were associated with wound healing. When these diagnostic parameters were examined in the presence of confounders (increasing age, chronic kidney disease, and concomitant revascularization), only toe pressure ≥ 47 mm Hg predicted amputation site healing (odds ratio: 3.1 [95% CI: 1.0-9.4], P = 0.04).

CONCLUSION

Preamputation toe pressures of 47 mm Hg and above are associated with wound healing. No other noninvasive vascular studies predicted wound healing in the presence of confounders. Thus, toe pressures may assist in clinical decision-making and should be routinely obtained preamputation.

Outcomes after foot surgery in people with a diabetic foot ulcer and a 12-month follow-up

OBJECTIVE

The aim of this study was to retrospectively measure the outcomes of foot-sparing surgery at one year follow-up for patients with diabetic foot ulcers (DFUs). We assessed wound healing and the need for further surgery in relation to the variables that influence healing.

METHOD

Data were retrospectively collected by reviewing the electronic files of patients attending the Wound Expert Clinic (WEC). Outcomes of surgical debridement, toe, ray and transmetatarsal amputations were assessed.

RESULTS

A total of 129 cases in 121 patients were identified for inclusion. The results demonstrated that complete wound healing was reached in 52% (61/117) of the patients within 12 months. The need for additional surgery or for major amputation was 56% (n=72/129) and 30% (n=39/129) respectively. The need for an additional procedure was particularly high after surgical debridement (75%, 33/44) and transmetatarsal amputation (64%, 7/11). Risk factors for non-healing or for a major amputation were: infection (p=0.01), ischaemia (p=0.01), a history of peripheral arterial occlusive disease (p<0.01) and smoking (p=0.01). Additional findings were that not all patients underwent vascular assessment and in half of the patients there was a delay in undergoing revascularisation.

CONCLUSION

The results of the study reveal some areas for improvement including timely revascularisation and performance of multiple debridement procedures if needed in order to save a limb.

Outcomes of dysvascular partial foot amputation and how these compare to transtibial amputation: a systematic review for the development of shared decision-making resources

BACKGROUND

Dysvascular partial foot amputation (PFA) is a common sequel to advanced peripheral vascular disease. Helping inform difficult discussions between patients and practitioners about the level of PFA, or the decision to have a transtibial amputation (TTA) as an alternative, requires an understanding of the current research evidence on a wide range of topics including wound healing, reamputation, quality of life, mobility, functional ability, participation, pain and psychosocial outcomes, and mortality. The aim of this review was to describe a comprehensive range of outcomes of dysvascular PFA and compare these between levels of PFA and TTA.

METHODS

The review protocol was registered in PROSPERO (CRD42015029186). A systematic search of the literature was conducted using MEDLINE, EMBASE, psychINFO, AMED, CINAHL, ProQuest Nursing and Allied Health, and Web of Science. These databases were searched using MeSH terms and keywords relating to different amputation levels and outcomes of interest. Peer reviewed studies of original research-irrespective of the study design-were included if published in English between 1 January 2000, and 31 December 2015, and included discrete cohort(s) with dysvascular PFA or PFA and TTA. Outcomes of interest were rate of wound healing and complications, rate of ipsilateral reamputation, quality of life, functional ability, mobility, pain (i.e., residual limb or phantom pain), psychosocial outcomes (i.e., depression, anxiety, body image and self-esteem), participation, and mortality rate. Included studies were independently appraised by two reviewers. The McMaster Critical Review Forms were used to assess methodological quality and identify sources of bias. Data were extracted based on the Cochrane Consumers and Communication Review Group's data extraction template by a primary reviewer and checked for accuracy and clarity by a second reviewer. Findings are reported as narrative summaries given the heterogeneity of the literature, except for mortality and ipsilateral reamputation where data allowed for proportional meta-analyses.

RESULTS

Twenty-nine unique articles were included in the review, acknowledging that some studies reported multiple outcomes. Eighteen studies reported all-cause proportionate mortality. A smaller number of studies reported outcomes related to functional ability (two), mobility (four), quality of life (three), ipsilateral reamputation (six) as well as wound healing and complications (four). No studies related to pain, participation or psychosocial outcomes met the inclusion criteria. Subjects were typically older and male and had diabetes among other comorbidities. More detailed information about the cohorts such as race or sociodemographic factors were reported in an ad hoc manner. Common sources of bias included contamination, co-intervention, or lack of operational definition for some outcomes (e.g., wound healing) as illustrative examples.

CONCLUSIONS

Aside from mortality, there was limited evidence regarding outcomes of dysvascular PFA, particularly how outcomes differ between levels of PFA and TTA. Acknowledging that there is considerable uncertainty given the small body of literature on many topics where the risk of bias is high, the available evidence suggests that a large proportion of people with PFA experience delayed wound healing and ipsilateral reamputation. People with TTA have increased risk of mortality compared to those with PFA, which may reflect that those considered suitable candidates for TTA have more advanced systemic disease that also increases the risk of dying. Mobility and quality of life may be similar in people with PFA and TTA.

SYSTEMATIC REVIEW REGISTRATION

CRD42015029186.

[Hallux amputation]

OBJECTIVE

Debridement of infected tissue with the main aim being the re-establishment of mobilization with preservation of standing and walking ability. Prevention of secondary pressure points or amputations due to inadequate resection or deficient soft tissue cover.

INDICATIONS

In the case of increasing necrosis of the big toe, surgical abrasion and/or amputation is considered unavoidable. Other indications where surgery could be considered include diabetes and its associated angiopathies together with peripheral arterial angiopathy.

CONTRAINDICATIONS

In the case of insufficient blood supply an expansion of the resection margins should be taken into account. If there are possible alternatives to amputation. Surgery for patients with renal failure requiring dialysis associated with increased complication rate.

SURGICAL TECHNIQUE

A dorsal cuneiform resection is performed to facilitate implantation of a plantar skin transplant and wound healing. Important is the resection of bone in a slide oblique technique. Amputation scars should be outside pressure zones. Partial amputations in the area of the first ray as exarticulation or via the individual amputated segments possible (as opposed to toes 2-5).

POSTOPERATIVE MANAGEMENT

Direct postoperative weight-bearing with rigid insole and dispensing aid for 6-8 weeks. Following complete wound healing, foot support with orthopedic arch and transverse strain relief should be advocated, together with a joint roll in ready-made individual shoes.

RESULTS

Both trauma and nontrauma cases were included in our present cohort. A total of 7 cases were surgically revised in 2014 due to superficial skin necrosis that was likely the result of skin tension from the wound stitches.

[Amputation and exarticulation of the lesser toes]

OBJECTIVE

Amputations and exarticulations of the toes may be necessary due to several reasons. The goal is to remove necrosis or infection prior to its spread to the midfoot region. From a functional or cosmetic point of view, amputation/exarticulation of a single toe plays no major role. However, this can be different with exarticulation of several toes.

INDICATIONS

Necrosis, trauma, infection, tumor, deformity.

CONTRAINDICATIONS

Conditions where amputation/exarticulation of a toe is insufficient, e. g., in progressing peripheral arterial disease.

SURGICAL TECHNIQUE

The toe can either be amputated through the distal phalanx or exarticulated in the metatarsophalangeal joint.

POSTOPERATIVE MANAGEMENT

Orthopedic shoes or orthotic devices are rarely necessary when a single toe is amputated/exarticulated. However, concomitant deformities of the foot have to be thoroughly addressed. If more than one toe is amputated, silicone spacers may be necessary to prevent the remaining toes from deviating.

RESULTS

Amputations and exarticulations of the toes are frequent and the procedure is technically simple. However, the complication rate is high due to typical indications making amputation necessary.

Cost of lower-limb amputation in U.S. veterans with diabetes using health services data in fiscal years 2004 and 2010

The purpose of this study was to estimate healthcare costs associated with diabetes-related lower-limb amputations (LLAs) within the Veterans Health Administration (VHA). We performed a cross-sectional comparative analysis of 3,381 VHA clinic users in fiscal year (FY) 2004 and 3,403 clinic users in FY2010 identified as having type 2 diabetes mellitus and nontraumatic LLA. LLA expenditures related to inpatient medical, inpatient surgical, and outpatient care were estimated using VHA Health Economics Resource Center average cost files. LLA-related pharmaceutical costs were obtained from VHA Decision Support System national extract files. From the Department of Veterans Affairs (VA) perspective, the mean cost associated with care for diabetes-related LLA per patient in the VA healthcare system in FY2004 was $50,351 (95% confidence interval [CI] = 48,939-51,803) in U.S. dollars; the total cost for all 3,381 patients was $170,236,037. In FY2010, cost per patient rose to $60,647 (95% CI = 59,143-62,188), with a total cost of $206,380,331 for 3,403 patients. In the VHA healthcare system, the economic burden associated with LLAs in patients with diabetes exceeded $200,000,000 in FY2010. This suggests that further improvements in care of patients with diabetes could be associated with significant cost savings.

Diabetic foot complications in a secondary foot hospital: A clinical audit

BACKGROUND

Previous studies conducted in Australian hospital settings suggest high variability in assessments, investigations, and management of diabetic foot infections and poor adherence to widely accessible evidence-based protocols and guidelines. Diabetic foot complications require a multidisciplinary approach and often involve both medical and surgical teams during inpatient care.

AIMS

The aim of this clinical audit was to better understand the scope of diabetes-related foot complications, evaluate whether current assessment and management strategies are in line with best practice guidelines, and to formulate future models of care.

METHODS

A retrospective review of patients was carried out between 12 July 2012 and 11 July 2013. Recorded assessments of inpatient care, including risk factors, surgery, length of stay, interdepartmental referrals, and antibiotic administration were reviewed.

RESULTS

There were 24 admissions in 12 months (total patients n=19). Fifty-eight per cent of patients were admitted to the medical ward. More than one-quarter had evidence of osteomyelitis. While one patient required intensive care unit (ICU) management, there was no inpatient mortality. Two patients experienced significant delay to undergo initial surgical intervention presumably because of failed medical treatment. Clinical data was recorded poorly, especially regarding neuropathy, HbA1c, and clinical examination findings. Twelve per cent of patients did not undergo any follow-up. The average length of stay was 12 days. One-half of the cohort was not evaluated by the endocrinology department.

CONCLUSION

This audit highlights the need for improved care for patients with diabetic foot complications and better coordination among the multidisciplinary teams involved.

Autologous G-CSF-mobilized peripheral blood CD34+ cell therapy for diabetic patients with chronic nonhealing ulcer

Recently, animal studies have demonstrated the efficacy of endothelial progenitor cell (EPC) therapy for diabetic wound healing. Based on these preclinical studies, we performed a prospective clinical trial phase I/IIa study of autologous G-CSF-mobilized peripheral blood (PB) CD34(+) cell transplantation for nonhealing diabetic foot patients. Diabetic patients with nonhealing foot ulcers were treated with 2 × 10(7) cells of G-CSF-mobilized PB CD34(+) cells as EPC-enriched population. Safety and efficacy (wound closure and vascular perfusion) were evaluated 12 weeks posttherapy and further followed for complete wound closure and recurrence. A total of five patients were enrolled. Although minor amputation and recurrence were seen in three out of five patients, no death, other serious adverse events, or major amputation was seen following transplantation. Complete wound closure was observed at an average of 18 weeks with increased vascular perfusion in all patients. The outcomes of this prospective clinical study indicate the safety and feasibility of CD34(+) cell therapy in patients with diabetic nonhealing wounds.