A systematic review of scoring systems for diabetic foot ulcers

Chapter V: Diabetic foot

Ulcerated diabetic foot is a complex problem. Ischaemia, neuropathy and infection are the three pathological components that lead to diabetic foot complications, and they frequently occur together as an aetiologic triad. Neuropathy and ischaemia are the initiating factors, most often together as neuroischaemia, whereas infection is mostly a consequence. The role of peripheral arterial disease in diabetic foot has long been underestimated as typical ischaemic symptoms are less frequent in diabetics with ischaemia than in non-diabetics. Furthermore, the healing of a neuroischaemic ulcer is hampered by microvascular dysfunction. Therefore, the threshold for revascularising neuroischaemic ulcers should be lower than that for purely ischaemic ulcers. Previous guidelines have largely ignored these specific demands related to ulcerated neuroischaemic diabetic feet. Any diabetic foot ulcer should always be considered to have vascular impairment unless otherwise proven. Early referral, non-invasive vascular testing, imaging and intervention are crucial to improve diabetic foot ulcer healing and to prevent amputation. Timing is essential, as the window of opportunity to heal the ulcer and save the leg is easily missed. This chapter underlines the paucity of data on the best way to diagnose and treat these diabetic patients. Most of the studies dealing with neuroischaemic diabetic feet are not comparable in terms of patient populations, interventions or outcome. Therefore, there is an urgent need for a paradigm shift in diabetic foot care; that is, a new approach and classification of diabetics with vascular impairment in regard to clinical practice and research. A multidisciplinary approach needs to implemented systematically with a vascular surgeon as an integrated member. New strategies must be developed and implemented for diabetic foot patients with vascular impairment, to improve healing, to speed up healing rate and to avoid amputation, irrespective of the intervention technology chosen. Focused studies on the value of predictive tests, new treatment modalities as well as selective and targeted strategies are needed. As specific data on ulcerated neuroischaemic diabetic feet are scarce, recommendations are often of low grade.

The ulcerated leg: when to revascularize

The role of peripheral arterial disease in ulcerated diabetic feet has long been underestimated. Progressive claudication, rest pain and the extent of irreversible tissue loss have frequently been indications for revascularization for neuroischaemic ulcers in diabetic patients. These typical ischaemic symptoms are warning signs that are less frequent in diabetic individuals with ischaemia than those without diabetes. Consequently, 30-50% of individuals with diabetes and foot ulcers already have gangrene at admission and are therefore often considered unsuitable for revascularization. Furthermore, the healing of a neuroischaemic ulcer is worsened by microvascular dysfunction, causing arteriovenous shunting, capillary ischaemia, leakage and venous pooling. Therefore, the threshold of revascularizing neuroischaemic ulcers should be lower than that of purely ischaemic ulcers. Comorbidity, ulcer characteristics and infection affect the decision as to when to intervene, as do the severity and extent of occlusive arterial lesions. The window of opportunity for vascular intervention in the neuroischaemic diabetic foot should not be missed, and the need for early vascular intervention as an integrated part of a strategy to achieve healing should be emphasized. Noninvasive vascular testing should be performed on all individuals with an ulcerated diabetic foot. The arterial tree should be imaged if noninvasive tests indicate ischaemia or when mild or questionable ischaemia is diagnosed and conservative treatment does not promote ulcer healing in 6 weeks. Revascularization should be performed whenever feasible to repair distal perfusion to achieve ulcer healing.

A systematic review of the effectiveness of revascularization of the ulcerated foot in patients with diabetes and peripheral arterial disease

In several large recent observational studies, peripheral arterial disease (PAD) was present in up to 50% of the patients with a diabetic foot ulcer and was an independent risk factor for amputation. The International Working Group on the Diabetic Foot therefore established a multidisciplinary working group to evaluate the effectiveness of revascularization of the ulcerated foot in patients with diabetes and PAD. A systematic search was performed for therapies to revascularize the ulcerated foot in patients with diabetes and PAD from 1980-June 2010. Only clinically relevant outcomes were assessed. The research conformed to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, and the Scottish Intercollegiate Guidelines Network methodological scores were assigned. A total of 49 papers were eligible for full text review. There were no randomized controlled trials, but there were three nonrandomized studies with a control group. The major outcomes following endovascular or open bypass surgery were broadly similar among the studies. Following open surgery, the 1-year limb salvage rates were a median of 85% (interquartile range of 80-90%), and following endovascular revascularization, these rates were 78% (70.5-85.5%). At 1-year follow-up, 60% or more of ulcers had healed following revascularization with either open bypass surgery or endovascular revascularization. Studies appeared to demonstrate improved rates of limb salvage associated with revascularization compared with the results of medically treated patients in the literature. There were insufficient data to recommend one method of revascularization over another. There is a real need for standardized reporting of baseline demographic data, severity of disease and outcome reporting in this group of patients.

A systematic review of interventions to enhance the healing of chronic ulcers of the foot in diabetes

The outcome of management of diabetic foot ulcers is poor, and there is continuing uncertainty concerning optimal approaches to management. It was for these reasons that in 2006 the International Working Group of the Diabetic Foot (IWGDF) working group on wound healing undertook a systematic review of the evidence to inform protocols for routine care and to highlight areas which should be considered for further study. The same working group has now updated this review by considering papers on the interventions to improve the healing of chronic ulcers published between December 2006 and June 2010. Methodological quality of selected studies was independently assessed by two reviewers using Scottish Intercollegiate Guidelines Network criteria. Selected studies fell into the following ten categories: sharp debridement and wound bed preparation with larvae and hydrotherapy; wound bed preparation using antiseptics, applications and dressing products; resection of the chronic wound; hyperbaric oxygen therapy (HBOT); compression or negative pressure therapy; products designed to correct aspects of wound biochemistry and cell biology associated with impaired wound healing; application of cells, including platelets and stem cells; bioengineered skin and skin grafts; electrical, electromagnetic, lasers, shockwaves and ultrasound; other systemic therapies which did not fit in the above categories. Heterogeneity of studies prevented pooled analysis of results. Of the 1322 papers identified, 43 were selected for grading following full text review. The present report is an update of the earlier IWGDF systematic review, but the conclusion is similar: that with the exception of HBOT and, possibly, negative pressure wound therapy, there is little published evidence to justify the use of newer therapies. This echoes the conclusion of a recent Cochrane review and the systematic review undertaken by the National Institute for Health and Clinical Excellence Guidelines Committee in the UK. Analysis of evidence presents considerable difficulties in this field particularly as controlled studies are few and the majority are of poor methodological quality.

[Diabetic foot syndrome]

Diabetic foot ulceration is a serious complication of diabetes mellitus worldwide and the most common cause of hospitalization in diabetic patients. The etiology of diabetic foot ulcerations is complex due to their multifactorial nature. The pathophysiologies of diabetic foot ulceration with polyneuropathy and angiopathy as well as wound-healing impairment in patients with diabetes mellitus are important. Proper adherence to standard treatment strategies and interdisciplinary cooperation can reduce the--compared with European data--noticeably higher rates of major amputations in Germany.

Factors related to outcome of neuroischemic/ischemic foot ulcer in diabetic patients

OBJECTIVES

Peripheral vascular disease (PVD) is an important limiting factor for healing in neuroischemic or ischemic diabetic foot ulcer. The purpose of this study was to identify factors related to healing in patients with diabetes with foot ulcers and severe PVD.

METHODS

Patients with diabetes with a foot ulcer, consecutively presenting at a multidisciplinary foot center with a systolic toe pressure <45 mm Hg or an ankle pressure <80 mm Hg were prospectively included, followed according to a preset program, and with the exception of specified exclusions, subjected to angiography offered vascular intervention when applicable. All patients had continuous follow-up until healing or death irrespective of the type of vascular intervention.

RESULTS

One thousand one hundred fifty-one patients were included. Eighty-two percent had a toe pressure <45 mm Hg and 49% had an ankle pressure <80 mm Hg. Eight hundred one patients (70%) underwent an angiography. Out of these, 63% had vascular intervention, either percutaneous transluminal angioplasty (PTA; 39%) or reconstructive surgery (24%). Nine percent of the patients had one or more complications after angiography. PTA was multisegmental in 46% and to the crural arteries in 46%. Reconstructive surgery was distal in 51%. Age (P < .001), renal function impairment (P = .005), congestive heart failure (P = .01), number and type of ulcer (P < .001), and severity of PVD (P = .003) affected the outcome of ulcers. PTA and reconstructive vascular surgery increased the probability of healing without amputation (odds ratio [OR], 1.77 and 2.05, respectively).

CONCLUSION

Probability of ulcer healing is strongly related to comorbidity, extent of tissue involvement, and severity of PVD in patients with diabetes with severe PVD.