A rational approach to ischemic and ischemic-diabetic foot reconstruction

A RATIONAL APPROACH TO ISCHEMIC AND ISCHEMIC-DIABETIC FOOT RECONSTRUCTION JOSEPH C. BANIS, JR, MD, JOHN W. DERR, JR, MD, and J. DAVID RICHARDSON, MD

Microsurgical techniques have been well documented to be of great use in reconstruction of post-traumatic defects of the lower extremity. The same techniques are also increasingly useful in reconstruction for chronic atherosclerotic disease of the lower extremities. Extremely small, heavily calcified vessels can be reliably reconstructed using delicate microsurgical techniques and high magnification. Additionally, revascularization followed by microsurgical free tissue transfer has proven to be a valuable alternative to amputation in patients with major soft tissue loss, or bony or tendon lesions requiring soft tissue reconstruction. Although this is an elderly population with a high number of comorbid risk factors, limb salvage can be obtained with a very low morbidity and mortality when carried out in a closely coordinated approach with the appropriate medical and surgical specialists. Microsurgical techniques have greatly expanded the number of patients that can be offered vascular reconstruction, including patients with severely calcified and tiny vessels (1 mm outflow vessels being routinely successful). Minor modifications in microsurgical technique (working with heavy calcification, presence of atherosclerotic plaques) allow these techniques to be applied to the chronic atherosclerotic and diabetic patient population, thus affording broadened horizons of reconstructive possibilities to these patients. Copyright 9 1997by W.B. Saunders Company KEY WORDS: diabetes, ischemia, atherosclerosis

Ischemia of the lower extremities as a result of atherosclerotic occlusive disease remains a major clinical problem, particularly in the aging and diabetic population. The problems associated with this disease cause significant morbidity, including claudication, ischemic rest pain, and nonhealing ulcerations. The consequences of these problems range from modest inconvenience and limitation of activities to major limb loss, long-term institutionalization resulting from loss of functional independence, and mortality. Diabetes accounts for the majority of the consequences and complications of ischemia of the lower extremity, with many series citing 55% to 75% preponderance of diabetics requiring arterial bypass reconstruction of the lower extremity. Approximately 14% of diabetics are hospitalized an average of six weeks per year for foot problems, and more than 80% of major amputations are in the diabetic population. Below-the-knee amputations are problematic because

From the Derr Center for Plastic Surgery, Louisville, KY. Parts of this article were adapted from Banis JC Jr, Richardson JD, Derr JW Jr, Acland RD: Microsurgical adjuncts in salvage of the ischemic and diabetic lower extremity. Clinics in Plastic Surgery 19:881-893, 1992 Address reprint requests to Joseph C. Banis, Jr, MD, Derr Center for Plastic Surgery, 100 E Liberty St, Suite 600, Louisville, KY 40202. Copyright 9 1997 by W.B. Saunders Company 1071-0949/97/0404-001655.00/0

of the rehabilitation and increased energy usage required, and above-the-knee amputations, which are also frequently necessary, require an almost prohibitive amount of energy for satisfactory use from most of these elderly patients. There is an expectation of approximately 10% annual loss of the contralateral leg, further jeopardizing the patient's independence. I-s The obvious problems associated with the consequences of lower extremity arterial occlusive disease account for the aggressive approaches and large volume of arterial bypass reconstructions being carried out in many centers to interrupt the progressive deterioration and threatened limb loss in these patients. We describe a rationale for a physiological approach to reconstruction of the ischemic lower extremity. This approach is best conducted in a close collaborative setting with the primary care physician or internist who thoroughly evaluates the patient's metabolic ability to safely withstand a series of surgical procedures, the vascular laboratory and interventional radiologists who help obtain the most detailed and complete physiological and anatomic diagnosis of the degree and sites of ischemia/stenosis, and the peripheral vascular and microsurgical-plastic-reconstructive surgical teams, to optimally carry out the appropriate procedure(s). Because of the severity of vascular disease, calcification, and small diameter vessels, microsurgical techniques have

Operative Techniques in Plastic and Reconstructive Surgery, Vol 4, No 4 (November), 1997: pp 217-235

217

Fig 1. Case one: (A) 18-year-old insulin-dependent diabetic man with severely infected necrotic wound of the right dorsal lateral foot. (B) Following serial debridement until clean, followed by latissimus dorsi muscle free flap transfer. (C) Skin graft with poor maturation of graft 2 weeks postoperatively. (D) Slowly improving maturation of skin graft 6 weeks postoperatively. (E) Mature, stable skin graft appearance of foot 18 months postoperatively. (F) Patient ambulatory 2 years postoperatively.

played a major positive role in achieving a successful outcome. 6-9

defects. The solution to this interdisciplinary problem, then, is approached by drawing on the most aggressive modalities available pertaining to the vascular and soft. tissue reconstructive arenas of specialization.

THE PHYSIOLOGICAL BASIS FOR LOWER EXTREMITY AMPUTATIONS Amputations of the lower extremity occur for one or more of three basic reasons: (1) the presence of nonreconstructible (severely calcific, stenotic, end stage) occlusive arterial lesions; (2) a failed attempt at arterial reconstruction; and (3) the presence of nonreconstructible defects of functionally critical areas of soft tissue, tendon, or bone. These conditions may pertain to the patient with atherosclerotic disease alone. They are particularly problematic when seen in the diabetic due to the increased severity and distal location of arterial disease, and recognized w o u n d healing compromise typical of diabetics. In conceptual terms, amputations occur because of failure to achieve satisfactory arterial supply, or inability to reconstruct tissue

218

DIABETIC WOUNDSNWHY WON'T THEY HEAL? When one analyzes the problems associated with healing of diabetic wounds, several factors stand out that identifiably compromise healing: (1) chronic severe bacterial colonization; (2) osteomyelitis; (3) wounds with bone and tendon involvement (ie, complex-compound wounds); (4) severe w o u n d fibrosis and local wound ischemia, even in the presence of normal macrovascular blood supply; and (5) diabetic microvascular disease, x~ The cause of these problems is generally related to (1) poor blood supply (macrovascular); (2) pressure points

BANIS, DERR, AND RICHARDSON

THE CHRONIC ULCERATED FOOT: A TREATMENT ALGORITHM THOROUGH PHYSICAL EXAM - Pulses, lschemic Signs - R i s k Factors (Diabetes, Nutrition, Etc.)

I

I I

I

I..ouD=eoor

9

9M A J O R E V I D E N C E I S C H E M I A -no pulse -rubor -skin atrophy -claudicafion -rest pain I

9M A R G I N A L V A S C U L A R DISEASE: QUESTIONAL ISCHEMIA -one vessel palpable I + -no rest pain -no claudication

9NO EVIDENCE ISCHEMIA -one or both DPA+ PTA pulses 2+

I

I

Diabetic

I.Non-Diabetic I 9Local wound care 9Skin Grafts 9Skin Flaps (pedlcled) 9Muscle Flaps (pedicled) 9Free Flaps

IVascular W/U :~ I ABI >0.6

I Vascular Workap ~1

I wcu~ w~ * I

ABI <0.6

ABI< 0.80 ABI >0.8

CAUTION!H

I

9L o c a l

OPTIMIZE ALL POSSIBLE HEALING PARAMETERS -PERFUSION -NUTRITION 9BLOOD SUGAR

I P.OCE o

T

Wound Care

+ 2~Healing 9Skin grafts I If Pedicied or Free Flaps Required

-Angiogram [ -Confwm ABI[ CAUTION Rarely[ Good Perfusion in [ Face of Clinical [ " ~ ' ~ l s c h e ~ -

I

l

l

!

IFINAL C O M M O N P A T H W A Y T O L I M B S A L V A G E - H E A L T H Y P E R F U S I O N iI VASCULAR WORKUP

-Diabetes -Steroid Dopendancy

-Doppler Arterial Studies

-Collagen Vasc Disease

-TcPOz (?)

-Arteriogram

-Uremic -Nutritional Depletion

Fig 2. Algorithm for the treatment of the ulcerated foot.

secondary to orthopaedic deformities, Charcot Foot deformities, and hyperkeratotic areas resulting in repeated local pressure and trauma; (3) neuropathic conditions resulting in repeated unrecognized trauma in the insensate foot; and (4) poor metabolic control of the underlying diabetic condition.4:1-14 Of these causal deficits, the only issue we can definitively and reliably address is that of the macrovascular blood supply. We currently have relatively little understanding of or ability to deal with the problems of the Charcot Foot, severe orthopaedic deformities, longitudinal and transverse bony arch collapse, or repeated unrecognized foot trauma caused by neuropathic problems. The current best method of dealing with these particular problems is that of constant vigilance, early wound care when any minor wounds develop, protection of the feet in orthotic-fitted, well-protected footwear, and education of the patient to be alert to these problems. Further, although there is increasing evidence suggesting that tightly man'aged diabetic metabolic control will help facilitate wound healing when wounds do occur, achieving patient compliance for long-term management is often difficult or impossible. It seems clear, however, that the one very prominent physiological factor that surgeons can optimize is that of ensuring the macrovascular blood supply is normal or maximal. It is then hoped that with optimization of the

ISCHEMIC AND ISCHEMIC-DIABETICFOOT RECONSTRUCTION

macrovascular blood supply, some of the other mechanical and physiological deficiencies will be ameliorated and certainly not compounded) s-21

DIAGNOSIS The patient with strictly atherosclerotic arterial occlusive disease, under appropriate medical treatment, will rarely have surgically nonreconstructible disease leading to an amputation. This type of patient should have any small lesions or nonhealing wounds evaluated quickly by his primary care physician, who would then institute or refer the patient for further vascular workup. Any necessary vascular reconstructive intervention can be carried out in a timely fashion so as to obviate the need for any more complex or destructive procedures. Patients with ischemia and ulcerations that put them at risk for amputations almost invariably have concomitant risk factors, such as diabetes mellitus, collagen vascular disease, or uremia. 22 The physical examination is the most critical part of the diagnostic evaluation. Signs of ischemia such as skin atrophy, absence of hair growth, the presence of poorly healing abrasions, cracks and fissures of the leg and foot, and dependent rubor denoting a slow circulatory time in the foot, all suggest ischemia. A thorough examination for

21 9

Fig 3. Case two: (A) necrotic right first toe in a 75-year-old insulin-dependent diabetic man. (B) Arteriograms showing occlusive disease at the level of the ankle junction of the anterior tibial artery and the dorsalis pedis artery (arrow). (C) Arteriotomy bridging the occlusive lesion at the anterior tibial artery (ATA) and dorsalis pedis artery (DPA) junction (arrow). (D) Long ("patch angioplasty") anastomosis (30 ram),

pulses should be made, including the femoral, popliteal, dorsalis pedis, and posterior tibial arteries. This must be done with the examiner's body and hand in a comfortable position so as to optimally allow detection of pulses, which are graded on a 0, 1+, and 2+ basis. An absent or questionable pulse would be graded as a 0, with a 1 + being a clearly identifiable but diminished pulse, and a 2 + being a full, normal pulsation. If a 2 + pulse is not palpable in at least one of the pedal vessels, the diagnosis of clinically significant arterial occlusive disease (but not necessarily ischemia) is presumed. The forefoot circulation usually collateralizes well with the hindfoot circulation through the pedal arch. In a small number of cases, the arch is so compromised by distal occlusive vascular disease that the forefoot and hindfoot vascularity is totally segmented, in which case a good pulse in one or the other vessel may not presume good blood supply collateralizing to the other portion of the foot. If a presumptive diagnosis of clinically

220

significant ischemia (not just atherosclerotic disease) is made, a Doppler noninvasive arterial study is indicated to darify the physiological parameters of flow. Although this test is used as a routine part of the vascular workup, it is notoriously fraught with inaccuracy and spurious results because of the high incidence of severely calcified noncompressible vessels leading to falsely high Doppler indices. Therefore, low Doppler indices will confirm a clinical diagnosis of ischemia, whereas normal Doppler indices in the face of clinical evidence of ischemia do not rule out ischemic disease; rather, it may paradoxically confirm, by its spurious elevation, the severity of calcific disease. Transcutaneous oxygen measurement may confirm ischemic disease as well or better than Doppler indices in the diabetic. 23 It follows that, whether the clinical exomination is corroborated or contradicted by the Doppler examination, the next step in workup will be the arteriogram. The

BANIS, DERR,AND RICHARDSON

Fig 4. (A) Necrotic tendo Achillis wound in a 71-year-old diabetic man, following the use of new footwear. (B) Digital subtraction angiogram of the tibia, with diffuse vascular disease.

importance of an accurate physical examination is underscored by this fact. The decision to proceed with an arteriogram should be based on a clear expectation of benefit to the patient of potentially undergoing a vascular reconstructive intervention. If the patient is not deemed medically suitable, or is not expected to have the rehabilitation potential to benefit from limb salvage, there is no point in undergoing this procedure, even given its relative safety. Thorough consultation with the patient, the family, the primary care physician, and the rehabilitation physician is advisable to ascertain the patient's potential for rehabilitation in the event that the limb can be salvaged. Situations occur where salvage of a single limb in a nonambulatory patient with a contralateral amputation is sometimes deemed sufficient reason to proceed with a limb salvage procedure, solely to allow the patient to stand and pivot out of bed and into a wheelchair. This capability may allow him to maintain his independent, noninstitutionalized status with the help of spouse, family, or caretakers. At this point, simultaneous priorities of thoroughly ascertaining the patient's medical condition (eg, cardiac, renal or cerebrovascular disease) and vascular status become critical, with key relative factors being that the angiographic picture and chances for surgical success may affect judg-

ISCHEMIC AND ISCHEMIC-DIABETIC FOOT RECONSTRUCTION

ments regarding relative surgical risk for a patient with a particular medical condition, and vice versa. The arteriogram should include proximal aortic and renal artery visualization, with distal flushes including the noninvolved as well as the involved extremity. It is important to discuss arteriographic needs with the radiologist to ensure that satisfactory visualization of the pedal arch is achieved. This may require digitally enhanced vascular imaging and subtraction studies to properly see these very distal vessels. It is important to keep the patient well hydrated, and minimize the amount of dye load if any evidence of renal compromise is present. Duplex imaging studies for the presence and satisfactory caliber of the greater and lesser saphenous venous systems is useful as a preoperative study. However, this examination has not been absolutely diagnostic in identifying whether veins are adequate for use as bypass segments.

TREATMENT ALGORITHM The patient with no evidence of vascular disease on clinical examination, or the patient who has been worked up and found to have no significant vascular disease can be treated

221

Fig 5. Case one: (A) 60-year-old white insulindependent diabetic man with ischemic infected right heel wound after revascularization, involving tendo Achilles and calcaneus before definitive debridement. (B and C) Two months after rectus abdominis muscle free flap reconstruction (native dorsalis pedis artery distal to bypass graft as recipient vessel) and skin graft reconstruction.

with the usual reconstructive armamentarium for wounds of the leg and foot. These include local w o u n d care and expectant healing, skin grafts, local flaps, or microsurgical free tissue transfer, which is particularly useful in the distal third of the leg and foot. 7 Every attempt is made to use plantar skin and plantar skin grafts for reconstruction of the

222

sole of the foot, employing the principle of reconstructing an area with tissue from a like area to optimize functional results. For patients who present with large infected wounds involving soft tissue, tendon, or bone, but who have evidence of satisfactory vascular anatomy and perfusion, free tissue transfer can be used.

BANIS, DERR, AND RICHARDSON

Fig 6. (A) Necrotic tendo Achilles wound in a 71-year-old diabetic man, following the use of new footwear. Notice absence of any venous filling in posterior calf. (B) Poor angiograms sent with patient on original consultation. (C) Digital subtraction angiogram of the tibia, with diffuse vascular disease. (D) Digital subtraction angiogram of the ankle and foot, showing posterior tibial artery (PTA) reconstitution through peroneal artery collateral vessels. (Continued on following page.)

Free tissue transfer techniques are ideal in these situations because: (1) they are able to resurface any size defect; (2) they allow aggressive resection of the ulcer to rid the liffnb of heavily colonized, fibrotic, unhealthy tissue; (3) the flap actually helps revascularize the defect; and (4) the defect is replaced with healthy nondamaged tissue that can then be protected, reversing a trouble-prone situation with a chronic wound and a propensity for repeated breakdown. For extremely large or complex wounds that are not

ISCHEMIC AND ISCHEMIC-DIABETIC FOOT RECONSTRUCTION

expected to be healed readily or are not amenable to local techniques, free flap transfer has been successful in obtaining healed wounds and salvaging the foot, thereby maintaining bipedal ambulation. Free flap reconstruction of major defects of the diabetic foot has been carried out 17 times in our unit with 88.2% primary and 100% secondary success in the flap transfer, complete healing of all wounds, and complete salvage of the foot. This experience has been duplicated in several other units dealing with these problems.25-27

223

E

.... -

\-,,.

Fig 6. (cont'd) (E) Heavily calcified vessel with l-ram internal luminal diameter into which arteriotomy has been created. Note irregularity and calcification of vessel wall. (F) Backwall-intimal damage, with one half of distal anastomosis opened. (G) Necrotic, mummified, left tendo Achilles defect 2 weeks after revascularization. Note excellent filling of the short saphenous vein. (H) Debrided, well-vascularized wound after revascularization. (Continued on facing page.)

CASE STUDY ONE Case one is that of a 60-year-old Caucasian insulindependent diabetic man with an ischemic infected pressure ulceration of the right heel, involving calcaneus and tendo Achilles. The patient underwent a femoral-proximal anterior tibial artery bypass graft, after which time the ulceration started showing some evidence of healing capacity, at which time rectus abdominis muscle free flap was carried out and covered with skin graft. He healed well, and continued long-term independent ambulation on the foot (Fig 1). This patient typifies our experience with free flap reconstruction in diabetics, who have shown excellent ability to undergo reconstruction with free tissue transfer techniques, and who derive long-term benefit from this intervention. The accompanying treatment algorithm for the ulcerated foot (Fig 2) emphasizes that the first issue that must be

224

addressed in treating ulcerated feet is perfusion. Several points have become clear in regard to this issue: (1)" the nonischemic foot can be treated with the usual armamentarium of reconstructive techniques, with good expectation of success. (2) Marginal ischemia in the nondiabetic allows secondary wound healing and use of skin grafts, but will require revascularization if pedicle or free flaps are to be reliably utilized. (3) Marginal ischemia is incompatible with reliable expectation of healing in the diabetic ulceration, and any detectable degree of ischemia must be corrected by revascularization. Hyperbaric oxygen therapy plays a clearly helpful but currently unquantified role in healing some ulcers in the diabetic population. (4) Patients with clear evidence of significant ischemia--absence of pulses, trophic changes of the skin, poor hair growth, dependent rubor, claudication or rest pa~n--categorically require revascularization to allow secondary wound heal-

BANIS, DERR, AND RICHARDSON

Fig 6. (Cont'd) (I) Scapular flap pattern. (J) Scapular flap revascularized and sutured into posterior ankle defect. (K) 18 months after revascularization procedure and scapular free flap reconstruction ankle. Patient has normal ambulation. (L) Postoperative angiogram showing marked improvement in the quality and diameter of the posterior tibial artery distal to the vein bypass graft, with the circumflex scapular artery originating proximally from the vein bypass graft. (M) Four years later, at age 75, the patient shows evidence of ischemia of the contralateral right foot with gangrenous changes right first toe. Preop for distal revascularization right lower extremity.

ing or primary wound healing by the aforementioned reconstructive techniques. In these patients with clinical signs of significant ischemia, the Doppler noninvasive arterial studies usually play a minor role in the decision whether or not to revascularize, and the major issue is that Of obtaining a very detailed arteriogram to achieve a good "road map" that will allow the most accurate anatomic planning for revascularization surgery. Transcutaneous oxygen (TcPOa) measurements have been documented to be of value in selection of patients for revascularization, and may aid also in the selection of

ISCHEMIC AND ISCHEMIC-DIABETIC FOOT RECONSTRUCTION

marginal patients that may benefit from hyperbaric oxygen therapy. 23

TREATMENT OF ARTERIAL OCCLUSIVE DISEASE OF THE LOWER EXTREMITY The patient with severe ischemia of the lower extremity resulting from atherosclerotic disease is approached with the objective of establishing an optimal macrovascular blood supply with the highest degree of reliability and

225

D

Ii ,

U

C,

2 i

Fig 7. This 34-year-old white insulin-dependent juvenile-onset diabetic woman presents with a chronic nonhealing ulceration for consideration for amputation salvage right lower extremity. (A and B) Indolent, nonhealing wound right heel, to calcaneus. No healing capability, with poor evidence of vascularity. (C) Digital subtraction arteriography showing tapering off and loss of significant vascularity in the mid and distal calf, with (D) no really "good" anterior tibial or dorsalis pedis'vessel noted. (E) Vascular calcifications in plantar arch suggest severely calcified vessels and medial calcific disease. (F) External luminal diameter of approximately 2.5 mm, note vascular calcifications visible through vessel wall. 226

SANIS, DERR, AND RICHARDSON

Fig 7. (Cont'd) (G) Popliteal to anterior tibial reversed saphenous vein bypass graft. Note patulous popliteal "patch angioplasty" anastomosis. (H) Early healing skin graft on plantar aspect of calcaneus I month postoperatively. (I and J) Quality of right heel 4 years postoperatively, after revisions and plantar flaps to obtain satisfactory weight bearing heel surface. (K) The patient maintained a full and active lifestyle, including wearing boots and horseback riding, until her death approximately 6 years after her operation.

ISCHEMIC AND 1SCHEMIC-DIABETICFOOT RECONSTRUCTION

227

Fig 8. This 30-year-old white insulin-dependent juvenileonset diabetic man with a renal transplant presented with severe ischemic disease and necrosis of his left great toe 4 months after a similar problem and limb salvage on his right foot. (A) Digital subtraction angiography showing severe disease in the left anterior tibial artery (ATA) at ankle, showing no clearly "good" distal vessels (ATA or PTA). (B) Distal ATA above ankle with severe intimal calcification. Note irregular adventitia and media, with calcific disease, after partialthickness arteriotomy; intima is still intact. Medial calcification required delicate "cracking-morselization" with clamp to allow microvascular clamp hemostatic control of vessel during anastomosis. (C) Perfusion in patient following femATA bypass graft to dorsalis pedis artery graft for severe occlusive disease at ankle level. Successful CFA-ATA bypass did not produce enough collateral flow across the ankle to heal his gangrenous toe lesion. Across ankle bypass graft to dorsalis pedis artery (DPA) ultimately successful, with longterm patency now at 9 years.

expectation of success. The primary underlying thesis is that satisfactory reperfusion is essential for wound healing to occur and to achieve limb salvage. Once satisfactory revascularization has been achieved, the surgeon can then treat the wounds with well-established and effective surgical and wound care algorithms to achieve healing.

228

Proximal large vessel vascular disease can frequently be treated with angioplastic techniques with a moderately good chance of success and with a great advantage of surgical noninvasiveness. When vascular disease involves the vessels of the popliteal artery and tibiol~eroneal vessels, as is frequently the case in the diabetic, surgical distal

BANIS, DERR, AND RICHARDSON

Fig 9. This 67-year-old white woman required a CFA-ATA bypass graft, which was successful but with residual of persistent indolent, poorly healing wounds of the left medial malleolus (vein-graft donor site) and incision at the ankle (distal anastomotic site). (A and B) Medial malleolar, anterior ankle areas of indolent wound healing after femoral-anterior tibial bypass to ankle. Now status post distal graft to lateral tarsal artery (1-mm external diameter), to bypass disease at ankle level. Original CFA-ATA vein graft shown to ankle, with secondary graft to lateral tarsal artery shown to foot. (C and D) Healed ulcerations medial malleolus, anterior ankle. (E) Schematic of vascular reconstruction architecture postoperatively. All vessels palpable, with excellent pulses. Foot warm with good perfusion I year postoperation.

ISCHEMIC AND ISCHEMIC-DIABETICFOOT RECONSTRUCTION

229

Fig 10. This middle-aged and diabetic man had ischemic rest pain and rubor of his forefoot, with identification of an excellent arterial tree down to the ankle, but severe across ankle occlusive disease. Schematic distal anterior Ubial artery to distal dorsalis pedis artery reversed saphenous vein bypass graft I year postoperatively. The patient is asymptomatic with warm foot and no ulcerations.

revascularization is indicated. In cases where revascularization is based on a proximal vessel such as the common femoral artery, a two-team approach is used--the expertise of the peripheral vascular team as well as the microsurgical team. In very distal revascularization, such as to the distal leg, ankle, and pedal vessels, a purely microsurgical approach may be indicated based on the quality of vessels expected or identified. 8,28,29

A PHYSIOLOGICAL RATIONALE FOR MICROSURGICAL REVASCULARIZATION A long-standing misperception has prevailed with regard to the potential for revascularization in patients with severe atherosclerotic peripheral vascular disease of the lower extremities. The perception is that these patients either cannot be revascularized, or can be reconstructed only with a very low degree of success and high morbidity.

230

There are two major reasons for this prevalent misunderstanding: (1) angiographic techniques previously have not been of satisfactory sensitivity to adequately identify and clearly delineate the small distal vessels of the leg and foot; and (2) even if the vessels could be clearly identified, surgical techniques were not sufficiently refined to allow reliable vascular reconstruction. It is axiomatic that in severe arterial occlusive disease, if blood cannot get beyond an obstruction, angiographic dye will similarly be unable to easily pass this same obstruction to allow filling and visualization of the distal diseased macrovasculature. This also explains why a Doppler signal may not be present in a distal vessel which may actually have minimal flow, but is nonetheless patent and available as a distal outflow vessel. However, these conditions do not indicate that no vessel lumen is present, and it is incumbent on the surgeon to ensure that these pathophysiological flow conditions do not obscure or prevent him or her from identifying a potentially reconstructible vessel (one with a good lumen and outflow) simply for lack of good identifiable evidence of vessel presence by the preoperative evaluation and workup examinations discussed above. It is clear that, notwithstanding the inability to identify a good Doppler signal or to see angiographic dye fill vessels distal to an arteriosclerotic occlusion, all living tissues must have blood supply and are being perfused, albeit in a marginal fashion. This understanding dictates the recognition that some vessels must be open. It has been our reasonably consistent finding that these vessels are of a size that, using microsurgical techniques, reconstruction can be achieved with a high degree of reliability. With this very aggressive approach to preoperative diagnosis and candidacy for reconstruction, we find that only 2% to 3% of patients presenting with limb salvage considerations cannot be reconstructed. Further, as our colleagues in the primary care specialties become more acquainted with the optimistic outlook for many of these previously denied "unreconstructible" situations, we are seeing less-severe soft tissue defects that lend themselves to a better functional outcome and less need for reconstructive measures other than the revascularization.

CASE STUDY TWO Severe distal occlusive vascular disease has produced a major soft-tissue and tendonous defect that will first require revascularization of the extremity, followed by microsurgical free flap reconstruction of the defect. J.H. is a 71-year-old insulin-dependent diabetic man with necrotic changes of his left tendo Achilles that developed after using new footwear. Preoperative angiographic workup identified severe tibial-peroneal occlusive disease, with essentially no significant satisfactory vasculature identified in the below-knee area. On-table angiogram identified a very small posterior tibial artery to which revascularization was attempted. A reversed saphenous vein bypass graft was carried out (with microscope magnification for the distal anastomosis) to a 1-mm internal-diameter heavily calcified vessel, the posterior tibial artery. Even under these

BANIS, DERR, AND RICHARDSON

Fig 11. Diabetic man with chronic renal insufficiency, bordering on requiring dialysis, who could not heal a medial calcaneal ulceration. Forefoot vasculature was satisfactory with good perfusion of the forefoot, but severe occlusive disease and an incomplete pedal arch prevented perfusion of the hindfoot. Proximal posterior tibial artery was occluded. (A) Note hyperkeratotic areamscarring right medial calcaneal area bordering on weight-bearing surface. Note very slight bulge irregularity in instep area--anterior ankle where vein bypass graft communicates with anterior tibial artery. (B) Schematic showing bypass graft from anterior tibial artery to posterior tibial artery reperfusing hindfoot, allowing healing of chronic wound.

optimal conditions, an intimal tear was created that required a U-stitch to control. Microsurgical revascularization was successful, and 2 weeks after revascularization, the necrotic w o u n d of his tendo Achilles area (which was preserved in a mummified condition with a povidoneiodine dressing before revascularization and throughout the period following revascularization before debridement) was then excised. Reconstruction was carried out using a scapular fasciocutaneous free flap revascularized directly to the arterialized vein graft constructed 2 weeks previously. This healed in a satisfactory fashion, and the patient has had a long-term satisfactory result, with maintenance of a healed w o u n d and continued ambulation on an essentially normal foot (Fig 3).

DISCUSSION Our experience with 17 free flaps for treatment of major wounds of diabetic lower extremities and use of microsurgical technique in over 200 distal vascular reconstruction

ISCHEMIC AND ISCHEMIC-DIABETIC FOOT RECONSTRUCTION

procedures suggests a large role for microsurgical techniques in vascular and flap reconstruction in the ischemic lower extremity. The major issues to be addressed are related first to diagnosis and workup, enabling the surgeon to preoperatively identify a useful distal vessel for revascularization, and secondly to be possessed of sufficiently precise surgical (microsurgical) techniques that will allow for reliable success in anastomosis of whatever size or quality vessels may be available in the distal extremity. It is probably accurate to say that, although microsurgical techniques per se are strictly necessary in less than a majority of these cases (15% to 30%), it is difficult if not impossible to know exactly in which cases these critical capabilities will be necessary for the success of the procedure. The University of Louisville series of microsurgical distal revascularization in ischemic extremities showed a better than 90% rate of early success in an unselected, all-patients-considered series. These included patients with vessels that could not be radiographically visualized or Doppler localized preoperatively. Long-term follow-up

231

Y

Fig 12. Elderly diabetic gentleman with gangrenous changes of his toe requiring revascularization, at level of posterior tibial bifurcation. (A) Posterior tibial artery and vein with branching at bifurcation distal to medial malleolus. (B) Arteriotomy, approximately 14 mm, note severe calcific disease in media. (C) Large spatulation of vein graft, using a branching point--tributary of the vein graft as the "heel" to facilitate anastomosis and tension free suturing ("Flange" technique).

s h o w s a v e r y small rate of occlusion, and an even smaller rate of limb loss when the graft has been patent for even 2 to 3 m o n t h s . Therefore, it is our policy to approach these cases o f distal vascular reconstruction in a two-team peripheral vascular surgical-microsurgical approach, believing this affords the patient the best of all of the specialists' expertise. Peripheral vascular surgeons are working well within their comfort zone in proximal vessels, and micros u r g e o n s similarly are working well within their comfort zone (or as much as possible) in the distal vessels. O n c e the extremity has been revascularized, the most appropriate method of reconstruction can be carried out for ulcerative defects of the foot in a well-vascularized limb. Microsurgical free flap transfer techniques of reconstruction of appropriate defects is recommended, as demonstrated b y our and others' experience (Figs 1 and 6). 6'28 w i t h o u t initial revascularization, however, all but the most fortuitous reconstructive attempts are doomed to failure.

SUMMARY Revascularization of distal occlusive disease in the diabetic has b e e n markedly enhanced by microsurgical techniques. Extremely small, heavily calcified vessels are able to be reliably reconstructed using delicate microsurgical techniques a n d high magnification. Additionally, revascularization followed by microsurgical free tissue transfer has

232

proven to be a valuable alternative to amputation in patients with major soft tissue loss, or bony or tendon lesions requiring soft tissue reconstruction. Although metabolic risks are potentially high, we have experienced a very low morbidity and mortality with a thorough medical workup and follow-through in conjunction with these major procedures. It is our expectation that judicious application of microsurgical techniques in treatment of the ischemic diabetic lower extremity will continu e to improve the chances for long-term bipedal ambulation and independence in this patient population.

COMMENTARY Dr Banis and his colleagues have put together a clear and concise approach to the management of foot ulceration in the most difficult patient population that plastic surgeons are asked to evaluate. Their approach is derived from extensive personal experience and is based on a close working relationship with their vascular surgery colleagues. They are to be commended for their diligence as well as the expert care they provide their patients. It is obvious that the fatalistic approach to limb salvage in these patients, which was fostered during the 1960s and 1970s, is no longer applicable. Although limb salvage surgery using peripheral vascular and microvascular approaches may be a "triumph of technique over reason" in

BANIS, DERR,AND RICHARDSON

Fig 13. A 46-year-old Caucasian diabetic man with painful ischemic gangrenous changes left third and small toes. The patient was noted to have excellent vasculature to ankle, with severe disease in ankle and foot. (A) Postoperative revascularization procedure left posterior tibial artery to lateral plantar artery, third and fifth toe ischemic changes. (B) Schematic of 12-cm vein bypass graft, left distal posterior tibial artery to lateral plantar artery, satisfactorily revascularizing foot. Excellent Doppler signal obtainable at mark distal to incision. The patient's wounds ultimately healed completely, with adjunctive surgical debridementmamputation of fourth toe. The patient is ambulatory and asymptomatic 9 months later, with improved sensation of his foot.

some patients, these authors have been able to clarify some of the major issues surrounding patient management and provide us with some useful guidelines. The authors' experience is unique in that plastic surgeons are performing the distal anastomosis in cases of distal bypass grafting rather than the vascular surgical team. This technical modification may permit a more distal extension of the bypass graft than would have otherwise been sought and may account for their extremely low incidence of patients with truly nonreconstructable disease. A corollary to the principles put forth in this article is the use of microvascular techniques to perform revasculariza,!ion procedures within the foot and ankle only. As pointed out by the authors, not all patients will have the normal communication between the plantar and dorsal circulations via the first intermetatarsal space perforator and the plantar arch. Homologous abnormalities in the hand in patients with symptomatic ischemia would be treated by small bypass grafts for palmar arch reconstruction. A

ISCHEMIC AND ISCHEMIC-DIABETIC FOOT RECONSTRUCTION

similar approach may be useful in the foot and may prevent the need for amputation or more formidable revascularization procedures in select patients. Although not directly addressed by the authors, the issue of nutrient flaps must be discussed. These are flaps placed in an ischemic foot without prior optimization of the limb's blood flow with angioplasty or bypass grafting techniques. These patients present with significant soft tissue loss and nonreconstructable vascular disease. Inflow to the free flap is sought proximally and a well-vascularized flap is placed in an ischemic wound bed. My personal experience with these clinical problems has been dismal-two successful free flaps that failed to incorporate into the foot and eventually led to two below-knee amputations. The foot must have good circulation for a free flap to heal to the wound bed. As the authors point out, every effort should be made to seek out a target vessel for distal bypass surgery. These efforts include digital subtraction angiography, magnetic resonance angiography, and surgical exploration. When approaches such as these are taken, the true

233

Fig 14. Distal revascularization--anastomotic technique: (A) Arteriotomy distal anterior tibial artery, approximately 15 mm in length. Note severe calcific disease and irregularity of arteriotomy. (B) "Flange" technique of using side branch to facilitate anastomotic design that allows a very oblique angle takeoff from recipient vessel to enable positioning of bypass graft without kinking. Note also technique of fat patch control of suture line arterial bleeding in delicate tissues when sutures will no longer hold. (C) Oblique view of proximal anastomosis using "Flange" technique of anastomotic heel design and fat patch hemostasis. (D) DPA, one half suture line completed. Oblique approach optimal, not requiring "Flange" technique. (E) Distal ATA to DPA bypass graft across ankle. (F) Wounds closed.

incidence rate of nonreconstructable vascular o n l y 1% o r 2 % as t h e a u t h o r s h a v e i n d i c a t e d .

d i s e a s e is

REFERENCES 1. Corson JD, Jacobs RL, Karmody AM, et al: The diabetic foot. Curr Probl Surg 10:721-788, 1986 2. Faris I, Duncan H, Young C: Factors affecting outcome of diabetic patients with foot ulcers or gangrene. J Cardiovasc Surg (Torino) 29:736-740, 1988 3. Gutman M, Kaplan O, Skornick Y, et ah Gangrene of the lower limbs in diabetic patients: A malignant complication. Am J Surg 154:305, 1987 4. Kucan JO, Robson MC: Diabetic foot infections: Fate of the contralateral foot. Plast Reconstr Surg 77:439-441, 1986 5. Pecoraro RE: The nonhealing diabetic ulcer-a major cause for limb loss. Prog Clin Biol Res 365:27-43, 1991 6. Lai CS, Lin SD, Chou CK, et ah Limb salvage of infected diabetic foot ulcers with microsurgical free-muscle transfer. Ann Plast Surg 26:21222O, 1991 7. Searles JM Jr, Colen LB: Foot reconstruction in diabetes mellitus and peripheral vascular insufficiency. Clin Plast Surg 18:467-483, 1991 8. Gloviczki Pet al: Microscope aided pedal bypass. Am J Surg 9. Serletti JM, Deuber MA, Guidera PM, et al: Atherosclerosis of the Lower Extremity and Free Tissue reconstruction for Limb Salvage. Plast Surg Ortho Univ of Rochester May 4, 1993 10. Goldenberg S: Nonatheromatous peripheral vascular disease of the lower extremity in diabetes mellitus. Diabetes 9:100, 1960 11. LoGerfo FW, Coffman JD: Vascular and microvascular disease of the foot in diabetes. N Engl J Med 311:1615, 1984 12, Penn I: Diabetes mellitus and the surgeon. Curt Probl Surg 24:535-603, 1987 13. Rudolph R: Nonhealing leg and foot wounds resulting from correctable arterial occlusion. Plast Reconstr Surg 71:209-211, 1983 14. Steer HW, Cuckle HS, Franklin PM, et al: The influence of diabetes mellitus upon peripheral vascular disease. Surg Gynecol Obstet 157:64-72, 1983

ISCHEMIC AND ISCHEMIC-DIABETIC FOOT RECONSTRUCTION

15. Hurley JJ, Auer AI, Hershey FB, et al: Distal arterial reconstruction: Patency and limb salvage in diabetics. J Vasc Surg 5:796-802, 1987 16. Klamer TW, Lambert GE, Richardson JD, et ah Utility of inframalleolar arterial bypass grafting, J Vasc Surg 11:164-170, 1990 17. Klamer TW, Towne JB, Bandyk DF, et al: The influence of sepsis and ischemia on the natural history of the diabetic foot. Am Surg 53:490-494, 1987 18. Taylor LM Jr, Porter JM: The clinical course of diabetics who require emergent foot surgery because of infection or ischemia. J Vasc Surg 6:454-459, 1987 19. Albrektsen SB, Henriksen BM, Holstein PE: Minor amputations on the feet after revascularization for gangrene. Acta Orthop Scand 683:291-293, 1997 20. Kwolek CJ et al: Pediph BPG Jodm - J Vasc Surg 21. Stonebridge PA, Murie JA: Infrainguinal revascularization in the diabetic patient. Br J Surg 1993 80:1237-1241, 1993 22. Griffiths GD, Wieman TJ: The influence of renal function on diabetic foot ulceration. Arch Surg 125:1567-1569, 1990 23. Ballard JL, Eke CC, Bunt TJ, et al: A prospective evaluation of transcutaneous oxygen measurements in the management of diabetic foot problems. Vasc Surg N A m e r Chapter Loma Linda Med Ctr 1995. 24. Armstrong MB, Villalobos RE, Leppink DM: Free-Tissue transfer for lower-extremity reconstruction in the immunosuppressed diabetic transplant recipient. Plast Surg Ohio State Univ 1997. 25. Atiyeh BS, Sfeir RE, Hussein MM, et al: Preliminary Arteriovenous Fistula for Free Flap Reconstruction in the Diabetic Foot. Plas Reconstr Surg and Vasc Surg Am Univ Beirut Med Ctr. Dec 13, 1993. 26. Matzke S, Tukiainen, Mauri JA, et al: Survival of a microvascular muscle flap despite the late occlusion of the inflow artery in a neuroischaemic diabetic foot: Case Report. Scand J Plast Reconstr Surg Hand Surg 31:71-75, 1997 27. Briggs SE, Banis JC, Kaebnick H, et al: Distal revascularization and microsurgical free tissue transfer: An alternative to amputation in ischemic lesions of the lower extremity. J Vasc Surg 2:806-811, 1985 28. Banis JC, Richardson JD, Derr JW, et al: Microsurgical adjuncts in salvage of the ischemic and diabetic lower extremity. Clin Plast Surg 19:881-893, 1992

235