Donor Limb Research Articles

Long-term results of endarterectomy, anatomic bypass and extraanatomic bypass for aortoiliac occlusive disease.

Over the past 20 years, 214 patients in our hospital were operated on for aortoiliac occlusion, including an endarterectomy for 88 legs in 64 patients, an anatomic bypass for 178 legs in 105 patients, and an extraanatomic bypass for 51 legs in 45 patients. The extraanatomic group was older than the other two groups (70 years versus 64 years), and also showed a higher instance of critical ischemic symptoms than the other groups (49% versus 16%). The 10-year primary patency rate was 88% for an endarterectomy, 91% for an anatomic bypass, and 73% for an extraanatomic bypass. The 10-year survival rate was 71% for an endarterectomy, 49% for an anatomic bypass, and 24% for an extraanatomic bypass. The possible complications related to each surgical method included sexual dysfunction resulting from endarterectomy, and graft infection and anastomotic aneurysm in the prosthetic bypass. No ischemic symptoms in the donor limb were noted following an extraanatomic bypass. The selection of the appropriate surgical method for aortoiliac occlusion should thus be made after a careful review of the patient's general condition, the morphology of arterial occlusion, and the risk of possible complications for each type of surgery.

Biomechanics of longitudinal arch support mechanisms in foot orthoses and their effect on plantar aponeurosis strain

Objective. The purpose of this investigation was to quantify the longitudinal arch support properties of several types of foot orthosis.Design. An in vitro method that simulated ‘static stance” was used to determine arch support capabilities, with plantar aponeurosis strain implemented as the performance measure.Background. A longitudinal arch support mechanism of an orthosis resists depression of the foot's arches by transferring a portion of the load to the medial structures of the foot. Since the plantar aponeurosis is in tension when the foot is loaded, a quantifiable decrease in strain should occur with an adequate orthotic arch control mechanism.Methods. A differential variable reluctance transducer was surgically implanted in the plantar aponeurosis of cadaveric donor limb feet (n= 7). Each specimen was mounted in an electromechanical test machine which applied a load of up to 900 N axially to the tibia. The test schedule was divided into seven test conditions: specimen barefoot; specimen with shoe and specimen with shoe and five different orthoses.Results. The University of California Biomechanics Laboratory Shoe Insert and two other foot orthoses significantly decreased the strain in the plantar aponeurosis compared to the barefoot control and were considered effective arch supports (P <0.05). The functional foot orthosis, stock orthosis, and test shoe did not effectively reduce plantar aponeurosis strain. Significant variations of time required to achieve the specified load levels were recorded among the test conditions, indicating the relative cushioning properties of the shoe/ orthosis systems.Conclusions. The patterns of plantar aponeurosis strain observed in cadaveric tests suggest that certain types of orthoses are more effective than others in the support of the foot's longitudinal arches. It is suggested that to support the longitudinal arches of the foot effectively the medial surface contours of the orthosis must stabilize the apical bony structure of the foot's arch.

The value of donor iliac artery pressure gradients in predicting the outcome of femorofemoral bypass

This study tests the clinical value of femoral artery pressure measurements by analysis of the relationship between iliac artery pressure gradients (PGs) and both femorofemoral bypass graft patency and the hemodynamic changes produced in the donor and recipient limbs. Systemic and donor femoral artery systolic and mean pressures were measured during surgery at rest and during papaverine-induced hyperemia before 94 femorofemoral bypasses. Ankle/brachial (A/B) pressure ratios and pulse volume recordings (PVRs) were measured before and early after surgery. Donor iliac artery stenosis was 25% +/- 23% (mean +/- 1 SD). Follow-up was 23+/- 20 months. Eight bypasses failed at 21 +/- 20 months. Patients with failed bypasses had a resting systolic and mean PG of 23 +/- 22 mm Hg and 5 +/- 7 mm Hg, respectively, compared with 10 +/- 11 mm Hg (p = 0.007) and 1 +/- 2 mm Hg (p = 0.001) for the 86 patent bypasses. Donor limb A/B ratios and PVRs decreased 9% +/- 5% and 15% +/- 14%, respectively, had a linear regression slope less than 0 (p < 0.05) with resting and hyperemic PGs, and correlated best with resting PGs (p < 0.05). Recipient limb A/B ratios and PVRs increased 86% +/- 48% and 191% +/- 111%, respectively, had a linear regression slope greater than 0 (p < 0.05) with all resting and hyperemic PGs, and correlated best with hyperemic systolic PGs (p < 0.05). However, all regressions had a large SD, wide 95% confidence limit, and a low correlation coefficient. Sensitivity-specificity receiver-operating characteristic curves for optimal PG criteria for both graft failure and donor limb hemodynamic impairment are weak, with an accuracy of 50% to 75%. Recommended criteria for not performing a femorofemoral bypass are a resting systolic PG of 28 mm Hg or greater or a resting mean PG of 6 mm Hg or greater. Although iliac artery PGs correlate with graft failure and both the degree of donor limb hemodynamic impairment and recipient limb improvement, the large variability in PGs between patients with similar outcomes and the low accuracy of optimal PG criteria indicate that they have limited clinical value in decision making.

In vitro method for quantifying the effectiveness of the longitudinal arch support mechanism of a foot orthosis

The purpose of this investigation was to develop a technique to quantify the effectiveness of the longitudinal arch support mechanism of a foot orthosis. The experimental model was based on the following principle of foot biomechanics: as the foot is subjected to a load, a proportion of the load is experienced as tension by the plantar aponeurosis. A differential variable reluctance transducer was implanted into the plantar aponeuroses of cadaveric lower limb feet through which the strain was calculated in three conditions, specimen barefoot, specimen with shoe, and specimen with shoe and orthosis. Each donor limb was mounted in an electromechanical test machine that applied a load of 900 N to the tibia. Time, load, and strain data were collected and analysed at four load levels (225, 450, 675, 900 N). In addition the measurements and test design were evaluated for reliability. Strain in the plantar aponeurosis decreased significantly in the specimen with shoe and orthosis compared to the specimen with shoe only. There was a significant increase in the time to load data in the specimen with shoe and orthosis condition in contrast to the barefoot measurements. There were no significant differences in strain between the barefoot tests and those of the shoe, indicating that the shoe tested provided minimal support to the foot's longitudinal arch.

Transplantation of the canine distal ulna as a free vascularized bone graft.

An autogenous free vascular bone graft of the canine distal ulna was evaluated. The vascularity of the graft was based on a musculoperiosteal sheath supplied solely by the caudal interosseous artery and vein. Four autogenous heterotopic (ulna to tibia) vascular transfers were performed. Two avascular transfers were performed to provide baseline criteria from which the success of vascularized transfers could be assessed. Clinical lameness evaluation, serial radiographs, bone scintigraphy, and sequential fluorochrome bone labeling were performed after surgery in both vascular and avascular transfers. All dogs were free of lameness in the donor limb by the 26th postoperative day. Serial radiographs revealed rapid graft incorporation and hypertrophy in all vascularized grafts and severe bone resorption in nonvascularized grafts. Histology, microangiography, and evaluation of fluorochrome bone labels were performed 90 days after surgery to determine graft viability, incorporation and temporal remodeling patterns. Microangiography and fluorochrome assessment complemented the histological findings. Based on these findings the distal ulnar bone graft was determined to be both viable and structurally adequate for selected cases of long bone reconstruction.

The versatility of free rectus femoris muscle flap: An alternative flap

In the 10-year period from June 1985 to December 1994, 54 free rectus femoris muscle or musculocutaneous flaps were performed at our hospital. It has been one of the most frequently used free muscle flaps in our institution and forms 2% of all free tissue transfers (total, 2,769 cases). In 26 patients, it was used for large wound coverage following debridement or tumor ablation, and in 27 patients, as a functioning free muscle transplantation for brachial plexus palsy or traumatic muscle loss. In one patient the components of the deep aponeurosis, muscle, and overlying skin were used for reconstruction of an abdominal wall defect after neurilemmoma excision. There were two complete failures, one due to diabetic foot infection and one due to venous occlusion. Four had superficial marginal skin necrosis. No significant disability of the donor limb was encountered. Easy approach, rapid harvest, large and reliable overlying skin flap, a single dominant neurovascular pedicle (with large vessel diameter and long motor nerve), easy primary closure of the donor site, and minimal donor site morbidity all make the rectus femoris flap a good alternative flap for free tissue transfer, in addition to the gracilis, rectus abdominis, and latissimus dorsi muscle flap.

Closure of an ischial pressure sore using a free gastrocnemius musculocutaneous flap with a long venous pedicle

The recurrent pressure sore in an active paraplegic can become a frustrating challenge as available simple flap options become depleted. The medial gastrocnemius musculocutaneous free flap is an alternative that offers the benefits of muscle from an expendable donor site and still preserves the remainder of the donor limb for future use. Inclusion of an intact greater saphenous vein could augment venous drainage and potentially might be the sole means of outflow if veins at the recipient site were inadequate. This case report describes the closure of a recurrent ischial pressure sore with a free medial gastrocnemius flap, including a greater saphenous vein pedicle.

Cellular mechanisms of alloimmune non-responsiveness in tolerant mixed lymphocyte chimeras induced by vascularized bone marrow transplants.

It has been demonstrated that the development of stable mixed lymphocyte chimerism is associated with alloimmune tolerance induction in vascularized bone marrow transplant (VBMT) recipients. The underlying mechanisms of immune non-responsiveness in tolerant VBMT chimeras remains unclear. Our VBMT model involves the transplantation of a parental donor limb (Lewis rats) onto a hybrid (Lewis x Brown Norway) F1 recipient. Tolerogenic mechanisms and cellular immune regulation to self and host allodeterminants were investigated during the early post-transplant phase of tolerance induction. Flow cytometric analysis of sIg+-depleted experimental peripheral blood lymphocytes from tolerant VBMT recipients demonstrated low level stable mixed immune chimerism. Chimeric cells tested for responsiveness against self-LEW determinants showed activated proliferation and immune dysregulation 30 days post-transplantation. However, direct immunocytolytic activity against LEW determinants was not found. Tolerant chimeras also demonstrated elevated cellular proliferation and cytolytic responses against host-specific BN allodeterminants at 30 days. Consistent with these in vitro findings, limited clinical signs compatible with GVH reactivity were evident in vivo at this time. Following this initial period, the tolerant VBMT animals returned to normal clinical condition and remained otherwise healthy throughout the study. Consistent with these results, VBMT chimeras then showed declining proliferative responses from the elevated values seen at 30 days against self-LEW determinants. Proliferative and immunocytolytic responses also decreased against host-specific BN allodeterminants from peak levels at 30 days. In conclusion, these results provide evidence that the initial phases of tolerance induction in VBMT chimeras consist of self- and alloimmune regulation that follow an early period of immune dysregulation. Sequential phases of immune dysregulation and re-regulation elucidated in VBMT stable mixed chimeras within the first 100-day period may represent important mechanisms of tolerance induction.

Progression of Occlusive Disease Following Femorofemoral Crossover Bypass Graft

Progression of distal disease is considered the most common cause of femorofemoral artery crossover bypass graft (FFBPG) failure. Twenty-seven patients with patient grafts (mean 53 months) were evaluated with segmental Doppler and duplex scan arterial studies for evidence of disease progression. In the early postoperative period (compared with preoperative levels), 26 patients (95.3%) showed a significant improvement (> 0.1) in the recipient limb ankle-brachial index (ABI) (mean increase of 0.38; SD = 0.24) and/or ankle spectral arterial waveform. However, there was a statistically significant decrease (p = 0.0001) in the donor limb ABI, and 12 patients (44.4%) had a > 0.1 deterioration. On long-term follow-up (compared with preoperative levels) this difference was no longer significant (p = 0.49); only seven donor limbs remained with a > 0.1 decrease in ABI. The recipient limbs maintained a significant improvement (> 0.1) in the ABI compared to preoperative levels (p < 0.0001; mean of 0.39; SD = 0.16) except for three limbs that had decreased by 0.1. However, eight patients (29.6%) developed an increase in their donor common femoral artery acceleration time > 133 msec and/or increased blood flow velocity without a simultaneous significant decrease in their recipient limb ABI. In the latter group the preoperative donor limb common femoral artery acceleration time and ABI and the immediate postoperative change in donor limb ABI were not significantly different (p > 0.05) than in the remaining patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Use of lower extremity deep veins as arterial substitutes: Functional status of the donor leg

Large veins (superior and inferior vena cava, portal vein) have been replaced successfully with lower extremity deep veins (superficial femoral-popliteal). Femoropopliteal bypass with superficial femoral-popliteal veins has been reported to give excellent long-term results. Nevertheless, this source of autogenous veins has not gained acceptance, in part because of the fear that deep vein removal will result in severe venous outflow restriction in the donor limb. To assess the clinical and functional effect of excising a deep vein, we compared a group of limbs in which the superficial femoral-popliteal vein was resected for use as a femoropopliteal bypass graft (25 legs) with a control group of 22 legs in which a saphenous vein or polytetrafluoroethylene graft was used for femoropopliteal bypass. No significant differences were found in age or sex distribution, time from surgery to the venous test, side of bypass, or the incidence of postoperative extremity swelling, either early or late. A mild but significant calf enlargement was observed in the deep vein group ( p < 0.05), and a pattern consistent with venous outflow obstruction was shown by plethysmography in 21 of 25 extremities (84%) in which a deep vein was used for femoropopliteal bypass but in only 11 of 22 (50%) control extremities ( p < 0.02). It is concluded that a lower extremity deep veins should be considered as a suitable replacement for a large vein or, when superficial vein is not available, as an infrainguinal arterial substitute.

Donor Limb Vascular Events Following Femoro-Femoral Bypass Surgery

Three hundred seventeen patients who had femorofemoral bypass surgery were examined for postoperative vascular changes that developed in the donor limb. "Unmasked" claudication developed in 7%, new claudication related to a "steal" developed in 3.5%, progression of preoperative claudication developed in 1%, new rest pain developed in 1.7%, and new necrosis developed in 0.7% of patients. Postoperatively, the donor limb ankle-brachial index decreased 0.30 or greater in 3% of the patients, decreased 0.15 to 0.29 in 6%, and decreased 0.10 to 0.14 in 6% of the patients. Only eight patients (3%) had a clinical and hemodynamic steal. Late vascular procedures for donor iliac stenosis were few, resulting in an iliac percutaneous transluminal angioplasty in 3% and inflow bypasses in 3%. Angiographic patterns of donor and recipient limbs were not predictive of "clinical" or "hemodynamic" steal events. Most new donor limb symptoms of claudication were an unmasking of arterial insufficiency previously present in the donor limb that became apparent when the recipient limb was improved.

A haemodynamic evaluation of the femoro-femoral cross-over bypass

The femoro-femoral cross-over bypass has become a popular choice for the management of unilateral iliac artery disease, being used in preference to aorto-femoral or extraperitoneal ilio-femoral bypasses. It is a relatively minor procedure and associated with a small incidence of side effects, the main one being the risk of development of a steal of blood from the donor limb by the bypass. Although this problem has been widely discussed, haemodynamic studies have been limited by the use of indirect measurements of blood flow, such as ankle systolic pressures or by the use of electromagnetic flowmetry at the time of surgery. No study employing volumetric blood flow measurements to identify and quantify blood steal in the postoperative patient has been reported to date. With aims of studying the haemodynamic effects of a femoro-femoral cross-over bypass on the circulation in both the recipient and donor limbs, and of identifying preoperatively, problems likely to lead to haemodynamic problems or to graft failure, the present study of 31 patients undergoing femoro-femoral bypass was undertaken. The patients, 18 of whom had rest pain and 13 intermittent claudication, were studied preoperatively using arteriography and a non-invasive assessment. At 3 months from the operation, all received a clinical assessment and a further non-invasive assessment, including a measurement of blood volume flow. Flow measurements were made in the bypass at rest and during a reactive hyperaemia test. In addition, flow measurements were made in the donor limb below the bypass origin at rest and during hyperaemic testing of the recipient limb in order to assess any steal effect the bypass might cause to the donor limb circulation. All 31 patients were improved by surgery, but five developed donor limb claudication which was attributed to steal in three cases. Resting blood flow in the bypasses, 161 (65-282)ml/min [median (range)], rose by 116% (5-428%) to 300 (82-1114)ml/min after hyperaemic testing. Simultaneously, bypass hyperaemia caused a fall in donor limb blood flow of 32% (0-74%). Of the preoperative non-invasive tests, only donor femoral artery pulse rise time was related to the later development of objective evidence of steal. Successful Gruntzig dilatation of four major stenoses resulted in a satisfactory outcome.

Non-invasive assessment of the steal phenomenon following femoro-femoral bypass

Clinical studies were performed on 42 patients who underwent femoro-femoral bypass and postoperative assessment of the ankle/brachial pressure index (API) and Doppler waveform for each limb was carried out. Patients who had poor runoff of the donor limb showed a significant decrease in API after ankle joint exercise (p less than 0.05), whereas no significant change was observed in patients who had poor runoff of the recipient limb. The response of pulsatility index was similar to that of API. Thirteen of the 42 patients underwent both pre- and postoperative assessments. Six of these patients underwent additional procedures such as thromboendarterectomy or profundaplasty on the anastomotic site of the donor limb, and the other 7 patients had no additional procedures performed. A decrease in API after exercise was prominent in the patients who had not undergone any additional procedures, in the postoperative stage (p less than 0.01). Thus, when performing femoro-femoral bypass, improving poor runoff in the donor limb by carrying out intraoperative additional procedures should be taken into consideration, as any imbalance of peripheral resistance must be kept to an absolute minimum.

Acute ischaemia in the donor limb after occlusion of axillo-femoral grafts

Acute ischaemia in the donor limb after occlusion of axillo-femoral grafts

Morbidity in the forearm flap donor arm

A restrospective study was carried out of the morbidity in the donor limb following use of the radial forearm flap in 27 patients. Of the 13 patients whose flaps contained bone, 4 sustained fractures of the radius. This was associated with a 50% loss of power of grip and pinch, and limitation of other movements, particularly pronation and supination. In the other patients little or no loss of power or range of movement was seen. No patient had cold intolerance; a few had areas of sensory loss, related to the radial nerve. Of the 12 patients whose radial arteries were reconstructed, 7 remained patent; no patient had any clinical features of ischaemia. These findings and their implications are discussed.

COMPOSITE TISSUE (LIMB) ALLOGRAFTS IN RATS

Eight LEW rat recipients possessing long-term-surviving (206-701 days) LBN vascularized hind limb allografts (CTAs) were tested for donor-host lymphoid chimerism. The recipients received various cyclosporine (CsA) treatment protocols in order to induce indefinite CTA acceptance. Histological examination of long-term-surviving CTAs demonstrated normal-appearing bone marrow in the donor limb. Lymphocytes isolated from host hemopoietic tissues (peripheral blood and/or spleen) by ficoll-hypaque density gradient centrifugation were tested against LEW-anti-BN antisera. Comparisons were made to standard curves employing various known concentrations of LBN and LEW cell combinations. The level of lymphocyte agglutination (dependent variable) showed a significant (P less than 0.025-0.005) linear relationship to the concentration of LBN donor cells (independent variable) present. Lymphocyte suspensions isolated from long-term CTA host peripheral blood and/or spleen showed a mean of 19.7% (+/- 9.7-95% confidence interval) donor LBN mononuclear cells present. Thus, it appeared that lymphoid cells originated from, and/or were released from LBN donor bone marrow into the circulation, resulting in chimeric repopulation of hemopoietic tissues. The presence of donor immunocytes in these limb allograft recipients may have been beneficial, and thus could have helped contribute to the long-term CTA survival observed.

Neural pathway constraints in the motor innervation of the chick hindlimb following dorsoventral rotations of distal limb segments

Several studies have demonstrated that motor axons can discriminate between dorsally and ventrally derived muscles. In this paper we present evidence that (1) the pathway axons take in the limb constrain their access to either dorsally or ventrally derived muscles, and therefore (2) the axon's ability to discriminate between dorsal and ventral is expressed already at the level of pathway selection into the limb. Surgically manipulated hindlimbs were produced consisting of a normal host thigh connected to a dorsoventrally rotated calf or to rotated and duplicated donor limb segments. The limb rotations were done distal to the level at which axons select a dorsally or ventrally destined pathway through the limb, such that at the level of the rotation, axons in each nerve were confronted with the opposite-from-normal set of muscles. In this situation, the relative influence of pathway availability versus dorsal/ventral muscle recognition could be assessed. The innervation of rotated limb segments was, in all cases, opposite from normal. Motoneurons which normally innervate dorsal muscles innervated ventrally derived muscles that had been rotated into a dorsal position. Likewise, normally ventrally destined axons served dorsal muscles in the rotated segments. Thus, motor axons did not alter their distal path to reach their normal set of muscles. While these results do not rule out intrinsic dorsal/ventral differences between muscles, they do demonstrate that muscle surface recognition is not necessary to account for dorsal/ventral discrimination in the innervation of normal, supernumerary, or duplicated limbs, nor is it sufficient to account for the innervation of rotated limb segments. These results also indicate that pathway guidance cues are an important influence on innervation patterns.

Morphogenetic properties of the skin in axolotl limb regeneration

A study has been made of the morphogenetic properties of anterior and posterior skin from the lower forelimb of the axolotl. The basic experiment consisted of a graft of a half cuff of skin from a donor to a host limb followed by a 2-week healing period, amputation through the graft, and a study of the resulting regenerate. Limbs with double posterior skin formed double posterior regenerates and, in contrast, limbs with double anterior skin formed normal or slightly hypomorphic regenerates. Posterior skin from post-metamorphic animals had a similar but weaker effect to that from ordinary axolotls. Immunological rejection of allografts could be completely avoided if the donor limb was transplanted to the flank of the host when both were at the stage of tail-bud embryos, and the skin graft was later carried out between the supernumerary limb and one of the host limbs. This technique was used to show that immunological rejection does not affect the formation of duplicates from the limbs with double posterior skin, and to facilitate the studies of the cellular provenance of the regenerate. The cellular composition of duplicate regenerates was studied by using both triploid donors and triploid hosts. It was shown that the posterior side of the duplications consisted wholly of host tissue and the anterior side consisted of mixed donor and host tissue. Formation of the duplicated regenerate therefore seems to involve positional reprogramming of both donor and host tissues together with metaplasia of the donor tissue. It was not possible to inhibit the duplication-inducing property of posterior skin by treatment with a variety of enzymes. A model based on the serial threshold theory of regeneration is advanced to explain the results. This model successfully accounts for the observed non-equivalence of anterior and posterior skin, and also explains the different regeneration behaviour of anterior and posterior half limbs, the limited regeneration of double anterior limbs, and the pattern expansion and contraction shown by regenerates from double posterior limbs.

Autonomous development of reciprocally exchanged regeneration blastemas of normal forelimbs and symmetrical hindlimbs

AbstractNormal upper arm blastemas and blastemas derived from double posterior or double anterior thighs of A. mexicanum were reciprocally exchanged either by autografting or homografting between dark and white animals. Those grafted blastemas which survived always regenerated a morphology and pigmentation characteristics of the donor limb. Thus, upper arm blastemas on double anterior or posterior thigh stumps regenerated normal forelimbs. Double anterior blastemas on normal upper arm stumps failed to regenerate, and double posterior blastemas on normal upper arm stumps regenerated posterior half hindlimbs. These results show that the morphogenetic field of the regenerate is reflected in the composition of the limb stump, and that its pattern is expressed autonomously.Supernumerary limbs formed where posterior and anterior tissues of graft and host were opposed in 35–43% of cases where normal upper arm blastemas were grafted to symmetrical thighs. The morphology and pigmentation of the supernumeraries suggests that they are probably derived from both graft and stump, although a singular origin from either graft or stump is not ruled out in some cases.

Pattern regulation in the embryonic chick limb: Supernumerary limb formation with anterior (non-ZPA) limb bud tissue

The formation of supernumerary limbs and limb structures was studied by juxtaposing normally nonadjacent embryonic chick limb bud tissue. A “wedge” (ectoderm and mesoderm) of anterior or mid donor right wing bud (stage 21) was inserted in a slit made in a host right limb bud (stage 21) at the same position as its position of origin or to a more posterior position. The AER of the donor tissue and host wing bud were aligned with each other. Donor tissue was grafted with its dorsalventral polarity the same as the host's limb bud or reversed to that of the host's. Depending on the position of origin of the donor limb bud tissue and the position to which it was transplanted in a host, supernumerary wings or wing structures formed. Furthermore, depending on the orientation of the graft in the host, supernumerary limbs with either left or right asymmetry developed. The results of experiments performed here are considered in light of two current models which have been used to describe supernumerary limb formation: one based on local, short-range, cell-cell interactions and the other based on long-range positional signaling via a diffusible morphogen.