Graft vasculopathy in clinical hand transplantation.

Allogeneic hand transplantation is now a clinical reality. While results have been encouraging, acute rejection rates are higher than in their solid-organ counterparts. In contrast, chronic rejections, as defined by vasculopathy and/or fibrosis and atrophy of skin and other tissues, as well as antibody mediated rejection, have not been reported in a compliant hand transplant recipient. Monitoring vascularized composite allograft (VCA) hand recipients for rejection has routinely involved punch skin biopsies, vascular imaging and graft appearance. Our program, which has transplanted a total of 6 hand recipients, has experience which challenges these precepts. We present evidence that the vessels, both arteries and veins may also be a primary target of rejection in the hand. Two of our recipients developed severe intimal hyperplasia and vasculopathy early post-transplant. An analysis of events and our four other patients has shown that the standard techniques used for surveillance of rejection (i.e. punch skin biopsies, DSA and conventional vascular imaging studies) are inadequate for detecting the early stages of vasculopathy. In response, we have initiated studies using ultrasound biomicroscopy (UBM) to evaluate the vessel wall thickness. These findings suggest that vasculopathy should be a focus of frequent monitoring in VCA of the hand.

Primary reconstruction of a degloved hand using multiple toe transfers on a single pedicle and a reversed radial artery flap.

This case study reports one-stage reconstructive surgery on an 18-year-old man who was injured by an industrial roller machine and who presented with a degloved hand. Non-replantable delgloving occurred in all fingers, with the loss of the palmar and part of the dorsal skin. Multiple free contiguous toes were transferred based on a single dorsalis pedis artery pedicle. The artery was anastomosed to a reversed radial artery flap, which was used to cover the palm for primary reconstruction of the degloved hand. Multiple toes were harvested from the same foot, based on a single pedicle, to contain the potential morbidity to one foot, to enable primary reconstruction, and to decrease the length of the operation. The flaps healed well, and the patient demonstrated adequate tripod pinch and key pinch with the transferred toes, with a two-point discrimination of 12 mm at 1-year follow-up. The patient was satisfied with both the appearance and function of the hand and foot.

Replantation of total degloving of the hand: case report.

This article reports a patient who had a total degloving of the hand, caused by a roller injury, up to the distal forearm level. The authors replanted the degloved skin using arteriovenous anastomosis of the radial artery at the wrist to the cephalic vein in the degloved skin in an end-to-side manner. To enhance the survival of the replanted skin, it was deepithelialized and buried in an abdominal pocket created specifically for this purpose. The replanted skin survived, except at the terminal portions of the fingers. The patient had reasonable function and cosmesis after the wound healed. The procedure may be used for the treatment of this rare injury to salvage a cosmetically acceptable and functional hand.

Major upper limb replantation.

Major amputations remain a challenge to the replantation surgeon. Proper patient selection, good surgical skills, and cooperation among the patient, surgeon, and rehabilitation team help achieve a better outcome.

Tip streaming from a drop in the presence of surfactants.

Drop breakup in a linear extensional flow is simulated numerically using a nonlinear model for the surface tension that accounts for maximum packing at the interface. Surface convection sweeps surfactant to the drop poles, where it accumulates and drives the surface tension to near zero. The drop assumes a transient shape with highly pointed tips. From these tips, thin liquid threads are pulled. Subsequently, small, surfactant-rich droplets are emitted from the termini of these threads. The scale of the shed drops depends on the initial surfactant coverage. Dilute initial coverage leads to tip streaming, while high initial coverage leads to the tip dropping breakup mode.

Initiation of microvascular protection by nitric oxide in late preconditioning.

The authors hypothesized that nitric oxide is induced by a brief period of ischemia/reperfusion (ischemic preconditioning, IPC) on postoperative day (POD) 1, and that this released nitric oxide is responsible for initiating a delayed microvascular protection against a prolonged period of ischemia in skeletal muscle on POD day 2. The cremaster muscle of male Sprague-Dawley rats underwent 4 hr of ischemia, and then 60 min of reperfusion. IPC consisted of 45 min of ischemia but was done 24 hr before the prolonged ischemia. Local intraarterial infusion of sodium nitroprusside (SNP, a donor of nitric oxide) or Nw-nitro-L-arginine (L-NA, a nonselective nitric oxide synthase antagonist) were also given 24 hr before prolonged ischemia. Arteriole diameters and capillary perfusion were measured using intravital microscopy. Four groups were compared: 1) control; 2) IPC; 3) SNP + sham IPC; and 4) L-NA + IPC. Four hours of ischemia followed by reperfusion created a significant vasoconstriction and capillary no-reflow in the microcirculation of cremaster muscles. These alterations were largely prevented by IPC. Local intraarterial infusion of SNP without IPC created a similar microvascular protection to that induced by IPC alone. In contrast, intraarterial infusion of L-NA prior to IPC eliminated the IPC-induced microvascular protection. In conclusion, in late preconditioning, nitric oxide contributes to the initiation of a delayed microvascular protection against prolonged ischemia in skeletal muscle.

Platelet-activating factor contributes to postischemic vasospasm.

BACKGROUND: The purpose of the present study was to determine if platelet-activating factor is an important mediator that produces vasospasm during reperfusion after ischemia in skeletal muscle. MATERIALS AND METHODS: A vascular isolated cremaster muscle in male Sprague-Dawley rats was coupled with local intraarterial drug infusion as a model to study microcirculation responses to ischemia/reperfusion injury. Arteriole diameters and capillary perfusion were measured using intravital microscopy. Group 1: platelet-activating factor dose response. Group 2: Effects of a cyclooxygenase inhibitor; indomethacin, and a thromboxane synthetase inhibitor, imidazole, on the response to platelet-activating factor. Group 3: Effects of nitric oxide synthesis inhibitor; N(omega)-nitro-L-arginine methyl ester, on the response to platelet-activating factor. Group 4: Effects of a platelet-activating factor receptor antagonist, CV-3988, indomethacin, and imidazole after 4 h of warm ischemia and reperfusion. RESULTS: Intraarterial infusion of platelet-activating factor produced a dose-related but mild vasoconstriction. Pretreatment with indomethacin or imidazole resulted in significant vasodilation actually emanating from platelet-activating factor infusion. Nitric oxide inhibition (with N(omega)-nitro-L-arginine methyl ester) enhanced the vasoconstriction produced by platelet-activating factor. Pretreatment with CV-3988, indomethacin, or imidazole significantly attenuated ischemia/reperfusion-induced vasospasm and capillary no-reflow in the cremaster muscles. CONCLUSIONS: Ischemia/reperfusion-induced vasoconstriction is at least in part mediated by platelet-activating factor and thromboxane A(2).

A comparative analysis of the six-strand double-loop flexor tendon repair and three other techniques: a human cadaveric study.

The ideal zone II flexor tendon repair would be easy to perform, cause minimal scarring, and be strong enough to allow early active motion. A 6-strand loop suture technique devised by the senior author (T.M.T.) was studied in vitro. Forty flexor tendons were harvested from fresh-frozen human hands and divided into 4 groups of 10 tendons each. Each group of tendons was repaired with a specific technique: group 1, the modified Kirchmayr (modified Kessler) technique; group 2, the single-loop 2-strand technique described by Tsuge; group 3, Tsai's double-loop 4-strand modification of Tsuge's technique; and group 4, Tsai's double-loop 6-strand modification of Tsuge's technique. Gap resistance of each repair technique was recorded on a computer using a Differential Variable Reluctance Transducer (MicroStrain, Burlington, VT) and on videotape to record first gap formation, 1-mm and 2-mm gap formation, and maximum load. Statistically significant differences between groups were as follows: at first gap formation between the 2-strand and 6-strand loop suture techniques, and at maximum load between the modified Kessler and 4-strand, modified Kessler and 6-strand, 2-strand and 4-strand, and 2-strand and 6-strand loop suture techniques. The 6-strand double-loop suture technique had a higher tensile strength than the other techniques, as measured in this model at each stage in our experiment. The 6-strand double-loop suture technique simplifies flexor tendon repair. It improves the repair's strength and its resistance to gapping without increasing tendon handling or bulk. This increased repair strength allows us to pursue a more aggressive rehabilitation program.

Late-preconditioning protection is evident in the microcirculation of denervated skeletal muscle.

We investigated whether ischemic preconditioning induces microvascular protection in skeletal muscle at the late phase (after 24 hours) when the same muscles are subjected to prolonged warm global ischemia. The cremaster muscle of the male Sprague-Dawley rat underwent vascular isolation and was subjected to 4 hours of ischemia and 60 minutes of reperfusion. Early preconditioning consisted of 45 minutes of ischemia followed by 15 minutes of reperfusion before prolonged ischemia/reperfusion; late preconditioning also consisted of 45 minutes of ischemia but was done 24 hours (24-hour period of reperfusion) before the prolonged ischemia/reperfusion. Arteriole diameters and capillary perfusion were measured with use of intravital microscopy. Four groups were compared: rats that underwent early preconditioning, their controls, rats that underwent late preconditioning, and their controls. Early and late preconditioning significantly attenuated vasospasm and capillary no-reflow compared with the controls for each. Average arteriole diameter was significantly larger in the rats that underwent late preconditioning than in any other rats; it was also significantly larger in the controls for late preconditioning than in those for early preconditioning. We introduce a model of the rat cremaster muscle that has been isolated from its vascular supply as a useful preparation to study the effects of late preconditioning on microcirculation in skeletal muscle. Late preconditioning provided better microvascular protection than did early preconditioning. The mechanism for this preconditioning protection is being investigated because it should provide a means for therapeutic intervention.

Cubital tunnel release with endoscopic assistance: results of a new technique.

We evaluated the results of cubital tunnel release with endoscopic assistance. The study included 76 patients (85 elbows); 47 women and 29 men. Nine patients had bilateral procedures. Patients were excluded if they had less than 1 year of follow-up, associated pathology at the elbow to account for the nerve compression, or recurrent cubital tunnel syndrome. Before surgery, cases were categorized by stage of cubital tunnel syndrome according to Dellon's classification: 33 (39%) elbows were classified as mild, 35 (41%) moderate, and 17 (20%) severe. Surgical results were assessed according to a modified Bishop rating system. The mean follow-up period was 32 months (range, 12-52 months). Results were excellent in 42% of the elbows, good in 45%, fair in 11%, and poor in 2%. Recurrence occurred in 3 elbows. There were no serious complications. The results of this study support our recommendation of cubital tunnel release with endoscopic assistance as a safe and reliable technique for the treatment of cubital tunnel syndrome, especially in patients with mild to moderate symptoms.

Single pedicle vascularized double joint transfer: anatomic study of two models.

This study examined the anatomic structures that communicate between the tibial and fibular digital arteries of the second toe at the distal phalanx to identify a channel for retrograde blood flow from the dominant pedicle to the distal joint flap. We also assessed the feasibility of two models designed to mobilize toe joints to perform single pedicle vascularized double-joint transfer. The continuity of the vascular pathway in both models was demonstrated by microfil injection and angiographic study. The average mobile distance between the PIP joint and the MTP joint was 5.6 +/- 0.6 cm in model I and 5.1 +/- 0.4 cm in model II. The dissection and mobilizing procedures of the neurovascular pedicle are more complicated and extensive in model II than in model I, and the risk of jeopardizing vascularity of the distal joint flap is higher. Both models may be suitable to replace two adjacent metacarpophalangeal (MCP) joints in the hand or two nonadjacent MCP joints (excluding the thumb) separated by no more than one normal metacarpal.

Ischemic preconditioning versus intermittent reperfusion to improve blood flow to a vascular isolated skeletal muscle flap of rats.

OBJECTIVES: We investigated whether intermittent restoration of blood flow just before reperfusion after ischemia could create beneficial effects similar to ischemic preconditioning, which involves intermittent stoppage of blood flow just before ischemia. METHODS: Male Sprague-Dawley rats were prepared with vascular isolated cremaster muscles, then subjected to 4 hours of ischemia and 60 minutes of reperfusion. Arteriole diameters and capillary perfusion were measured by using intravital microscopy. Four groups were used: (1) untreated, (2) ischemic preconditioning (IP), (3) intermittent reperfusion (IR), and (4) ischemic preconditioning plus intermittent reperfusion (IP+IR). RESULTS: Our results showed that IP significantly attenuated both ischemia/reperfusion-induced vasospasm and capillary noreflow. IR was effective in attenuating vasospasm in terminal arterioles. However, IR alone was unable to significantly attenuate capillary no-reflow. Combining both IP and IR achieved the best results. CONCLUSION: Our results suggest both ischemic preconditioning and intermittent reperfusion are useful techniques for attenuating ischemia/reperfusion injury.

Major replantation versus revision amputation and prosthetic fitting in the upper extremity: a late functional outcomes study.

The functional outcomes of amputated arms that were either replanted or had a prosthesis were compared. In addition, factors that influenced the functional outcome of replants were evaluated. The Carroll test was used to evaluate functional capacity of 22 successful upper extremity replantations at or proximal to the wrist as well as 22 amputees (at similar levels) fitted with a variety of prosthetic devices. The outcome was excellent or good in 8 (36%) replanted limbs. This proportion was statistically higher than those grades in the prosthetic group. When the groups were more closely matched (adults with below elbow injuries), the replantation group had 6 (50%) good or excellent outcomes and the prosthetic group had none. An analysis of covariance of the replantations demonstrated a statistical association between a better outcome in younger patients with more distal injuries. This study indicates that replantation produces superior functional results compared with amputation and a prosthesis.

Free vascularized transfer of the metatarsophalangeal and proximal interphalangeal joints of the second toe for reconstruction of the metacarpophalangeal joints of the thumb and index finger using a single vascular pedicle.

Previously described double-joint transfers from a single toe have required a separate vascular pedicle for each joint transferred. In this case report, however, we describe the use of a single vascular pedicle to perform a free vascularized double-joint transfer of the metatarsophalangeal and proximal interphalangeal joints of a single toe to the metacarpophalangeal joints of the thumb and index finger. Although a pollicization could have restored adequate function to the patient's hand, she desired five digits. Given the increased distance between the metacarpophalangeal joints of the thumb and index finger, an increased interjoint pedicle length was needed. We obtained this by mobilizing the digital vessels away from the joints of the second toe. This involved transecting the tibial digital vascular branches of the proximal interphalangeal joint and the fibular vascular branches of the metatarsophalangeal joint. Based on a single pedicle, the vascularity of the proximal interphalangeal joint was maintained by preserving the distal commissural vessels at the distal phalanx. Advantages of this technique include using a single donor artery and reconstruction of two metacarpal joints with a single toe.

Effects of ofloxacin administration on the reliability of urine glucose testing.

OBJECTIVE: To study the effects of ofloxacin on the reliability of urine glucose testing. DESIGN: Open-label, nonrandomized. SETTING: A university-affiliated tertiary care hospital, ambulatory clinic. PARTICIPANTS: Ten healthy volunteers (8 men and 2 women) aged 22-39 years. MAIN OUTCOME MEASURES: Phase I (in vitro) involved the addition of selected amounts of ofloxacin to a set of standard 50-mL urine samples prepared to simulate glycosuria. Phase II (in vivo) involved the oral administration of ofloxacin 400 mg to 10 subjects. Urine was collected: (1) immediately predose, (2) pooled 0-4 hours postdose, and (3) pooled 4-8 hours postdose. Known glucose concentrations were then added to these samples. Clinitest and Diastix tests were performed on all samples. The accuracy of these tests in determining glucose concentrations was compared among urine samples taken before and after ofloxacin dosing. RESULTS: None of the ofloxacin concentrations in phase I (0, 25, 50, 100, 200, 400, and 800 micrograms/mL) influenced these testing methods at the urine glucose concentrations of 0.0%, 0.5%, 1%, and 2%. Likewise, the accuracy of these two tests was unaffected by ofloxacin administration in phase II. CONCLUSIONS: In single-dose administration, ofloxacin does not interfere with Clinitest or Diastix for determining urine glucose concentrations.

A neurovascular island flap for volar-oblique fingertip amputations. Analysis of long-term results.

A neurovascular island flap has been developed to reconstruct volar-oblique fingertip amputations. This study analyzes the data collected on 16 patients who were treated with this flap and had at least 2 years follow-up. The average active/passive range of motion was 54/55 degrees at the DIP joint, 96/98 degrees at the PIP joint, and 83/83 degrees at the MP joint. Twelve out of 16 flaps (75%) had two-point discrimination better than 10 mm. Moderate and severe problems included cold intolerance (six patients), hypersensitivity (three patients), stiffness (three patients), and numbness (two patients). Out of the 16 patients treated with this technique, 14 were satisfied with their surgical outcome. In experienced hands, this technique is a safe and reliable method with which to reconstruct volar-oblique fingertip amputations.

Vascularized bone grafts for congenital pseudarthrosis of the tibia.

Eight vascularized fibula grafts and two vascularized rib grafts were used for the treatment of 10 Boyd's Type II congenital pseudarthrosis of the tibia. All but one vascularized fibula graft united within 4 months. The two vascularized rib grafts did not unite until receiving a conventional bone graft. Nine spontaneous fractures were seen in four patients; all were subsequently treated successfully with cast or conventional bone graft. Corrective osteotomies were done in two patients. Follow-up averaged 8 years and 5 months (range, 5 years and 1 month to 14 years and 4 months). Average age at end of follow-up was 13 years and 6 months (range, 7 years and 10 months to 20 years and 4 months). After bony union was achieved, shortening of the affected leg averaged 3.8 centimeters, flexion deformity averaged 20 degrees, and valgus deformity averaged 24 degrees. In three patients, whose leg discrepancy averaged 4.9 centimeters, the leg was lengthened at an average patient age of 13 years and 9 months (age range, 11 years and 7 months to 15 years and 2 months). The resulting limb length discrepancy averaged 2.2 centimeters. Vascularized bone grafting is a reliable technique for achieving bony union in congenital pseudarthrosis of the tibia. Residual shortening may be corrected later by limb lengthening.