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Shin, Alexander Y

0000-0001-9658-8192

Mayo Clinic

Mayo Clinic

Citations 86

Epstein–Barr virus infection as a complication of transplantation of a nerve allograft from a living related donor

Journal of Neurosurgery | January 24, 2008 | Volume: 106 | Issue: 5 | Pages: 924-928

10.3171/jns.2007.106.5.924 | PMID 17542543

✓Reconstruction of extensive nerve defects is hampered by the amount of autogenous nerve tissue available for transplantation and by donor site morbidity. Nerve allografts, being of foreign origin and potentially unlimited in supply, provide a solution to these problems. Studies have shown that nerve allotransplants require immunosuppression only until end-organ connections are made and that immunosuppressant therapy may be subsequently discontinued with no negative effect on functional outcome. Also, recent experimental and clinical focus has been on shorter periods of immunosuppression in order to reduce risk, even stopping immunosuppression after regeneration has reached the distal suture line rather than before recovery of end-organ connections. In the pediatric population, the increased disease burden and increased potential for nerve regeneration as well as the frequent availability of a living related donor make allografts all the more attractive as solutions to nerve reconstructive problems. Nevertheless, the risks of immunosuppression must not be underemphasized, and they deserve more attention in the current nerve transplantation literature. The authors report on a child who, at the age of 1 year, received a nerve allograft from a living related donor who was positive for Epstein–Barr virus (EBV). The child quickly developed a symptomatic EBV infection concurrent with immunosuppressant drug therapy. The immunosuppression regimen was stopped prematurely, and the patient suffered only a short illness, but the EBV infection could have developed into a life-threatening posttransplant lymphoproliferative disorder (PTLD). The patient is consequently predisposed to develop PTLD and will have to be monitored for the rest of his life. This case highlights the importance of considering the potentially fatal risks associated with this elective procedure. Future studies are needed to quantify and minimize this complication. Nevertheless, it should be weighed against the potential functional benefit from using nerve allografts.
Reverse Radial Forearm Fascial Flap with Radial Artery Preservation

HAND | May 1, 2007 | Volume: 2 | Issue: 3 | Pages: 159-163

10.1007/s11552-007-9041-7 | PMID 18780079

The reverse radial forearm fascial (RRFF) flap is widely used in soft-tissue reconstruction of the hand. The traditional RRFF flap incorporates the radial artery from the forearm and is perfused by retrograde flow through the palmar arch. In patients with an abnormal Allen test because of an incomplete palmar arch, the traditional RRFF flap is contraindicated unless a vein graft is used to reconstruct the radial artery. A simpler alternative approach for hand reconstruction in such patients is a distally based RRFF flap based on radial artery perforators, which preserves the radial artery. We used RRFF flaps based on radial artery perforators in five patients who had palmar or dorsal soft-tissue loss. All five recovered full hand function, and only one had any complications (full-thickness skin graft loss at recipient site). The RRFF flap based on distal radial artery perforators is suitable for thin coverage of soft-tissue defects in hands with either a complete or an incomplete palmar arch.
Results of Vascularized Rib Grafts in Complex Spinal Reconstruction

Journal of Bone and Joint Surgery | March 1, 2007 | Volume: 89 | Issue: 2 | Pages: 128-141

10.2106/jbjs.f.01282 | PMID 17332132

BACKGROUND: The application of vascularized rib grafts in spine surgery has been limited to the treatment of kyphosis with anterior placement of the rib graft to facilitate anterior spine arthrodesis. The outcomes following use of vascularized rib grafts in complex spinal reconstruction have not been adequately evaluated. The purpose of this study was to determine the results, including the time to osseous union and complications, following anterior or posterior placement of pedicled vascularized rib grafts for complex spinal reconstruction. METHODS: The medical records and images of all patients in whom a vascularized rib graft had been used for a multisegmental spine reconstruction at a single institution between 1994 and 2004 were retrospectively reviewed. Eighteen patients (mean age, 45.3 years) who had been followed for an average of 31.8 months were identified. Details regarding indications, the levels that were spanned, the graft length, the time to union, and complications were evaluated. RESULTS: The preoperative diagnoses included metastatic or primary tumor (thirteen patients) and progressive kyphosis secondary to chronic osteomyelitis (two), injury (one), congenital anomalies (one), or implant failure (one). On the average, 4.4 levels were fused and 1.9 vertebral bodies were excised. All eighteen arthrodeses included various forms of allograft and/or autograft material, and instrumentation was used, in addition to the vascularized rib graft, in twelve patients. The mean rib length was 16.1 cm, and a rib between the fifth and eleventh ribs, inclusive, was used, depending on the location of the spinal reconstruction. The average time to union was 6.8 months, and all rib grafts united. There were no complications specific to the rib-harvesting procedure. CONCLUSIONS: The use of a vascularized rib graft in complex spinal reconstruction adds little time to the overall procedure, is associated with low morbidity, and appears to offer substantial benefits to the patient.
The Diagnostic Utility of Midcarpal Anesthetic Injection in the Evaluation of Chronic Wrist Pain

HAND | January 26, 2007 | Volume: 2 | Issue: 2 | Pages: 39-45

10.1007/s11552-006-9014-2 | PMID 18780061

The evaluation of chronic wrist pain can be a diagnostic dilemma. Lidocaine injections combined with corticosteroids are often used for both diagnosis and therapy. The purpose of this study was to determine if a midcarpal injection of lidocaine could serve as a diagnostic tool in patients with chronic wrist pain. Specifically, the relationship of pain relief from the injection and improvement of grip strength were compared to the presence of intracarpal pathology as confirmed by wrist arthroscopy. Forty-five patients with chronic wrist pain underwent a midcarpal injection of lidocaine with or without corticosteroids. Forty of the 45 underwent comcomitant steroid injections; a majority of the 40 patients reported relief of pain for two or more weeks. Improvement of pain and improvement of grip strength were determined. Each of these patients subsequently underwent a radiocarpal and midcarpal arthroscopy, and the pathologic findings of arthroscopy were compared to the improvement of pain and grip strength. These data were compared to a cohort of six volunteers without history of wrist pain or trauma that underwent midcarpal injection of lidocaine. Statistical analysis was performed using Reciever-Operator-Characteristic analysis. The average age of patients with chronic pain was 30.3 years, with an average of 9.8 months of wrist pain. The ultimate diagnoses included 35 patients with carpal instability dissociative, two with nondissociative instability, seven with complex instability of the carpus, three with extensor carpi ulnaris tendonitis and one with deQuervain's tenosynovitis. After lidocaine injection, the normal cohort had a mean loss of 2 kg (-5.3%) ( p=0.02) in grip strength, whereas the experimental cohort had a mean improvement in grip strength of 5.73 kg (34.4%). Improvement of pain after injection did not correlate with pathologic arthroscopic findings ( p=0.92). Improvement in grip strength after midcarpal lidocaine injection of 6 kg or 28% had a 73% sensitivity and a 70% specificity ( p=0.02) of having intracarpal pathology at the time of arthroscopy. Of the chronic wrist pain patients, only four had a normal arthroscopy, and the remainder had at least one area of significant pathology attributing to their pain. We conclude that a midcarpal injection of lidocaine can serve as an effective diagnostic tool in the evaluation of the patient with chronic wrist pain. Improvement of grip of 28% with or without relief of pain is highly correlated with intracarpal pathology.
Atypical Tensile-Sided Femoral Neck Stress Fractures

The American Journal of Sports Medicine | July 20, 2004 | Volume: 32 | Issue: 6 | Pages: 1528-1534

10.1177/0363546503262195 | PMID 15310582

Kienböck’s Disease and Gout

Journal of Hand Surgery | September 19, 2002 | Volume: 24 | Issue: 3 | Pages: 363-365

10.1054/jhsb.1999.0072 | PMID 10433457

A relationship between gout and Kienböck’s disease has been proposed on the basis of a previously published case report. A review of patients at our institution identified a single case with the combination of both Kienböck’s disease and gout. We believe that the association is coincidental.