Investigation of Predictors of Successful Replantation of Distal Digits at the Nail Bed Level: The Contribution of Digital Nerve Repair to Survival Rate

Abstract

Background: Replantation of amputated digits at the nail bed level is surgically challenging and differs from replantation at a more proximal amputation level. This study aimed to determine the predictors influencing the success rate of fingertip replantation. Methods: Overall, 239 digits of 226 patients who underwent replantation surgery from August of 2009 to March of 2020 were considered. A total of 15 independent variables (i.e., sex; age; injured hand; digit; history of smoking; history of hypertension or diabetes; injury mechanism; amputation level; ischemia duration; surgeon’s expertise; numbers of repaired arteries, veins, and nerves; and the need for a vein graft) were investigated for their effects on the survival of the replanted digits. Results: Of all 239 digits, 190 (79.5 percent) survived. Univariate analysis indicated that non–crush-avulsion injury, expertise and experience of the surgeon, vein repair, and nerve repair contributed to increasing the survival rate. Binary logistic regression analysis demonstrated that injury mechanism, vein repair, and nerve repair were significant predictive factors. In addition, in non–vein-repaired, blunt cut, or Ishikawa subzone II cases, digital nerve repair contributed significantly to promote the success rate relative to vein-repaired, crush-avulsion–type injury, and subzone I cases. Conclusions: Vein repair, nerve repair, non–crush-avulsion injury, and surgeon’s expertise and experience were the predictors for successful replantation. Intraoperative vein and nerve repair are recommended to improve the survival rate of fingertip replantation at the nail bed level. CLINICAL QUESTION/LEVEL OF EVIDENCE: Risk, III.

Selection Bias in Avoiding Vein Graft in Replantation/Revascularization May Exist in Distal and Proximal Amputations, Respectively

“…Recent studies have suggested that the success rate is similar between replantation/revascularization with and without vein graft. [4][5][6][7][8][9] However, the success rate of replantation/revascularization using interpositional vein graft may be improved if difficult cases are avoided.…”

“…The success rate of replantation/revascularization varies between studies and depends on the surgeon's technique and wide-ranging indications in difficult cases. [1][2][3][4][5] A vein graft is more readily used in crush and avulsion amputations compared with guillotine amputations. 6 According to recent reports, there is no difference in the success rate between vein graft and non-vein graft groups.…”

“…6 According to recent reports, there is no difference in the success rate between vein graft and non-vein graft groups. [4][5][6][7][8][9] However, the same concern may occur in replantation/ revascularization using the vein graft. The success rate of replantation/revascularization using interpositional vein graft may also depend on the surgeon's technique and various indications; in addition, there may be a selection bias in avoiding a vein graft.…”

“…7 Former reports solely focused on the replantation/ revascularization of the fingertips or did not consider different aspects between the amputation of fingertips and proximal fingers. [4][5][6][7][8][9] We divided the cohort into the fingertip and proximal finger groups and investigated each group separately. This study aimed to investigate the occurrence of selection bias in performing a vein graft in the distal and proximal amputations, as well as whether said selection bias affects the success rate.…”

“…6 According to recent reports, there is no difference in the success rate between vein graft and non–vein graft groups. 4–9…”