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

Repair of distal finger soft-tissue defects with free fibular great toe neurovascular flaps

BACKGROUND

This work aimed to investigate the change in fingerprint depth and the recovery rule of fingerprint biological recognition function after repairing finger abdominal defects and rebuilding fingerprint with a free flap.

METHOD

From April 2018 to March 2023, we collected a total of 43 cases of repairing finger pulp defects using the free flap of the fibular side of the great toe with the digital nerve. After surgery, irregular follow-up visits were conducted to observe fingerprint clarity, perform the ninhydrin test or detect visible sweating with the naked eye. We recorded fingerprint clarity, nail shape, two-point discrimination, cold perception, warm perception and fingerprint recognition using smartphones. The reconstruction process of the repaired finger was recorded to understand the changes in various observation indicators and their relationship with the depth of the fingerprint. The correlation between fingerprint depth and neural repair was determined, and the process of fingerprint biological recognition function repair was elucidated.

RESULT

All flaps survived, and we observed various manifestations in different stages of nerve recovery. The reconstructed fingerprint had a clear fuzzy process, and the depth changes of the fingerprint were consistent with the changes in the biological recognition function curve.

CONCLUSION

The free flap with the digital nerve is used to repair finger pulp defects. The reconstructed fingerprint has a biological recognition function, and the depth of the fingerprint is correlated with the process of nerve repair. The fingerprint morphology has a dynamic recovery process, and it can reach a stable state after 6-8 months.

Success Rates of Finger Revascularization and Replantation

Background

Revascularization surgery has been reported to have a higher success rate than replantation due to sufficient venous return. However, in complex cases, success depends on a wide range of indications. This study aimed to investigate success rates in cohorts that included severe cases.

Methods

This single-center, noninterventional, retrospective cohort study included 292 patients (349 digits) who underwent revascularization or replantation at our institution between January 2000 and December 2022. Sex, age, smoking history, comorbidities, affected digit, amputation level, complete or incomplete amputation, type of fracture and mechanism, artery diameter, needle, vein anastomosis in the revascularization subgroup, vein grafting, warm ischemic time, and outcomes were investigated and compared between the revascularization and replantation subgroups of the distal and proximal amputation groups.

Results

In the distal amputation group, the arterial diameter in the revascularization subgroup was larger than that in the replantation subgroup (P < 0.05). In the proximal amputation group, the revascularization subgroup had a lower frequency of multiple amputations than the replantation subgroup (P < 0.05). Vein grafts were more frequently used in both revascularization subgroups than in the replantation subgroups (P < 0.05). However, the other injury severity indices were similar, and the success rates were not significantly different between the subgroups.

Conclusions

The revascularization success rate was similar to that of replantation. Vein anastomosis or vein grafting to the veins should be advocated for revascularization in severe cases where skin bridges may not have sufficient venous return.

Replantation of digit-tip amputation caused by crush injuries with supermicrosurgery technique

PURPOSE

Digit-tip amputation caused by crush injury is a common emergency scenario, and the management is full of challenges. The objective of this study was to demonstrate the application of the supermicrosurgery technique in replantation procedures for complex digit-tip amputations resulting from crush injuries, while also assessing functional and aesthetic outcomes.

METHODS

We conducted a retrospective analysis of the data from 12 patients who underwent replantation of 15 digits in our department between July 2022 and June 2023. The outcomes of replantation, functional recovery (including return to work, cold tolerance, bone union, DASH score, VAS score, and two-point discrimination test), aesthetic results (including digit appearance, nail deformity, and pulp atrophy), and patient satisfaction were assessed.

RESULTS

The amputation of 7 digits occurred within Tamai zone I level, 8 digits within Tamai zone II level, while 4 digits occurred within Ishikawa zone I level, 3 digits within Ishikawa zone II level, 7 digits within Ishikawa zone III level, and 1 digit within Ishikawa zone IV level. The replanted digits all survived (100%) without any indications of arterial insufficiency or venous congestion. The follow-up procedures were conducted on all 12 patients, with an average duration of 9.6 months (range, 6 to 18 months). The fracture successfully underwent healing at 9.2 weeks (range, 8 to 13 weeks). The mean VAS score was 1.75 points (range 0 to 4 points), the mean two-point discrimination test result was 5.72 mm (range 4.0 to 7.0 mm), and the mean DASH score was 9.78 points (range 3.33 to 22.5 points). All patients demonstrated cold tolerance and successfully resumed their pre-injury occupational activities. The nail deformity was observed in one digit following replantation within Tamai zone I, and in three digits following replantation within Tamai zone II; moreover, eight digits exhibited varying degrees of pulp atrophy. All patients expressed satisfaction with both functional and aesthetic outcomes.

CONCLUSION

The successful replantation of digit-tip amputation caused by crush injury can be achieved through the application of supermicrosurgery technique, resulting in improved functional and aesthetic outcomes. Digit-tip replantation is a favorable and meaningful procedure with high patient satisfaction.

Effect of multiple-digit replantation in patients with amputated digits

PURPOSE

The replantation of multiple amputated digits is a technically challenging procedure for reconstructive surgeons that requires more time than the replantation of a single digit. We evaluated the effect of multiple-digit replantation on the success of digital replantation.

METHODS

Patients who experienced digital amputation and underwent digital replantation from January 2018 to December 2021 were studied retrospectively. Patients who experienced successful and failed replantation were compared, as were digits that survived or became necrotic after replantation. A multivariate logistic regression (MLR) analysis was performed to evaluate the independent factors of replanted digit survival.

RESULTS

There were 378 patients with 497 amputated digits who underwent digital replantation. Of all 378 patients, 298 underwent single-digit replantation, and the other 80 patients underwent multiple-digit replantation. A total of 83.3% of the replanted digits survived (414 of 497). Compared with patients with surviving replanted digits, significantly more patients with necrotic replanted digits underwent multiple-digit replantation (37.7% vs. 17.5%, p < 0.001). On the other hand, a digit that developed necrosis after replantation was more likely to have been involved in the replantation of three or more digits (16% vs. 29%, p = 0.005). The subsequent MLR analysis revealed that the likelihood of necrosis was 2.355 (p = 0.003) times higher in the replantation of three or more digits than in the replantation of one or two digits.

CONCLUSION

Patients who underwent multiple-digit replantation exhibited a higher incidence of necrosis in the replanted digits. In cases involving patients with multiple-digit amputation, it is crucial to prioritize and perform selective replantation based on the amputated digits.

Is Prolonged Use of Antibiotic Prophylaxis and Postoperative Antithrombotic and Antispasmodic Treatments Necessary After Digit Replantation or Revascularization?

BACKGROUND

Ensuring the patency of repaired vessels is pivotal in improving the success rate of digit replantation. There is no consensus on how to best approach postoperative treatment for digit replantation. The influence of postoperative treatment on the risk of failure of revascularization or replantation remains unclear.

QUESTIONS/PURPOSES

(1) Is there an increased risk of postoperative infection with early discontinuation of antibiotic prophylaxis? (2) How are anxiety and depression affected by a treatment protocol consisting of prolonged antibiotic prophylaxis and administration of antithrombotic and antispasmodic drugs and by the failure of a revascularization or replantation procedure? (3) Are there differences in the risk of revascularization or replantation failure based on the number of anastomosed arteries and veins? (4) What factors are associated with failure of revascularization or replantation?

METHODS

This retrospective study was conducted between July 1, 2018, and March 31, 2022. Initially, 1045 patients were identified. One hundred two patients chose revision of amputation. In all, 556 were excluded because of contraindications. We included all patients in whom the anatomic structures of the amputated part of the digit were well preserved, and those with an ischemia time for the amputated part that did not exceed 6 hours. Patients in good health without any other serious associated injuries or systemic diseases and those without a history of smoking were eligible for inclusion. The patients underwent procedures that were performed or supervised by one of four study surgeons. Patients were treated with antibiotic prophylaxis (1 week); patients treated with antithrombotic and antispasmodic drugs were categorized into the prolonged antibiotic prophylaxis group. The remaining patients treated with antibiotic prophylaxis for less than 48 hours and no antithrombotic and no antispasmodic drugs were categorized into the nonprolonged antibiotic prophylaxis group. Postoperative follow-up was for a minimum of 1 month. Based on the inclusion criteria, 387 participants with 465 digits were selected for an analysis of postoperative infection. Twenty-five participants with a postoperative infection (six digits) and other complications (19 digits) were excluded from the next stage of the study, in which we assessed factors associated with the risk of failure of revascularization or replantation. A total of 362 participants with 440 digits were examined, including the postoperative survival rate, variation in Hospital Anxiety and Depression Scale scores, the association between the survival rate and Hospital Anxiety and Depression Scale scores, and the survival rate based on the number of anastomosed vessels. Postoperative infection was defined as swelling, erythema, pain, purulent discharge, or a positive bacterial culture result. Patients were followed for 1 month. The differences in anxiety and depression scores between the two treatment groups and the differences in anxiety and depression scores based on failure of revascularization or replantation were determined. The difference in the risk of revascularization or replantation failure based on the number of anastomosed arteries and veins was assessed. Except for statistically significant variables (injury type and procedure), we thought that the number of arteries, number of veins, Tamai level, treatment protocol, and surgeons would be important. A multivariable logistic regression analysis was used to perform an adjusted analysis of risk factors such as postoperative protocol, injury type, procedure, number of arteries, number of veins, Tamai level, and surgeon.

RESULTS

Postoperative infection did not appear to increase without prolonged use of antibiotic prophylaxis beyond 48 hours (1% [3 of 327] versus 2% [3 of 138]; OR 2.4 [95% confidence interval (CI) 0.5 to 12.0]; p = 0.37). Intervention with antithrombotic and antispasmodic therapy increased the Hospital Anxiety and Depression Scale scores for anxiety (11.2 ± 3.0 versus 6.7 ± 2.9, mean difference 4.5 [95% CI 4.0 to 5.2]; p < 0.01) and depression (7.9 ± 3.2 versus 5.2 ± 2.7, mean difference 2.7 [95% CI 2.1 to 3.4]; p < 0.01). In the analysis based on the failure of revascularization or replantation, the Hospital Anxiety and Depression Scale scores for anxiety (11.4 ± 4.4 versus 9.7 ± 3.5, mean difference 1.7 [95% CI 0.6 to 2.8]; p < 0.01) and depression (8.5 ± 4.6 versus 7.0 ± 3.1, mean difference 1.5 [95% CI 0.5 to 2.5]; p < 0.01) were higher in the failed revascularization or replantation group than in the successful revascularization or replantation group. There was no increase in the artery-related risk of failure (one versus two anastomosed arteries: 91% versus 89%, OR 1.3 [95% CI 0.6 to 2.6]; p = 0.53). For patients with anastomosed veins, a similar outcome was observed for the two vein-related risk of failure (two versus one anastomosed vein: 90% versus 89%, OR 1.0 [95% CI 0.2 to 3.8]; p = 0.95) and three vein-related risk of failure (three versus one vein anastomosed: 96% versus 89%, OR 0.4 [95% CI 0.1 to 2.4]; p = 0.29). Factors associated with failure of revascularization or replantation included the mechanism of injury (crush: OR 4.2 [95% CI 1.6 to 11.2]; p < 0.01, avulsion: OR 10.2 [95% CI 3.4 to 30.7]; p < 0.01). Revascularization had a lower risk of failure than replantation (OR 0.4 [95% CI 0.2 to 1.0]; p = 0.04). Treatment with a protocol of prolonged antibiotics, antithrombotics, and antispasmodics was not associated with a lower risk of failure (OR 1.2 [95% CI 0.6 to 2.3]; p = 0.63).

CONCLUSION

With proper wound debridement and patency of repaired vessels, prolonged use of antibiotic prophylaxis and regular antithrombotic and antispasmodic treatment may not be necessary for successful digit replantation. However, it may be associated with higher Hospital Anxiety and Depression Scale scores. Postoperative mental status is associated with digit survival. Well-repaired vessels, instead of the number of anastomosed vessels, could be critical to survival and decrease the influence of risk factors. Further research on consensus guidelines that compare postoperative treatment and the surgeon's level of expertise after digit replantation should be conducted at multiple institutions.

LEVEL OF EVIDENCE

Level III, therapeutic study.

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

No difference in the success rate has been reported between the vein graft and non-vein graft groups in replantation/revascularization. However, this depends on a wide range of indications in difficult cases. This study aimed to investigate the selection bias in avoiding vein grafts.

Methods

This is a single-center, noninterventional, retrospective cohort study comprising 229 patients (277 digits) who underwent replantation/revascularization between January 2000 and December 2020 at our institution. Sex, age, smoking history, comorbidities, affected side, level of amputation, complete or incomplete amputation, type of fracture and mechanism, diameter of the artery, needle, warm ischemic time, and results were investigated and compared between the subgroups with and without vein graft. Results were investigated between the subgroups with and without a vein graft in the distal and proximal groups.

Results

In the distal group, the mean arterial diameter of the vein graft subgroup was larger than that of the non-vein graft subgroup [0.7 (0.1) mm and 0.6 (0.2) mm, respectively, P < 0.05]. In the proximal group, the vein graft subgroup had higher severity than the non-vein graft subgroup (comminuted fracture, 31.1% versus 13.4%; and avulsion or crush amputation, 57.8% versus 37.1%, respectively, P < 0.05). However, the success rate was not significantly different between the aforementioned subgroups.

Conclusion

There was no significant difference between the vein graft and non-vein graft subgroups owing to the selection bias avoiding small arteries in the distal amputation and the absence of said bias in the proximal amputation.

A Nationally Validated Novel Risk Assessment Calculator for Prediction of Unplanned Reoperations and Readmissions in Hand Surgery

BACKGROUND

Risk predictors are an emerging tool as the need for individualized risk estimation in clinical decision-making persists. Existing risk indices have had limited success in accurately predicting hand surgery risks. This study provides a novel risk calculator for reliably predicting reoperations and readmissions in hand surgery.

METHODS

Hand surgeries from the National Surgical Quality Improvement Program (NSQIP) 2012-2019 database were identified. Independent predictors of 30-day unplanned reoperation and readmission were identified in the modeling sample (2012-2019) and subsequently weighted to generate a Novel Risk Score (NRS). The NRS was validated on a 2020 NSQIP hand surgery cohort and compared to the modified frailty index (mFI-5) and the modified Charlson Comorbidity Index (mCCI) with receiver operating characteristics (ROC) analysis.

RESULTS

Eighty-three thousand four hundred nine hand surgeries were identified for modeling. Reoperations and readmissions rates were 1.1% and 1.3%, respectively. Independent risk factors included male gender, inpatient status, smoking, dialysis dependence, transfusion within 72 h of surgery, wound classification, ASA class, diabetes mellitus, CHF, sepsis or septic shock, emergent case, and operative time longer than 75 min (all P < 0.05). ROC analysis of the 2020 cohort rendered an area under the curve (AUC) of 0.730, which demonstrates the accuracy of this prediction model. The mFI-5 and mCCI rendered AUCs of 0.580 and 0.585, respectively.

CONCLUSION

We present a validated risk prediction tool for unplanned reoperations and readmissions following hand surgery that outperforms the mFI-5 and mCCI that are available online. Future studies should evaluate clinical efficacy.