Intramedullary Venous Drainage System for Distal Fingertip Replantations

Amputated Digit Replantations: Critical Digit Ischemia Timing, Temperature, and Other Predictors of Survival

INTRODUCTION

A common consideration for replantation success is the ischemia time following injury and the preservation temperature. A classic principle within the hand surgery community describes 12 hours of warm ischemia and 24 hours of cold ischemia as the upper limits for digit replantation; however, these limits are largely anecdotal and based on older studies. We aimed to compare survival data from the large body of literature to aid surgeons and all those involved in the replantation process in hopes of optimizing success rates.

METHODS

The PubMed database was queried on April 4th, 2023, for articles that included data on digit replantation survival in terms of temperature of preservation and ischemia time. All primary outcomes were analyzed with the Mantel-Haenszel method within a random effects model. Secondary outcomes were pooled and analyzed using the chi-square statistic. Statistical analysis and forest plot generation were completed with RevMan 5.4 software with odds ratios calculated within a 95% confidence interval.

RESULTS

Our meta-analysis identified that digits preserved in cold ischemia for over 12 hours had significantly higher odds of replantation success than the amputated digits replanted with 0-12 hours of warm ischemia time ( P ≤ 0.05). The odds of survival in the early (0-6 hours) replantation group were around 40% greater than the later (6-12 hours) replantation group ( P ≤ 0.05). Secondary outcomes that were associated with higher survival rates included a clean-cut amputation, increased venous and arterial anastomosis, a repair that did not require a vein graft, and replants performed in nonsmokers ( P ≤ 0.05).

DISCUSSION

Overall, these findings suggest that when predicting digit replantation success, time is of the essence when the digit has yet to be preserved in a cold environment. This benefit, however, is almost completely diminished when the amputated digit is appropriately maintained in a cold environment soon after injury. In conclusion, our results suggest that there is potential for broadening the ischemia time limits for digit replant survival outlined in the literature, particularly for digits that have been stored correctly in cold ischemia.

Fingertip Replantation: Surgical Technique, Tips, and Tricks

SUMMARY

Replantation of fingertip amputations restores the original tissue and is the ideal treatment to provide the best aesthetic and functional outcome. However, successful fingertip replantation is considered challenging because it requires supermicrosurgery techniques. This article provides a detailed surgical technique for fingertip replantation and the authors' preferences and recommendations. In the authors' experience, the most important factors for successful fingertip replantation are meticulous vascular dissection, reliable arterial repair, and venous anastomosis to avoid postoperative venous congestion. Proximal arterial dissection until pulsatile bleeding is encountered avoids the zone of vascular injury, and is particularly important in crush or avulsion amputations. Distal arterial dissection is performed until undamaged intima is identified. The authors believe anastomosis to the central artery is reliable even in a Tamai zone II amputation. When an arterial defect is present, the authors recommend using a vein graft to anastomose to the central artery. In addition, the authors highly recommend at least one venous anastomosis to avoid postoperative venous congestion. In Tamai zone I, available veins can be found on the palmar side of the pulp. It is important to search directly below the dermis and remove adipose tissue around the vessels to secure space for anastomosis. The authors consider nerve suture in Tamai zone I and II replantations inessential, because spontaneous sensory recovery can be expected. Postoperative management of venous congestion, spasm in artery, and arterial thrombosis are as important as surgery.

Sequential Clinical Recovery after Replantation for Complete Finger Amputation in Tamai Zone 1

Background  The clinical results of replantation for an amputated distal finger are functionally acceptable. However, few reports exist regarding sequential clinical postoperative recovery. The purpose of this study was to examine the clinical recovery at every 3 months up to 1 year postoperatively. Methods  Nineteen patients (16 patients were men), representing 19 fingers with complete amputation at Tamai's zone 1 and replanted successfully, were included in this study. Total active motion (TAM), grip strength (GS), Semmes-Weinstein monofilament (SW) test result, static two-point discrimination (s2PD), and Disability of the Arm, Shoulder, and Hand (DASH) score questionnaire results were obtained postoperatively at 3, 6, 9, and 12 months. Pulp atrophy and nail deformity were assessed at 12 months postoperatively. Results  The postoperative %TAM (compared to the uninjured side, 81.8 ± 18.1 at 3 months vs. 91.5 ± 11.9 at 6 months, p  < 0.01), %GS (compared with the uninjured side, 61.3 ± 25.9 at 3 months vs. 78.3 ± 20.4 at 6 months, p  = 0.02), s2PD (excellent and good/poor; 7/12 at 3 months vs. 18/1 at 6 months, p  < 0.01), and DASH scores (26.1 ± 23.1 at 3 months vs. 12.0 ± 12.9 at 6 months, p  < 0.01) recovered significantly from 3 to 6 months but did not change significantly from 6 months onward. The SW test results showed a significant recovery between 3 and 12 months postoperatively (2.83 and 3.61/4.31, 6.65, and undetectable, 1/18 at 3 months vs. 7/12 at 12 months, p  = 0.04). The DASH score at 12 months postoperatively was significantly associated with %TAM ( r  = -0.64, p  < 0.01) and %GS ( r  = -0.58, p  < 0.01) at 12 months postoperatively and age ( r  = 0.52, p  = 0.02). Five fingers had pulp atrophy and four fingers had nail deformity. Conclusion  This 1-year follow-up study showed the sequential clinical recovery after replantation for complete amputation in Tamai zone 1. Postoperative %TAM, %GS, and the DASH score recovered significantly between 3 and 6 months but significant recovery up to 1 year was not observed.

Management of Artery-Only Digit Replantation: A Systematic Review of the Literature

BACKGROUND

Artery-only replantation may be necessary in circumstances when venous repair cannot be performed due to their size or vessel injury. Venous congestion of the replanted part is inevitable. A systematic review was performed to identify techniques for mitigating congestion and analyze the outcomes of those techniques.

METHODS

A comprehensive literature search was performed to identify relevant articles related to artery-only replantation. An initial query identified 1286 unique articles. A total of 55 articles were included in the final review. Included studies were categorized by decongestive technique. Data from each article included the number of patients treated, level of amputation, graft use, anticoagulation or antiplatelet therapy, replant viability, and follow-up duration. Weighted averages were determined from studies that reported five or more digits.

RESULTS

A total of 1498 individual digital replantations were described. Very rarely did studies report artery-only replantation proximal to the distal interphalangeal joint. An overall survival rate of 78.5 percent was found irrespective of technique but was variable based on each particular study. Studies utilizing medicinal leech therapy were more likely to report use of intravenous anticoagulation, whereas surface bleeding techniques were more likely to report use of topical or local anticoagulant.

CONCLUSIONS

Lack of a vein for anastomosis should not be regarded as a contraindication to replantation. These digits instead require a method to establish reliable drainage sufficient to allow for low resistance inflow and maintain a physiologic pressure gradient across capillary beds. The surgeon should select a decongestive technique that best suits the patient and their specific injury.

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

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.

Negative-Pressure Wound Therapy Application in Fingertip Replantations and a Systematic Review

BACKGROUND

Fingertip replantation is technically challenging. Venous congestion is one of the most common causes of replantation failure. Therefore, various venous drainage procedures and salvage techniques have been used in venous congestion. Negative-pressure wound therapy has proven beneficial in limb injuries, yet limited studies of fingertip replantation exist. This study aims to analyze risk factors in fingertip replantation and to evaluate the feasibility and clinical benefits of negative-pressure wound therapy compared with other salvage techniques.

METHODS

From January of 2015 to December of 2019, 27 patients (27 digits) who experienced fingertip amputation over Tamai zone I or II underwent replantation. Salvage negative-pressure wound therapy was applied for venous congestion postoperatively. Replantation data were collected for further analysis.

RESULTS

The overall survival rate of digit replantation with salvage negative-pressure wound therapy was 92.6 percent (25 of 27). The blood transfusion rate was 11.1 percent (three of 27). The average hospitalization time was 8.04 ± 1.43 days and the median duration of negative-pressure wound therapy was 6 days (range, 4 to 8 days; interquartile range, 2 days). There is no significant difference between the survival and failure groups for all risk factors evaluated.

CONCLUSION

Negative-pressure wound therapy is a simple and effective salvage option to relieve venous congestion in fingertip replantation with a satisfactory survival rate, low blood transfusion rate, and short inpatient stay.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, IV.

Assessment of sensory outcomes after successful fingertip replantation with or without nerve repair according to amputation level

BACKGROUND

Good sensory outcome in fingertip replantation is a major part of the success of reconstruction and using the finger. Although some sensorial outcomes have been reported in various series in the literature, there is no controlled study, which demonstrates the anatomical levels where nerve repair should or should not be performed. We aimed to assess sensorial outcomes of fingertip amputations with or without nerve coaptation according to amputation level.

METHODS

Between January 2013 and July 2018, patients with Tamai Zone 1 and Zone 2 amputations underwent replantation. The patients were divided two main groups. Patients underwent nerve coaptation were grouped as Group 1, and those coaptation not performed as Group 2. In addition, subgroups were designed according to level of the amputation. Tamai zone 1 amputations were grouped as groups 1a and 2a. Tamai zone 2 amputations were grouped as groups 1b and 2b. The mean age was 30.8 ± 30.8 years in Group 1a, 33.2 ± 12.6 years in Group 1b, 34.1 ± 13.6 years in Group 2a, 34.3 ± 11.1 years in Group 2b. Type of injury were evaluated as clean cut (with knife, saw etc.), moderately crushed, and severely crushed and/or avulsion. In Group 1a, one prominent branch of the nerve was repaired, and in Group 1b, the nerve in both side was repaired. The mean duration of replantation in Group 1a was 1 h and 40 min (1 h and 15 min-2 h), whereas this time was 1 h and 15 min (1 h - 1 h and 35 min) in Group 2a. Then, 2 h 15 min (1 h and 55 min-2 h and 50 min) in Group 1b, and 2 h (1 h and 45-2 h 25 min) in Group 2b. Mean age, type of injury and length of follow-up were statistically compared. Sensorial outcome was evaluated by 2-point discrimination test and the Semmes-Weinstein test.

RESULTS

According to the Semmes-Weinstein test, 33% of the fingers tested were normal, 58% had diminished light touch, 8% had diminished protective sensation, and 0% had loss of protective sensation in Group 1a; In Group 1b, these values were 35% (7/20), 55% (11/20), 10% (2/20), 0%; in Group 2a, 38% (6/16), 56% (9/16), 6% (1/16), 0%; in Group 2b, 25% (4/16), 44% (7/16), %25 (4/16), 6% (1/16), respectively Mean static two-point discriminations in Groups 1a, 1b, 2a, and 2b were 4.17 ± 0.58, 4.55 ± 0.69, 4.25 ± 0.68, and 5.9 ± 1.26 mm, respectively. The mean follow-up duration was 24 months in Group 1a, 24 months in Group 1b, 26 months in Group 2a, 21 months in Group 2b. Then, 17 (3 in Group 1a, 6 in Group 1b, 4 in Group 2a, 4 in Group 2b) of the 64 fingers were clean cut amputation, 45 (9 in Group 1a, 14 in Group 1b, 11 in Group 2a, 11 in Group 2b) were moderately crushed amputation, and 2 (1 in Group 2a, 1 in Group 2b) were severely crushed and/or avulsion injury. There was no statistically significant difference between groups 1a and 2a (p = .71). On the other hand, there was a statistically significant increase in sensory outcomes of patients in Group 1b compared to Group 2b (p = .009). There was no statistically significant between the groups in terms of mean age, type of injury and length of follow-up.

CONCLUSION

We think that nerve repair does not have a positive effect on sensorial recovery in Tamai Zone 1 amputations, but nerve coaptation should be performed in Tamai Zone 2 replantations if possible for better sensorial result.

Long-Term Outcomes of Successful Fingertip Replantation: A Follow-Up of at Least 10 Years

BACKGROUND

The purpose of this study was to evaluate the long-term outcome of successful fingertip replantations with more than 10 years of follow-up after surgery.

METHODS

A total of 34 successfully replanted digits in 31 patients with a mean period to follow-up of 16.5 years were included in this study. The main outcome measures were time to return to work, pain, cold intolerance, sensory recovery, nail deformity, grip strength, range of motion of the thumb interphalangeal or finger distal interphalangeal joint, fingertip atrophy, nonunion, bone shortening, use in activities of daily living, and patient satisfaction.

RESULTS

None of the patients reported chronic pain. No cold intolerance was experienced in 32 digits. Semmes-Weinstein monofilament testing showed recovery of protective sensation in 27 digits. The moving two-point discrimination test showed excellent or good recovery in 91 percent of the patients. Sensory recovery was satisfactory, and there was no significant difference regardless of nerve repair or injury type. Moderate to severe nail deformity was found in six digits. Fingertip atrophy was evaluated by comparing the volume of the replanted fingertip with the contralateral digit. The volume was 82 ± 17 percent of the contralateral normal side. There was no significant difference in the volume comparing the level of amputation, injury type, or incidence of postoperative vascular complication. Ninety-seven percent of the patients were satisfied with the results.

CONCLUSION

Long-term outcome of fingertip replantation more than 10 years after surgery was found to be favorable.

Survival and Comparison of External Bleeding Methods in Artery-Only Distal Finger Replantations

PURPOSE

If there are no veins available in a distal amputation, an artery-only replantation is performed, and an external bleeding method is commonly used. We conducted a survival analysis in a large series of artery-only replantations and compared 2 different external bleeding methods in artery-only distal replantations: nail matrix or hyponychial area bleeding and pulp skin area bleeding, which we have called the crater method.

METHODS

Two hundred twenty-eight artery-only distal finger replantations in 199 patients were included in the study. The replanted digits were divided into 2 groups according to the external bleeding methods. One group (n = 94; 41.2%) included the patients in whom the external bleeding was performed using a traditional nail bed incision and the second group (n = 134; 58.8%) included the patients in whom external bleeding was performed using the crater method. The finger survival rates and postoperative circulatory problems were examined. The impact of the injury mechanism, injury level, and external bleeding method on survival were evaluated.

RESULTS

Clinical findings indicating venous insufficiency were observed in 198 (86.8%) replanted fingers. One hundred eighty-two (79.8%) survived, and complete necrosis developed in 46 (20.2%). Viability was maintained in 84% of patients treated with the nail bed bleeding method and 76.9% of patients treated using the crater method. Clean-cut cases had the best results and subzone 3 cases had the worst results.

CONCLUSIONS

The artery-only replantation was associated with a 79.8% survival rate. The method of achieving venous outflow did not appear to have an impact on survival.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

Retrograde versus anterograde palm venous anastomosis in avulsion distal fingertip trauma: Functional and therapeutic outcomes (FTO) analysis

BACKGROUND/OBJECTIVES

The advance in the microvascular surgeries has made successful replantation of amputee fingertip or toe. Anterograde palm venous anastomosis is generally preferred in avulsion distal fingertip trauma surgeries but is technically challenging. The retrograde venous anastomosis is proved to be easy and effective in larger defects hand reconstruction surgeries. The purposes of the analysis were to compare functional and therapeutic outcomes of retrograde palm venous anastomosis against anterograde palm venous anastomosis in the avulsion distal fingertip and thumb microvascular surgery.

METHODS

Digits were replanted by retrograde palm venous anastomosis (n = 130, RPVA cohort) or anterograde palm venous anastomosis (n = 220, APVA cohort). The data regarding the survival of transplanted tissues, analgesia, 2-points discrimination, and total active movement after 2-years of surgeries were collected and analyzed.

RESULTS

A higher percentage of digits with survived transplanted tissues found in the RPVA cohort than the APVA cohort (p = 0.004). 2-points discrimination found higher in the APVA cohort than the RPVA cohort (5.22 ± 1.56 mm vs. 4.81 ± 1.39 mm, p = 0.014). The pain was fewer in the RPVA cohort than the APVA cohort (p = 0.041). A total active motion was higher in the RPVA cohort than the APVA cohort (p = 0.025). Anterograde palm venous anastomosis (p = 0.021) were associated with the failure of transplanted digits tissues.

CONCLUSIONS

Retrograde palm venous anastomosis had better functional and therapeutic outcomes than anterograde palm venous anastomosis in avulsion distal fingertip trauma.

LEVEL OF EVIDENCE

III.