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

[Successful microsurgical Replantation of a completely amputated Finger Pulp frozen in Ice: Case Report and Literature Review]

The microsurgical replantation of incorrectly stored and transported amputates is generally considered impossible and without prospects of success. In particular, this applies to amputates that show cold damage due to the freezing of tissue. We present a case of successful replantation of an amputated finger pulp frozen in ice. We provide an overview of the literature on the subject of incorrect storage of amputates and the prospects of success for replantation.

Evidence-based postoperative replantation protocols

Postoperative care is essential to upper extremity replantation success and includes careful and frequent monitoring of the replanted part. During this period, pharmacologic agents such as antithrombotic and anticoagulants may prevent complications such as arterial thrombosis and venous congestion. Dressings and therapy can also impact short- and long-term outcomes following replantation. This article reviews the literature to provide guidance for postoperative protocols following upper extremity replantation.

Limiting Levels of Fingertip Replantation Without Venous Anastomosis

PURPOSE

This study aimed to compare the success rates of fingertip replantation with and without venous anastomosis.

METHODS

This retrospective study included 132 patients with 148 fingertip injuries who had undergone fingertip replantation (Ishikawa's classification I‒IV) between 2003 and 2020 at our hospital. Among them, 117 and 15 were men and women respectively, and their mean age was 43 years. There were 53, 44, and 51 fingertips with Ishikawa subzone II, III, and IV amputations respectively, and no cases were classified as Ishikawa subzone I. Venous anastomosis was performed on 64 fingertips (group A). This was not possible in the remaining 84 fingertips; thus, an external bleeding method was used (group B). Our external bleeding protocol consisted of 4-hourly skin pricks of the distal pulp with a 23-gauge needle for the first 5 days. The analyses included survival rates, hemoglobin levels (Hb), and blood transfusions administered.

RESULTS

The overall survival rate was 90.5% (134 of 148). In group A, survival was achieved in 92.3%, 100%, and 94.3% of those with subzones II, III, and IV amputations, respectively. In group B, survival was achieved in 100%, 82.1%, and 62.5% of those with subzones II, III, and IV, respectively. Subzone IV in group B showed a significantly lower rate of replantation success. In groups A and B, the preoperative and 7-day postoperative Hb levels were 14.5 g/dL and 14.6 g/dL, and 11.3 g/dL, and 11.6 g/dL, respectively. In addition, blood transfusion was required for five patients (7.9%) in group A and six patients (7.9%) in group B. Thus, the Hb levels and blood transfusion administered were similar between the two groups.

CONCLUSIONS

Subzone IV is an important threshold for artery-only replantation. Furthermore, our external bleeding protocol is a safe and effective method.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

A Comparison of Outcomes between Finger and Pulp Replantation/Revascularization in a Single Center

Supermicrosurgery has allowed the replantation/revascularization of the pulp, but how does this currently compare with more proximal digit replantation/revascularization?

Methods

In a retrospective case study over a 5-year period at our institute, a total of 21 patients (n = 21) had either finger or pulp replantation-revascularization posttrauma. All pulp replants had a single-vessel anastomosis viz., "artery-to-artery" or "artery-to-vein" only, with venous outflow dependent on the skin-shave technique, while more proximal replants had both arterial and venous anastomoses. Age, sex, ischemic time, handedness, smoker status, and injury-replant interval were compared between the two groups, with all procedures performed by a single surgeon. The outcome parameters studied were length of hospital stay, timeline for wound healing, viability, and functional outcomes.

Results

Our patients consisted of 18 men and three women, of which 14.3% were smokers and 85.7% were right-handed. There were 11 finger replantation/revascularizations (n = 11) versus 10 pulp replantation/revascularizations (n = 10). The average age of digit replantation/revascularization patients was 44.8 years compared with 26.4 years in pulp replantation/revascularization patients (Student t test, P = 0.04). Mean ischemia time in digital replants was 67 minutes versus 32.3 minutes in pulp replantation/revascularization (Student t test, P = 0.056). Digital replantation/revascularization was viable in 72% of cases versus a 90% viability in the pulp subcohort.

Conclusions

In our patient cohort, pulp replantation/revascularizations produced better postoperative viability. Where supermicrosurgery expertise is available, pulp replantation/revascularization should be considered a worthwhile option when compared with digital replantation/revascularization.

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.

Pulp De-epithelialization for Venous Outflow Augmentation after Digital Replantation

Traumatic amputation injuries account for a substantial portion of emergency department visits. This includes digital amputations that may be considered for replantation. Following surgery, venous congestion is the most common cause of replant failure. To address this, several methods have been proposed to augment venous outflow. In this article, a simple and straightforward method that can be utilized to establish or augment venous outflow in cases of venous insufficiency is described. This method entails de-epithelization of the replanted digit pulp skin with use of postoperative anticoagulation. The area can be further expanded or stimulated to increase bleeding as needed and is allowed to heal by secondary intention. This method allows for reliable venous outflow with relative ease of implementation.

Postoperative Digit and Hand Replantation Protocols: A Review of the Literature

Successful replantation and revascularization of the hand and digit require a skilled team with urgent access to an operating room with microsurgical capabilities. Although careful indications and surgical techniques contribute to success, postoperative management also plays a vital role in the survival of a replanted digit. Previous research has assessed surgical efficiency and techniques to conduct these procedures, but few studies evaluate postoperative protocols to care for patients undergoing these procedures. Because of the lack of high-level evidence specific to replantation, many common postoperative practices related to monitoring, anticoagulation, and diet have been inferred from elective microsurgical procedures, despite notable differences in operating conditions. The highest level of evidence pertaining to digital replantation was found with the use of peripheral nerve blockade, leeching/bleeding, and nicotine use. This review provides an in-depth evaluation of the literature and insight into the rationale and level of evidence that support each postoperative intervention. It highlights institutional variability and a paucity of high-level evidence pertaining to this topic while identifying the areas of future research.

Fingertip Replantation: Technique Details and Review of the Evidence

Fingertip replantation is technically challenging, but in a motivated patient excellent aesthetic and functional outcomes can be achieved. Fingertip microanatomy by zone is described to facilitate the classification and treatment of these injuries. In this article, we outline our preferred techniques for fingertip replantation and review the current body of evidence surrounding indications, techniques, and outcomes while highlighting opportunities for future study.