Antithrombotic Therapies in Digit Replantation with Papaverine Administration: A Prospective, Observational Study

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.

Development and external validation of a prediction model for digit replantation failure after traumatic amputations based on a prospective multicenter cohort

BACKGROUND

Failure of digit replantation after traumatic amputation is difficult to predict. The authors aimed to develop a prognostic model to better identify factors that better predict replantation failure following traumatic digit amputation.

MATERIALS AND METHODS

In this multicenter prospective cohort, the authors identified patients who had received digit replantation between 1 January 2015 and 1 January 2019. Univariable and multivariable analyses were performed successively to identify independently predictive factors for failure of replanted digit. To reduce overfitting, the Bayesian information criterion was used to reduce variables in the original model. Nomograms were created with the reduced model after model selection. This model was then internally validated with bootstrap resampling and further externally validated in validation cohort.

RESULTS

Digit replantation was failed in 101 of 1062 (9.5%) digits and 146 of 1156 digits (12.6%) in the training and validation cohorts, respectively. The authors found that six independent prognostic variables were associated with digit replantation failure: age, mechanism of injury, ischemia duration, smoking status, amputation pattern (complete or incomplete), and surgeon's experience. The prediction model achieved good discrimination, with concordance indexes of 0.81 (95% CI: 0.76-0.85) and 0.70 (95% CI: 0.65-0.74) in predicting digit failure in the training and validation cohorts, respectively. Calibration curves were well-fitted for both training and validation cohorts.

CONCLUSIONS

The proposed prediction model effectively predicted the failure rate of digit replantation for individual digits of all patients. It could assist in selecting the most suitable surgical plan for the patient.

The effect of dobutamine treatment on salvage of digital replantation and revascularization

PURPOSE

One of the most common causes of a failure after replantation and revascularization surgeries is 'no reflow' from proximal artery that occurs, especially following crush and avulsion injuries. In this study, we aimed to evaluate the effect of dobutamine treatment on salvage of replanted and revascularized digits.

METHODS

The patients with no reflow phenomenon detected in the salvage operations of replanted/revascularized digits between the years 2017 and 2020 were included in the study. Dobutamine treatment was infused at a rate of 4 µg·kg-1·min-1 intraoperatively and of 2 µg·kg-1 min-1 postoperatively. Demographic data (age, sex), digit survival rate, ischemia time, and level of injury were retrospectively analysed. Pre-infusion, intraoperative and postoperative values of cardiac index (CI), mean arterial pressure (MAP), and heart rate (HR) were recorded.

RESULTS

The phenomenon of 'no reflow' was encountered in 35 digits of 22 patients who underwent salvage surgery due to vascular compromise. The survival rate in the revascularization group was 75%, while it was 42.1% in the replanted digits. Metaphysis level of proximal phalanx was the most common localization for 'no reflow' phenomenon. The least values of CI, MAP and HR to obtain sufficient perfusion in salvaged digits were as follows: 4.2 l.min-1.m-2, 76 mm Hg, and 83 beat·min-1, respectively.

CONCLUSIONS

It was demonstrated that dobutamine infusion at a rate of 4 µg·kg-1·min-1 intraoperatively and at 2 µg·kg-1·min-1 postoperatively has favorable effects on the vascular compromise derived from no reflow of proximal artery.

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.

Influence on emergency digit replantation and outcome assessment after COVID-19 virus nucleic acid testing normalization

Objective

The study aims to compare the implementation and prognosis of emergency digit replantation surgery before and after normalized corona virus disease 2019 (COVID-19) nucleic acid testing for patients taking emergency operation and to explore the influence of normalized COVID-19 nucleic acid testing on replantation surgery.

Method

Normalized COVID-19 nucleic acid testing for patients taking emergency operation has been carried out since 1 August 2021 at our hospital, which means each patient who needs emergency surgical treatment has to obtain either positive or negative results of COVID-19 nucleic acid before entering the operating room. This research reviewed and compared the prognosis of the injured extremity that had emergency severed digit replantation between June and September 2021, at the Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, and analyzed the impact of normalized COVID-19 nucleic acid testing on the outcome of the replanted fingers of different severity using disability of arm-shoulder-hand (DASH) and hand injury severity scoring (HISS) scoring systems.

Results

A total of 54 cases with 74 severed replanted phalanges were included replanted by the research group between 1 August and 30 September 2021, without any COVID-19 suspected/confirmed case detected. Compared with previous period (1 June to 31 July, 2021), although the interval between emergency visits and emergency replantation did increase significantly after normalized COVID-19 nucleic acid testing [(3.83 ± 0.94) to (1.77 ± 0.67) h, P < 0.05], we observed no significant difference in the improvement rate of the DASH scoring of the disabled upper extremity 3-month postoperatively (P = 0.538) nor in the complication rate (P = 0.344). Moreover, there was no significant difference in the improvement rate of the DASH scoring of the disabled upper extremity 3-month postoperatively in patients with different traumatic severities before and after normalized COVID-19 nucleic acid testing (moderate P = 0.269, severe P = 0.055, major P = 0.149).

Conclusion

Despite the preoperative delay, the policy of COVID-19 nucleic acid testing normalization does not have explicit influence on the short-term outcomes of emergency digit replantation surgery. With this evidence, microsurgeons could pay attention to the patients' anxiety and spend more effort in comforting them during the prolonged preoperative wait. These insights may have implications for other emergency department resource management whenever a social crisis occurs.

Indications, anaesthesia and postoperative protocol for replantation and revascularization in the hand in Nordic countries

In this survey, we compared the current postoperative practices in the largest replantation units of four Nordic countries. The topics included were indication for surgery, anaesthesia, postoperative monitoring, use of antibiotics, anticoagulation and postoperative intravenous fluids, change of dressings, duration of bed rest and hospital stay, hand therapy and follow-up after discharge. Although there were many similarities between the units in the postoperative protocols, we found a large variety of practices. There is no robust evidence to assess or support or reject most of the strategies in postoperative care. The differences in practice warrant prospective studies in order to establish an evidence-based postoperative protocol for replantation surgery.

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.

Perioperative Thromboprophylaxis in Digital Replantation: A Systematic Review

Supplemental Digital Content is available in the text.

There is no international consensus on the use of perioperative thromboprophylaxis in digital replantation. Suboptimal perioperative management may lead to replant failure, which compromises extremity function, worsens psychosocial outcomes for patients, and incurs significant cost. This systematic review evaluates and compares the efficacy and safety of perioperative antithrombotic protocols used in digital replantation.

Replantation of a Completely Amputated Thumb with Assistance of High-Speed Video Recording

Background

Generally, surgeons assess the quality of vascular anastomosis in digit replantation on the basis of their experience.

Description

The steps for replantation of a completely amputated thumb, with assistance of high-speed video recording, consist of (1) debridement, (2) fixation, (3) tendon suture, (4) anastomosis, and (5) wound closure^1,2.

Alternatives

Revision amputation or flap coverage.

Rationale

With the assistance of high-speed video recording, the refilling velocity ratio (RVR) is an objective index for the quality assessment of the vascular anastomosis.

Patency Test of Vascular Anastomosis with Assistance of High-Speed Video Recording in Digit Replantation

BACKGROUND

Quality assessment of vascular anastomosis primarily depends on the experience of the treating surgeon. This highlights the need for an objective index. The main goal of our study was to establish a method of assessing the quality of vascular anastomosis in digit replantation.

METHODS

A total of 182 digits from 141 patients were included in this study. The patients underwent replantation of completely amputated digits between June 1, 2015, and February 1, 2017. Patency tests of arterial and venous anastomoses were conducted for each replantation and recorded on digital video at 1,000 frames per second. We divided the study into 2 phases. In phase I (103 digits from 80 patients), we investigated whether the refilling velocity ratio (RVR) was associated with replantation failure. In phase II (79 digits from 61 patients), we adopted the RVR as a guiding parameter during surgery and compared the replantation success rate with that of the historical control of phase I.

RESULTS

In phase I, ischemia time (>12 hours), arterial RVR (<0.4), and venous RVR sum (<1.0) were significantly associated with the rate of replantation failure in 82 cases with single arterial anastomosis. In phase II, we set the arterial RVR goal to 0.4 and venous RVR sum goal to 1.0. Under the guidance of the RVR test, the survival rate significantly increased compared with that of the historical control of phase I (96% versus 87%; p = 0.037).

CONCLUSIONS

The patency test, with assistance of high-speed video recording, is a useful tool that can improve the success rate of digit replantation.

LEVEL OF EVIDENCE

Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.