Intravenous heparin use in digital replantation and revascularization: The Quebec provincial replantation program experience

Principles of microvascular surgery in the upper extremity

Upper extremity replantation and microsurgery can be challenging even for the experienced hand and upper extremity surgeon and requires thoughtful consideration and evaluation. This review aims to discuss the general considerations in upper extremity replantation management from the preoperative through the postoperative period.

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.

Technical considerations for replantation: from bony fixation to soft tissue coverage

Digital replantation is a challenging and at-time tedious operation, but if approached thoughtfully and with reasonable expectations can be a reliable and rewarding undertaking. This article summarizes technical considerations for digital replantations involving flexor tendon zone II. The article has been ordered according to the recommended sequence of a structure-by-structure repair in a non-thumb digit. Special considerations are described for thumb, multiple digits, and heterotopic 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.

The Role of Intravenous Heparin Following Digital Replantation: A Retrospective Cohort Study on 1,155 Digits

PURPOSE

The purpose of this study was to determine if the use of postoperative therapeutic dose intravenous heparin (POTDIVH) was indicated in digital replantation and revascularization by assessing digit survival and complications associated with heparin.

METHODS

All patients with amputation distal to the carpal tunnel treated at our center from 2004 to 2020 were included for chart review. Digit survival and complication rates were compared between patients who received POTDIVH (group A) and those who did not (group B). Logistic regression analysis and subgroup analysis were conducted.

RESULTS

A total of 795 patients (1,155 digits) were included in this study (248 patients/374 digits in group A and 547 patients/781 digits in group B). The overall revascularization and replantation success rate was 79.9% in the POTDIVH group and 92.8% in the non-POTDIVH group. In our retrospective regression and subgroup analyses, group A demonstrated increased odds of failure compared with group B and was associated with increased bleeding-related complications. Subgroup analyses stratified by the mechanism of injury and vein grafting also showed a significantly decreased survival in the POTDIVH group.

CONCLUSIONS

Our retrospective data seem to indicate that heparin in digit replantation and revascularization appears to have no benefit on digit survival across all subgroups, including crush and avulsion injuries, and is associated with a significantly increased rate of complications.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

Determinants of Success in Single- and Multi-Digit Replant

Purpose: Understanding the variables that influence success in digital replant surgery is essential to guide clinical decision-making and to counsel patients. The purpose of this study was to determine the replant success rate and identify predictors of success at our tertiary care centre. Methods: This was a single centre, retrospective cohort study of consecutive patients who underwent digital replantation from January 2000 to September 2018. Adult patients with flexor zone I to III amputations were included. Patient demographics, comorbidities, injury pattern, operative data, and post-operative care were reviewed. The primary outcome was survival of the replanted digit at discharge. Results: A total of 146 patients met inclusion criteria. Of these, 100 had single-digit replants and 46 underwent multi-digit replants for a total of 220 digits. The success rate was 71%. Predictors of success included sharp mechanism of injury (P < .01), incomplete amputation (P < .01), amputation proximal to zone I flexor level (P = .02), post-operative acetylsalicylic acid use (P < .01), absence of leech use (P = .05), and absence of operative re-exploration (P < .01). Daytime replants had similar outcome compared to nighttime replants despite having increased ischemia time (7.9 ± 3.9 hours vs 6.8 ± 2.6 hours, P = .02). However, daytime operative time (7.8 ± 3.7 hours) was significantly shorter than nighttime replant time (9.6 ± 5.9 hours, P = .01). Conclusion: Sharp amputation, intact venous drainage, proximal amputation, and acetylsalicylic acid use were associated with replant survival and are factors to consider when managing patients for digital replantation. Leech therapy and operative re-exploration were associated with poor outcome. Nighttime replants required significantly longer operative time than daytime replants despite similar survival outcome.

The clinical effectiveness and safety of intravenous unfractionated heparin following digital replantation and revascularization: A narrative systematic review

BACKGROUND

Digital replants and revascularization (DRV) have been performed since the 1960s but there are no recognized standard peri-operative anticoagulation practices. A narrative systematic review of the clinical effectiveness and safety of therapeutic peri-operative unfractionated heparin following DRV was undertaken.

METHODS

A review of the literature from 1985 to March 2022 was conducted using Medline, Embase, CINAHL and EBM reviews. Unfractionated heparin (UFH) use following DRV was compared to low-molecular weight heparin, other anticoagulants or no anticoagulation. Randomized trials, observational studies as well as guidelines were selected and independently screened. The Revised Cochrane risk-of-bias (RoB 2) tool and ROBINS-I were used to appraise risk of bias.

RESULTS

While the search strategy identified 1490 references, only six studies met the inclusion criteria. Significant heterogeneity and the low methodological quality of the evidence precluded a meta-analysis. Among the four studies that documented the surgical success rate associated with the use of a therapeutic dose of UFH post DRV, only two reported improved clinical outcomes. Evidence of a higher complication rate related to UFH use was found in four studies. Low quality evidence suggests that a therapeutic dose of unfractionated heparin leads to a higher risk of complications when compared with heparin given as an intermittent bolus of unfractionated heparin or subcutaneous heparin, or prostaglandin E1 or no heparin.

CONCLUSIONS

Current evidence suggests that IV UFH use following DRV has no significant impact on the success of the intervention. Heparin use may not be innocuous as some studies showed increased bleeding complications.

Systematic Review of Replant Salvage and Cost Utility Analysis of Inpatient Monitoring After Digit Replantation

PURPOSE

Digit replantation is a high-stakes procedure that has been shown to be cost-effective, especially for multiple-digit replantation. However, it is associated with prolonged lengths of stay (LOS) for monitoring and attempts at salvage. The cost-effectiveness of prolonged inpatient stays presumes that this is necessary and inherent to the replantation. We hypothesized that prolonged monitoring of replanted digits, in the hope of possible salvage after primary failure, is cost-ineffective due to the low rates of vascular compromise and salvage after replantation.

METHODS

Using previously published data comparing quality adjusted life years lost after traumatic digit amputation versus digit replantation, we devised a cost utility model to evaluate the incremental cost-effectiveness ratio of inpatient monitoring. To determine rates of vascular compromise and salvage after digit replantation, we performed a systematic review of the literature through MEDLINE and SCOPUS database searches to identify relevant articles on digital replantation since 1990. Cost-effectiveness was stratified based on the number of digits replanted.

RESULTS

Fewer than 9% of replanted digits both experience vascular compromise and are successfully salvaged. Adjusting for this, inpatient monitoring for single-digit and thumb replantation becomes cost-ineffective after 1 day of admission and monitoring for multiple-digit replantation becomes cost-ineffective after 2 days of admission.

CONCLUSIONS

In the United States, prolonged admissions for inpatient monitoring quickly become cost-ineffective, especially with relatively low rates of salvage. Surgeons should avoid extended hospitalizations for replant monitoring and should pursue enhanced recovery protocols for replantation, especially considering burgeoning health care costs in the United States.

TYPE OF STUDY/LEVEL OF EVIDENCE

Economic/Decision Analysis III.

Prevention of Venous Thromboembolism in Microvascular Surgery Patients Using Weight-Based Unfractionated Heparin Infusions

BACKGROUND

 Unfractionated heparin infusions are commonly used in microvascular surgery to prevent microvascular thrombosis. Previously, fixed-dose heparin infusions were believed to provide sufficient venous thromboembolism (VTE) prophylaxis; however, we now know that this practice is inadequate for the majority of patients. Anti-factor Xa (aFXa) level is a measure of unfractionated heparin efficacy and safety. This study evaluated the pharmacodynamics of weight-based dose heparin infusions and the impacts of real-time aFXa-guided heparin dose adjustments.

METHODS

 This prospective clinical trial enrolled adult microvascular surgery patients who received a weight-based heparin dose following a microsurgical procedure. Steady-state aFXa levels were monitored, and patients with out-of-range levels received dose adjustments. The study outcomes assessed were aFXa levels at a dose of heparin 10 units/kg/hour, time to adequate aFXa level, number of dose adjustments required to reach in-range aFXa levels, and clinically relevant bleeding and VTE at 90 days.

RESULTS

 Twenty-one patients were prospectively recruited, and usable data were available for twenty patients. Four of twenty patients (20%) had adequate prophylaxis at a heparin dose of 10 units/kg/hour. Among patients who received dose adjustments and achieved in-range aFXa levels, the median number of dose adjustments was 2 and the median weight-based dose was 11 units/kg/hour. The percentage of patients with in-range levels was significantly increased (65 vs. 15%, p = 0.0002) as a result of real-time dose adjustments. The rate of VTE at 90 days was 0%, and clinically relevant bleeding rate at 90 days was 15%.

CONCLUSION

 Weight-based heparin infusions at a rate of 10 units/kg/hour provide a detectable level of anticoagulation for some patients following microsurgical procedures, but most patients require dose adjustment to ensure adequate VTE prophylaxis.

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.

A four-year community hospital experience regarding procedures for the replantation and revascularization of fingers

Objectives

This study aims to evaluate the clinical results and experiences in a community hospital regarding procedures for the replantation and revascularization of fingers.

Patients and methods

Between June 2015 and December 2019, a total of 58 patients (51 males, 7 females; mean age: 33.4±6.3 years; range, 23 to 46 years) who were followed after total and/or subtotal amputation and replantation were retrospectively analyzed. The patients were evaluated at nine months in terms of cold intolerance, static two-point discrimination, and functional results using the range of motion (ROM) and Quick Disabilities of the Arm, Shoulder and Hand (QuickDASH) questionnaire.

Results

The majority of the patients presented with work-related injuries (70%), most commonly by the mechanism of guillotine (64%), and to the dominant hand (76%) and the third finger (36%) most frequently. The overall success rate of digit salvage was 72.9% (n=51). Of 19 digits with unsuccessful surgical outcomes, seven were from total and 12 were from subtotal amputations. In the long-term, cold intolerance was observed in 14 patients (24.1%) according to the cold intolerance severity scale. The mean static two-point discrimination value was 6.0±0.7 mm and the mean QuickDASH score was 22.3±5.0. The mean ROM measured at nine months after surgery in the metacarpophalangeal and interphalangeal joints of the third and fourth digits was significantly lower than that in the others (p<0.05).

Conclusion

The predictors of survival of a replanted digit indicated in this study can be used as a guide and decision-making aid for any attempts for replantation.

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.

Low molecular weight heparin for prevention of microvascular occlusion in digital replantation

BACKGROUND

The success of digital replantation is highly dependent on the patency of the repaired vessels after microvascular anastomosis. Antithrombotic agents are frequently used for preventing vascular occlusion. Low molecular weight heparin (LMWH) has been reported to be as effective as unfractionated heparin (UFH) in peripheral vascular surgery, but with fewer adverse effects. Its benefit in microvascular surgery such as digital replantation is unclear. This is an update of the review first published in 2013.

OBJECTIVES

To assess if treatment with subcutaneous LMWH improves the salvage rate of the digits in patients with digital replantation after traumatic amputation.

SEARCH METHODS

The Cochrane Vascular Information Specialist searched the Cochrane Vascular Specialised Register, CENTRAL, MEDLINE, Embase, AMED and CINAHL databases, and the World Health Organization International Clinical Trials Registry Platform and ClinicalTrials.gov trials registers, to 17 March 2020. The authors searched PubMed, China National Knowledge Infrastructure (CNKI) and Chinese Electronic Periodical Services (CEPS) on 17 March 2020 and sought additional trials from reference lists of relevant publications.

SELECTION CRITERIA

We included randomised or quasi-randomised controlled trials comparing treatment with LMWH versus any other treatment in participants who received digital replantation following traumatic digital amputation.

DATA COLLECTION AND ANALYSIS

Two review authors (PL, CC) independently extracted data and assessed the risk of bias of the included trials using Cochrane's 'Risk of bias' tool. Disagreements were resolved by discussion. We assessed the certainty of evidence using the GRADE approach.

MAIN RESULTS

We included two new randomised trials in this update, bringing the total number of included trials to four. They included a total of 258 participants, with at least 273 digits, from hospitals in China. Three studies compared LMWH versus UFH, and one compared LMWH versus no LMWH. The mean age of participants ranged from 24.5 to 37.6 years. In the studies reporting the sex of participants, there were a total of 145 men and 59 women. The certainty of the evidence was downgraded to low or very low because all studies were at high risk of performance or reporting bias (or both) and there was imprecision in the results due to the small numbers of participants. The three studies comparing LMWH versus UFH reported the success rate of replantation using different units of analysis (participant or digit), so we were unable to combine data from all three studies (one study reported results for both participants and digits). No evidence of a benefit in success of replantation was seen in the LMWH group when compared with UFH, regardless of whether the outcomes were reported by number of participants (risk ratio (RR) 0.98, 95% confidence interval (CI) 0.87 to 1.10; 130 participants, 2 studies; very low-certainty evidence); or by number of digits (RR 0.97, 95% CI 0.90 to 1.04; 200 digits, 2 studies; low-certainty evidence). No studies reported the incidence of compromised microcirculation requiring surgical or non-surgical therapy, or any systemic/other causes of microvascular insufficiency. There was no evidence of a clear difference between the LMWH and UFH groups in occurrence of arterial occlusion (RR 1.08, 95% CI 0.16 to 7.10; 54 participants, 1 study; very low-certainty evidence) or venous occlusion (RR 0.81, 95% CI 0.20 to 3.27; 54 participants, 1 study; very low-certainty evidence). Two studies reported adverse effects. The LMWH and UFH groups showed no evidence of a difference in wound bleeding (RR 0.53, 95% CI 0.23 to 1.23; 130 participants, 2 studies; low-certainty evidence), haematuria (RR 0.43, 95% CI 0.09 to 2.11; 130 participants, 2 studies; very low-certainty evidence), ecchymoses (RR 0.82, 95% CI 0.21 to 3.19; 130 participants, 2 studies; very low-certainty evidence), epistaxis (RR 0.27, 95% CI 0.03 to 2.32; 130 participants, 2 studies; very low-certainty evidence), gingival bleeding (RR 0.18, 95% CI 0.02 to 1.43; 130 participants, 2 studies; very low-certainty evidence), and faecal occult blood (RR 0.27, 95% CI 0.03 to 2.31; 130 participants, 2 studies; very low-certainty evidence). We could not pool data on coagulation abnormalities as varying definitions and tests were used in the three studies. One study compared LMWH versus no LMWH. The success rate of replantation, when analysed by digits, was reported as 91.2% success in the LMWH group and 82.1% in the control group (RR 1.11, 95% CI 0.93 to 1.33; 73 digits, 1 study; very low-certainty evidence). Compromised microcirculation requiring surgical re-exploration, analysed by digits, was 11.8% in the LMWH group and 17.9% in the control group (RR 0.86, 95% CI 0.21 to 3.58; 73 digits, 1 study; very low-certainty evidence). Compromised microcirculation requiring incision occurred in five out of 34 digits (14.7%) in the LMWH group and eight out of 39 digits (20.5%) in the control group (RR 0.72, 95% CI 0.26 to 1.98; 73 digits; very low-certainty evidence). Microvascular insufficiency due to arterial occlusion, analysed by digits, was 11.8% in the LMWH group and 17.9% in the control group (RR 0.66, 95% CI 0.21 to 2.05; 73 digits, 1 study; very low-certainty evidence), and venous occlusion was 14.7% in the LMWH group and 20.5% in the control (RR 0.72, 95% CI 0.26 to 1.98; 73 digits, 1 study; very low-certainty evidence). The study did not report complications or adverse effects.

AUTHORS' CONCLUSIONS

There is currently low to very low-certainty evidence, based on four RCTs, suggesting no evidence of a benefit from LMWH when compared to UFH on the success rates of replantation or affect microvascular insufficiency due to vessel occlusion (analysed by digit or participant). LMWH had similar success rates of replantation; and the incidence rate of venous and arterial microvascular insufficiency showed no evidence of a difference between groups when LMWH was compared to no LMWH (analysed by digit). Similar rates of complications and adverse effects were seen between UFH and LMWH. There was insufficient evidence to draw conclusions on any effect on coagulation when comparing LMWH to UFH or no LMWH. The certainty of the evidence was downgraded due to performance and reporting bias, as well as imprecision in the results. Further adequately powered studies are warranted to provide high-certainty evidence.

Postoperative Management and Rehabilitation of the Replanted or Revascularized Digit

Postoperative care of amputated digits begins before replantation. Detailed informed consent should be obtained and completion amputation discussed if revascularization is not ultimately successful. Complications and failure of the replanted digit should also be addressed. Postoperative pharmacologic treatment should consist of aspirin, at minimum. Complications, such as venous congestion or occlusion, and arterial thrombosis, should be dealt with expediently. Digital motion rehabilitation should start after 5 to 7 days of digital viability and splinting of the affected digit. Early protective motion protocol is implemented to maintain digital motion with emphasis on tendon glide and joint motion.

Appropriate Use of Intravenous Unfractionated Heparin after Digital Replantation: A Randomized Controlled Trial Involving Three Groups

BACKGROUND

The purpose of this study was to clarify the appropriate use of unfractionated heparin as an anticoagulation agent after digital replantation.

METHODS

This study was a prospective, randomized, single-blind, blinded-endpoint method, three-arm, parallel-group, controlled clinical trial conducted at a single institution. A total of 88 patients (101 fingers) following digital amputation and subsequent repair by anastomosis of both arteries and veins were randomly allocated into three groups: (1) control group (no heparin dose), (2) low-dose heparin group (10,000 IU/day), and (3) high-dose heparin group (start at 15,000 IU/day, then adjust the dose to achieve an activated partial thromboplastin time of 1.5 to 2.5 times the baseline). The outcomes were assessed regarding the proportion of success at 2 weeks after replantation of amputated digits, total or partial necrosis, and occurrence of complications.

RESULTS

No significant differences were found among the three groups, except for complications of congestion. The odds ratio of the heparin group compared with the control group for a success proportion was 5.40 (95 percent CI, 0.85 to 34.20; p = 0.027) in subjects aged 50 years or older. Significant elevations of activated partial thromboplastin time, aspartate transaminase, and alanine aminotransferase occurred in high-dose heparin groups on day 7.

CONCLUSION

Unfractionated heparin administration is considered effective for patients aged 50 years or older, although the routine use of unfractionated heparin is not necessary after digital replantation.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, II.

The Effect of Smoking on Necrosis Rate in Digital Replantation and Revascularization with Prostaglandin E1 Therapy: A Retrospective Study

BACKGROUND

Most microsurgeons believe that smoking and severity of injury adversely affect the outcome of digital replantation surgery. As countermeasures, several pharmacologic agents have been used for the perioperative period. The purpose of this retrospective study was to examine whether the rate of necrosis is appreciably different across smokers versus nonsmokers with prostaglandin E1 therapy.

METHODS

The authors' study subjects included 144 patients (184 digits) who underwent replantation or revascularization between August of 2013 and August of 2015.The primary outcome was the incidence of total necrosis after replantation surgery, and the secondary outcomes were the rate of overall necrosis, proportion of total necrosis to overall necrosis, and total success. Intravenous administration of prostaglandin E1 was performed at the rate of 120 μg/day for 7 days after surgery in all patients. These outcomes of each injury type were compared between smoking and nonsmoking groups.

RESULTS

Among the 184 injured digits, the incidence of total necrosis in smokers (23 percent) was higher than that in nonsmokers (17 percent), although no significant difference was shown (p = 0.36). The adjusted odds ratio was 1.17 (95 percent CI, 0.51 to 2.69). Similarly, there was no significant difference in the secondary outcomes between the two groups.

CONCLUSION

The authors' retrospective study found no significant difference in the formation or extent of necrosis after replantation or revascularization between smoking and nonsmoking groups when all patients were treated with prostaglandin E1.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Risk, II.

Microvascular replantation of head and neck amputated parts: A systematic review

BACKGROUND

As opposed to upper and lower extremity amputations representing a considerable volume of admissions, the prowess of microsurgeons is seldom solicited in complex cases of head and neck replantation. Our aim was to determine the rate of successful replantation of craniofacial parts in a systematic review of the literature.

METHODS

We performed a systematic review of English literature using PubMed/MEDLINE for every replantation of a head and neck parts. Articles selected for analysis required to describe microvascular surgical techniques to be considered a replantation. The measured endpoint for a successful replantation was survival at hospital discharge.

RESULTS

From 113 articles from the literature, reported cases of replanted craniofacial parts included 90 scalps, 56 ears, 34 lips, 26 noses, 1 eyebrow, and 1 midface. A significant majority of amputations were described as an avulsion mechanism (78.4%), as opposed to cutting/sharp (17.3%) or crush-type (1.9%). The overall success rate at hospital discharge was 72.1%, with a partial failure at 20.2% and a complete failure at 7.7%.

CONCLUSION

Urgent replantation of head and neck amputated parts allow patients to recover in a timely manner and to decrease the need for secondary reconstructive procedures. The significant rate of success is a strong argument in favor of promoting access to care for replantation of craniofacial parts.

Management of complications with flap procedures and replantation

Replantation and flap procedures employ microvascular techniques to salvage or reconstruct a severely damaged limb or digit. The most devastating complications include complete or partial flap loss, or replantation failure due to vascular complications. Often, these complications can be prevented by appropriate patient selection, careful surgical planning, meticulous technique, and proper postoperative management. This article discusses complications related to replantation and flap procedures in the upper limb, focusing on preventing and managing these complications.

Upper extremity replantation: current concepts

BACKGROUND

Upper extremity replantation is a procedure that has revolutionized hand surgery. Since its introduction, a rapid evolution has occurred with a shifting focus from implant survival to optimization of functional outcomes and surgical efficiency. In this review, the current concepts surrounding the indications for replantation, variations in surgical technique, the factors affecting outcomes, and future directions of the specialty are analyzed.

METHODS

A literature review was performed of all recent articles pertaining to digit, hand, and upper extremity replantation surgery. Particular emphasis was placed on comparative studies and recent meta-analyses.

RESULTS

The indications and contraindications for replantation surgery are largely unchanged, with mechanism of injury remaining one of the most important determinants of implant survival. With advances in surgical technique, improved outcomes have been observed with avulsion injuries. Distal tip replantations appear to be more common with improved microsurgical techniques, and for these distal injuries, digital nerve and vein repair may not be necessary. Cold ischemia time for a digit amputation should not preclude transfer to a replantation facility or significantly affect the decision to perform a replantation. However, transferring physicians should thoroughly review the options with patients to prevent unnecessary transfers, which is an area where telemedicine may be useful.

CONCLUSION

This review provides an update on the current concepts of the practice of replantation and the treatment and management of patients with upper extremity amputations.

Protective effects of activated protein C (APC) on free groin flaps after secondary venous stasis in the rat model

BACKGROUND

The goal of this study was to determine whether the focused delivery of APC by rinsing of free adipocutaneous groin flaps shows protective effects on flap survival following a fatal secondary venous stasis in a rat model.

METHODS

36 Sprague Dawley rats were randomized to three groups and free microvascular groin flaps were transplanted to the neck in each animal. 20 hours postoperatively the flap pedicle was re-explored and the distal stump of the flap artery was catheterised. Animals in group I (n = 12) remained untreated, whereas animals of group II were treated with 1 ml of Ringer's solution. Those in group III received 1 ml of APC (2 mg/kg). Afterwards the flap vein was clamped for 35 minutes. The skin of the flaps and the native contralateral groin was examined by intravital video microscopy using FITC-Dextran and CFDA-SE-labelled thrombocytes.

RESULTS

APC-pretreatment significantly increased the functional capillary density (FCD) of the flaps. Flap viability was 8% in group I (n = 1/12), 9% in group II (n = 1/11) and 60% in group III (n = 6/10), respectively. No partial flap loss was detected.

CONCLUSIONS

The focused delivery of APC resulted in significantly improved flap salvage.

Low molecular weight heparin for prevention of microvascular occlusion in digital replantation

BACKGROUND

The success of digital replantation is highly dependent on the patency of the repaired vessels after microvascular anastomosis. Antithrombotic agents are frequently used for preventing vascular occlusion. Low molecular weight heparin (LMWH) has been reported to be as effective as unfractionated heparin (UFH) in peripheral vascular surgery, but with fewer adverse effects. Its benefit in microvascular surgery such as digital replantation is unclear.

OBJECTIVES

To assess whether subcutaneous LMWH treatment improves the salvage rate of the digits in patients with digital replantation after traumatic amputation.

SEARCH METHODS

The Cochrane Peripheral Vascular Diseases Group Trials Search Co-ordinator (TSC) searched the Specialised Register (October 2012), CENTRAL (2012, Issue 10) and trials databases. In addition, the authors searched PubMed, CNKI (China National Knowledge Infrastructure) and CEPS (Chinese Electronic Periodical Services), and sought additional trials from reference lists of relevant publications.

SELECTION CRITERIA

We selected randomised or quasi-randomised controlled trials of LMWH in patients who received digital replantation.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data and assessed the risk of bias of the included trials. Disagreements were resolved by discussion.

MAIN RESULTS

Two randomised trials involving 114 patients with at least 122 replanted digits met the inclusion criteria and were included. Both trials compared the efficacy and safety of LMWH with UFH. We found no trials comparing LMWH with placebo or other anticoagulants. The data from the two included studies were insufficient for meta-analysis. The overall success rate of replantation did not differ between the LMWH and UFH groups, 92.3% versus 89.2% in one trial (risk ratio (RR) 1.03; 95% confidence interval (CI) 0.87 to 1.22) and 94.3% versus 94.15% in the other trial (RR 1.00; 95% CI 0.89 to 1.13). The incidence of both postoperative arterial and venous insufficiency were reported in one trial and did not significantly differ between the LMWH and UFH groups (RR 1.08; 95% CI 0.16 to 7.10 and RR 0.81; 95% CI 0.20 to 3.27, respectively). Direct and indirect causes of microvascular insufficiency were not reported in the trials. Different methods were used to monitor the adverse effects related to anticoagulation in the two trials. Bleeding tendency was monitored for the LMWH and UFH groups in one trial and was reported by the incidence of wound haemorrhage (11.5% versus 17.9%; RR 0.65; 95% CI 0.17 to 2.44), ecchymoses (3.8% versus 10.7%; RR 0.36; 95% CI 0.04 to 3.24), haematuria (3.8% versus 7.1%; RR 0.54; 95% CI 0.05 to 5.59), nasal bleeding (0% versus 7.1%; RR 0.21; 95% CI 0.01 to 4.28), gingival bleeding (0% versus 10.7%; RR 0.15, 95% CI 0.01 to 2.83) and faecal occult blood (0% versus 3.6%; RR 0.36; 95% CI 0.02 to 8.42). The bleeding tendency was increased in the UFH group but this was not statistically significant. This trial also monitored coagulability changes using parameters such as antithrombin activity, factor Xa activity, bleeding time, clotting time and activated partial thromboplastin time (aPTT). No comparison was made between the LMWH and UFH groups but all data consistently showed that coagulability was reduced more in the UFH group than in the LMWH group. The other trial reported a postoperative decrease in platelet count in the UFH group (preoperative 278.4 ± 18.7 x 10(9)/L, postoperative 194.3 ± 26.5 x 10(9)/L; P < 0.05) but not in the LMWH group (preoperative 260.8 ± 32.5 x 10(9)/L, postoperative 252.4 ± 29.1 x 10(9)/L; P > 0.05).

AUTHORS' CONCLUSIONS

Current limited evidence based on two small-scaled low-to-medium quality randomised trials found no differences in the success rate of replantation between LMWH and UFH, but a lower risk of postoperative bleeding and hypocoagulability after the use of LMWH. Further well-designed and adequately powered clinical trials are warranted.

Technical considerations in microsurgical treatment of paediatric hand injuries

Microsurgical techniques are vital for the treatment of many aspects of trauma in the child, both in initial management and later reconstructive surgery. The basic principles of microsurgery pertain to all patients, but there are nuances of technique and of the psycho-social and peri-operative aspects of treatment which are particularly important in the child. It is these distinctions that are examined in this paper.