Type of injury and number of anastomosed vessels: Impact on digital replantation

Overview and management of complications after digital replantations

The main complications after digital replantation are discussed in this review article. These complications include vascular compromise, infection, partial necrosis, delayed union or nonunion, atrophy and so on. The countermeasures for these complications are reviewed and the authors' methods are also introduced and discussed.

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.

Factors associated with early and late digital revascularization and replantation failure: a retrospective cohort study

Factors associated with failure of digital revascularization and replantation procedures have been well characterized, but studies have not investigated failures occurring beyond the early postoperative period. A single-centre retrospective chart review included 284 patients (434 digits) who underwent digital revascularization or replantation. Patient-, injury- and surgery-related characteristics were compared among successful procedures, digits that failed while in hospital (early failure), and initially viable digits that failed after hospital discharge (late failure). Overall, 202 patients had successful procedures (71%). There were 51 early failures (18%) and 31 late failures (11%). Crush injuries and vein grafting were associated with early failure only. Complete amputations and leeching were strongly associated with both early and late failure. This study revealed that a substantial proportion of initially viable digits fail after discharge from hospital. Patients with signs of venous congestion may benefit from longer observation periods in hospital to avoid late failure.Level of evidence: IV.

Variation in Surgeon Proficiency Scores and Association With Digit Replantation Outcomes

IMPORTANCE

Risk-adjusted variation in surgeon outcomes has been traditionally explained by surgeon volume and hospital infrastructure, yet it is unclear how a surgeon's operative proficiency directly contributes to their patients' outcomes.

OBJECTIVE

To assess the variation of surgeons' operative proficiency and investigate its association with surgical outcomes.

DESIGN, SETTING, AND PARTICIPANTS

This case series was a retrospective analysis of all digit replantations and revascularizations at a single US university medical center between January 2000 and August 2020. Surgeons were assigned a proficiency score based on the expected procedure difficulty and outcomes from a sample of their cases. Surgeon proficiency scores were then used to determine associations with outcomes from subsequent cases. The expected difficulty of each case was calculated using a novel scoring system that applied pooled relative risks from a meta-analysis of risk factors for replantation and revascularization failure.

EXPOSURES

Digit replantation and revascularization.

MAIN OUTCOMES AND MEASURES

Digit survival at 1-month follow up (case success) and number of complications.

RESULTS

A total of 145 patients and 226 digits were treated by 11 surgeons with training in hand or microsurgery (mean [SD] age, 41.9 [15.2] years; 204 [90%] men); there were 116 replantations and 110 revascularizations. Surgeon proficiency scores ranged from 1.3 to 5.7, with a mean (SD) of 3.4 (1.4). Case success rates among surgeons varied from 20.0% to 90.5%, with a mean (SD) of 64.9%. Higher proficiency scores were associated with fewer case failures: each point increase was associated with 40% decreased odds of failure (odds ratio, 0.60; 95% CI, 0.38-0.94). Every 3-point increase in proficiency score was associated with 1 less complication (effect estimate, -0.29; 95% CI, -0.56 to 0.02). Surgeon proficiency score had a greater association with case failure than surgeon volume (16.7% vs 12.0%). The final model's association with case failure had an area under the receiver operating characteristics curve of 0.93.

CONCLUSIONS AND RELEVANCE

Operative proficiency varied widely among practicing surgeons and accounted for 17% of estimative ability for success of digit replantation and revascularization. Greater surgeon proficiency was associated with better outcomes, indicating that the value of surgical care may be optimized by improving surgeon proficiency.

Relationships Between Vein Repairs, Postoperative Transfusions, and Survival in Single Digit Replantation

Background: The general teaching is that increased number of vein repairs in digit replantation leads to improved venous outflow, resulting in lower need for iatrogenic bleeding, lower postoperative transfusion requirements, and better survival rates. The purpose of this study was to determine whether the traditional teaching that emphasizes the repair of multiple veins per arterial anastomosis results in superior survival rates. Methods: A retrospective review of a single urban replant center's single-digit replants distal to the mid-metacarpal level in adult patients from 2007 to 2017 was performed. Data on patient demographics, mechanism and level of injury, veins repaired, iatrogenic bleeding, postoperative transfusions, and replant survival were obtained. Results: There were a total of 54 single-digit replants. The most common mechanism was lacerations (N = 38), and the most common injury level was at the proximal phalanx (N = 21). All digits were replanted with a single arterial anastomosis-44% via grafting. In all, 0 to 3 veins were repaired per digit (mean = 1.5 veins). The mean transfusion requirement was 1.7 units. The survival rate was 50%. Digits with 1 or 2 veins repaired had lower transfusion requirements (1.1-1.3 units) and higher survival rates (56%-61%) compared with those replanted with 0 or 3 veins repaired (2.9-3.5 transfused units, 25%-29% survival). There were no differences between those digits replanted with either 1 or 2 veins repaired for transfusion requirements or survival. Conclusions: More veins repaired do not necessarily improve survival or possibly venous outflow, calling into question the traditional teaching that 2 veins should be repaired for every arterial anastomosis.

Value of the Two-Point Discrimination Test: Evaluation of 238 Isolated Finger Nerve Injuries

Background: It may be difficult to diagnose a nerve injury on a finger or a hand under emergency settings. The goal of this study was to elaborate whether the clinical testing of two-point discrimination was a safe and reliable method in the diagnosis of acute finger nerve injuries. Methods: Through a retrospective assessment, patients' records were analyzed whether the result of the two-point discrimination test corresponded with the intraoperative findings of a damaged nerve. Patients with a prolonged or missing two-point discrimination, who had undergone surgery at our institution between the years 2008 and 2017, were included in the study. The control groups were identified in the same manner and as an additional group, patients with Dupuytren's contracture were included to serve as a healthy cohort regarding finger nerves. Results: A total of 249 patients with nerve lesion were enrolled in the study; apart from this, 25 patients with Dupuytren's contracture were included. The sensitivity of the two-point discrimination test was 99%, with a positive predictive value of 0.93 and with high inter-observer reliability. Conclusions: The two-point discrimination is a valid test to use in the routine examination of suspected nerve injuries on the hands and fingers; it is very reliable and safe for indicating surgical interventions.

Replantation of digits: a review of predictive factors for survival

The survival of 75 consecutive digital replantations carried out between 2006 and 2010 at a regional hand centre in the United Kingdom was determined. The patient demographics, mechanism of injury, co-morbid factors, operative and post-operative details were extracted and reviewed from the medical and hand therapy notes. Predictive factors of survival were determined by using univariate and multivariate statistical analysis. The survival rate was 70%. Arterial thrombosis was the leading cause of replant failure, followed by venous congestion. Smoking, level of amputation, number of nerves repaired, warm ischaemia time and timing of replantation were independent predictors of replant survival. However, only warm ischaemia time less than 6 hours and 30 minutes and replantations done within 'office hours' showed significance on multivariate logistic regression. Our study suggests that replantations done in daylight hours, when feasible, with rested staff and a full complement of the theatre team are likely to have better outcomes.

LEVEL OF EVIDENCE

Level IV case series.

Effects of non-surgical factors on digital replantation survival rate: a meta-analysis

This study aimed to evaluate the risk factors affecting survival rate of digital replantation by a meta-analysis. A computer retrieval of MEDLINE, OVID, EMBASE, and CNKI databases was conducted to identify citations for digital replantation with digit or finger or thumb or digital or fingertip and replantation as keywords. RevMan 5.2 software was used to calculate the pooled odds ratios. In total, there were 4678 amputated digits in 2641 patients. Gender and ischemia time had no significant influence on the survival rate of amputation replantation (P > 0.05). Age, injured hand, injury type, zone, and the method of preservation the amputated digit significantly influence the survival rate of digital replantation (P < 0.05). Children, right hand, crush, or avulsion and little finger are the risk factors that adversely affect the outcome.

THE LEVEL OF EVIDENCE

Level 5*.

Combined Subdermal Pocket Procedure and Abdominal Flap for Distal Finger Amputations in a Toddler

A girl (aged 1 year and 9 months) sustained traumatic amputation to her middle and ring fingers (zone 1C) by a cup-sealing machine. Full-thickness dorsal skin burn over amputated fingertips was also noted. Emergent finger replantation was performed. Following bone fixation, bilateral digital arteries and nerves were repaired. After complete debridement of the necrotic dorsal skin, the extensor tendon and joint were exposed. Moreover, all dorsal veins were destroyed. The pulps (middle and ring fingers) were de-epithelialized and inserted into the subdermal pocket over her left abdomen. The 2 raised skin flaps were transferred to reconstruct the dorsal skin defects. Division of the replanted finger from abdomen was performed at the 14th postoperative day. The fingers survived completely. Good functional and aesthetic outcomes were achieved.

Replantation: current concepts and outcomes

Techniques to improve the chance of successful replantation of digits are well established. Indications and contraindications for replantation are generally agreed on, but they continue to evolve as excellent outcomes are achieved at centers with experience and expertise. Form and function can be restored with avulsion injuries and distal amputations, with good results and high patient satisfaction. Increased financial pressure to control the costs of health care and increased accountability for evidence-based outcomes may lead to the regionalization of replantation care and shared decision making in recommending replantation or revision amputation.

Nonsurgical factors of digital replantation and survival rate: A metaanalysis

The aim of this metaanalysis was to evaluate the association between nonsurgical factors and survival rate of digital replantation. A computer search of MEDLINE, OVID, EMBASE and CNKI databases was conducted to identify literatures for digital replantation, with the keywords of "digit," "finger" and "replantation" from their inception to June 10, 2014. Based on the inclusion and exclusion criteria, data were extracted independently by two authors using piloted forms. Review Manager 5.2 software was used for data analysis. The effect of some nonsurgical factors (gender, age, amputated finger, injury mechanisms, ischemia time and the way of preservation) on the survival rate of digital replantation was assessed. The metaanalysis result suggested that gender and ischemia time had no significant influence on the survival rate of amputation replantation. However, the survival rate of digital replantation of adults was significantly higher than that of children. The guillotine injury of a finger was easier to replant successfully than the crush and avulsion. The little finger was more difficult for replantation than thumb. Survival rate of fingers stored in low temperature was higher than that in common temperature. The present metaanalysis suggested that age, injury mechanism, amputated finger and the way of preservation were significantly associated with the survival rate of digital replantation.

Economic analysis of revision amputation and replantation treatment of finger amputation injuries

BACKGROUND

The purpose of this study was to perform a cost-utility analysis to compare revision amputation and replantation treatment of finger amputation injuries across a spectrum of injury scenarios.

METHODS

The study was conducted from the societal perspective. Decision tree models were created for the reference case (two-finger amputation injury) and seven additional injury scenarios for comparison. Inputs included cost, quality of life, and probability of each health state. A Web-based time trade-off survey was created to determine quality-adjusted life-years for health states; 685 nationally representative adult community members were invited to participate in the survey. Overall cost and quality-adjusted life-years for revision amputation and replantation were calculated for each decision tree. An incremental cost-effectiveness ratio was calculated if a treatment was more costly but more effective.

RESULTS

The authors had a 64 percent response rate (n = 437). Replantation treatment had greater costs and quality-adjusted life-years compared with revision amputation in all injury scenarios. Replantation of single-digit injuries had the highest incremental cost-effectiveness ratio ($136,400 per quality-adjusted life-year gained). Replantation of three- and four-digit amputation injuries had relatively low cost-to-benefit ratios ($27,100 and $23,800 per quality-adjusted life-year, respectively). Replantation for distal thumb amputation had a relatively low incremental cost-effectiveness ratio ($26,300 per quality-adjusted life-year) compared with replantation of nonthumb distal amputations ($60,200 per quality-adjusted life-year).

CONCLUSIONS

The relative cost per quality-adjusted life-year gained with replantation treatment varied greatly among the injury scenarios. Situations in which indications for replantation are debated had higher cost per quality-adjusted life-year gained. This study highlights variability in value for replantation among different injury scenarios.

Replantation surgery

The current concepts of replantation surgery, a procedure that has been practiced for half a century, can be discussed in terms of patients' demands and expectations, present indications for the procedure, available evidence that influences decision making, and technical refinements practiced to produce better outcomes.

Digital replantation

The final judgment of whether to replant may not be determined until after microscopic inspection of vessels and nerves is complete. Once committed, it is ultimately the attention to detail that will determine function; bone shortening and rigid fixation, multiple strand flexor tendon repair, and quality, meticulous repair of the extensor mechanism to permit early movement, periosteal approximation to aid gliding, radical debridement of damaged vessels and primary skin closure.