Children are at a higher risk of transfusion due to severe blood loss during salvage procedures after fingertip replantation: a retrospective matched case-control study
Article information
Abstract
Purpose
This study compared outcomes and assessed transfusion risk factors in children and adults after fingertip replantation.
Methods
From 2005 to 2019, 27 children (36 digits, 21 males and 6 females) underwent replantation due to either zone I or zone II amputation of digits. Twenty-seven adult patients (32 digits) were assigned to the control group based on matching criteria, including sex, diagnosis, level of amputation, and anastomotic vessels. Logistic regression analysis was performed to identify the risk factors for replantation failure in all subjects. Perioperative hemoglobin change, frequency of transfusion, and survival rates were compared between the groups.
Results
The mean age at index surgery in the child and adult groups was 8.6 years (range, 6 months–16 years) and 47.3 years (range, 25–64 years), respectively (p<0.001). Although the survival rates in the child and adult groups after replantation of digits were not significantly different (p=0.242), the mean preoperative hemoglobin level and that on the postoperative day 2 were 12.8 g/dL vs. 14.3 g/dL (p<0.001) and 10.9 g/dL vs. 12.3 g/dL (p=0.002), respectively. The rate of transfusion in the child group was significantly higher than that in the adult group (8/27 patients vs. 1/27 patients, p=0.012). Younger age, type of anastomosis, and preoperative and postoperative day 2 hemoglobin levels are important risk factors for salvage procedure and transfusions after fingertip replantation.
Conclusion
This case-control study showed that after replantation of fingertip amputation in children, hemodynamic changes in the perioperative periods were common, with a high transfusion rate.
Introduction
Finger amputations are the most common type of amputation injuries to the upper extremities, and the replantation of amputated fingers in children is considered technically challenging for microsurgeons [1-4].
Young age (less than 18 years) was found to be an important risk factor that lowered the survival rate of digital replantation in a recent meta-analysis [5]. This is because amputated digits may be treated more aggressively in children than in adults, and the smaller structures in children also make the procedure more technically challenging [5-7]. Moreover, digital amputations in children are usually caused by crush or avulsion injuries, which may be another cause of the lower success rate [6].
Several factors should be considered in the treatment of amputated digits in children, such as surgical techniques, small-sized vessels and related structures, and perioperative management [8]. Although it is mandatory to operate on digital arteries during replantation surgery, vein anastomosis is comparatively more difficult as veins are very thin and sometimes difficult to find [9]. Therefore, salvage procedures are frequently necessary to maintain venous drainage [9,10]. Blood loss is inevitable during salvage procedures, and even small amounts of blood loss in children could possibly necessitate transfusion due to hemodynamic change. Transfusion is required more frequently in children than in adults during the salvage procedure after replantation [10]. However, no study has yet assessed the frequency of salvage procedures, perioperative hemoglobin change, frequency of transfusion, and survival rate in children with digital amputations.
Therefore, a case-control study was designed in children with fingertip amputation. This study aimed to compare perioperative hemoglobin change, frequency of transfusion, and survival rates between child and adult patients after replantation with fingertip amputation. The risk factors for transfusion after the salvage procedure were also assessed between the two groups.
Methods
Ethics statement: The design and protocol of this retrospective study were approved by the Institutional Review Board of Chung-Ang University Hospital (No. 1901-0003-16242). Written informed consent was obtained from the patients for the publication of this study including all clinical images.
From 2005 to 2019, 38 children visited our emergency room with zone I or zone II amputated digits. Of these 38 patients, 11 patients could not undergo replantation due to severe crushing or complete degloving of the amputated parts, improper preservation, medical comorbidity, delayed transport of amputated parts, or delayed presentation of the patient. The remaining 27 children (21 males and six females) who underwent replantation surgery were included in the study. For a control group, they were matched with 27 adult patients in terms of sex, diagnosis, level of amputation, and anastomotic vessels.
In the children group, 27 patients with 36 amputations underwent replantation due to a segmental vessel defect. Patient age ranged from 6 months to 16 years (mean, 8.6 years). Twenty patients (26 fingers) had crushing amputations, two patients had blunt cut, three patients (5 fingers) avulsion, and two patients (three fingers) had clean-cut amputations (Table 1). The basic information reviewed included age, sex, injured hand and level of injury, perioperative blood transfusion requirement, and postoperative functional results.
Demographics of the child and adult groups
Surgical technique
A pneumatic tourniquet inflated to a pressure of 200 mmHg in children and 280 mmHg in adults was applied after general anesthesia, followed by debridement and dissection of the amputated stump. The tendons, nail bed, and nail matrix were preserved as much as possible during debridement. All amputated digits were stabilized with Kirschner wires before the microscopic work. Among six infants, amputated digits were stabilized with small needles in four patients and skin sutures without bone fixation in two patients. For zone II amputations, the digital artery on either side was dissected for arterial anastomosis. For zone I amputation, the largest terminal branch of the central artery, branching from the distal transverse palmar arch, was dissected to a segment where the healthy intima could be observed. For venous anastomosis, in zone II amputations, one dorsal vein was used; in zone I amputations, we used the volar vein if possible, but the technique of artery-only anastomosis was used in some cases. The vein grafts in three children and six adults were usually harvested from the distal volar forearm. For salvage procedures, a fish-mouth incision in the digital pulp was performed in case of insufficient venous drainage.
Patients in the adult group were managed with the same perioperative protocol. Prostaglandin E1 (0.41 μg; Alprodil, Bukwang Inc., Seoul, Korea) was infused at 40 mL/hr, and 50 U/mL unfractionated heparin was infused at 10 mL/hr both pre- and intraoperatively. These doses of prostaglandin and heparin were administered for postoperative day (POD) 5 and POD 7, respectively. Low-dose aspirin was also prescribed for POD 14. Medical leech therapy was applied to patients with venous congestion or arterial insufficiency. However, in the children group, anticoagulant therapy was not administered.
To prevent venous congestion, procedures for inducing continuous bleeding (salvage procedure) were necessary in 18 children (24 digits) and 24 adults (28 digits). Among 42 patients, leech applications were used to prevent venous congestion in seven children and three adults. Transfusion in both groups was indicated when the level of hemoglobin on POD 2 was 8.0 g/dL or less. If a patient met the criteria for blood transfusion, one unit of packed red blood cells was transfused. After transfusion, the Hb level was confirmed by laboratory examination.
Rehabilitation
Patients started performing protected early active motion exercise on POD 7. Therapy initiation depended on the conditions of the replanted fingers. More aggressive active and passive range of motion exercise was performed a minimum of 2 weeks after surgery when bone and tendon repair pain was tolerable.
Evaluation
Replantation survival and postoperative vascular complications were evaluated for two weeks after surgery. Functional outcomes were assessed at the last follow-up.
Statistical analyses
Demographic data such as those of sex, age, injury side, type of amputation, injured finger, level of injury, type of anastomosis, number of salvage procedures, perioperative hemoglobin change, number of transfusions, and survival rate were calculated and compared between the children and adult groups. We used either the chi-square or Fisher exact tests for categorical variables and the t-test for numerical variables. All two-sided p-values less than 0.05 were considered significant.
Variables with p-values less than 0.10 (sex, age group, type of amputation, level of amputation, number of amputations, type of vessel anastomosis, preoperative hemoglobin levels, and hemoglobin levels on POD 2) were included in the multivariate analysis. A logistic regression analysis was carried out to identify independent factors predicting transfusion after replantation. Statistical analyses were performed using IBM SPSS Statistics ver. 20.0 (IBM Corp., Armonk, NY, USA).
Results
The mean age at index surgery in the adult group was 47.3 years (range, 25–64 years), which was significantly higher than that in the children group (p<0.001) (Table 1). However, other characteristics including sex (p=0.232), type of amputation (p>0.999), injured finger (p=0.658), and level of injury (p=0.985) were not different between the two groups (Table 1).
Among the three patients (seven digits) with treatment failure in the children group, two children (six digits) had crushing injuries involving multiple digits. The survival rates after replantation of digits in the children and adult groups were 80.6% (29/36 digits) and 90.6% (29/32 digits), respectively (p=0.242). On comparing intraoperative and perioperative variables, the mean preoperative hemoglobin level was significantly lower in the children group than in the adult group (12.8 g/dL vs. 14.3 g/dL, p<0.001). The mean hemoglobin level on POD 2 was also lower in the children group than in the adult group (10.0 g/dL vs. 12.3 g/dL, p=0.002). Although 18 children (24 digits) and 24 adults (28 digits) had similar needs for salvage procedures (p=0.102), the transfusion rate was significantly higher in the children group than in the adult group (8/27 patients vs. 1/27 patients, p=0.012) (Fig. 1, Table 2).
A 7-year-old boy with a zone I crushing amputation and a segmental arterial defect (A). (B, C) One artery was anastomosed using an interposition vein graft, and a salvage procedure was performed for 5 days. (D) Serial hemoglobin changes and transfusion during the 14-day follow-up period. POD, postoperative day.
Comparison of hemoglobin change, transfusion rate, and survival between the child and adult groups
The risk factors for transfusion after salvage procedures were assessed. The binary logistic regression analysis revealed that young age (OR, 4.256; 95% CI, 1.452–14.215; p=0.042), artery-only anastomosis (OR, 37.901; 95% CI, 1.351–1,063.547; p=0.033), preoperative hemoglobin level (OR, 5.523; 95% CI, 1.568–21.678; p=0.024), and hemoglobin levels on POD 2 (OR, 4.277, 95% CI, 1.131–16.182; p=0.032) were significant risk factors. However, sex (p=0.981) was not a risk factor (Table 3).
Adjusted odds ratios for salvage procedures and transfusions after fingertip replantation (binary logistic regression analysis)
At the final follow-up, 29 out of 36 digits in the children group and 29 out of 32 digits in the adults group survived (p=0.242).
Discussion
Children frequently experience hemodynamic changes during perioperative management of fingertip amputation. This case-control study demonstrated that the survival rates after replantation of digits in the children and adult groups were 80.6% (29/36 digits) and 90.6% (29/32 digits), respectively (p=0.242). The mean preoperative hemoglobin levels and those on POD 2 in the children and adult groups were 12.8 g/dL vs. 14.3 g/dL (p<0.001) and 10.9 g/dL vs. 12.3 g/dL (p=0.002), respectively. The rate of transfusion in the children group was significantly higher than that in the adult group (8/27 patients vs. 1/27 patients, p=0.012). Younger age, type of anastomosis, preoperative hemoglobin levels, and those on POD 2 are important risk factors for salvage procedure and transfusions after fingertip replantation.
Fingertip replantation in children is technically demanding due to the small arteries and difficulty in handling the venous outflow [11]. Therefore, venous drainage could be achieved with a salvage procedure when venorrhaphy, which is often used for reperfusion, is impossible. Salvage procedures in young children frequently result in a significant decrease in hemoglobin levels, necessitating transfusion; this is likely due to the smaller blood volume in children [9,11]. Shi et al. [9] performed fingertip replantation with only one artery anastomosis among 12 salvage procedures in children with a mean age of 5.2 years (range, 4–10 years); it was reported that three children (25%) received blood transfusions for blood loss. Baker and Kleinert [11] reported that 41% of 33 children under 34 months of age required transfusion, with 41 digits amputated over 15 years. In this study, only one of 27 adults (4%) received blood transfusion, but eight of 27 children (29.6%) received blood transfusion. AS risk factors for blood transfusion after replantation of fingertip amputation were found to be younger age, type of anastomosis, preoperative hemoglobin level, and hemoglobin level on POD 2 in this study.
Although a direct comparison of survival rate is difficult due to the different mechanisms of injury and other differences in demographics, the reported survival rate after replantation in children with finger amputation ranges from 43% to 100% [4,8,10,12-14]. Lafosse et al. [10] reported a finger survival rate of 43% in children less than 6 years of age. In this study, the finger survival rate was not significantly different between the children and Adult groups (80% vs. 90%). Our findings regarding survival rates for both children and adults are similar to those of previous reports [5,10,13,14].
This study presents a paper on saving an amputated finger by performing a salvage procedure (hemorrhage therapy) in cases where venorrhaphy cannot be performed for fingertip replantation (zones I and II) in children including infants or when venorrhaphy is not effective but venous drainage is not satisfactory. We found that although the prevalence of salvage procedures for replantation in children was not different from that in adults in this study, replantation in children was associated with a greater decrease in hemoglobin and an increased risk of transfusion compared to adults. Therefore, the family of children should be informed of the possibility of transfusion risk before and after surgery.
This study had several limitations. First, it was a retrospective, single-center, case-control study; this study design could be a source of selectin bias. Second, this study is a retrospective design, and there are clear limitations in randomization. Therefore, a control group was selected retrospectively by adjusting other variables except age, which is considered most important. In addition, accurate comparisons can be made only when all patients from the same patient recruitment period are included. Therefore, it might be difficult to draw concrete conclusions that children are more likely to receive blood transfusions based on matched controls. Third, in comparison to that in other studies, salvage procedures were performed more frequently in the children group (67%) in this study. However, this is because venorrhaphy is often impossible or technically difficult in fingertip amputation in the children group. Therefore, using a bloodletting technique in a patient with fingertip amputation is sometimes inevitable to prevent venous congestion. Finally, we did not perform additional analysis on the effects of recovery according to the presence or absence of blood transfusion in the children group. However, many problems related to blood transfusion such as prolonged hospital stays, risk of allergic reaction, transfusion-related acute lung injury, circulatory overloading, venous thromboembolism, and hematogenous infections, have been reported in the literature.
Conclusion
This case-control study showed that after replantation of fingertip amputation, hemodynamic changes in perioperative periods were more common and the rate of transfusion was higher in children than in adults. Younger age, type of anastomosis, preoperative hemoglobin levels, and hemoglobin levels on POD 2 were found to be risk factors for transfusion after fingertip amputation.
Notes
Conflicts of interest
The authors have nothing to disclose.
Funding
None.