End-to-end versus end-to-side anastomoses in free flap reconstruction: single centre experiences

End to end versus end to side microvascular anastomosis for traumatic lower limb free flap reconstructions: A systematic review and meta-analysis

Background

Free flap reconstruction of the lower extremity is technically challenging and may suffer from higher complication rates than other anatomical sites. One important vascular consideration in the reconstructive process is the microsurgical anastomotic technique, namely whether an end-to-end (ETE) or end-to side (ETS) technique is used. The ETS technique is often preferred by lower limb microsurgeons, who describe its benefits of improved distal perfusion. However, this preference remains based on individual experience or poor evidence.

Methods

A systematic review of the evidence was performed, with inclusion of specifically traumatic lower limb wounds requiring free tissue transfer. Flap failure was utilised as the primary outcome, with secondary outcomes including thrombosis.

Results

Six articles, with 1153 microvascular anastomoses were included. Meta-analysis results revealed no statistical significance in flap failure when comparing ETS to ETE (OR 0.72, CI 0.45-1.15). Included articles were limited by study design (case series) and therefore only provided level IV evidence.

Conclusion

Although further research is required to elucidate the outcomes of both microvascular anastomotic techniques, the results of this review and the wider literature at present do not provide support for any microvascular anastomotic technique over the other.

Soft Tissue Coverage for Foot and Ankle Trauma

Lower extremity trauma can result in extensive soft tissue loss, which can require a staged multispecialty approach. Flaps can be an excellent choice for significant soft tissue loss. A variety of variables goes into the selection of a flap including understanding what the recipient site needs, available donor sites, nature of trauma, and utilization of indices to predict limb salvageability in order to strategically select the correct flap option.

Updates in Traumatic Lower Extremity Free Flap Reconstruction

SUMMARY

Lower extremity reconstruction, particularly in the setting of trauma, remains one of the most challenging tasks for the plastic surgeon. Advances in wound management and microsurgical techniques in conjunction with long-term outcomes studies have expanded possibilities for limb salvage, but many aspects of management have continued to rely on principles set forth by Gustilo and Godina in the 1980s. The purpose of this article is to provide a comprehensive update on the various management aspects of traumatic lower extremity microvascular reconstruction based on the latest evidence, with an examination of recent publications.

Long-Term Outcomes in Patients With Peripheral Arterial Disease Who Undergo Free Flap Reconstruction for Chronic Lower Extremity Wounds

BACKGROUND

Free tissue transfer (FTT) is critical for limb salvage of chronic lower extremity (LE) wounds. In patients with peripheral arterial disease (PAD), FTT LE reconstruction can be challenging due to limited vessel selection for anastomosis. The study aims to evaluate our surgical and functional outcomes after FTT to LE in patients with PAD.

METHODS

A retrospective review identified patients who underwent LE free flap reconstruction between 2011 and 2021. All patients underwent preoperative arteriogram and subsequent FTT. Patients were classified into PAD or non-PAD cohorts, based on the presence of LE arterial stenoses or occlusions identified on arteriogram. Primary outcomes included complications, flap success, need for post-FTT vascular reintervention, limb salvage, and ambulatory status.

RESULTS

A total of 253 patients underwent FTT to LE, with 84 patients (33.2%) in the PAD cohort. Patients with PAD had a higher prevalence of diabetes (83.3% vs 39.1%, P < 0.001) and end-stage renal disease (8.3% vs 2.4%, P = 0.028). Osteomyelitis was more common in the PAD group (73.8% vs 55.0%, P = 0.004). Free tissue transfer donor sites and flap composition were similar between cohorts. At a mean follow-up of 21.1 months, limb salvage rates were similar between non-PAD and PAD cohorts (90.5% vs 84.5%, P = 0.158), with no significant differences in ambulatory status or mortality. Higher complication rates occurred in the PAD cohort (38.1% vs 20.7%, P = 0.003), of which partial flap necrosis was more prevalent in the PAD group (6.0% vs 0.6%, P = 0.016). There was no difference in flap success rates between groups (P = 0.430). More postflap angiograms were performed in the PAD group (29.8% vs 7.1%, P < 0.001), with repeat percutaneous endovascular intervention performed in 68.0% of the PAD group versus 33.3% of the non-PAD group (P < 0.001).

CONCLUSIONS

This is the largest study to demonstrate excellent long-term limb salvage outcomes in patients with PAD who undergo FTT to LE. Percutaneous endovascular intervention and FTT are effective methods to achieve limb salvage in vasculopathic patients with chronic LE wounds.

End-to-side Anastomosis on Digital Arteries: Just a Technical Choice or a Real Benefit?

High-quality evidence is currently poor regarding the benefits of end-to-end (ETE) or end-to-side (ETS) anastomosis in arterial and venous anastomoses, despite being postulated as a potential influence on outcomes. A sufficient microvascular anastomosis is indispensable for the success of any free tissue transfer. ETS microvascular anastomoses have been becoming increasingly important as they allow reconstruction even in patients with impaired vascular status. To the authors’ knowledge, no studies have examined the choice of ETE or ETS anastomoses specifically for digital arteries.

Reconstrução microcirúrgica em um hospital ortopédico: Indicações e desfechos em adultos

Objective  Advances in reconstructive microsurgery in orthopedic surgery provided better functional and aesthetic results and avoided many indications for amputation. In high-volume trauma and orthopedic hospitals, microsurgical reconstruction is essential to reduce costs and complications for these complex orthopedic defects. We describe a microsurgical approach to traumatic wounds, tumor resection, bone defects, and free muscle transfer, performed by an orthopedic microsurgery unit. The objective of the present study was to evaluate predictor factors for outcomes of microsurgical flaps for limb reconstruction, and to provide a descriptive analysis of microsurgical flaps for orthopedic indications.

Methods  Cross-sectional prospective study that included all consecutive cases of microsurgical flaps for orthopedic indications from 2014 to 2020. Data were collected from personal medical history, intraoperative microsurgical procedure, and laboratory blood tests. Complications and free-flap outcomes were studied in a descriptive and statistical analysis.

Results  We evaluated 171 flaps in 168 patients; the indications were traumatic in 66% of the patients. Type III complications of the Clavien-Dindo Classification were observed in 51 flaps. The overall success rate of the microsurgical flaps was 88.3%. In the multivariate analysis, the risk factors for complications were ischemia time ≥ 2 hours ( p  = 0.032) and obesity ( p  = 0.007). Partial flap loss was more common in patients with thrombocytosis in the preoperative platelet count ( p  = 0.001).

Conclusion  The independent risk factors for complications of microsurgical flaps for limb reconstruction are obesity and flap ischemia time ≥ 2 hours, and presence of thrombocytosis is a risk factor for partial flap loss.

A Novel Method of End-to-Side Microvascular Anastomosis Using T-Shaped Metal Stents: A Porcine Study

ABSTRACT

End-to-side anastomosis requires highly specialized techniques. An easy end-to-side anastomosis technique enables anastomosis of vessels with different diameters and under various situations. We invented T-shaped metal stents and evaluated novel methods of end-to-side sutureless anastomosis, confirming their safety, effectiveness, and operability. We performed 8 end-to-side sutureless anastomoses in 4 7- to 11-month-old, male Mexican hairless piglets. After induction of anesthesia, the left femoral artery was resected by approximately 8 cm, and the superior and posterior stumps of the resected femoral artery underwent an end-to-side anastomosis with the right femoral artery by the placement of the metal stents with subsequent use of adhesive for the circumferential area. The patency of blood vessels and the presence of thrombosis were evaluated by ultrasonography or contrast-enhanced computed tomography and histology 4 weeks postoperatively. All the animals survived the procedure; no thrombosis was identified in any of the 8 anastomosis sites according to imaging studies performed 4 weeks postoperatively. Histological examination confirmed the probe patency of blood vessels and neointimal cell proliferation around stent branches. End-to-side anastomosis is possible with T-shaped metal stents. In the future, we aim for the practical application of these stents by improving their operability.

Red Blood Cell Transfusion and its Relationship with Pedicle Thrombosis in Microvascular Free Flaps

BACKGROUND

 Free flaps have become a highly valuable tool for complex reconstructive surgeries. The requirement of red blood cell transfusion (RBCT) during the perioperative period is common and its effect on the free flap survival is debatable. The aim of this study was to determine the relationship between perioperative RBCT and vascular pedicle thrombosis (VPT).

METHODS

 For this study 302 free flaps performed between January 2006 and December 2019 were retrospectively analyzed. It included their characteristics from before, during, and after the surgical procedure. The incidence of VPT and flap survival were calculated based on Kaplan Meier's method and the relationship between VPT and perioperative variables were analyzed by Cox regression models.

RESULTS

 The transfusion group was represented by 62 flaps (20.5%) and no transfusion by 240 flaps. The overall transfusion requirement was 20.5% and the cumulative incidence of VPT was 9.11%. A statistically significant relationship was not demonstrated between flap survival and transfusion status (HR = 1.73 IC 95%: 0.5 to 3.96; p = 0.192) (p = 0.192) independently from the number of units transfused, the preoperative diagnosis of anemia, and the type of flap used and did not establish an increased risk of VPT.

CONCLUSIONS

 This study did not demonstrate an association between RBCT during preoperative period and the risk for VPT or microvascular free flap survival rate on postoperative follow up.

The Double Stitch Everting Technique in the End-to-Side Microvascular Anastomosis: Validation of the Technique Using a Randomized N-of-1 Trial

BACKGROUND

 The double stitch everting (DSE) technique, in which time is won by leaving the needle inside the vessel wall in-between stitching, is a modification of the end-to-side (ETS) anastomosis in the interest of reducing anastomosis time. This ensures proper wall eversion, intima-to-intima contact, and improved suture symmetry.

METHODS

 We designed an N-of-1 randomized trial with each microsurgeon as their own control. We included 10 microsurgeons of different levels of experience who were then asked to perform classic and DSE ETS anastomoses on the chicken leg and rat femoral models. Every anastomosis was cut and evaluated using blinded assessment. Two-way analysis of variance (ANOVA) and multivariable logistic regression were used to analyze the results and for confounder adjustment.

RESULTS

 A total of 210 anastomoses were performed, of which 177 on the chicken leg and 43 on the rat femoral artery and vein. From the 210 anastomoses, 111 were performed using the classic technique and 99 using the DSE technique. The mean anastomosis time was 28.8 ± 11.3 minutes in the classic group and 24.6 ± 12 minutes in the DSE group (p < 0.001, t-test). There was a significant reduction (p < 0.001, two-way ANOVA) in the number of mistakes when using the DSE technique (mean 5.5 ± 2.6) compared with those using the classic technique (mean 7.7 ± 3.4).

CONCLUSION

 The DSE technique for ETS anastomoses improves anastomoses times in experienced and moderately experienced microsurgeons while also improving or maintaining suture symmetry and lowering the number of mistakes.

The "Double hit": Free tissue transfer is optimal in comorbid population with irradiated wounds for successful limb salvage

BACKGROUND

Radiation therapy causes histopathologic changes in tissues, including fibrosis, loss of tissue planes, and vascular damage, which can lead to chronic wound formation. Patients with nonhealing, irradiated wounds and comorbidities that affect microvasculature suffer a "double hit", which leads to delayed wound healing. Local wound care and grafts are commonly insufficient. In this study, we evaluated limb salvage outcomes and long-term complications after free tissue transfer (FTT) in patients with chronic, irradiated leg wounds.

METHODS

We retrospectively reviewed patients with irradiated lower extremity wounds who underwent FTT from 2012 to 2017. Primary outcomes included limb salvage, ambulation, and overall flap success. Reconstruction involved complete excision of irradiated tissue and coverage with well-vascularized tissue.

RESULTS

Seven free flaps in six patients were identified. Average age was 68.4 years and average BMI was 27.8 kg/m². Comorbid conditions included hypertension (57.1%), peripheral vascular disease (57.1%), underlying hypercoagulability (42.9%), diabetes (14.3%), and tobacco use (14.3%). Wounds were present for an average of 25.5 months prior to FTT. Donor sites included anterolateral thigh (71.4%), vastus lateralis (14.3%), and latissimus dorsi (14.3%). Overall flap success rate was 100% with one patient requiring reoperation for dehiscence. Limb salvage rate was 85.7% with one patient undergoing elective amputation due to pain. All patients could ambulate (one used a prosthesis) at a mean follow-up time of 1.4 years.

CONCLUSIONS

Radiation therapy in a comorbid population often leads to the formation of chronic nonhealing wounds. We advocate for earlier consideration of FTT to provide healthy vascularized tissues, thereby avoiding prolonged wound care and patient burden. Successful limb salvage outcomes can be achieved.

Limb Salvage Rates and Functional Outcomes Using a Longitudinal Slit Arteriotomy End-to-Side Anastomosis for Limb-Threatening Defects in a High-Risk Patient Population

BACKGROUND

Limb salvage techniques using free tissue transfer in patients with chronic wounds caused by longstanding osteomyelitis, diabetes, and peripheral vascular disease are technically challenging. The longitudinal slit arteriotomy end-to-side anastomosis is the authors' preferred technique because it is the least invasive arteriotomy and is especially important for diseased recipient arteries. The authors reviewed highly comorbid patients who underwent free tissue transfer with this technique to understand the success rates, overall outcomes, and long-term limb salvage rates.

METHODS

A retrospective review was performed to analyze outcomes of free tissue transfer using longitudinal slit arteriotomy end-to-side anastomosis between 2012 and 2018 performed by the senior surgeon (K.K.E.).

RESULTS

One hundred fifteen free flaps were identified. Patients were, on average, 55.9 years old, with a body mass index of 29.2 kg/m. Comorbidities included osteomyelitis (83.5 percent), hypertension (60.9 percent), tobacco use (46.1 percent), diabetes (44.3 percent), peripheral vascular disease (44.3 percent), hypercoagulability (35.7 percent), and arterial calcifications (17.4 percent). Overall flap success was 93.0 percent; 27.8 percent required reoperation perioperatively because of complications. On univariate analysis, diabetes mellitus, hypertension, and hypercoagulability were significantly associated with eventual amputation (p < 0.05). Multivariate analysis showed that intraoperative thrombosis and take back was independently associated with flap failure. There was an overall limb salvage rate of 83.5 percent, and of those salvaged, 92.7 percent were ambulating without a prosthesis at a mean follow-up of 1.53 years.

CONCLUSIONS

This is the largest series of longitudinal slit arteriotomy end-to-side anastomosis for patients undergoing free tissue transfer for limb-threatening defects in the compromised host. Overall flap success, limb salvage rates, and functional outcomes are high using this technique.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, IV.

Anatomic Study and Clinic Application of Transverse Circumflex Scapular Artery Perforator Flap Repair of Lower Limb Soft Tissue Defects in Children

PURPOSE

The aim of this study was to demonstrate the viability of the transverse circumflex scapular artery perforator flap (TCSAPF) in children with soft tissue defects of the lower limb.

METHODS

In an anatomic study, 25 fresh cadavers were injected with lead oxide-gelatin for spiral computed tomography and 3-dimensional image reconstruction. In a 3-year clinical application study, children with soft tissue defects and exposed tendons and/or bones in the lower limb underwent free-TCSAPF repair of the defect.

RESULTS

Perforators from the transverse branch of the circumflex scapular artery were identified in both anatomical and clinical studies. The average external diameter was 0.9 ± 0.3 mm. Each perforator supplied an average area of 63.5 ± 16.8 cm in anatomical. Twenty-one children were included in this group (9 boys, 12 girls, mean age, 6.6 ± 2.7 years). The size of the flaps ranged from 6 to 17 cm × 4.5 to 7 cm (average, 65.3 ± 22.6 cm). The average flap harvesting time was 30.1 ± 8.5 minutes, average operation time was 138.6 ± 31.5 minutes, and average blood loss was 89.5 ± 21.9 mL. The average length of the vessel pedicle was 8.2 ± 2.4 cm. Arterial congestion occurred in one child, 18 hours postoperatively; subsequent re-exploration and great saphenous vein transplantation were successful. Of the 3 children who had bulky flaps, 1 patient underwent defatting. Satisfactory outcomes included good appearance and function of the recipient and donor areas.

CONCLUSIONS

The TCSAPF provides high-quality skin and vessel flexibility, providing a reliable blood supply in children. The flap has potential benefits over existing perforator flaps.

Characteristics and outcomes of lymphaticovenular anastomosis in older patients with bilateral involvement versus younger patients with unilateral involvement in lower extremity lymphedema

OBJECTIVE

We have previously reported that patients with idiopathic primary lymphedema of adult onset can be classified into an older group with bilateral involvement and a younger group with unilateral involvement and that there are significant differences in the characteristics of these groups. The aims of this study were to investigate the features of these two groups further by evaluating the lymphatics while performing lymphaticovenular anastomosis (LVA) and to compare the effectiveness of LVA between the two groups.

METHODS

This study enrolled 74 patients (136 edematous legs) in whom indocyanine green (ICG) lymphography and LVA were performed. The rate of detection and the diameter of the lymphatic vessels were recorded. The lower extremity lymphedema index (the total sum of the squares of the circumference for five areas in each leg divided by the body mass index) was obtained before and 6 months after LVA. The rate of improvement in the affected lower limbs after LVA was also calculated.

RESULTS

The clinical lymphedema pattern was determined to be bilateral in 62 patients and unilateral in 12. Patients with bilateral lymphedema were significantly older than those with unilateral lymphedema (77.1 ± 7.8 years vs 55.5 ± 12.77 years; P < .01). A linear pattern was seen in 23 patients (46 legs), a low enhancement (LE) pattern in 12 patients (24 legs), a distal dermal backflow (dDB) pattern in 20 patients (40 legs), and an extended dermal backflow (eDB) pattern in 7 patients (14 legs). The lymphedema was unilateral in 12 patients (12 legs). There were significant between-group differences in lymphatic diameter in relation to lower leg area: linear (0.9 ± 0.1 mm) vs dDB (0.7 ± 0.2 mm), linear vs eDB (0.7 ± 0.2 mm), linear vs unilateral (0.5 ± 0.1 mm), LE (0.9 ± 0.2 mm) vs dDB, LE vs eDB, LE vs unilateral, and dDB vs unilateral, P < .01; and eDB vs unilateral, P < .05. There were also significant between-group differences in the rate of improvement in the lower extremity lymphedema index according to the ICG lymphography pattern and laterality: linear (10.5% ± 2.4%) vs unilateral (6.7% ± 0.6%), LE (10.4% ± 1.5%) vs unilateral, dDB (11.0% ± 1.3%) vs eDB (8.9% ± 1.5%), and dDB vs unilateral, P < .01; linear vs eDB, P < .05; and eDB vs unilateral, P < .05.

CONCLUSIONS

The lymphatic vessel diameter tended to be greater in older patients with bilateral lymphedema than in younger patients with unilateral lymphedema. The rate of detection and improvement tended to decrease with worsening of the ICG lymphography pattern. LVA is thought to be more effective in older patients with early-stage bilateral lower leg lymphedema than in their younger counterparts with late-stage unilateral lymphedema.