Microvascular Muscle Flap Research Articles

Mid-term Clinical Outcome of Microvascular Gracilis Muscle Flaps for Defects of the Hand

Purpose: Gracilis muscle flaps are useful to cover defects of the hand. However, there are currently no studies describing outcome measurements after covering soft tissue defects using free flaps in the hand. Aim: To analyze mid-term results of gracilis muscle flap coverage for defects on the hand, with regard to functional and esthetic integrity. Methods: 16 patients aged 44.3 (range 20–70) years were re-examined after a mean follow-up of 23.6 (range 2–77) months. Mean defect size was 124 (range 52–300) cm2 located palmar (n = 9), dorsal (n = 6), or radial (n = 1). All flaps were performed as microvascular muscle flaps, covered by split thickness skin graft. Results: Flaps survived in 15 patients. 6 patients required reoperations. Reasons for revisions were venous anastomosis failure with total flap loss (n = 1) requiring a second gracilis muscle flap; necrosis at the tip of the flap (n = 1) with renewed split thickness skin cover. A surplus of the flap (n = 2) required flap thinning and scar corrections were performed in 2 patients. Mean grip strength was 25% (range 33.3–96.4%) compared to the contralateral side and mean patient-reported satisfaction 1.4 (range 1–3) (1 = excellent; 4 = poor). Conclusions: Gracilis muscle flaps showed a survival rate of 94%. Patients showed good clinical outcomes with acceptable wrist movements and grip strength as well as high reported satisfaction rates. Compared to fasciocutaneous free flaps, pliability and thinness especially on the palmar aspect of the hand are advantageous. Hence, covering large defects of the hand with a gracilis muscle flap can be a very satisfactory procedure.Level of evidence: IV observational.

Comparison of Lymphatic Drainage of the Lower Limbs After Soft Tissue Reconstruction by Microvascular Muscle Flap Versus Fasciocutaneous Flaps.

Complex traumatic injuries of the lower limb are increasingly being salvaged. The common long-term morbidity includes secondary lymphedema. The role of microvascular flaps is often discussed for lymph flow restoration. However, the differential effect of using muscle flap versus fasciocutaneous flap in the lower-limb trauma to avoid secondary lymphedema is not studied. Forty patients who underwent microvascular flap reconstruction were reviewed retrospectively to obtain data regarding clinical demographics and surgical procedure. Assessment for presence of clinical lymphedema was done. The lymphatic drainage in all these patients was assessed by 99mTc lymphoscintigraphy. Of the 40 patients included in the study, group A (n = 23) underwent muscle-based free flap reconstruction, and group B (n = 17) had fasciocutaneous flaps. Clinical lymphedema was present in 21 patients, of which 18 were of group A and 3 of group B. On lymphoscintigraphy, 14 patients had either partial or complete obstruction in the reconstructed lower limb, 11 in group A and 3 in group B. All of them (n = 14) were found to have associated clinical lymphedema. The association of clinical lymphedema (P < 0.001) and obstructive pattern on lymphoscintigraphy (P < 0.05) with muscle flaps was found to be statistically significant. With the advancement in surgery and techniques, not only salvageability but also stable and morbidity free outcomes are the goals. Fasciocutaneous flaps may have better lymphatic outcomes than the muscle-based flaps, and the criteria for lower-limb reconstruction can be reformed to include simultaneous soft tissue and lymphatic reconstruction.

40 years of microvascular reconstruction with latissimus dorsi muscle free flap

Introduction: The first use of the latissimus dorsi as a myocutaneous flap was described as early as the end of the 19th century, in the coverage of an extensive defect following radical mastectomy (Tansini 1895). Subsequently, the surgical procedure was forgotten and later re-introduced as a pedicled flap for breast reconstruction (Olivari 1976). Olivari prompted the microsurgical team from Ljubljana to perform a free muscle transfer (Godina 1978). The first emergency free flap transfer in Ljubljana was performed in 1979.Patients and Methods: Latissimus dorsi flap can be used as a muscle or musculocutaneous flap, in a pedicle or a free form. The procedure of reconstructing large tibial defects always proceeded as a two-team procedure simultaneously. For the continuity of the axial blood flow of the tibia, M. Godina developed end-to-side anastomosis.Results: Using latissimus dorsi free flap for reconstruction of tibial defects the first statistics by M. Godina from 134 patients showed a 0.75% flap loss rate and 1.5% infection rate; an average healing time of 6.8 months and a bed rest period estimated at 27 days. In the case of delayed reconstruction, the author reported an infection rate of 17.5%.Conclusions: Due to clinical experience, good results and a new doctrine of the Ljubljana School of microsurgery played a historical role in the reconstruction of the tibia with a muscular microvascular muscle flap.

Random-pattern versus perforator-based adipocutaneous skin paddles for postoperative monitoring of free muscle flaps—a comparative retrospective cohort study

Free microvascular muscle flaps represent well-established reconstructive options for complex soft tissue defects. However, due to their lack of cutaneous capillary beds, they are difficult to monitor postoperatively. To this end, random and axial-pattern adipocutaneous skin paddles are often included. The objective of the study was to compare the impact of random-pattern versus perforator-based adipocutaneous skin paddles on operative efficacy and muscle flap safety. Between August 2014 and July 2016, a total of 120 free muscle flaps were included in this retrospective monocentric cohort study. Based on their skin-paddle type, they were either grouped into a 'perforator-based' (group Pb) or 'random-pattern' (group Rp) cohort. The electronic medical records and operative reports of all patients were subsequently reviewed and patient, defect, and flap characteristics of both groups were compared. The effect of the competing skin paddle types on the overall operative time, incidences of flap loss or microvascular complications, and total length of hospital stay were then assessed. Group Pb comprised 72 flaps, whereas 48 flaps constituted group Rp. Patient, defect, and flap characteristics were similar between both groups. Groups Pb and Rp were comparable regarding patient age (group Pb: 61 (10-90) vs. Rp: 59 (13-81), p = 0.556), ASA (American Society of Anesthesiologists) class (group Pb: 3 (1-4) vs. Rp 3 (1-3), p = 0.977), and comorbidities, summarized by the Charlson comorbidity index (CCI; group Pb: 1 (0-4 vs. Rp: 1 (0-5), p = 0.295). Both types of monitoring skin paddles were equally reliable. There was no significant difference in the mean operation time between both groups (group Pb: 373 ± 122 min vs. Rp: 342 ± 84 min, p = 0.124). In-patient treatment after flap surgery and total length of hospital stay were significantly shorter in group Pb (group Pb: 24 ± 10 days vs. Rp: 32 ± 17 days, p = 0.002 and group Pb: 39 ± 15 vs. Rp: 48 ± 24, p = 0.022). Perforator-based skin paddles are a reliable tool for postoperative perfusion monitoring of free muscle flaps and help avoid additional surgical interventions as opposed to their random-pattern counterparts. Thus, the overall and postoperative length of hospital stay is significantly reduced.

Eradication of Acinetobacter baumannii/Enterobacter cloacae complex in an open proximal tibial fracture and closed drop foot correction with a multidisciplinary approach using the Taylor Spatial Frame\xae: a case report

BackgroundMulti-drug-resistant bacteria (e.g. Carbapenem-resistant Acinetobacter baumannii, extended-spectrum betalactamase or carbapenemase-producing enterobacteriaceae) are emerging in early-onset infections. So far, there is no report describing the eradication of these bacteria in a osseous infection of an open proximal tibial fracture in combination with the hexapod technology to address both osseous consolidation and closed drop foot correction.Case presentationAfter sustaining a proximal tibial fracture (Gustilo 3B), a 41-year-old man was primarily treated with open reduction and internal fixation by a locking plate and split-thickness skin graft in the home country. At the time of admission to our hospital there was a significant anterolateral soft tissue defect covered with an already-necrotic split-thickness graft and suspicious secretion. CAT and MRI scans revealed no signs of osseous healing, intramedullary distinctive osteomyelitis, as well as a large abscess zone in the dorsal compartment. Multiple wound smears showed multi-drug-resistant bacteria: Acinetobacter baumannii (Carbapenem resistant) as well as Enterobacter cloacae complex (AmpC overexpression). After implant removal, excessive osseous and intramedullary debridements using the Reamer Irrigator Aspirator (RIA®) as well as initial negative pressure wound therapy were performed. Colistin hand-modelled chains and sticks were applied topically as well as an adjusted systemic antibiotic scheme was applied. After repetitive surgical interventions, the smears showed bacterial eradication and the patient underwent soft tissue reconstruction with a free vascularized latissimus dorsi muscle flap. External fixation was converted to a hexapod fixator (TSF®) to correct primary varus displacement, axial assignment and secure osseous healing. A second ring was mounted to address the fixed drop foot in a closed fashion without further intervention. At final follow-up, 12 months after trauma, the patient showed good functional recovery with osseous healing, intact soft tissue with satisfactory cosmetics and no signs of reinfection.ConclusionsA multidisciplinary approach with orthopaedic surgeons for debridement, planning and establishing osseous and joint correction and consolidation, plastic surgeons for microvascular muscle flaps for soft tissue defect coverage as well as clinical microbiologists for the optimized anti-infective treatment is essential in these challenging rare cases.Level of evidenceLevel IV.

Treatment of compound tibia fracture with microvascular latissimus dorsi flap and the Ilizarov technique: A cross-sectional study of long-term outcomes

Extensive compound tibial fractures present reconstructive challenges. The present study aimed to assess the outcomes of microvascular latissimus dorsi (LD) flap combined with the Ilizarov technique for extensive compound tibial fractures with bone loss and bone healing complications. Patient records were reviewed retrospectively. The Lower Extremity Functional Scale (LEFS), the Disabilities of the Arm, Hand and Shoulder (DASH), and the 15D health-related quality of life (HRQoL) instrument were applied. Between 1989 and 2014, 16 patients underwent reconstruction with a microvascular LD flap and bone transport (11/16) or late bone lengthening (5/16). The mean clinical follow-up time was 6.6 (standard deviation (SD): 6.5) years. Three patients had minor complications requiring reoperation. Partial necrosis of one flap required late flap reconstruction in one case. Late bone grafting was used to enhance union in eight of 16 cases. The mean new bone gain was 3.8cm (SD: 2.5). Overall, 11 patients completed the questionnaires in a mean of 22.3 years (SD: 2.4) after surgery. The main findings revealed a relatively good function of the reconstructed limb and good shoulder function. The mean HRQoL was comparable to that of an age-standardized sample of the general population. Segmental tibia transport and lengthening to correct limb length discrepancy do not compromise the microvascular muscle flap. Combined microvascular LD flap reconstruction and the Ilizarov technique can be used in treating acute compound tibial defects, pseudoarthrosis, and osteitis, all associated with significant amputation risk. Fair long-term functional outcomes and HRQoL are achieved when these combined techniques are used.

M. gracilis Lappenplastik mit plantarem Spalthauttransplantat – Fallbericht und Literaturübersicht zur speziellen Anatomie der Hohlhand und ihrer funktionellen Rekonstruktion

Skin and soft-tissue architecture of the palm are unique. Coverage of extensive soft-tissue defects restoring the functional capacity of the palm remains a challenging task. Anatomic restoration with skin from another area is hardly possible. In manual labourers, reconstruction of mechanical soft-tissue stability is required in addition to sensation, range of motion and grip strength. Sensate fasciocutaneous flaps bear disadvantages of tissue mobility, shifting and bulkiness. Published criteria for defect-related flap selection are sparse. Defect analysis (anatomy, units of tactile gnosis, individual parameters) provides information to weigh needs for sensation or tissue stability, influencing selection of most appropriate procedures. We distinguished 4 units: hypothenar (H), thenar (T) and central palm (Z). (Z) consists of a central palmar unit (c') and the distal palm (d'). Individual parameters (age, profession, dominant hand, psychosocial aspects) were also considered. Units (T) and (H), regions of secondary touch, demand protective sensation by applying sensate fasciocutaneous flaps. In labourers tactile gnosis in (Z) is of less, tissue stability of greater value. An extensive palmar defect (9×13 cm, affecting unit (Z), partially affecting units (T) and (H), of the dominant hand) with combined vessel, nerve, tendon injuries (male labourer, 21 years) was covered after defect analysis with a free gracilis muscle flap and a glabrous intermediate (0.5 mm) thickness skin graft from the instep region. 29 months postoperatively anatomic conditions of palmar soft tissue (Vancouver scar scale: 1), high mechanical soft-tissue stability including normal hand function were evident. Semmes Weinstein testing showed positive pressure sensation. Professional reintegration after 5 months was possible. Defect coverage of the palm must not consist of merely providing sensate vascularised tissue. The most appropriate procedure can be derived from careful defect analysis focusing on the affection of units of tactile gnosis to achieve near to anatomic reconstruction. In labourers, patient- and defect-related demands need close correlation with the value of the selected flaps regarding the sensation and mechanical stability to be expected. In selected cases (mechanical irritation, affection of unit (Z), younger age) by combining microvascular muscle flaps with plantar intermediate thickness skin grafts promising functional results with early professional reintegration can be achieved by reconstructing like with like.

Neoadjuvant Treatment of Locally Advanced Soft Tissue Sarcoma of the Limbs: Which Treatment to Choose?

Soft tissue sarcomas (STSs) form a heterogeneous group of malignant neoplasms arising in the mesenchymal connective tissues. They can develop at any anatomic site but 60% occur in the extremities. Initially, treatment of STS relied solely on excision. In the 1970s, Enneking et al. developed the concept of compartmental resection to reduce the local failure rate. Later, Rosenberg et al. demonstrated, in a randomized study, that there was no difference in local tumor control and disease-free survival (DFS) in patients treated with amputation versus limb-saving surgery followed by 50-70 Gy external-beam radiotherapy (EBRT). A considerable proportion of patients present with locally advanced tumors as a primary or recurrent disease and cannot be resected with adequate clearance margins. These patients are threatened with amputation for complete tumor removal. Improvements in surgical techniques, such as microvascular muscle flaps, allow for the avoidance of limb loss in the majority of cases. However, the use of frozen sections to determine intraoperatively whether clear margins have been achieved is limited by the multiplanarity of resection specimens. Thus, local failure rates are 15%-25%, and preoperative measures to sterilize the invasive margin of sarcomas have been explored. High-dose preoperative EBRT for high-grade STS was developed, and its combination with intra-arterial or i.v. chemotherapy was reported to be effective. Recently, systemic chemotherapy combined with deep wave hyperthermia was shown to result in a longer DFS time in a large, randomized, phase III study. Treatment concepts differ significantly among centers and are influenced more by availability of technical equipment than by data. It is the aim of this review to elucidate the rationale of different regimens and analyze their potentials as well as weaknesses.

Microvascular free muscle flap reconstruction of soft-tissue defects with bone exposure after the distal tibial fracture

目的 介绍应用吻合血管的游离肌肉瓣加网状皮片移植修复胫骨骨折合并骨外露及感染创面的新方法.方法 26例胫骨骨折合并骨外露及感染创面患者依伤情选择手术时机,5例采用一期吻合血管的游离肌肉瓣加网状皮片移植覆盖骨外露创面;6例急诊清创术后2周行二期修复;其余15例入院前胫骨远端感染严重,均采用二期肌肉瓣加网状皮片移植覆盖骨外露创面.结果 26例中22例术后肌肉瓣及皮片全部成活;2例皮片部分坏死,2例创口延迟愈合,经换药均二期愈合.随访10～24个月(平均18个月),皮片色泽、质地、弹性均良好,无瘢痕挛缩.骨折均已愈合.结论 肌肉瓣血运丰富,是修复胫骨远端感染及骨外露创面的理想方法,比较适合覆盖大面积软组织损伤合并骨外露创面和小腿远端慢性窦道及慢性骨髓炎骨外露创面。

Open-window thoracostomy and microvascular muscle flap for severe intrathoracic infection around aortic prosthetic graft

Open-window thoracostomy and microvascular muscle flap for severe intrathoracic infection around aortic prosthetic graft

Long‐term morphometric and immunohistochemical findings in human free microvascular muscle flaps

Reinnervation, muscle regeneration, density of microvessels, and muscle-type specific atrophy were studied 3-4 years after surgery in surgically nonreinnervated free microvascular muscle flaps to 13 patients transplanted to the upper or lower extremities. Routine histology and immunohistochemistry for PGP 9.5 and S-100 (neuronal markers), Ki-67 (cell proliferation), myosin (muscle fiber types), and CD-31 (endothelium) were carried out, and results were analyzed morphometrically. Three to 4 years after surgery, severe atrophy of predominantly slow-type fibers was seen in 9 cases. In 4 cases, muscle-fiber diameter and fiber-type distribution were close to normal. Long intraoperative muscle ischemia and postoperative immobilization were associated with poor muscle bulk in flaps. The density of microvessels in flaps did not differ from control muscles. PGP 9.5 and S-100 immunopositive nerve fibers were detected in 7 patients. Reinnervation was associated with good muscle bulk. In 4 patients, activation of satellite cells was evident. The results suggest that in some cases, spontaneous reinnervation may occur in free muscle flaps, and that several years after microvascular free flap transfer, the muscle still attempts to regenerate.

Satellite cell proliferation, reinnervation, and revascularization in human free microvascular muscle flaps 1

Background Satellite cell proliferation, reinnervation, and revascularization were studied in human nonreinnervated free microvascular muscle flaps to characterize mechanisms of muscle regeneration after flap surgery. Materials and methods Patient biopsies ( n = 19) were taken at operation and five timepoints up to 9 months after operation, and corresponding clinical data were obtained. Immunohistochemistry for Ki-67 was used to detect proliferating satellite cells, CD-31 to identify endothelial cells, and S-100 and PGP 9.5 proteins to detect reinnervation. Results Two weeks after operation, the expression of PGP 9.5 and S-100 had virtually disappeared in all larger nerve fibers and half of smaller nerve fibers. By 6 months, however, a strong expression of PGP 9.5 and S-100 had reappeared in larger nerve fibers in three of four flaps, suggesting that reinnervation had taken place. The number of mitotic satellite cells already peaked at 2 weeks, indicating onset of muscle regeneration. The number of intramuscular capillaries first increased but later decreased to lower than original level. Flaps with more muscle volume showed more reinnervation and satellite cell mitotic activity. In cases of a delay occurring in reconstructive surgery, a low level of reinnervation was seen. Conclusion Three patients of four showed spontaneous muscle reinnervation in microvascular free flaps with satellite cell activation followed by restored morphology. Late reconstruction and obesity lead to poor reinnervation, placing emphasis on timing of surgery and patient selection.

Radical excision and reconstruction of chronic tibial osteomyelitis with microvascular muscle flaps.

We report a series of 21 patients with chronic osteomyelitis of the tibia treated with microvascular muscle flap reconstruction. All patients underwent a radical bone and soft-tissue excision until healthy, well-bleeding tissue was exposed. Six patients required cancellous bone grafting. Latissimus dorsi was used in 14 patients, gracilis in 4, and rectus abdominis in 4. One gracilis flap was lost due to vessel thrombosis and was replaced with a rectus abdominis free flap. Average follow-up was 2.5 years. There was no evidence of clinical infection in 20 patients at follow-up; the bone had healed, the soft-tissue cover was stable, and the laboratory parameters were normal. Bone infection recurred in 1 patient, resulting in a below-knee amputation. The radical excision of infected bone and affected soft tissue and reconstruction with a well-vascularized large free-muscle flap is an excellent solution in most difficult chronically infected cases.

Close-Range Shotgun and Rifle Injuries to the Face

The treatment of extensive shotgun and rifle injuries to the face is extremely difficult and demands experience in microsurgery and craniofacial surgery. Early aggressive surgery with immediate bone and soft tissue reconstruction is recommended for the management of extensive facial gunshot wounds. Experience has shown that early three-dimensional bone replacement can be achieved with bone grafts in the midfacial area if the bone grafts are covered with well-vascularized tissues. Large midfacial defects can be reconstructed safely and effectively with free-tissue transfers, including bone. In the acute stage, microvascular muscle flaps are preferred because of their good vascularity and good filling capacity. These flaps are able to cover the anterior cranial fossa. When vascularized bone is needed, the authors' first choice is a latissimus dorsi flap with scapular bone. Patients treated with an early and aggressive surgical strategy develop fewer problems in form of infection, contraction, scarring, and require fewer secondary corrections. Successful primary treatment allows the surgeon to use multiple modalities, including tissue expansion, free-tissue transfers, and local flaps in a noninfected environment. The treatment is rewarding, and the results are surprisingly good. It is extremely unusual for patients with self-inflicted gunshot injuries to reattempt suicide.

Histological changes in free micro-vascular muscle flaps in 19 patients

Histological changes in free micro-vascular muscle flaps in 19 patients

Combined vascular reconstruction and microvascular muscle flap transfer for salvage of ischaemic legs with major tissue loss and wound complications

To assess the safety and short-term efficacy of combined vascular revascularisation and free microvascular muscle flap transfer in patients with advanced lower limb ischaemia caused by occlusive arterial disease. A prospective follow-up study of 2-72 months. Academic referral centre. Consecutive first 15 patients with extensive tissue loss due to advanced leg ischaemia or wound complications after bypass surgery. Graft patency, free tissue transfer viability, amputation rate. There was no perioperative mortality. The cumulative rates for secondary vascular patency, microvascular graft viability and limb salvage were 80%, 87% and 76% at one year provided that vessels and grafts that were functioning at the time of amputation were considered lost to follow-up rather than failed at that point. If, however, amputation was also regarded as vessel and graft failure the corresponding rates were 68%, 62% and 76%, respectively. Combining microvascular muscle flap transfer with vascular reconstruction for salvage of legs with extended ischaemic tissue loss or wound complications after bypass surgery gave acceptable preliminary results and deserves an attempt in selected patients.

Magnetic resonance imaging of free muscle flaps

Postoperative behaviour and changes in the structure of free microvascular muscle flaps are unknown. Magnetic resonance imaging was used to monitor postoperative structural changes in free muscle flaps. MRI was conducted on 10 patients 2 weeks and 6 months postoperatively. The results were correlated with our earlier findings using ultrasonography and computed tomography. Oedema and fat degeneration were visually assessed (scale 1–4) and T2-dependent signal intensity, flap thickness and volume were measured from the MR images. When the 2 weeks values were compared with the 6 month's ones it was found that intramuscular oedema decreased from 3±0.5 (moderate) to 1.7±0.5 (slight) (p<0.05) and fat degeneration increased from 1.1±0.33 (normal) to 1.9±0.78 (slight) (p<0.05). T2-weighted signal intensity, representing postoperative inflammatory changes, oedema, and also reflecting changes induced by denervation, declined by 28%. The volume of the free flap increased by a mean of twice (from 162±81 ml to 305±135 ml) the initial values in a 2 week period (p<0.05), and attained its initial volume in 6 months (132±69 ml). The thickness of the transplant increased from 11.8±2 mm to 24±4 mm in 2 weeks (p<0.05) and decreased to 13.8±3.5 mm at 6 months. MRI also shows that a free microvascular muscle tightly fills cavities. The correlation between MRI and earlier US studies was 0.71 and between MRI and CT 0.83. MRI is an accurate but expensive research tool to evaluate noninvasively changes in free muscle flaps after the surgical procedure. A 6-month follow up, this study showed that after extensive postoperative swelling the flap attains its initial thickness. The structure of the free flap changes: muscle is replaced by fatty degeneration and also the surface of the flap becomes thicker. Signs indicating denervation induced intramuscular changes in the flap were also noted.

Management of infected tibial intramedullary nailing using an organized treatment protocol

Twenty cases of osteomyelitis following intramedullary nailing of the tibial shaft fracture were managed with a prospective treatment protocol comprising intramedullary reaming debridement, antibiotic-bead depot, external skeletal fixation, microvascular muscle flap and early cancellous bone grafting. The follow-up period ranged from 25 to 48 months (average, 34.3 months). Pseudomonas aeruginosa (37.5%) and staphylococcus aureus (20.8%) were the organisms most commonly involved. There were 8 united and 12 ununited fractures after reaming debridement surgery. Nineteen infections were initially arrested by one debridement. One infection was arrested by two sequential debridements. All 12 ununited fractures were stabilized by Hoffmann unilateral external fixation until the fracture healed. The time spent in external fixation ranged from 3 to 7 months (average, 5.2 months). Early cancellous bone grafting was successfully accomplished for 9 ununited fractures with major debridement bone loss. The average union time of the 9 fractures with bone grafting was 7.2 months (range, from 6 to 8 months). We believe that this treatment protocol gives a predictable and rapid recovery. The complications were infection recurrence in two cases at the old tibial shaft fracture sites, minor pin tract infection of Hoffmann external fixators in two cases, and stiffness in two ankles and one knee.

Free flap reconstructions of tibial fractures complicated after internal fixation.

The cases of 15 patients are presented where microvascular soft-tissue reconstructions became necessary after internal fixation of tibial fractures. Primarily, seven of the fractures were closed. Eleven fractures had originally been treated by open reduction and internal fixation using plates and screws, and four by intramedullary nailing. All of the patients suffered from postoperative complications leading to exposure of the bone or fixation material. The internal fixation material was removed and radical revision of dead and infected tissue was carried out in all cases. Soft tissue reconstruction was performed using a free microvascular muscle flap (11 latissimus dorsi, three rectus abdominis, and one gracilis). In eight cases the nonunion of the fracture indicated external fixation. The microvascular reconstruction was successful in all 15 patients. In one case the recurrence of deep infection finally indicated a below-knee amputation. In another case, chronic infection with fistulation recurred postoperatively. After a mean follow-up of 26 months the soft tissue coverage was good in all the remaining 13 cases. All the fractures united. Microvascular free muscle flap reconstruction of the leg is regarded as a reliable method for salvaging legs with large soft-tissue defects or defects in the distal leg. If after internal fixation of the tibial fracture the osteosynthesis material or fracture is exposed, reconstruction of the soft-tissue can successfully be performed by free flap transfer. By radical revision, external fixation, bone grafting, and a free flap the healing of the fracture can be achieved.

Blood flow in free muscle flaps measured by color Doppler ultrasonography.

Color Doppler ultrasonography, a noninvasive method for studying changes in blood flow, has been used to monitor 18 patients with free microvascular lower limb muscle flaps. The peak, mean, and minimum velocities, resistance indices, and diameters of the flap pedicle arteries and also of the limb recipient arteries proximal to the microvascular anastomoses were measured at 2 and 6 weeks and 3, 6, and 9 months after surgery. The peak velocities did not significantly differ from each other, but the mean velocity in the flap pedicle arteries was 12.5% higher than that in the recipient arteries throughout the study period. End diastolic velocity in the pedicle was positive (toward the ultrasound probe) at 2 weeks (mean, 2 cm/sec, SD 10), 6 weeks (mean, 5 cm/sec, SD 16), and 3 months (mean, 3 cm/sec, SD 13) after surgery and significantly higher (P < 0.05) than at 6 months (mean, 7 cm/sec, SD 11), when the pattern of blood flow was normal forward/backward flow during systole/diastole. The resistance indices of the pedicle at 2 weeks (Ri = 0.978), 6 weeks (Ri = 0.936), and 3 months (Ri = 1.001) were significantly lower (P < 0.05) than at 6 months (Ri = 1.108), when the pedicle and recipient artery indices were the same. The diameter of the pedicle arteries was 14% smaller than those of the recipient arteries, but did not change during follow-up. This prospective clinical study shows that blood flow in the pedicle of a free microvascular muscle flap is increased until 6 months after surgery, mainly due to the increased minimum velocity of the pedicle in diastole and decreased resistance index. These findings can be attributed to the loss of vessel tone after denervation and are in accordance with earlier studies showing that denervated muscles lose their autoregulation and that blood flow increases, but that these phenomena subside with time. Increased blood flow in free muscle flaps can explain the high success rate of microanastomoses and positive effect on wound healing.