Preoperative high-frequency color Doppler ultrasound assessment of the blood vessels of the fibular myocutaneous flap.

OBJECTIVE: The fibular myocutaneous flap is a classic flap used to reconstruct oral and maxillofacial defects. This study aimed to evaluate the effectiveness of high-frequency color Doppler ultrasound in detecting the blood vessels in the fibular myocutaneous flap, analyze the influence of variations in the peroneal vessels and perforating peroneal arteries on the surgical design, and explore the value of this technology in preoperatively assessing the blood vessels of the fibular myocutaneous flap. METHODS: Twenty-five patients with mandibular disease or defect underwent preoperative evaluation of the blood vessels of the calf by high-frequency color Doppler ultrasound. The inner diameter and peak systolic velocity (PSV) of the peroneal arteries and veins and the perforating peroneal arteries were compared between different groups. The consistency between the perforating peroneal arteries marked by ultrasonography and the intraoperative findings was analyzed. RESULTS: The initial segment of the peroneal artery had a larger inner diameter (p<0.001) and lower PSV (p<0.05) than the middle segment. The perforating peroneal arteries were mainly distributed in the middle of the fibula. The inner diameter of the perforating peroneal artery was larger in men than in women (p<0.05). In comparison with surgical exploration as the gold standard, high-frequency color Doppler ultrasound results showed good consistency (Kappa=0.684, 95% CI: 0.512-0.856, p<0.001), with a sensitivity of 89.36%, specificity of 78.57%, and accuracy of 85.33%. CONCLUSION: High-frequency color Doppler ultrasound can detect, quantitatively evaluate, and accurately mark the peroneal artery and vein and perforating peroneal artery before fibular myocutaneous flap transplantation.

Standardize routine angiography assessment of leg vasculatures before fibular flap harvest: lessons of congenital and acquired vascular anomalies undetected by color Doppler and physical examinations.

BACKGROUND: Fibular flaps have been widely used for mandibular and maxillary reconstructions. On occasion, anatomical variants of fibular arteries (FA) will be encountered. PURPOSE: Although anatomical variants of FA during fibular harvest have been reported, controversy exists regarding whether simple color Doppler ultrasonography (CDU) and physical examinations (PE) are sufficient for early preoperative detection. MATERIAL AND METHODS: A 10-year retrospective analysis in our department was performed to find the patients with various FA anomalies confirmed by computed tomography angiography (CTA) or intraoperative findings. RESULTS: A total number of 19 FA anomalies were found either pre- or intraoperatively in 16 patients, in whom three cases were with bilateral FA variants. Type IIIC variants, also called arteria peronea magna (great peroneal artery), were confirmed in two legs, while the majority (13 legs) had type IIIA hypoplastic/aplastic posterior tibialis arteries (PTA). Four legs had new type IIID (low FA and PTA bifurcations). Preoperative CDU and PE only suspected anomalies in two legs. Six cases proceeded with using the affected fibulas, within whom vascular grafts were used in half of them for lengthening the FA pedicle. Local ischemia, partial soleus muscle necrosis, and claudication were reported in one. CONCLUSIONS: Routine CTA before every fibular harvest, rather than simple PE and CDU, should be added for screening contraindications and ensuring safety for fibular flap harvest.

Surgeon-Based 3D Printing for Microvascular Bone Flaps.

Background Three-dimensional (3D) printing has developed as a revolutionary technology with the capacity to design accurate physical models in preoperative planning. We present our experience in surgeon-based design of 3D models, using home 3D software and printing technology for use as an adjunct in vascularized bone transfer. Methods Home 3D printing techniques were used in the design and execution of vascularized bone flap transfers to the upper extremity. Open source imaging software was used to convert preoperative computed tomography scans and create 3D models. These were printed in the surgeon's office as 3D models for the planned reconstruction. Vascularized bone flaps were designed intraoperatively based on the 3D printed models. Results Three-dimensional models were created for intraoperative use in vascularized bone flaps, including (1) medial femoral trochlea (MFT) flap for scaphoid avascular necrosis and nonunion, (2) MFT flap for lunate avascular necrosis and nonunion, (3) medial femoral condyle (MFC) flap for wrist arthrodesis, and (4) free fibula osteocutaneous flap for distal radius septic nonunion. Templates based on the 3D models allowed for the precise and rapid contouring of well-vascularized bone flaps in situ, prior to ligating the donor pedicle. Conclusions Surgeon-based 3D printing is a feasible, innovative technology that allows for the precise and rapid contouring of models that can be created in various configurations for pre- and intraoperative planning. The technology is easy to use, convenient, and highly economical as compared with traditional send-out manufacturing. Surgeon-based 3D printing is a useful adjunct in vascularized bone transfer. Level of Evidence Level IV.

A critical assessment of the fibula flap donor site.

BACKGROUND: The free fibula flap has become popular for mandibular reconstruction. The purpose of this study was to propose comprehensive functional assessments of the donor site. METHODS: Thirty free fibula flaps for mandible reconstruction were prospectively enrolled in the study. Objective assessments included isokinetic testing of the ankle joint, electromyographic examination of the superficial peroneal nerve (SPN), and preoperative and postoperative foot scans. The Patient and Observer Scar Assessment Scale (POSAS) was used to subjectively assess the donor site. RESULTS: The isokinetic values of the donor side showed a significant decrease 1 year postoperatively. The results of the electromyographic test of the SPN were categorized as 3 types. The plantar center pressure shifted to the heel on the donor side 6 months postoperatively. The aesthetic outcome was satisfactory. CONCLUSION: The functional parameters of the donor site indeed declined in our assessments. Further refinements in the surgical technique are needed to improve the donor site status. © 2016 Wiley Periodicals, Inc. Head Neck 39: 279-287, 2017.

Asymptomatic Deep Peroneal Vein Thrombosis During Free Fibula Flap Harvest: A Review of the Literature, Strategies for Preoperative Assessment, and an Algorithm for Reconstruction.

The free fibula flap is the preferred reconstructive method for oncologic defects of the mandible. Arterial inflow of the extremity is routinely evaluated with several modalities; however, venous screening is rarely performed. Patients with cancer are at elevated risk of occult deep venous thrombosis (DVT). An asymptomatic thrombus encountered during free fibula reconstruction is a serious concern. Although such cases have been reported, we suspect the incidence of DVT during fibula free flap harvest is underappreciated. This monograph uses a case example to review risk factors for occult DVT, present a strategy for preoperative assessment, and provide a reconstructive algorithm to for mandibular reconstruction in such instances.

Assessment of Fibula Flap Skin Perfusion in Patients Undergoing Oromandibular Reconstruction: Comparison of Clinical Findings, Fluorescein, and Indocyanine Green Angiography.

IMPORTANCE: Complications of partial flap necrosis contribute substantially to morbidity in patients who undergo head and neck reconstructive surgery. OBJECTIVE: To assess the usefulness of clinical findings, intraoperative fluorescein angiography, and intraoperative indocyanine green angiography (ICGA) for evaluation of flap skin paddle perfusion in patients undergoing oromandibular reconstruction who are at high risk of partial skin paddle necrosis. DESIGN, SETTING, AND PARTICIPANTS: Retrospective medical record review from May 21, 1996, to May 27, 2015, at a tertiary care academic medical center. Participants were 73 patients who underwent reconstruction of through-and-through defects of the mucosa, mandible, and skin using fibula free flaps that contained large bilobed skin paddles. MAIN OUTCOMES AND MEASURES: The rates of partial skin paddle necrosis and revision reconstructive surgery. RESULTS: The rates of partial flap necrosis were 8% (n = 2) among 25 patients in whom the skin paddle was trimmed based on ICGA and 33% (n = 16) among 48 patients in whom the skin paddle was trimmed according to clinical findings (P = .02). The rates of revision reconstructive surgery were 20% (5 of 25) when flap skin paddles were trimmed using ICGA and 42% (20 of 48) when trimmed per clinical findings (P = .06). CONCLUSIONS AND RELEVANCE: The use of ICGA may reduce the risk of partial skin flap necrosis in free flaps used in patients undergoing head and neck reconstruction who are at high risk of developing flap necrosis. Indocyanine green angiography imaging should be considered in any flap in which skin paddle viability is uncertain based on clinical findings and in patients in whom the skin paddle extends beyond the primary and adjacent angiosomes. LEVEL OF EVIDENCE: 3.

Evaluation of the vessels of the lower leg before microsurgical fibular transfer. Part II: magnetic resonance angiography for standard preoperative assessment.

The peroneal artery is the dominant supply of the osteomyocutaneous fibular flap. It has been shown that there can be anatomical variants that could jeopardise the blood supply to the lower limb during harvest of the flap. To avoid postoperative ischaemia of the lower leg, preoperative evaluation of adequate collateral perfusion is essential. We investigated whether magnetic resonance angiography (MRA) accurately shows anatomical variants and pathological stenoses of the vessels of the lower leg and whether it can replace conventional invasive techniques. Conventional digital subtraction angiography (DSA) was used in a prospective study of 15 patients, and contrast-enhanced MRA postoperatively. Arteries were evaluated by three radiologists for: size of vessel at the trifurcation; hypoplastic or missing vessels; appreciable stenosis or vascular occlusion, or both; atherosclerotic malformations; and overall vascular topography. High resolution MRA enabled a reliable judgement to be made of the vessels of the lower leg. MRA definitively detected hypoplastic vessels, stenoses, occlusion, or atherosclerotic changes of the vessels, and enabled both accurate assessment of the quality of vessels and the preferred site for the harvest of the flap. As it is a low risk procedure, it can be done in the outpatient department with no risk of radiation. It can easily replace conventional DSA.

Devascularizing complications of free fibula harvest: peronea arteria magna.

The authors present a case report of devascularizing complications following free fibula harvest. A retrospective review of 93 consecutively imaged limbs demonstrated a peronea arteria magna (PAM) prevalence of 5.3 percent in an urban population, which was used to perform a cost-effectiveness analysis for preoperative vascular imaging of the donor limb using magnetic resonance angiography (MRA) and traditional angiography (TA). Donor-site complications of fibula harvest range from 15 to 30 percent, but are rarely limb-threatening. Limb loss is a dreaded complication of congenital PAM, which can be present with a normal vascular exam. Some microsurgery groups advocate using no preoperative imaging of the donor limb; they rely on intraoperative assessment of the vascular anatomy. An aborted harvest due to aberrant anatomy leads to both direct and indirect added costs. The authors believe that MRA imaging of the donor limb, being minimally invasive, is cost-effective and indicated for free fibula transfers. For equivocal results, conversion to more invasive and costly TA may be necessary.

Preoperative vascular assessment of the lower limb for harvest of a fibular flap: the views of vascular surgeons in the United Kingdom.

Adequate preoperative vascular assessment of the lower limb is essential before harvesting fibular free flaps to prevent ischaemic complications or failure of the flap. The best method of assessment remains controversial. Clinical examination, conventional angiography, colour flow Doppler, and magnetic resonance angiography have all been advocated. We asked 206 UK vascular surgeons for their opinions on preoperative assessment and potential issues of negligence and 85 (42%) completed the questionnaire. All respondents thought that further imaging should be done in addition to clinical examination, most of whom (n = 70) favoured colour flow Doppler (82%). In addition 75 (88%) considered that the surgeon would be judged to be negligent if clinical examination was the only preoperative assessment. In the light of these findings, we suggest that an objective assessment of the vasculature of the leg should be obtained before a fibular flap is harvested.

[Magnetic resonance arteriography in peripheral vascular surgery. A new, non-invasive method for visualization of arteries]. / Magnetisk resonans-arteriografi i perifer karkirurgi. En ny og ikke-invasiv metode til visualisering af arterier.

Based on a MEDLINE search, we present the current status of magnetic resonance arteriography (MRA) and peripheral vascular surgery. Non-enhanced MRA (TOF-MRA) is more time-consuming than is gadolinium-enhanced MRA (CE-MRA), and the gadolinium-enhanced technique seems to perform more accurately and pose fewer problems. The sensitivity and specificity of TOF-MRA are 93% (range 64-100%) and 88% (range 57-100%) respectively, and that of CE-MRA 96% (range 71-100%) and 96% (63-100%), respectively, with conventional arteriography as the gold standard. Some studies report an incidence of run-off vessels suitable for distal bypass that are visible on MRA, but invisible on conventional arteriography. Gadolinium contrast is given intravenously and is not nephrotoxic. CE-MRA is accurate, compared to conventional arteriography, has the potential to increase the limb salvage rate for selected patients, is non-invasive, and well tolerated.

Accuracy of clinical assessment of deep-vein thrombosis.

The clinical diagnosis of deep-vein thrombosis is generally thought to be unreliable. From experience, we hypothesised that this widely held view might be incorrect. We developed a clinical model and prospectively tested its ability in three tertiary care centres to stratify symptomatic outpatients with suspected deep-vein thrombosis into groups with high, moderate, or low probability groups of deep-vein thrombosis. We evaluated our clinical model in combination with venous ultrasonography to determine the potential for an improved and simplified diagnostic approach in patients with suspected deep-vein thrombosis. All patients were clinically assessed to determine the probability for deep-vein thrombosis before they had ultrasonography and venography. All tests were performed and interpreted by independent observers. In 529 patients, the clinical model predicted prevalence of deep-vein thrombosis in the three categories: 85% in the high pretest probability category, 33% in the moderate, and 5% in the low category. There was no statistical difference in the performance of the model in the three centres. The model demonstrated excellent interobserver reliability (Kappa = 0.85). There were important differences with ultrasonography between the high and low pretest probability groups for both positive predictive values (100% (95% CI, 94-100%) vs (63% [35-85%], respectively). Thus, use of the clinical model combined with ultrasonography would decrease the number of false positive and negative diagnosis if venography were done when the ultrasound result and pretest probability were discordant. The diagnostic process could be simplified by excluding those patients with low pretest probability and normal ultrasound results from serial testing.

Vascularized bone allografts: in vitro assessment of cell-mediated and humoral responses.

The immunologic consequences of transplantation of vascularized bone allografts have not been previously characterized. In this study, knee allografts, both vascularized and nonvascularized, were transplanted from Lewis rats to Brown Norway rats across a strong histocompatibility barrier. A total of 66 transplants and 8 control animals were evaluated. The vascularized knee grafts consisted of 1 cm of proximal tibia and distal femur with a minimal muscular cuff isolated on the femoral vessels, and these were transplanted to a heterotopic, subcutaneous position on the abdominal wall of the recipient rat. Nonvascularized allografts (identical but without anastomoses) were transplanted for comparison. The cell-mediated response was measured by lymphocytotoxicity assay, and the humoral response was measured by cytotoxic antibody assay, both employing 51Cr-labeled target cells. The timing and intensity of the immune response differed according to the type of graft. The vascularized bone allografts generated significant cell-mediated and humoral responses as early as 5 days posttransplant. A significant humoral response in nonvascularized bone allografts was not apparent until day 14, while cell-mediated response in these grafts was variable. These findings were correlated with the histologic appearance of the grafted tissue. Cyclosporine, which was administered to one group of vascularized bone allografts, resulted in the suppression of both types of immune responses. The histologic appearance of this group resembled that of isografts transplanted as controls. The clinical application of vascularized bone allografts may offer significant advantages over nonvascularized allografts in the reconstruction of massive bone defects. Complications such as nonunion, fracture, and collapse of articular segments seen in nonvascularized allograft transplantation may be avoided by preservation of the blood supply to the graft. Characterization of the immune response to vascularized bone allografts may subsequently allow the manipulation of the host and/or graft tissue and promote graft incorporation.