Microvascularized fibular graft for mandibular reconstruction: detection of viability by bone scintigraphy and SPECT

Use of an Omental Flow-Through Flap for Recipient Vessels in the Reconstruction of a Lumbar Spine Defect: A Case Report

CASE

Spine reconstruction after en bloc spondylectomy is challenging and may require multidisciplinary intervention. En bloc spine tumor resection with embolization of local recipient vessels for tumor control limits reconstructive options. Herein, we describe a case where combined efforts from orthopaedic, general, and plastic surgery teams permitted the successful reconstruction of a multilevel lumbar vertebral defect.

CONCLUSION

A fibula-free flap within a titanium cage construct anastomosed to the left gastroepiploic vessels via a pedicled omental flow-through flap is a viable and novel method for reconstruction of a multilevel vertebral defect.

Predicting Vascularized Bone Graft Viability Using 1-Week Postoperative Bone SPECT/CT After Maxillofacial Reconstructive Surgery

Purpose

We aimed to evaluate the performance of hybrid bone single-photon emission computed tomography (SPECT)/computed tomography (CT) in predicting bone graft viability after maxillary or mandibular reconstructive surgery with vascularized bone grafts.

Methods

We retrospectively reviewed 46 bone planar scintigraphy and SPECT/CT images of 45 adult patients taken at 1 week (5-8 days) after maxillary or mandibular reconstructive surgery with vascularized bone grafts. By visual analysis, two nuclear medicine physicians scored the uptake degrees of each bone graft segment compared with the calvarium uptake on planar bone scintigraphy and SPECT/CT, respectively (0 = absence of uptake, 1 = less uptake, 2 = similar uptake, and 3 = more uptake). The imaging results were compared with clinical follow-up for assessing bone graft viability.

Results

During follow-up, five bone graft segments were surgically removed and confirmed as nonviable-one had a score of 0, although the other four had a score of 1-3 on planar bone scintigraphy. All five bone graft segments were scored 0 on SPECT/CT and eventually confirmed as nonviable. All other graft segments with a score of > 1 on SPECT/CT were viable and uneventful. The anatomical CT information on SPECT/CT images was helpful in discriminating bone graft uptake from adjacent bone or soft tissue uptake.

Conclusions

The absence of tracer uptake by the vascularized bone graft on bone SPECT/CT at 1 week after maxillary or mandibular reconstructive surgery can predict graft failure. Bone SPECT/CT can be used to predict vascularized bone graft viability postoperatively.

Determination of structural femoral head allograft viability and integrity with a novel diagnostic tool: SPECT/CT. A preliminary study

OBJECTIVE

To evaluate the viability and integrity of fresh frozen bulk femoral head allografts obtained from the institutional bone bank that were used to reconstruct severe acetabular defects and to validate the SPECT/CT method which gives both anatomical and functional data for this purpose.

METHODS

We retrospectively reviewed 9 patients (6 female, 3 male; mean age 63.6 years). Preoperative and postoperative leg lengths, existence of the Trendelenburg sign, range of motion of the hip, visual analogue score (VAS), Harris Hip Score (HHS) and any complication were assesed at each follow-up. Radiographically, position of the cup, signs of loosening or migration, and union of the graft were all determined. At the latest follow-up, patients were evaluated with hybrid SPECT/CT.

RESULTS

The average duration of follow-up was 38.1 months (24-50 months). The overall mean HHS and VAS scores were significantly improved (p<0.05). When hybrid SPECT/CT results were evaluated, the vascular phase of scintigraphy showed hyperaemia of the graft and the bone phase of scintigraphy showed normal or increased radiotracer uptake in the graft site in 7 patients. SPECT/CT images were used to determine the exact localisation of osteoblastic activity. 1 patient with minor resorption of the graft without clinical symptoms revealed mild osteoblastic activity. The patient who had no activity in the graft site was rerevised because of infection.

CONCLUSIONS

Institutional bank allografts are still excellent options for treating large acetabular defects in revision total hip arthroplasty where trabecular metals are not available or in common use. The Hybrid SPECT/CT method is a reliable, noninvasive method for evaluating both the integrity and viability of a bulk graft in 3-D.

Bone Scan in Detection of Biological Activity in Nonhypertrophic Fracture Nonunion

Biological activity of the fracture site is very important factor in treatment planning of fracture nonunion. If no biological activity is detected, then an autologous bone graft can be supplemented or osteogenic supplementations, such as bone morphogenetic protein is given. If biological activity is present, then secure fixation is sufficient to achieve bony union. Biological activity of nonunions is usually assessed by conventional radiographs. The presence of callus formation is usually assessed as the presence of biological activity. However, high number of radiologically nonhypertrophic nonunion demonstrates intense, uniform tracer uptake on bone scan, a sign of biological activity. Poor or absent callus visualization on radiographs does not always mean a lack of biological activity and it underestimates it. Uptake in bone scintigraphy reflects blood flow and new bone formation and being functional imaging technique, it is more suitable for assessing biological activity.

Scintigraphic and histopathologic evaluation of combined bone grafts

OBJECTIVES

We aimed to assess various bone grafts on bone formation using bone scintigraphy and histology, especially the first study that evaluated the demineralized bone matrix (DBM) + tricalcium phosphate (TCP) + hyaluronic acid (HA) combination.

MATERIALS AND METHODS

A total of 44 pieces in groups of autogenous bone graft, TCP, DBM, DBM + TCP combination, and DBM + TCP + HA combination were applied to parietal bones of 24 New Zealand rabbits. Bone scintigraphies of the rabbits were performed at 2, 6, and 12 weeks. The uptake ratios were compared for the different types of grafts. In addition, in 2, 6, and 12 weeks, the graft areas were taken from the sacrificed rabbits and examined histologically.

RESULTS

In the 2-week evaluation, DBM + TCP combination and DBM + TCP + HA combination had more osteoblastic activity accumulation than the TCP and DBM groups. These findings supported that the DBM + TCP combination group showed new bone formation earlier in the histopathological evaluation. The DBM + TCP + HA combination had more uptake than the TCP and DBM groups on bone scintigraphy at 2 weeks, and this uptake ratio decreased in the following weeks. It was thought that the increased uptake in DBM + TCP + HA combination at 2 weeks was due to severe inflammation seen in the histopathological evaluation.

CONCLUSION

The DBM + TCP + HA combination should not be used for graft repair, although it was thought to be a good combination in the early weeks.

Femoral head bone viability after free vascularized fibular grafting for osteonecrosis: SPECT/CT study

PURPOSE

To evaluate femoral head bone viability following free vascularized fibular grafting (FVFG) for osteonecrosis using SPECT/CT imaging.

METHODS

Ten hips (9 patients) with osteonecrosis of the femoral head (ONFH) undergoing FVFG were prospectively enrolled. Four cases showed ARCO stage II, while six showed ARCO stage III. The mean age at surgery was 15.7 years (range, 13-22 years). Hip Harris Score (HHS) was measured pre- and post-operative. Bone scintigraphy with SPECT/CT was performed at 2 weeks and 6 months following surgery.

RESULTS

Mean follow-up was 4.0 years (range, 2-5.9 years). Mean HHS increased from 37.2 to 92.3. SPECT/CT findings revealed a progressive increase of femoral head uptake in all cases, suggesting subchondral graft bone viability. No progressive deformation of the femoral head was evidenced in radiographic evaluation at final follow-up.

CONCLUSIONS

This study demonstrates FVFG's capacity for revitalizing femoral head subchondral bone grafting in patients with ONFH, surgically treated following Urbaniak's technique. © 2015 Wiley Periodicals, Inc. Microsurgery 36:573-577, 2016.

Cranioplasty with autologous cryopreserved bone after decompressive craniectomy: complications and risk factors for developing surgical site infection

Background

Renewed interest has developed in decompressive craniectomy, and improved survival is shown when this treatment is used after malignant middle cerebral artery infarction. The aim of this study was to investigate the frequency and possible risk factors for developing surgical site infection (SSI) after delayed cranioplasty using autologous, cryopreserved bone.

Methods

This retrospective study included 74 consecutive patients treated with decompressive craniectomy during the time period May 1998 to October 2010 for various non-traumatic conditions causing increased intracranial pressure due to brain swelling. Complications were registered and patient data was analyzed in a search for predictive factors.

Results

Fifty out of the 74 patients (67.6 %) survived and underwent delayed cranioplasty. Of these, 47 were eligible for analysis. Six patients (12.8 %) developed SSI following the replacement of autologous cryopreserved bone, whereas bone resorption occurred in two patients (4.3 %). No factors predicted a statistically significant rate of SSI, however, prolonged procedural time and cardiovascular comorbidity tended to increase the risk of SSI.

Conclusions

SSI and bone flap resorption are the most frequent complications associated with the reimplantation of autologous cryopreserved bone after decompressive craniectomy. Prolonged procedural time and cardiovascular comorbidity tend to increase the risk of SSI.

Comparison of radiographic appearance and bone scintigraphy in fracture nonunions

Many surgeons assess the biological activity of fracture nonunions by the presence or absence of callus on radiographs. However, the assessment of biological activity by radiographic appearance alone is controversial. Bone scintigraphy reflects blood flow and new bone formation; therefore, it is useful in assessing such biological activity in nonunion cases. This retrospective study compared radiographs with Tc-99m bone scintigraphy in 48 patients with uninfected nonunions. Positive uptake was observed in all cases. The uptake patterns were classified into 4 types: type 1, intense, uniform uptake; type 2A, a definite photon-deficient cleft between 2 areas of intense uptake; type 2B, a photon-deficient area other than type 2A; and type 3, an intermediate pattern with uneven, distributed uptake. The percentage of type 1 with intense uptake does not decrease with time, and type 2 does not increase. When uptake was compared in patients with a nonunion and a united fracture, higher uptake in nonunion was seen in 46% and lower uptake was seen in 27%. All cases of hypertrophic and more than half of oligotrophic nonunions were type 1. Type 2 was seen in 17% of oligotrophic, 67% of comminuted, 100% of defect, and 57% of atrophic nonunions. Poor callus visualization may not preclude biological activity. Long duration from injury may not equate to declines in biological activity. Comparing uptake in nonunions and united fractures in the same patient may help to assess biological activity. The photon-deficient area is helpful to assess the necessity of bone graft or other osteogenic supplementation.

The use of nuclear bone scanning after fibula free tissue transfer

OBJECTIVES/HYPOTHESIS

To understand the role of nuclear bone scanning in the evaluation of threatened osteocutaneous free tissue transfers, identify patients who may benefit from nuclear bone scanning after head and neck reconstructive surgery, and be able to use nuclear bone scanning to help guide management of the threatened free flap.

STUDY DESIGN

Retrospective case series design set in a tertiary referral center.

METHODS

Records of patients undergoing bone scan in the context of threatened osteocutaneous free tissue transfer between July 1998 and December 2008 were reviewed.

RESULTS

Over a 10-year period, 205 fibula free tissue transfers were performed, with an overall 94% success rate. Fifteen fibular free flaps in 14 patients were determined to be threatened in the late postoperative period, and nuclear bone scanning was performed. Seven of 15 flaps had regions of certain flap nonviability, with five flaps clearly appearing viable on bone scanning. No graft read as potentially viable eventually failed. All grafts read as nonviable underwent exploration and debridement, with confirmation of nonviability in all cases. In eight cases, bone scanning allowed preoperative planning for soft tissue flap reconstruction.

CONCLUSIONS

In those instances in which the skin paddle dies in the late postoperative period and determination of bone viability is required, a bone scan can demonstrate whether or not the bone is alive. This information can help determine the future operative and reconstructive options available for the patient.

Head and neck reconstruction with free flaps: a report on 213 cases

The aim of this retrospective study is to review the experience of our institution in performing microvascular head and neck reconstruction between 2000 and 2004. During this period, 213 free flaps, including 146 radial forearm free flaps, 60 fibular flaps and 7 scapular flaps, were performed. Free flap success rate and complications were reported. The pre-treatment factors influencing these results were subsequently analyzed. Functional and aesthetic outcomes were evaluated by the same clinician. There were 14 free flap failures, giving an overall free flap success rate of 93.4%. Salvage surgery for recurrent cancer was the only factor correlated with a higher risk of free flap failure (P = 0.0004). The local complication rate was 20.9%. High level of comorbidity (P = 0.009), salvage surgery for recurrent cancer (P = 0.03) and hypopharyngeal surgery (P = 0.002) were associated with a higher risk of local complications. An unrestricted oral diet and an intelligible speech were recovered by respectively 76 and 88% of the patients. Microvascular free flaps represent an essential and reliable technique for head neck reconstruction and allow satisfactory functional results.

Early postoperative bone scintigraphy in the evaluation of microvascular bone grafts in head and neck reconstruction

BACKGROUND

Bone scintigraphy was performed to monitor anastomotic patency and bone viability.

METHODS

In this retrospective study, bone scans were carried out during the first three postoperative days in a series of 60 patients who underwent microvascular bone grafting for reconstruction of the mandible or maxilla.

RESULTS

In our series, early bone scans detected a compromised vascular supply to the bone with high accuracy (p < 10-6) and a sensitivity that was superior to the sensitivity of clinical monitoring (92% and 75% respectively).

CONCLUSION

When performing bone scintigraphy during the first three postoperative days, it not only helps to detect complications with high accuracy, as described in earlier studies, but it is also an additional reliable monitoring tool to decide whether or not microvascular revision surgery should be performed. Bone scans were especially useful in buried free flaps where early postoperative monitoring depended exclusively on scans. According to our experience, we recommend bone scans as soon as possible after surgery and immediately in cases suspicious of vascularized bone graft failure.

La reconstruction mandibulaire par lambeaux libres osseux: résultats fonctionnels

OBJECTIVES

The aim of this retrospective study is to evaluate functional results of oromandibular reconstruction with osseous free flaps.

MATERIAL AND METHODS

A total of 67 patients who underwent oromandibular reconstruction with fibula (n=60) or scapular (n=7) free flap between 2000 and 2004 were included in this study. We analysed functional results (alimentation, elocution, mouth opening and cosmetic appearance) and researched the potentially predictive factors of these results (age, comorbidity, preoperative irradiation, type of defect...; Chi(2) test).

RESULTS

The rate of free flap success was 89.6%. A functional result considered as normal or subnormal was obtained by more than 50% of patients. Oral alimentation (without tube feeding) and intelligible speech were recovered by 92.5% of patients. Through and through defects and free flap failures were determinant predictive factors of worse functional outcomes.

CONCLUSION

Fibula free flap is considered as the flap of choice for oromandibular reconstruction and allows excellent functional results.

Preoperative MR Angiography in Free Fibula Flap Transfer for Head and Neck Cancer: Clinical Application and Influence on Surgical Decision Making

OBJECTIVE

We review the fibular free flap surgical procedure to illustrate the usefulness of preoperative lower limb MR angiography and to show how calf vascular anatomy on MR angiography affects patient surgical management.

CONCLUSION

With its high positive predictive value and sensitivity, preoperative MR angiography can improve the chances of a successful outcome at the recipient mandibular site. It provides the reconstructive surgeon with a road map, revealing vascular anomalies or disease that could alter or contraindicate surgery.

Evaluation of vascularized graft reconstruction of the mandible with Tc-99m MDP bone scintigraphy

AIM

The aim of this study was to evaluate the value of bone scintigraphy for the assessment of graft viability following vascularized bone grafts in patients with mandibular reconstruction.

METHODS

We investigated 16 patients with vascularized grafts from the fibula (13 patients) and iliac crest (3 patients) in the last 8 years. For the follow up of all these patients, Tc-99m MDP bone scintigraphy was performed between 2-10 days postoperatively. SPECT study was included in 5 patients. For the evaluation of the grafts, a six-grade scoring system was used. The grading system was based on a comparison of tracer uptake between graft and the cranium. The uptake was defined as increasing from grade 6 to grade 1.

RESULTS

Thirteen of the 16 grafts had an uncomplicated clinical course. Complications in the graft occurred in three patients. In the analysis of planar scintigrams, patients with uncomplicated healing showed increased uptake in 12 of the 13 grafts (grade 1-3) and 1 showed the same level tracer uptake compared to cranium (grade 4). In the failed 3 grafts, decreased uptake was observed (grade 5 and 6). In 5 patients, SPECT was performed in addition to planar imaging. In these patients, 4 of the 5 grafts had an uncomplicated clinical course and 1 had a complicated one. In the analysis of SPECT images, while all the grafts with an uncomplicated clinical course exhibited increased uptake (grade 1-3), the failed graft showed decreased uptake (grade 6).

CONCLUSION

Three-phase bone scintigraphy performed within 10 days after the mandibular reconstruction is a useful tool to monitor the viability and early complications of vascularized mandibular bone grafts. SPECT is also recommended. It may contribute to interpretation of the bone scans and to precise assessment of graft viability.

[Free fibula transfer. Analysis of 76 consecutive microsurgical procedures and review of the literature]

Since its introduction by Taylor in 1975, microvascular free fibula transfer has become the gold standard in osseous reconstructions requiring vascularized bone transfer. Various modifications of the free fibula have been described in the literature. We reviewed a series of 76 free vascularized fibula transfers during a 7-year period. Data was retrospectively analyzed with respect to type of procedure and outcome, general surgical complications, and flap-related (specific) complications. Of all 76 free fibula flaps, 47 cases healed uneventfully (62%). Interestingly, 53% of all extremity reconstruction cases had at least one of the above complications, whereas in maxillofacial cases the complication rate was only 25%. Complete osseous consolidation at the time of evaluation was confirmed in 58 patients (76%). Complete flap failure occurred in four patients (5%). The complication rates reflect the complexity of the procedures and appear strongly related to the underlying disease and predisposing medical risk factors. Time will tell if advances, e.g., in the field of tissue engineering, will eventually replace autologous vascularized bone transfer.