Complications after microsurgical tissue transfer in the head and neck region

Laser-Assisted Microvascular Anastomosis of Free Flaps in Reconstruction of Orofacial Defects: A Comparative Study Among Conventional Methods and Diode Laser Anastomosis

Background

The key role played by anastomosis determines the outcome of any free flap surgery. Besides many methods, the application of LASERS for performing microvascular anastomosis gaining popularity in recent times. The ease of application, utilizing lesser time for performing anastomosis than the conventional methods and minimal injury to the vessel layers, are contributing factors to the success of free flap surgery. Laser-assisted vascular anastomosis (LAVA) fulfills the criteria of lesser vessel wall damage and faster anastomosis and thus resulting in reduced flap ischemic time and overall outcome of the surgery.

Methods

A prospective randomized case-control trial comparing conventional suturing methods (group I) with Laser-assisted vascular anastomosis (group II) on free flaps were performed for the reconstruction of orofacial defects. The parameters assessed for evaluation were anastomotic time, ischemic time and vessel patency following anastomosis. Student's t test and Fisher's exact tests were implied for statistical analysis.

Results

The mean time taken for anastomosis was 19.75 min in the conventional group and 3.86 min in LAVA anastomosis. This difference was found to be extremely statistically significant (p < 0.00001). The mean ischemic time of the free flap harvested was 384.87 min in group I and 138.7 min in group II. This difference was also found to be extremely statistically significant (p < 0.00001).

Conclusion

The average anastomosis time for LAVA group was considerably reduced and total ischemic time was considerably less with successful uptake of the flap. In LAVA group, the post-operative complication was less when compared to the conventional anastomosis technique.

Is the preoperative MPV value related to early thrombus formation in microvascular anastomosis?

OBJECTIVE

One of the most common encountered problems in free flap surgeries is anastomotic thrombosis. The mean platelet volume (MPV) may indicate the concentration of intra-platelet proactive substances and the thrombogenic potential of the platelets. MPV is used as a clinical monitoring index in routine blood counts, it has not yet been effectively used in free flap surgery.

METHODS

This study evaluates the relationship between the preoperative MPV value and anastomotic thrombus formation during the postoperative 48 hours in 32 free flap operations from September 2013 to September 2014. The mean patient age was 36.75 years. The preoperative MPV value, which was obtained from the complete blood count, was recorded and correlation of MPV and postoperative thrombus formation was investigated.

RESULTS

Four anastomotic thrombus were encountered in 34 free flaps during the postoperative 48 hours. Two of them were salvaged by performing thrombectomy and/or administration of i.v. heparin. There was no statistical relationship between MPV value and postoperative thrombus formation during 48 hours follow-up (p = 0.925).

CONCLUSION

Even though this study didn't find a correlation between preoperative MPV value and postoperative early anastomotic thrombus, it would be helpful to validate the results using multi-centre and comprehensive studies with larger patient cohorts.

Free flap reconstruction in the head and neck region following radiotherapy: a cohort study identifying negative outcome predictors

BACKGROUND

With the increased use of radiotherapy in the treatment of head and neck cancers, free tissue transfer in an irradiated field is now common. Reported outcomes with free tissue transfer reconstructions in irradiated areas are often unclear and contradictory. This is attributable in part to small sample size and heterogeneity in patients and procedures. The goals of this study were, first, to determine the outcome of head and neck reconstructions in an irradiated field using a large retrospective cohort and, second, to identify negative outcome predictors that could potentially be modified to reduce the morbidity in these procedures.

METHODS

Patients undergoing free flap reconstruction in irradiated head and neck regions between July of 2005 and July of 2007 were identified. Charts, including operative and radiotherapy records, were reviewed. Multiple logistic regressions were performed to identify negative outcome predictors.

RESULTS

During the study period at the authors' institution, 984 patients underwent head and neck free flap reconstruction. Of these, 137 had free tissue transferred to irradiated fields. Patients received an average radiotherapy dose of 64.5 Gy. The overall flap success rate was 96.4 percent. The postoperative complication rate was 47 percent. There was an overall 22 percent reoperation rate and a 28 percent infection rate. Segmental mandibulectomy, larger flap size, and infection were found to be significant negative outcome predictors.

CONCLUSIONS

This study confirms that free flap transfer to previously irradiated head and neck areas has a success rate comparable to that of transfer to nonirradiated zones. However, previously irradiated patients have a high risk of complications. Infection, as a modifiable risk factor, should be treated aggressively.

Free Flap Reexploration: Indications, Treatment, and Outcomes in 1193 Free Flaps

BACKGROUND

Microvascular free tissue transfer is a reliable method for reconstruction of complex surgical defects. However, there is still a small risk of flap compromise necessitating urgent reexploration. A comprehensive study examining the causes and methods of avoiding or treating these complications has not been performed. The purpose of this study was to review the authors' experience with a large number of microvascular complications over an 11-year period.

METHODS

This was a retrospective review of all free flaps performed from 1991 to 2002 at Memorial Sloan-Kettering Cancer Center. All patients who required emergent reexploration were identified, and the incidence of vascular complications and methods used for their management were analyzed.

RESULTS

A total of 1193 free flaps were performed during the study period, of which 6 percent required emergent reexploration. The most common causes for reexploration were pedicle thrombosis (53 percent) and hematoma/bleeding (30 percent). The overall flap survival rate was 98.8 percent. Venous thrombosis was more common than arterial thrombosis (74 versus 26 percent) and had a higher salvage rate (71 versus 40 percent). Salvaged free flaps were reexplored more quickly than failed flaps (4 versus 9 hours after detection; p = 0.01). There was no significant difference in salvage rate in flaps requiring secondary vein grafting or thrombolysis as compared with those with anastomotic revision only.

CONCLUSIONS

Microvascular free tissue transfer is a reliable reconstructive technique with low failure rates. Careful monitoring and urgent reexploration are critical for salvage of compromised flaps. The majority of venous thromboses can be salvaged. Arterial thromboses can be more problematic. An algorithm for flap exploration and salvage is presented.

Scapula osteocutaneous free flap reconstruction of the head and neck: Impact of flap choice on surgical and medical complications

BACKGROUND

The scapula osteocutaneous free flap is frequently used to reconstruct complex head and neck defects given its tissue versatility. Because of minimal atherosclerotic changes in its vascular pedicle, this flap also may be used as a second choice when other osseous flaps are not available because of vascular disease at a preferred donor site.

METHODS

We performed a retrospective chart review evaluating flap outcome as well as surgical and medical complications based upon the flap choice.

RESULTS

The flap survival rate was 97%. The surgical complication rate was similar for the 21 first-choice flaps (57.1%) and the 12 second-choice flaps (41.7%; p = .481). However, patients having second-choice flaps had a higher rate of medical complications (66.7%) than those with first-choice flaps (28.6%; p = .066). Age and the presence of comorbidities were associated with increased medical complications. All patients with comorbidities that had a second-choice flap experienced medical complications, with most being severe.

CONCLUSIONS

The scapula osteocutaneous free flap has a high success rate in head and neck reconstruction. Surgical complications occur frequently regardless of whether the flap is used as a first or second choice. However, medical complications are more frequent and severe in patients undergoing second-choice flaps.

Influence of Previous Radiotherapy on Free Tissue Transfer in the Head and Neck Region: Evaluation of 455 Cases

OBJECTIVE/HYPOTHESIS

The aim of this retrospective cohort study was to investigate the effect of prior radiotherapy (XRT) on the outcome of microvascular free tissue transfer in the head and neck region.

METHODS

Four hundred fifty-five patients, subdivided into three groups, were analyzed. Groups I (no previous XRT, n=110), II (previous radiochemotherapy with 50 Gy focus dosage in the primary treatment regime for oral cancer, n=322), and III (secondary reconstruction after XRT-induced complications, n=23) were compared regarding flap success rate, postoperative complications, postoperative mortality, duration of intensive care (DOIC), and hospitalization (DOH).

RESULTS

Flap success did not differ significantly across groups (I: 95.5%, II: 93.2%, III: 91.3%. Risk of postoperative complications was significantly lower for group I (12.7%) compared with groups II (23.9%) and III (39.1%). DOIC and DOH were significantly shorter for patients in group I than for those in groups II and III.

CONCLUSIONS

XRT before free tissue transfer does not significantly increase flap loss or postoperative mortality but does increase postoperative complications and length of hospitalization.

Management of flaps with compromised venous outflow in head and neck microsurgical reconstruction

Microvascular tissue transfer has become an indispensable procedure for head and neck reconstruction. Although remarkable progress has been made technically, anastomosed vessel occlusion is still a serious complication. Even with technically skilled microsurgeons, anastomosed vessel occlusion occurs because the technique is not the sole prophylaxis against thrombosis in microsurgery. Therefore, to minimize the possibility of an unfavorable result in microsurgery, microsurgeons must be familiar with management options for a vascular compromised flap. Most investigators have agreed that venous obstruction occurs more often than arterial obstruction. Here, we reviewed the published literature on the salvage of venous compromised flaps from the viewpoints of surgical correction, including reanastomosis and catheter thrombectomy, and nonsurgical procedures, such as a medicinal leech, hyperbaric oxygen, and thrombolytic therapy.

The effect of head rotation on the diameter of the internal jugular vein: implications for free tissue transfer

PURPOSE

To determine the effects of medial (inwards) and lateral (outwards) rotation of the head on the transverse diameter of the internal jugular vein.

MATERIAL

The original study sample included 26 patients. Duplex ultrasound was used to measure the transverse diameter of the internal jugular vein at a fixed point on either side of the neck. Measurements were taken with the head central (neutral position), rotated laterally and medially.

RESULTS

Using Student's t-test we found that lateral rotation of the head produced a reduction in the mean of the transverse diameters of the left and right ipsilateral vein from 6.9 mm to 5.4 mm (p < 0.03) and 5.9 mm to 5.0 mm (p = 0.2173) respectively. One patient excluded from the study because of previous neck surgery showed complete occlusion of the ipsilateral internal jugular vein on lateral rotation of the head.

CONCLUSION

There is a possibility that patency of the vein could be compromised if the head is turned laterally. This situation may arise immediately after surgery in the ventilated and paralysed patient when the head may be unsupported. It could be of particular importance if the vein has been used as a recipient vein for free tissue transfer.