Microvascular Free Flaps

Microvascular free-tissue transfers in elderly patients: the leeds experience

Free-tissue transfer in the elderly has received increasing attention in the literature. Existing reports are limited by small samples or inadequate definition of the term elderly. This study reviewed 5 years' experience with free-tissue transfer in a geriatric population (mean age 75 years, range 70 to 83 years). Forty-nine free flaps were performed in 42 patients between 1986 and 1991. This review focuses on the 39 flaps undertaken in 33 head and neck cancer patients, the main indication being reconstruction after tumor resection (80 percent). In the head and neck cancer group, donor sites included the radial forearm (20), rectus abdominis (6), jejunum (5), and others (8). Thirty-four flaps (87 percent) were primarily successful. Reexploration was required in 10 patients (26 percent) for compromised flaps (5) and bleeding (5). Three of the compromised flaps were salvaged, giving an overall flap success rate of 95 percent. One patient (3 percent) died within 30 days of surgery. These results compare favorably with other published series in elderly patients, as well as with larger cohorts of younger subjects. Free flaps are safe in the elderly. Chronologic age alone should not be an exclusion criterion when selecting patients for free-tissue transfer.

Choice of flap and incidence of free flap success

A review of 854 consecutive free flaps was performed to determine whether the choice of flap used for the reconstruction influenced the probability of a successful outcome. Flaps were grouped into nine categories: rectus abdominis, free transverse rectus abdominis myocutaneous, radial forearm, jejunum, latissimus dorsi, fibula, scapula, iliac crest, and other. There were significant differences among the success rates of different flaps (p < 0.0001). Rectus abdominis-based flaps used for breast or head and neck reconstruction had lower failure rates (0.9 percent) than did non-rectus abdominis flaps (6.6 percent; p < 0.0001). Flaps requiring vein grafts had a higher rate of flap loss (18.4 percent) than did flaps that did not require vein grafts (2.9 percent; p < 0.0001). There was a strong trend favoring survival of flaps without a bone component (compared with osteocutaneous flaps), and a weaker trend favoring survival of flaps in nonobese patients (compared with flaps in obese patients). Smoking, age, and previous irradiation had no significant effect on flap failure rates. Surgeons should consider the flap success rate as one (but not necessarily the most important) factor in choosing the best reconstruction for any individual patient.

Prediction of outcomes in 150 patients having microvascular free tissue transfers to the head and neck

Medical records of 150 patients who had undergone microvascular free tissue transfer to the head and neck (85% for malignancy) were retrospectively assessed to identify predictors of postoperative outcomes and complications. 5% of flaps failed and 20% required re-exploration. Surgical and medical problems occurred in 23% and 67% patients respectively; mortality was 4.7%. 132 records were analysed by logistic regression. Mortality and stroke were commoner in patients with previous myocardial infarction or steroid medication. Chest infection was commoner in men and with increasing age. Hypoxaemia was associated with bronchodilator therapy. Thromboembolism was commoner in patients on diuretics. Nutritional problems were more frequent in patients on opioids, with low weight or hypertension. Donor site infection was related to haemoglobin concentration, cerebrovascular disease, hypertension, opioid consumption or previous radiotherapy. Recipient site infection was associated with hypertension. Flap failure was related to nitrate or bronchodilator treatment. Re-exploration was associated with opioid or bronchodilator therapy. It was concluded that several factors predicted complications and death following microvascular surgery to the head and neck.

Measurements of tissue oxygen tension in vascularised jejunal autografts in pigs

Tissue oxygen measurements were evaluated as a monitor of the jejunal flap in seven female landrace pigs. A small polarographic sensor (diameter 0.55 mm) was used in which interstitial tissue oxygen tension was measured continuously in a jejunal flap and a muscle flap (rectus abdominis) during arterial and venous occlusion. Mean (SEM) tissue oxygen tension in the two types of flap were 44(9) mmHg (jejunal flap) and 47(8) mmHg (rectus flap). After arterial occlusion for 30 minutes the values dropped to 17(4) mmHg for the jejunal flap and 12(2) mmHg for the muscle flap. The decline became significant after five minutes. During venous occlusion (30 minutes) the values fell to 20(4) mmHg and 14(1) mmHg. The arterial occlusion was undetectable by the naked eye, but the enteric tissue after venous occlusion became severely congested and blue-black in colour. The condition returned to normal after release of the clamp. We conclude that direct measurement of tissue oxygen tension in a jejunal flap is a reliable method of detecting impaired perfusion. This method may in the future be used to monitor vascularised jejunal autografts.

Tumor-ablative surgery, microvascular free tissue transfer reconstruction, and postoperative radiation therapy for advanced head and neck cancer

OBJECTIVE

The objectives of this study were to determine whether the combination of complex tumor-ablative surgery and microvascular free tissue transfer reconstruction delays the onset of postoperative radiation therapy, whether free tissue transfers are lost after a course of radiation therapy, and what patterns of tumor recurrence and survival rates are present in patients who undergo this type of multidisciplinary treatment.

DESIGN

A retrospective review was conducted in 37 patients who underwent tumor-ablative surgery and reconstruction between November 1987 and August 1991.

MATERIAL AND METHODS

Of the 30 men and 7 women who underwent tumor-ablative surgery, microvascular free tissue transfer reconstruction, and postoperative radiation therapy, recurrent or T4 primary tumors were treated in 84%. Sixty-two percent of the patients had nodal metastatic disease. The median dose of postoperative irradiation was 60 Gy (range, 32.4 to 76.8). Follow-up in all patients was until death (21 patients) or for a median of 17.5 months (range, 4.1 to 43.2).

RESULTS

The median duration of overall survival and the 2-year overall survival rate were 17 months and 46%, respectively. For cause-specific survival, the median duration and 2-year rate were 17 months and 50%, respectively. Local recurrence developed in 8 patients, neck recurrence in 10, and distant metastatic disease in 11. No microvascular free tissue transfers failed.

CONCLUSION

Radiation therapy can begin in most patients within 8 weeks postoperatively, microvascular free tissue transfers seem to tolerate postoperative radiation therapy well at the doses administered, and the rates of local and neck control are reasonable relative to the advanced stage of the cancers treated.

Effects of combined cold and hyperbaric oxygen storage on free flap survival

We have previously reported that hyberbaric oxygen (HBO) improved the survival rate of experimental free flaps. The purpose of this study was to evaluate the effects of combined hypothermia and HBO administered during storage on free flaps and on the xanthine oxidase system in rats. Epigastric skin flaps were stored cold for 48 and 72 hours either in room air or under HBO (2.9 atmospheres absolute, 100% oxygen) before free flap transfer. The success rates of free flaps were 80% (8/10) after 48 hours and 20% (2/10) after 72 hours of cold storage in room air. HBO produced no effect after 48 hours but significantly increased the success rate to 70% (7/10) after 72 hours of cold storage. Tissue hypoxanthine (plus xanthine) levels increased to 210% of normal after 48 hours of cold storage in room air and to 176% in HBO. Elevated hypoxanthine levels returned toward normal by 72 hours of cold storage in room air, while the increased levels remained under HBO. Xanthine oxidase activities significantly increased by 60 to 80% during 72 hours of room air storage. HBO treatment inhibited xanthine oxidase activity to 48% of normal by 72 hours of storage. Free flaps exhibited no significant alterations in GR and G6PDH activity after 48 hours of cold storage in room air or HBO. After 72 hours of cold storage, the room air control displayed a trend of decreasing GR activity and a significant 20% decrease in G6PDH activity, while HBO groups showed no significant alterations in both GR and G6PDH activity compared to normal. Protection of the antioxidative enzymes by hypothermia and inhibition of the xanthine oxidase activity by HBO appear to be one of the mechanisms of improved skin flap survival in free flaps.

[Indications for vein interposition in microsurgical reconstruction of complex defects of the lower extremity after tumor and trauma]

Reconstructive microsurgery has become a routine procedure in plastic surgery. Success rates in major centers range between 95 and 98%. In selected "high risk" cases, vein grafts are required to facilitate microsurgical anastomoses, as in complex defects of the lower leg, post ischemic syndrome (PIS) or following major tumor resections. The indications and results of vein grafts or A-V loops are demonstrated in these three groups. 25 patients with defects of the lower leg were operated using vein interposition grafts. Ten A-V loops were created prior to flap transfer. Three flaps had to be revised, only one flap was lost due to recurrent arterial thromboembolism from an injured proximal segment. Data show that vein grafts are clinically reliable and may be used without hesitation in appropriate clinical situations.

A-O reconstruction plate and sternal osteomyocutaneous flap in primary mandibular reconstruction

Mandibular arch reconstruction remains a functional and aesthetic challenge for the head and neck surgeon. The recent popularity of vascularized free composite flaps has made them a first choice for many surgeons. However, the increased operating time, high failure rate, frequent need for operative rescue, specialized postoperative care and facilities, and specialized training required to perform them have prompted many extirpative surgeons to attempt other techniques or to leave the mandible unreconstructed. Six sternal osteomyocutaneous flaps, a variant of the familiar pectoralis major myocutaneous flap, were utilized to reconstruct mandibular defects of up to 10 cm in patients undergoing composite resection for cancer, with or without preoperative radiotherapy. The use of the A-O reconstructive plate to secure the bony portion of the flap to the unresected mandible has considerably simplified and speeded the procedure over external fixation as originally described. When both soft tissue and bone are required to rehabilitate the operative defect, the sternal osteomyocutaneous flap has proven to be a reliable and time-effective procedure.

Amelioration of secondary ischaemic injury by perfusion with University of Wisconsin (UW) solution in rat skin flaps

This study was designed to observe the effect of perfusion with University of Wisconsin (UW) preservation solution on skin flap survival following secondary ischaemia caused by venous obstruction in rats. An epigastric flap model was used. Saline-perfused flaps exhibited no significant improvement in survival compared to untreated animals (NS). Skin flaps perfused with UW solution, however, had a significant increase in survival to 40% (8/20) (p < 0.01) when perfused before the onset of primary ischaemia and 30% (p < 0.05) when given before the onset of secondary ischaemia. These results show that UW solution improves skin flap survival, presumably through preservation of the microvasculature.

Vascularized free-tissue transfer in head and neck surgery

Microsurgical vascularized free-tissue transfer has had a dramatic impact on the field of head and neck reconstruction. This technique has extended the extirpative limits of resection by facilitating complex reconstruction of head and neck defects in one stage with very high success and minimal patient morbidity. Although its impact on improving cure rates and survival statistics has yet to be determined, it has proven very valuable in the palliation of patients with advanced malignancies. The horizons for future applications are infinite. Neurotization of free-flap transfer may potentially improve the functional outcome for patients. In the future, free flaps may be prefabricated to allow for improved mandibular reconstruction or tracheal reconstruction. These tissue composites may potentially be a vehicle through which adjuvant therapy can be better delivered to the tumor bed. Microsurgical free-tissue transfer will have an expanding role in the treatment of patients with head and neck tumors, and continued refinements in these techniques will open new vistas for the reconstructive surgeons in the future.

Transfer of innervated latissimus dorsi free musculocutaneous flap for the restoration of finger flexion

Transfer of functioning free muscle for the restoration of finger flexion is an uncommon procedure. We present our experience with five patients with severe forearm injuries in whom a latissimus dorsi musculocutaneous free tissue transfer was performed in an attempt to provide soft tissue coverage and active digital flexion. Four patients had active finger flexion with volitional control of the transferred muscle between the tenth and the fifteenth weeks. On average, active flexion lags were 2.0 cm in the index finger, 2.1 cm in the long finger, 2.3 cm in the ring finger, and 1.4 cm in the small finger. Although preoperative grip strength was doubled, postoperative strength was still only about 31% of that on the opposite side. All patients required at least one tenomyolysis or revision tenorrhaphy before the best clinical outcome was achieved.

Complications in head and neck microsurgery

Microvascular surgery plays a vital role in head and neck reconstruction. This paper deals with the complications arising from this form of surgery. They can be classified as general complications, anastomotic problems, and specific problems related to particular donor and recipient sites.

Team approach to tibial fracture. 37 consecutive type III cases reviewed after 2-10 years

During a 10-year period, we managed 35 patients with 37 cases of Type III open tibial fractures, 15 cases within 1 week and 22 as late referrals. In all cases, simultaneous assessment and management by a microvascular and an orthopedic surgeon were mandatory throughout the treatment period. 6 of the 15 acute cases had a primary amputation. Of the remaining 31 cases, limb salvage was possible in 27. 31 flaps, pedicle and microvascular free flaps were used. Major complications occurred in 6 cases, but in 27 cases infection-free solid union was obtained. At long-term follow-up, average 5 years, the function was good or acceptable in 23 cases. We conclude that: (1) patients with Type III tibial injuries should preferably be transferred within a week after injury to a hospital where major reconstructive procedures are commonly performed, (2) early soft tissue coverage is essential in the management of these injuries, (3) unilateral external fixation should be the preferred technique of stabilization, and, finally, (4) plastic surgery expertise is important in management of severe tibial fractures.

Delayed debulking of free muscle flaps for aesthetic contouring debulking of free muscle flaps

Although denervated muscle and myocutaneous free flaps atrophy over a period of time, when used for surface coverage they may remain bulky, resulting in a less than optimal aesthetic result. With the availability of a number of donor sites, soft tissue defects can often be reconstructed with like tissue in a single stage. Even though the goal of all plastic surgeons is to achieve a good cosmetic result, special circumstances might dictate that need take precedence over form. We have had six cases where a bulky muscle was used to achieve well vascularised coverage. After wound closure had been successfully accomplished, a secondary debulking procedure was performed safely for a final acceptable aesthetic result.

Simultaneous comparison of pre- and post-microanastomotic hemodynamic profiles using a Tandem Doppler Probe

The use of High-Frequency Pulsed Doppler Ultrasound (HFPDU) for evaluation of microvascular hemodynamics is well established. Due to technical limitations of existing probes, quantitation of anastomotic stenoses and detailed waveform analyses are difficult to perform and impractical for clinical use. We present a new Tandem Doppler Probe (TDP) for simple and accurate study of blood flow in vessels smaller than 1 mm in diameter. Its unique ability to compare the pre- and post-anastomotic waveforms simultaneously allows for quantitative detection of anastomotic narrowing of as little as 5%, as well as identification of subtle pathologic anastomotic waveform changes not seen with single probes. Such early and precise delineation of anastomotic problems in the operating room can provide an invaluable, objective assessment of the technical adequacy of the anastomoses as well as an important baseline for later post-operative monitoring of free-tissue transfers with implantable Doppler devices.

Free vascularized tissue transfer for limb salvage in peripheral vascular disease

In patients with tissue necrosis, higher limb salvage rates can be accomplished with free tissue transfers performed by a vascular and plastic surgeon team. We treated 10 patients with severe ischemic soft tissue defects in their legs with radical debridement and free tissue transfer alone (two patients) or after revascularization (eight patients). Arteriography was performed to plan revascularization to evaluate bypass results, and to identify appropriate recipient vessels for free tissue transfer. Soft tissue defects treated with free tissue transfer included nonhealing amputation sites in five patients and proximal skin and muscle necrosis in the remaining patients, one of which resulted in an exposed in-situ graft in one leg. One patient underwent a distal bypass specifically to provide arterial inflow for free tissue transfer, whereas seven other patients received free tissue transfers following bypass due to persistently nonhealing wounds. The remaining two patients had diabetes mellitus with necrosis near a major joint with nonhealing amputation sites. Free tissue transfers were taken from the latissimus dorsi in six patients, and from the gracilis, rectus abdominis, rectus femoris, and scapula flaps in other patients. Recipient vessels for free tissue transfers were the external iliac artery (one patient), saphenous vein bypass grafts (two patients), popliteal artery (one patient), posterior tibial (three patients), and dorsalis pedis vessels (three patients). Eight of the 10 flaps were viable at follow-up (four months-six years), with a mean follow-up of 20 months. One patient underwent above-knee amputation 15 months after operation and one underwent below-knee amputation three years later due to central flap necrosis. The remainder achieved functional limb salvage allowing patients to resume ambulation. Vascular surgeons should consider free tissue transfer in patients with nonhealing soft tissue defects following optimal revascularization to further extend our ability to salvage the threatened limb.

Reconstruction of massive defects of the scalp, cranium, and dura after resection of scalp neoplasms

Massive defects of the scalp, cranium, and dura can be covered with local rotation, transposition scalp flaps. Five cases of massive defects of up to 300 square centimeters resulting from resection of scalp neoplasms were reconstructed by this technique. Excellent cosmetic and functional results were obtained in all cases. Although the emphasis in the recent literature has been on free flap coverage of these massive defects, our series demonstrates that these extensive scalp defects can be reconstructed using large local scalp flap transposition.

The use of the latissimus dorsi muscle as an active motor unit for digital flexion

A technique is described to restore flexion of the fingers and thumb using a latissimus dorsi muscle island as an active motor unit. It has been performed in a ten-year-old child with a satisfactory result.

Microsurgery for macrodefects: microvascular free-tissue transfer for massive defects of the head and neck

Despite defect location and the fear of creating complex massive defects, coverage of large areas of soft tissue loss, with or without exposed calvaria, dura, and brain, can be reconstructed reliably with microvascular free tissue transfer. This technique permits separation of the oronasopharynyx from the intracranial contents, coverage of dural grafts, restoration of composite tissue loss, and achievement of superior aesthetic results in a single stage. When choosing vascular anastomotic sites, free-flap transfer permits a greater latitude in flap orientation, tailoring, and inset than is possible when using fixed pedicled rotation flaps. When confronted with a deeply invasive or gigantic malignancy, a multidisciplinary team approach is optimal. The risk associated with sophisticated ablative and reconstructive operative procedures is justified when dealing with potentially curable lesions. The success of these extensive procedures is related not only to the functional result and the aesthetic appearance, but most importantly to the resultant quality of life they allow.

Microvascular free flaps in early reconstruction of burns in the hand and forearm. Case reports

In the reconstructive plastic surgery a free flap provides a one-stage method to achieve an optimal functional an aesthetic result. We report five acute burns or early contractions of the hand and forearm with free-flap reconstruction. In each case an attempt was made to design the flap to restore missing tissue components. We used three different musculocutaneous free flaps and two free skin flaps: a latissimus dorsi, a rectus abdominis and a rectus femoris renervated musculocutaneous flap, as well as a dorsalis pedis and a horizontal fasciocutaneous upper arm flap. In all five cases, the hand and wrist showed early restoration of function.