Neurovascular free-muscle transfer for the treatment of established facial paralysis following ablative surgery in the parotid region

Neurovascular free-muscle transfer for facial reanimation was performed as a secondary reconstructive procedure for 45 patients with facial paralysis resulting from ablative surgery in the parotid region. This intervention differs from neurovascular free-muscle transfer for treatment of established facial paralysis resulting from conditions such as congenital dysfunction, unresolved Bell palsy, Hunt syndrome, or intracranial morbidity, with difficulties including selection of recipient vessels and nerves, and requirements for soft-tissue augmentation. This article describes the authors' operative procedure for neurovascular free-muscle transfer after ablative surgery in the parotid region. Gracilis muscle (n = 24) or latissimus dorsi muscle (n = 21) was used for transfer. With gracilis transfer, recipient vessels comprised the superficial temporal vessels in 12 patients and the facial vessels in 12. For latissimus dorsi transfer, recipient vessels comprised the facial vessels in 16 patients and the superior thyroid artery and superior thyroid or internal jugular vein in four. Facial vessels on the contralateral side were used with interpositional graft of radial vessels in the remaining patient with latissimus dorsi transfer. Cross-face nerve grafting was performed before muscle transfer in 22 patients undergoing gracilis transfer. In the remaining two gracilis patients, the ipsilateral facial nerve stump was used as the primary recipient nerve. Dermal fat flap overlying the gracilis muscle was used for cheek augmentation in one patient. In the other 23 patients, only the gracilis muscle was used. With latissimus dorsi transfer, the ipsilateral facial nerve stump was used as the recipient nerve in three patients, and a cross-face nerve graft was selected as the recipient nerve in six. The contralateral facial nerve was selected as the recipient nerve in 12 patients, and a thoracodorsal nerve from the latissimus dorsi muscle segment was crossed through the upper lip to the primary recipient branches. A soft-tissue flap was transferred simultaneously with the latissimus muscle segment in three patients. Contraction of grafted muscle was not observed in two patients with gracilis transfer and in three patients with latissimus dorsi transfer. In one patient with gracilis transfer and one patient with latissimus dorsi transfer, acquired muscle contraction was excessive, resulting in unnatural smile animation. The recipient nerves for both of these patients were the ipsilateral facial nerve stumps, which were dissected by opening the facial nerve canal in the mastoid process. From the standpoint of operative technique, the one-stage transfer for latissimus dorsi muscle appears superior. Namely, a combined soft-tissue flap can provide sufficient augmentation for depression of the parotid region following wide resection. A long vascular stalk of thoracodorsal vessels is also useful for anastomosis, with recipient vessels available after extensive ablation and neck dissection.     

Neurovascularized free short head of the biceps femoris muscle transfer for one-stage reanimation of facial paralysis

The single-stage technique for cross-face reanimation of the paralyzed face without nerve graft is an improvement over the two-stage procedure because it results in early reinnervation of the transferred muscle and shortens the period of rehabilitation. On the basis of an anatomic investigation, the short head of the biceps femoris muscle with attached lateral intermuscular septum of the thigh was identified as a new candidate for microneurovascular free muscle transfer. The authors performed one-stage transfer of the short head of the biceps femoris muscle with a long motor nerve for reanimation of established facial paralysis in seven patients. The dominant nutrient vessels of the short head were the profunda perforators (second or third) in six patients and the direct branches from the popliteal vessels in one patient. The recipient vessels were the facial vessels in all cases. The length of the motor nerve of the short head ranged from 10 to 16 cm, and it was sutured directly to several zygomatic and buccal branches of the contralateral facial nerve in six patients. One patient required an interpositional nerve graft of 3 cm to reach the suitable facial nerve branches on the intact side. The period required for initial voluntary movement of the transferred muscles ranged from 4 to 10 months after the procedures. The period of postoperative follow-up ranged from 5 to 42 months. Transfer of the vascularized innervated short head of the biceps femoris muscle is thought to be an alternative for one-stage reconstruction of the paralyzed face because of the reliable vascular anatomy of the muscle and because it allows two teams to operate together without the need to reposition the patient. The nerve to the short head of the biceps femoris enters the side opposite the vascular pedicle of the muscle belly, and this unique relationship between the vascular pedicle and the motor nerve is anatomically suitable for one-stage reconstruction of the paralyzed face. As much as to 16 cm of the nerve can be harvested, and the nerve is long enough to reach the contralateral intact facial nerve in almost all cases. The lateral intermuscular septum, which is attached to the short head, provides "anchor/suture-bearing" tissue, allowing reliable fixations to the zygoma and the upper and lower lips to be achieved. In addition, the scar and deformity of the donor site are acceptable, and loss of this muscle does not result in donor-site dysfunction.     

Dynamic reconstruction of eye closure by muscle transposition or functional muscle transplantation in facial palsy

For patients with facial palsy, lagophthalmus is often a more serious problem than the inability to smile. Dynamic reconstruction of eye closure by muscle transposition or by free functional muscle transplantation offers a good solution for regaining near-normal eye protection without the need for implants. This is the first quantitative study of three-dimensional preoperative and postoperative lid movements in patients treated for facial paralysis. Between February of 1998 and April of 2002, 44 patients were treated for facial palsy, including reconstruction of eye closure. Temporalis muscle transposition to the eye was used in 34 cases, and a regionally differentiated part of a free gracilis muscle transplant after double cross-face nerve grafting was used in 10 cases. Patients' facial movements were documented by a three-dimensional video analysis system preoperatively and 6, 12, 18, and 24 months postoperatively. For this comparative study, only the data of patients with preoperative and 12-month postoperative measurements were included. In the 27 patients with a final result after temporalis muscle transposition for eye closure, the distance between the upper and lower eyelid points during eye closing (as for sleep) was reduced from 10.33 +/- 2.43 mm (mean +/- SD) preoperatively to 5.84 +/- 4.34 mm postoperatively on the paralyzed side, compared with 0.0 +/- 0.0 mm preoperatively and postoperatively on the contralateral healthy side. In the resting position, preoperative values for the paralyzed side changed from 15.11 +/- 1.92 mm preoperatively to 13.46 +/- 1.94 mm postoperatively, compared with 12.17 +/- 2.02 mm preoperatively and 12.05 +/- 1.95 mm postoperatively on the healthy side. In the nine patients with a final result after surgery using a part of the free gracilis muscle transplant reinnervated by a zygomatic branch of the contralateral healthy side through a cross-face nerve graft, eyelid closure changed from 10.21 +/- 2.72 mm to 1.68 +/- 1.35 mm, compared with 13.70 +/- 1.56 mm to 6.63 +/- 1.51 mm preoperatively. The average closure for the healthy side was from 11.20 +/- 3.11 mm to 0.0 +/- 0.0 mm preoperatively and from 12.70 +/- 1.95 mm to 0.0 +/- 0.0 mm postoperatively. In three cases, the resting tonus of the part of the gracilis muscle transplant around the eye had increased to an extent that muscle weakening became necessary. Temporalis muscle transposition and free functional muscle transplantation for reanimation of the eye and mouth at the same time are reliable methods for reconstructing eye closure, with clinically adequate results. Detailed analysis of the resulting facial movements led to an important improvement of the authors' operative techniques within the last few years. Thus, the number of secondary operative corrections could be significantly reduced. These qualitative and quantitative studies of the reconstructed lid movements by three-dimensional video analysis support the authors' clinical concept of temporalis muscle transposition being the first-choice method in adult patients with facial palsy. In children, free muscle transplantation is preferred for eye closure, so as not to interfere with the growth of the face by transposition of a masticatory muscle. In addition, a higher degree of central plasticity in children might be expected.     

Cross-face nerve graft with free-muscle transfer for reanimation of the paralyzed face: a comparative study of the single-stage and two-stage procedures

The most accepted method for reanimation of the paralyzed face is the two-stage method that combines cross-face nerve graft with free-muscle transfer. Although the results of reconstruction with this method are satisfactory, there is an excessive delay between stages, which prolongs the period of rehabilitation. In 1995, Kumar overcame this and presented his preliminary results from a single-stage transfer of the gracilis. We compared the long-term results of the single-stage with the two-stage method of reconstruction. Patients selected the method of reconstruction on the basis of the information, photographs of scars, and video recording of results given to them at a special facial palsy clinic. Ten patients selected the single-stage reconstruction and 15 selected the two-stage reconstruction. The mean follow-up period was 3 years. The results of the two methods are comparable, with 90 percent of the patients who underwent the single-stage and 93 percent of those who underwent the two-stage procedures having good and fair results. However, the two-stage method scored good symmetry at rest in 67 percent, compared with 20 percent for the single-stage method. There were fewer complications with the single-stage method, and none of the patients had any problems relating to the donor site. The period of rehabilitation was reduced by 10 months with the single-stage method.     

Free proximal gracilis muscle and its skin paddle compound flap transplantation for complex facial paralysis

Gracilis functioning free-muscle transplantation for the correction of pure facial paralysis has been a preferred method used by many reconstructive microsurgeons. However, for complex facial paralysis, the deficits include facial paralysis along with soft-tissue, mucosa, and/or skin defects. No adequate solution has been proposed. Treatment requests in those patients are not only for facial reanimation but also for correction of the defects. Of 161 patients with facial paralysis treated with gracilis functioning free-muscle transplantation from 1986 to 2002, eight patients (5 percent) presented with complex deficits requiring not only facial reanimation but also aesthetic correction of tissue defects. The tissue defects included an intraoral defect created following contracture release (one patient), infra-auricular radiation dermatitis with contour depression (one patient), temporal depression following a temporalis muscle-fascia transfer (one patient), ear deformity (two patients), and infra-auricular atrophic tissue with contour depression (three patients). A compound flap, consisting of a gracilis muscle with its overlying skin paddle separated into two components, was transferred for simultaneous correction of both problems. The blood supply to the gracilis and to the skin paddle originated from the same source vessel and therefore required the anastomosis of only one set of vessels. The versatility of this compound flap allows for a wide arc of rotation of the skin paddle around the muscle. All flaps were transferred successfully without complications. Satisfactory results of facial reanimation were recorded in five patients after all stages were completed. The remaining three patients are undergoing physical therapy and waiting for revision of the skin paddle.     

Results of management of facial palsy with microvascular free-muscle transfer

This paper reports our experience in facial reanimation using free innervated muscle transfer in 69 patients with long-term facial palsy. The majority of patients were treated in two stages with cross-facial nerve graft as the first stage and microvascular muscle transfer at the second stage. The gracilis muscle was used in 62 patients. A system of grading results has been utilized in the long-term evaluation. The overall final result was excellent or good in 51 percent of 47 patients who were available for follow-up. Although the results are not completely satisfactory, they justify the use of this approach to a difficult clinical problem. The results are improving as technical modifications to the procedure have evolved. The gracilis muscle is a reliable free transfer with internal anatomy conductive to use for reanimation of the paralyzed face. This type of transfer, in our experience, has proved superior to nonmicrosurgical methods for treatment of complete and severe incomplete facial palsy. The seventh cranial nerve is used in the innervation of the transferred muscle, the ipsilateral being preferable if available. The authors believe that use of the same cranial nerve is superior to methods that involve other cranial nerves, where spontaneity is often not achieved.     

Neurovascular musculus obliquus internus abdominis flap free transfer for facial reanimation in a single stage

A study of the anatomy and transplantation of the musculus obliquus internus abdominis with a neurovascular pedicle transfer for facial reanimation in one stage is presented. Eleven adult cadavers (22 face sides) were dissected to observe the shape, thickness, innervation, and blood supply of the musculus obliquus internus abdominis. The blood supply of this muscle primarily comes from the musculus obliquus internus abdominis branch of the deep circumflex iliac artery (diameter, 1.3 +/- 0.2 mm), but it can also come from the eleventh intercostal artery (diameter, 1.14 +/- 0.3 mm) and the infracostal artery (diameter, 1.5 +/- 0.2 mm). The branch of the deep circumflex iliac artery and its vena comitans, or the infracostal artery and its vena comitans, could be anastomosed for muscle transplantation. The innervation of the musculus obliquus internus abdominis comes from the tenth and eleventh intercostal nerves (length, 12.7 +/- 1.5 cm) and the infracostal nerve (length, 12.9 +/- 1.3 cm). The eleventh intercostal nerve and the infracostal nerve were selected for anastomosis of muscle transplantation. From November of 1995 to November of 1999, 14 patients with long established facial paralysis were treated with transplantation of a musculus obliquus internus abdominis flap in one stage and were followed for 10 months to 6 years. In 13 patients, the dynamic functions of the transplanted muscles were restored, the obliqueness of the mouth and philtrum while static was corrected, and the facial muscle activities while smiling were harmonized. The eyelids of the paralyzed side could be closed postoperatively, indicating that the function of the orbicularis oculi of the paralyzed side was restored. The single-stage transplantation of a free musculus obliquus internus abdominis flap with one vascular, multi-nerve pedicle is a new method for facial reanimation in the treatment of long established facial paralysis. Because of the simplicity of the procedure and the completeness of the functional reanimation of the paralyzed facial muscles, compared with the results of other free muscle flap transfers, it is an ideal procedure for facial reanimation.     

Comparative anatomical study of the gracilis and coracobrachialis muscles: implications for facial reanimation

Since the introduction of cross-facial nerve grafting and free vascularized muscle transfer for the treatment of longstanding facial paralysis, substantial progress has been made toward restoration of facial expression that is as normal as possible. Much of the focus has remained on the gracilis as a donor muscle. However, its inherent anatomical characteristics may preclude it from ever being more than simply a mass of contractile tissue in the face. The coracobrachialis muscle, which is the analogue in the arm of the lower limb adductor mass, was proposed as an alternative donor muscle because it was thought that certain features would allow it to improve on the overall results that are currently possible with the gracilis. A comparative anatomical study was conducted to gauge this potential. A total of 133 muscles were analyzed, including 96 dissected specimens, 16 arterial and 14 venous study specimens, and seven neurovascular study specimens. Anatomical parameters were recorded for each muscle and later tabulated. Histological analysis of the nerves to 10 gracilis and 10 coracobrachialis muscles was performed, and the findings were confirmed with intraneural dissection of an additional 20 nerves under an operating microscope. The coracobrachialis was observed to be a practical alternative to the gracilis. Indeed, it has many of the attributes that initially drew attention to the gracilis as a possible donor muscle, including a reliable neurovascular supply, minimal donor-site morbidity, and the option of having two teams operate simultaneously. In addition, it has a size, shape, and form that make it an excellent choice for transfer to the face. It could be easily attached in the face to provide static support as well as animation, because of its long proximal tendon, the thick intermuscular septum along its lateral surface, and, when present, the ligament of Struthers.     

Extensive and complex defects of the scalp, middle third of the face, and palate: the role of microsurgical reconstruction

Twenty-one patients with gigantic defects of the scalp and middle third of the face and palate following excision of neglected or recurrent tumors, burns, and infections have undergone microsurgical reconstruction. Wide resection of the middle third of the face, orbit, and palate requires "complex" three-dimensional volume reconstruction, whereas extensive defects of the scalp and skull (exceeding 80 cm2) require coverage of the larger surface area soft-tissue defect and the exposed brain and dura. The latissimus dorsi free-muscle flap and split-thickness skin graft have become our methods of choice for extensive scalp and skull defects. The latissimus dorsi musculocutaneous free flap is preferable for reconstruction of complex palatal and external skin and orbital defects of the middle third of the face. Microsurgical free-tissue transfer reliably frees the oncologic surgeon from the constraints imposed by conventional reconstructive techniques and may therefore allow improved curative or at least palliative resection of these extensive tumors.     

Significance of shoulder function in the reconstruction of prehension with double free-muscle transfer after complete paralysis of the brachial plexus

Reconstruction of shoulder stability and movement in cases with complete paralysis of the brachial plexus was performed to improve the outcomes for universal function of prehension after double free-muscle transfer (Doi's procedure). In cases in which the C5 or C6 nerve root was available as a donor, neurotization of the supra-scapular nerve was performed with a nerve graft. If the C5 or C6 nerve root was not available, then the contralateral C7 nerve root was chosen as the donor motor nerve and was transferred to the suprascapular nerve by using a vascularized ulnar nerve graft. Seven cases with ipsilateral C4, C5, or C6 nerve root transfer to the suprascapular nerve and one with contralateral C7 transfer were evaluated, and the functional outcomes for the range of shoulder motion were compared with those for patients who had undergone arthrodesis of the humeroscapular joint or had undergone no procedures for shoulder function reconstruction. The patients who underwent supra-scapular nerve repair demonstrated statistically significantly better ranges of motion for flexion and abduction of the shoulder, compared with the other two groups. Shoulder function is important for achieving prehensile function among patients with complete paralysis of brachial function, when they undergo double free-muscle transfer.     

Free latissimus dorsi muscle flap with skin graft for treatment of traumatic chronic bony wounds

Based on this review of 35 cases of chronic bony wounds, it would appear that the free-muscle flap method of wound closure and nourishment after thorough dead bone debridement is an attractive and successful alternative to local skin flaps, staged skin flaps, or extend skin-muscle flaps in areas where reliable muscle flaps are not available. It would also seem that the latissimus dorsi muscle flap with skin graft is an ideal donor-muscle transfer with features allowing a favorable and contoured surface in the recipient site and minimal aesthetic and functional deformity in the donor site.     

Management of the chest-wall deformity in male patients with Poland's syndrome

The chest-wall deformity associated with Poland's syndrome was reconstructed in eight male patients 16 to 38 years old (average age 20 years). Follow-up ranged from 1 to 10 years. Two patients had custom silicone implants placed subcutaneously. In one of these patients, the edge of the implant could be seen. Three patients had transfer of an ipsilateral pedicled latissimus dorsi muscle flap with intact thoracodorsal nerve. All these patients had noticeable atrophy of the flap, and one underwent subsequent implantation of a custom silicone implant beneath the flap. Three other patients had a custom silicone implant covered immediately by a latissimus dorsi muscle flap. All four patients who had a combination of silicone implant and latissimus dorsi muscle flap had satisfactory correction of their deformity.     

Free gracilis muscle transplantation, with microneurovascular anastomoses for the treatment of facial paralysis. A preliminary report.

A clinical operative technique for free muscle transplantation by microneurovascular anastomoses is presented. Two cases of free transfer of the gracilis muscle for dynamic reconstruction of facial paralysis are described, including a follow-up study with electromyography, light microscopy, and electron microscopy. We feel this new technique will have a wide range of application in reconstructive surgery.     

Continued twitching of the latissimus dorsi miniflap after breast conservation therapy: a case report

We report a case of continued twitching of the latissimus dorsi muscle following breast conservation therapy, along with immediate reconstruction with a latissimus dorsi miniflap, which continued despite several attempts at control including BTX-A percutaneous local injection, and was finally cured by delayed division of the thoracodorsal nerve via a small well-tolerated axillary incision.     

Hemifacial microsomia: use of the OMENS-Plus classification at the Royal Children's Hospital of Melbourne

Hemifacial microsomia is the most common facial congenital disability after cleft lip and palate, but as yet its pathogenesis remains unknown. Clinical classification systems have evolved over the last 30 years from those classifying only single components of the disorder, to those classifying according to the combination of deformities, to the most recent systems that grade each anatomical component separately, such as the Orbit, Mandible, Ear, Nerve, and Soft tissue (OMENS) system. The aim of the present study was to review the classification of patients with hemifacial microsomia treated by the Melbourne Craniofacial Unit at the Royal Children's Hospital using the OMENS-Plus system of classification and to correlate the findings with data from other centers. Records of patients treated by the craniofacial unit were reviewed and included in the study if adequate clinical records, photographs, and radiographs (anteroposterior, lateral, basal cephalometry, panoramic views) were available. The data were entered into a database file developed for this purpose. Seventy-one patients were identified from the hospital database, of which six were excluded because of incomplete data. Of the 65 patients, there were 31 (48 percent) with right-sided microsomia, 25 (38 percent) with left-sided microsomia, and nine (14 percent) with bilateral microsomia, with an overall male-to-female ratio of 1.2:1. The majority of patients had a normal orbit (77 percent), mildly hypoplastic mandibular ramus-condyle with functioning temporomandibular joint (57 percent with type M1 or M2a), normal facial nerve (76 percent), and mild soft-tissue hypoplasia (73 percent). There was a similar proportion of patients with mild ear anomalies (53 percent with grade 0 or 1) compared with those with more severe anomalies (47 percent with grade 2 or 3). Correlative analysis demonstrated a slight but positive correlation between the severity gradings of the five individual components. The correlation was lowest between the grading of the nerve and ear and that of the mandible and nerve. The data demonstrate the phenotypic variability of hemifacial microsomia and suggest a degree of relationship among the components of hemifacial microsomia. The OMENS-Plus system has provided a major advancement in the classification of hemifacial microsomia. The authors suggest refinements to the grading of the orbit and nerve components.     

Composite reconstruction for chest wall and scalp using multiple ribs-latissimus dorsi osteomyocutaneous flaps as pedicled and free flaps

A composite flap is presented based on the latissimus dorsi myocutaneous unit together with the underlying ninth to eleventh ribs. Three patients are presented. In two, a full-thickness chest-wall defect was present. In one, a full-thickness scalp and cranial defect was present. Use of the composite osteomyocutaneous latissimus dorsi free flap as a pedicled flap in two patients and as a free flap in one patient resulted in successful definitive reconstruction in all with no complications. This procedure necessitates no transplantation of soft tissue prior to bone grafting to maintain local vascularity, so the simultaneous one-stage reconstruction of an osseous-soft-tissue defect becomes possible easily.     

Use of the latissimus dorsi muscle to restore elbow flexion in arthrogryposis

The successful use of ipsilateral pedicle latissimus dorsi muscle to restore elbow flexion in a child with arthrogryposis multiplex congenita is described. In appropriately selected patients, use of the latissimus dorsi muscle for elbow flexor reconstruction is a strong, reliable flexorplasty without significant donor-site morbidity.     

One-stage reconstruction of composite bone and soft-tissue defects in traumatic lower extremities

Management of bone loss that occurs after severe trauma of open lower extremity fractures continues to challenge reconstructive surgeons. Sixty-one patients who had 62 traumatic open lower extremity fractures and combined bone and composite soft-tissue defects were treated with the following protocol: extensive debridement of necrotic tissues, eradication of infection, and vascularization of osteocutaneous tissue for one-stage bone and soft-tissue coverage reconstruction. The mechanism of injury included 49 motorcycle accidents (80.3 percent), five falls (8.2 percent), three crush injuries (4.9 percent), two pedestrian-automobile accidents (3.3 percent), and two motor vehicle accidents (3.3 percent). The bone defects were located in the tibia in 49 patients (79 percent; one patient had bilateral open tibial fractures), in the femur in seven patients (11.3 percent), in the calcaneus bone in four patients (6.5 percent), and in the metatarsal bones in two patients (3.2 percent). The size of soft-tissue defects ranged from 5 x 9 cm to 30 x 17 cm. The average length of the preoperative bony defect was 11.7 cm. The average duration from injury to one-stage reconstruction was 27.1 days, and the average number of previous extensive debridement procedures was 3.4. Fifty patients had vascularized fibula osteoseptocutaneous flaps, six had vascularized iliac osteocutaneous flaps, and five patients had seven combined vascularized rib transfers with serratus anterior muscle and/or latissimus dorsi muscle transfers. One patient received a second combined rib flap because the first combined rib flap failed. The rate of complete flap survival was 88.9 percent (56 of 63 flaps). Two combined vascularized rib transfers with serratus anterior muscle and latissimus dorsi muscle flaps were lost totally (3.2 percent) because of arterial thrombosis and deep infection, respectively. Partial skin flap losses were encountered in the five fibula osteoseptocutaneous flaps (7.9 percent). Postoperative infection for this one-stage reconstruction was 7.9 percent. Excluding the failed flap and the infected/amputated limb, the primary bony union rate after successful free vascularized bone grafting was 88.5 percent (54 of 61 transfers). The average primary union time was 6.9 months. The overall union rate was 96.7 percent (59 of 61 transfers). The average time to overall union was 8.5 months after surgery. Seven transferred vascularized bones had stress fractures, for a rate of 11.5 percent. Donor-site problems were noted in six fibular flaps, in two iliac flaps, and in one rib flap. The fibular donor-site problems were foot drop in one patient, superficial peroneal nerve palsy in one patient, contracture of the flexor hallucis longus muscle in two patients, and skin necrosis after split-thickness skin grafting in two patients. The iliac flap donor-site problems were temporary flank pain in one patient and lateral thigh numbness in the other. One rib flap transfer patient had pleural fibrosis. Transfer of the appropriate combination of vascularized bone and soft-tissue flap with a one-stage procedure provides complex lower extremity defects with successful functional results that are almost equal to the previously reported microsurgical staged procedures and conventional techniques.     

The effect of muscle transplantation after unilateral partial facial paralysis on craniofacial growth and development: relationship between muscle and nerve histomorphometric findings

Muscle transplantation has become an indispensable tool to restore the smile in patients with long-standing or congenital facial paralysis. However, little is known of the effect of this surgical intervention on craniofacial growth and development or of the adaptation of the transplant to its recipient site under circumstances of growth. The present study investigates these phenomena in the rabbit model. Twelve-day-old New Zealand White rabbits were randomly assigned to three experimental groups. The control group was used to study normal craniofacial growth and development (n = 15). In the nerve ablation group, unilateral paralysis of the buccal branches of the facial nerve was surgically induced (n = 15). In the transplant group, the surgically induced unilateral paralysis of the buccal branches was immediately followed by a neuromuscular graft (n = 12). All animals were operated on at the age of 12 days, and follow-up evaluations were performed at the ages of 2 months and 6 months. Computerized dorsoventral roentgencephalometric and computed tomography investigations were performed at both ages. Nerve and muscle histomorphometric measurements were performed at the age of 6 months to relate the quality of nerve and muscle regeneration to the growth parameters. The roentgencephalometric measurements revealed that analogous disturbed parameters were present in the nerve ablation and the transplant groups. However, in the transplant group, an additional significant effect of time between 2 and 6 months was seen for some parameters. This resulted in significant differences between the nerve ablation and transplant groups at 6 months for these parameters. Computed tomography measurements showed no significant differences in maxillary or mandibular volume in the transplant group compared with the control or nerve ablation groups. However, a significantly diminished increase in bone volume existed in the transplant group for the time period between 2 and 6 months in comparison with the control and nerve ablation groups. Muscle histomorphometric findings revealed a significant change in muscle fiber composition in the graft compared with the normal latissimus dorsi muscle; this was due to a major decrease in type IIB fibers, with an increase in type I and type IIA fibers. Compared with the normal zygomaticoauricular muscle, the amount of type I fibers was significantly increased. No fiber atrophy was found. Macroscopically, the transplanted muscle failed to increase its length during growth. Nerve histomorphometric findings demonstrated a normal amount of nerve fibers; however, they had significantly decreased diameters and reduced myelin areas. The nerve histomorphometric parameters were related to the muscle histomorphometric findings, which in turn were related to craniofacial growth disturbances. These findings suggested that the main growth differences between the transplant group and the control group may have been due to altered nerve function influencing muscle function. Scar tissue formation and the development of more intense muscle activity later are suggested as the causes of the additional effect of time between 2 and 6 months for the several parameters in the transplant group. Reasons for the failure of complete conversion of the graft to a fast muscle and the failure of the transplant to elongate during growth are discussed.     

Vascularization of the myocutaneous latissimus dorsi flap. Injection study on the thoracodorsal artery

This study reports on investigations of the thoracodorsal artery by injection studies. This artery has a long proximal extramuscular course before it enters the muscle. A consistent neurovascular hilum was found at a considerably constant location on the inferior muscle surface, 2-3 cm medial to its lateral edge and about 5 cm distal to the inferior scapular border. A constant branching pattern of the thoracodorsal artery into a lateral and a medial vessel stem was found. A high number of muscle-perforating arteries from a dense network in the cutaneous and subcutaneous layer. The thoracodorsal artery supplies the whole cutaneous area adjacent to the latissimus dorsi muscle plus a streak of about 2 cm at the medial and distal muscle borders. The presented anatomical landmarks are useful for locating the neurovascular hilum, and the intramuscular course of the thoracodorsal artery for exploration of the vessel by Doppler sonography or dissection. The length of the pedicle and the relatively big vessel gauge are good anatomical markers for the free transfer of a latissimus dorsi flap.