The physiology, microcirculation and clinical application of the shunt-restricted arterialized venous flaps for the reconstruction of digital defects

Reconstruction of digital defects using the venous flap offer several advantages but remained unpopular owing to levels of venous congestion rates. We performed animal studies to test the hypothesis that an arterio-venous shunt increases pressure for peripheral flap perfusion and decreases venous congestion. Using an abdominal adipofascial flap model in six male Sprague-Dawley rats, microcirculation was modified as follows: type I - arterial flap; type II - flow-through arterio-venous flap (AVF); and type III - shunt-restricted AVF. In type I flaps, blood flow was observed to be unidirectional in both arterioles and venules. In type I flaps, blood flow was observed to be unidirectional in both arterioles and venules. In type II flaps, blood flow oscillated without a dominant direction and came to a standstill. In type III flaps, blood flowed proximally in a reverse direction whereas distally, flow was similar to type I flaps. In a clinical series, 21 patients received a total of 22 shunt-restricted AVFs. All 22 clinical flaps survived; four flaps suffered epidermolysis but recovered without full thickness loss.

A reappraisal of functional reconstruction of extension of the knee following quadriceps resection or loss

The current indications for functional restoration of extension of the knee following quadriceps resection or loss require reappraisal. The contribution of pedicled and free functional muscle transfer is likely to be over-emphasised in many studies, with good functional outcomes predominantly reported only in the context of cases with residual quadriceps function. In cases with total quadriceps resection or loss, all forms of reconstruction perform poorly. Furthermore, in smaller resections with loss of two or fewer components of the quadriceps, minimal impairment of function occurs in the absence of functional reconstruction, suggesting that functional restoration may not be warranted. Thus there is a paradox in the current approach to quadriceps reconstruction, in that small resections are likely to be over-treated and large resections remain under-treated. This review suggests a shift is required in the approach and rationale for reconstructing functional extension of the knee after quadriceps resection or loss. A classification based on current evidence is suggested that emphasises more clearly the indications and rationale for functional transfers.

Functional MR imaging of the human sensorimotor cortex after toe-to-finger transplantation

BACKGROUND

A model of toe-to-finger transplantation has been used in studying peripheral nerve regeneration and central reorganization. It was found that recovery of sensory perception depends not only on peripheral reinnervation but also on central integrative mechanisms.

OBJECTIVE

Our aim was to investigate functional changes of the brain and somatotopic representation of the transplanted toes after toe-to-finger transplantation.

MATERIALS AND METHODS

Six patients who had toe-to-finger transplantation from 3 to 8 years earlier underwent motor and sensory functional MR imaging studies of transplanted toes and opposite corresponding normal fingers. The motor task was performed by repetitively tapping of the transplanted toe or finger against the thumb, whereas the sensory task was applied by tactilely stimulating the pulp of the transplanted toe or finger.

RESULTS

The main activation areas from both types of stimulations were located in the expected location of the finger homunculus of the primary sensorimotor cortex. In addition, activated volumes from the transplanted toes were significantly greater than those from the opposite fingers (P = .017 for motor task and P = .005 for tactile sensory task, paired samples Student t test).

CONCLUSIONS

Functional recruitment in the primary sensorimotor cortex seemed to have occurred following toe-to-finger transplantation. The transplanted toe was somatotopically represented in the hand area.

Clinical experience of 1284 free anterolateral thigh flaps

The past decade has witnessed yet another rebirth in reconstructive surgery with the introduction of the so-called "perforator flaps". The demonstration of safe harvest of skin flaps based on dissection of cutaneous pedicles regardless of the course taken (through muscle or septum) has been revolutionary in allowing much greater choice in donor sites. Based on our experience in 1284 cases, the anterolateral thigh (ALT) region has proven itself to be an ideal donor site with reliable vascularity, ease of harvest and tremendous versatility. Inclusive in this flap is a large cutaneous territory, multiple components (adipofascial, muscle, fascia and skin) and possibility of chimeric applications. Although particularly useful in the head and neck (911 cases), the ALT flap was applied to reconstruct defects throughout the body. Donor site morbidity is limited as well. In short, the anterolateral thigh flap represents one of the most useful soft tissue flaps for free tissue transplantation.

Specificity of reinnervation and motor recovery after interposition of an artificial barrier between transected and repaired nerves in adjacency--an experimental study in the rat

Non-specific re-innervation of target organs caused by misdirected axonal growth at the repair site is regarded as one reason for a poor functional outcome after peripheral nerve transsection and repair. This study investigates the rate of aberrant re-innervation and its influence on motor recovery in the rat sciatic nerve using artificial sheets as barrier between tibial and peroneal nerves. The sciatic nerve was transsected and repaired as follows: epineural sutures (A x 6), fascicular repair of tibial and peroneal nerves respectively (B x 8), and the same as in group B, but separating both nerves using an Integra-sheet with silicone (C x 8), or Integra without silicone (D x 8). As control, solely the tibial nerve was transsected and repaired (E x 5). Final investigations after 4 months revealed that in group C, 50% of the Integra-silicone sheets were dislocated. No dislocation was found in group D. Muscle contraction force of the gastrocnemius muscle was significantly higher in group E as compared to all other groups. However although not significant, group D showed a consistently higher muscle contraction force than groups A, B, and C. Histology in groups A, B, and C with dislocated sheets demonstrated multiple axons growing from the tibial to the peroneal nerve and vice versa. In groups D and E, no such axonal growth was visible. These findings were confirmed by a significantly higher rate of specific reinnervation of the soleus muscle using sequential retrograde double labelling technique. Results of this study suggest that an artificial sheet such as Integra bears the potential of preventing aberrant re-innervation between repaired adjacent nerves resulting in improved motor recovery. Clinically, this technique may be of importance for brachial plexus, sciatic nerve, and facial nerve repair.

The outcome of failed free flaps in head and neck and extremity reconstruction: what is next in the reconstructive ladder?

The indications for free flaps have been more or less clarified; however, the course of reconstruction after the failure of a free flap remains undetermined. Is it better to insist on one's initial choice, or should surgeons downgrade their reconstructive goals? To establish a preliminary guideline, this study was designed to retrospectively analyze the outcome of failed free-tissue transfers performed in the authors hospital. Over the past 8 years (1990 through 1997), 3361 head and neck and extremity reconstructions were performed by free-tissue transfers, excluding toe transplantations. Among these reconstructions, 1235 flaps (36.7 percent) were transferred to the head and neck region, and 2126 flaps (63.3 percent) to the extremities. A total of 101 failures (3.0 percent total plus the partial failure rate) were encountered. Forty-two failures occurred in the head and neck region, and 59 in the extremities. Evaluation of the cases revealed that one of three following approaches to handling the failure was taken: (1) a second free-tissue transfer; (2) a regional flap transfer; or (3) conservative management with debridement, wound care, and subsequent closure by secondary intention, whether by local flaps or skin grafting. In the head and neck region, 17 second free flaps (40 percent) and 15 regional flaps (36 percent) were transferred to salvage the reconstruction, whereas conservative management was undertaken in the remaining 10 cases (24 percent). In the extremities, 37 failures were treated conservatively (63 percent) in addition to 17 second free flaps (29 percent) and three regional flaps (5 percent) used to salvage the failed reconstruction. Two cases underwent amputation (3 percent). The average time elapsed between the failure and second free-tissue transfer was 12 days (range, 2 to 60 days) in the head and neck region and 18 days (range, 2 to 56 days) in the extremities. In a total of 34 second free-tissue transfers at both localizations, there were only three failures (9 percent). However, in the head and neck region, seven of the regional flaps transferred (47 percent) and four cases that were conservatively treated (40 percent) either failed or developed complications that lengthened the reconstruction period because of additional procedures. Six other free-tissue transfers had to be performed to manage these complicated cases. Conservative management was quite successful in the extremities; most patients' wounds healed, although more than one skin-graft procedure was required in 10 patients (27 percent). In conclusion, a second free-tissue transfer is, in general, a relatively more reliable and more effective procedure for the treatment of flap failure in the head and neck region, as well as failed vascularized bone flaps in the reconstruction of the extremities. Conservative treatment may be a simple and valid alternative to second (free) flaps for soft-tissue coverage in extremities with partial and even total losses.

Microsurgical tissue transplantation or replantation in patients with psychoneurological impairment

Sometimes patients with a psychoneurological impairment present with a traumatic injury that requires either microsurgical replantation or free-tissue transfer. We reviewed 38 patients undergoing 40 microvascular operations; the patients included 26 patients with psychological impairment (group 1), 3 with mental disability (group 2), and 9 with an acquired head injury and consciousness disturbance (Glasgow Coma Scale score < or =14) (group 3). Patients with a psychological impairment, especially those with a self-inflicted injury, are often uncooperative and do not recognize the necessity of restorative procedures. A multidisciplinary approach by the trauma surgeon, plastic surgeon, psychiatrist, and neurosurgeon, with coordinated assistance from the physician, nurse, therapist, and family, is required for treatment. In our study the success rate of replantation was 77.8 percent (14 of 18); for free tissue transfer the success rate was 95.5 percent (21 of 22). The overall success rate of microsurgical procedures (87.5 percent, 35 of 40) was similar to that in the population at large. Patients with psychological impairment tend to be lost during follow-up; therefore, their functional results may be poorer than expected. Nonetheless, patients with psychological impairment should not be deprived of the benefits of restorative surgery.

[Experimental study on bioglass application in extending alveolar bone crest in rabbit]

OBJECTIVE

To observe the effect of Bioglass guiding bone regeneration and forming normal new bone in extending alveolar bone crest by surgery.

METHODS

Thirty-six rabbits were randomly divided into three groups. The first group was treated with Bioglass and the second with hudroxyapectite (HA). The third group was control group. At 4 8 12 weeks after surgery, the condition of bone regeneration was observed with radiological and pathological methods.

RESULTS

Statistical analysis showed that there was a significant difference between the third group and the other two groups (P<0.05). In addition, Bioglass can guide bone regeneration faster than hydroxyapatite, and it can be substituted by new bone to form completely normal bone.

CONCLUSION

Since Bioglass is more effective than HA in guiding bone regeneration, it is an ideal bone graft substitute.

Debrisoquine 4-hydroxylase (CYP2D6) genetic polymorphisms and susceptibility to schizophrenia in Chinese patients from Taiwan

Debrisoquine 4-hydroxylase (CYP2D6) is one of the cytochrome P450 enzyme families that metabolize many compounds. Polymorphic activities of debrisoquine 4-hydroxylase were suggested to be associated with some complex diseases, such as cancer and Parkinson's disease. Schizophrenia is also a complex disorder, and hence we are interested in understanding if the CYP2D6 gene is a susceptibility gene for schizophrenia in Chinese. We determined the genotype and allele frequencies of four molecular variants of CYP2D6 gene (i.e. 188C/T, 1934G/A, 2938C/T and 4268C/G) in 162 Chinese schizophrenic patients and 94 non-psychotic control subjects from Taiwan. No significant differences of allele or genotype frequencies of three polymorphisms (i.e. 188T/C, 2938C/T and 4268C/G) were detected between patients and control subjects. The 1934A allele, which accounts for the majority of poor metabolizers in Caucasians, was not detected in either patients or control subjects, indicating that the 1934A allele is very rare in Chinese. Our data suggest that the CYP2D6 gene may not be a susceptibility gene for schizophrenia in Chinese schizophrenic patients.

Free vascularized bone grafts for reconstruction of traumatic bony defects of mandible and maxilla

Small bone defects of the mandible and maxilla can be surgically treated with conventional bone grafts provided local conditions are optimal for bone healing. However, when the bone defect is large, is associated with soft tissue loss, or when conventional bone grafting fails, a free vascularized bone graft often becomes an important alternative to ensure adequate healing. As free vascularized bone grafting is today considered a more reliable procedure for bone reconstruction, with success rates over 96%, we prefer to treat even smaller segmental bone defects with this technique when local conditions are less than ideal. The technique also allows for simultaneous insertion of osteointegrated dental implants at the time of vascularized bone grafting, thereby facilitating earlier total oral rehabilitation.

Upper eyelid mycobacterial infection following Oriental blepharoplasty in a pulmonary tuberculosis patient

Bilateral upper blepharoplasty for the Oriental eyelid was performed in a 20-year-old female on antituberculous therapy for 3 months. The postoperative course was smooth and the patient was back to normal life. But unfortunately, at 3 months after the upper blepharoplasty, a spherical tumescence and red granuloma developed over the right upper eyelid. The granuloma was resected, and on pathological examination the specimen revealed epitheloid granuloma with Langhan's giant cells and a few acid-fast positive bacilli. The clinical events and pathological findings were suggestive of Mycobacterium tuberculosis rather than Mycobacterium chelonei as the possible cause of infection. Thus the patient was advised to continue antituberculous therapy and no antibiotic was prescribed. The eyelid swelling resolved gradually and was completely normal at the end of antituberculous therapy. Though it has been suggested that aesthetic surgery can be performed safely 3 months after antituberculous therapy in a patient with pulmonary tuberculosis, the remote risk of such a complication is always a possibility.

Concomitant ipsilateral pedicled fibular transfer and free muscle flap for compound tibial defect reconstruction

Three patients with compound injuries of the lower extremities were treated with pedicle fibular grafts and a free muscle flap concomitantly. There were 1 female and 2 male patients, all of whom sustained high-energy trauma in a motor vehicle accident. The bone defect of the tibia ranged from 8 to 12 cm. The size of the soft-tissue defect ranged from 24 x 15 cm to 28 x 15 cm. All patients underwent preoperative angiography to ensure the patency of the peroneal artery and to avoid its use by risking viability of the leg. All patients were treated with an antegrade-flow pedicle fibular graft. The fibular graft was inserted as a single strut in 2 patients and as a double-barrel strut in 1 patient. The pedicle of the free muscle flap was anastomosed to the distal runoff of the fibular bone flap. All free muscle flap transfers succeeded without complication. Bone scans performed on postoperative day 7 showed viability of transferred bone. The average time to radiological union was 9 months, and the average time to full weight bearing was 12 months. Screw loosening occurred in 2 patients and osteomyelitis was noted in another patient who was treated successfully with sequestrectomy and antibiotics. Indications for this technique are a large segmental bone defect with a huge soft-tissue defect, and patency of the peroneal artery and at least one other major artery. This method provides the advantages of one-stage reconstruction, avoidance of contralateral donor site morbidity, easy control of infection, and chance for early weight bearing. When selected carefully, this technique can be considered when one wants to avoid a two-stage, two free flap transfer.

Bilateral small radial forearm flaps for the reconstruction of buccal mucosa after surgical release of submucosal fibrosis: a new, reliable approach

Oral submucous fibrosis is a collagen disorder affecting the submucosal layer and often severely limiting mouth opening. Previous surgical treatments have been disappointing. This article introduces a new surgical approach: reconstructing the bilateral buccal mucosa with two small radial forearm flaps. The surgical method includes the complete surgical release of fibrotic buccal mucosa and, if necessary, a bilateral coronoidectomy and temporalis muscle myotomy. From 1997 to 1999, 15 patients with moderate-to-severe trismus received reconstructive surgery, for a total of 30 small radial forearm flaps after surgical release. The flap size was between 1.5 x 5 and 2.5 x 7 cm. All donor sites were directly closed, and all flaps survived completely, except for one with partial necrosis. Six flaps required minor revisions because of size redundancy. Two patients developed buccal cancer in the area of reconstruction. At an average of 12 months' follow-up, the inter-incisal distance averaged 33 mm, an increase of 17 mm compared with the preoperative value. The donor-site morbidity was minimal, except in one heavy smoker who developed dry gangrene of his fingertips. The use of two small free forearm flaps for buccal mucosa reconstruction allows more radical release of fibrotic tissue. Coronoidectomy and temporal muscle myotomy further contribute to the effect of trismus release. The combined effects of this approach have consistently given good results. An aggressive approach toward surgical treatment of this precancerous lesion also facilitates the detection of cancer at an early stage.

Free anterolateral thigh flap for extremity reconstruction: clinical experience and functional assessment of donor site

From August of 1995 through July of 1998, 38 free anterolateral thigh flaps were transferred to reconstruct soft-tissue defects. The overall success rate was 97 percent. Among 38 anterolateral thigh flaps, four were elevated as cutaneous flaps based on the septocutaneous perforators. The other 34 were harvested as myocutaneous flaps including a cuff of vastus lateralis muscle (15 to 40 cm3), either because of bulk requirements (33 cases) or because of the absence of a septocutaneous perforator (one case). However, vastus lateralis muscle is the largest compartment of the quadriceps, which is the prime extensor of the knee. Losing a portion of the vastus lateralis muscle may affect knee stability. Objective functional assessments of the donor sites were performed at least 6 months postoperatively in 20 patients who had a cuff of vastus lateralis muscle incorporated as part of the myocutaneous flap; assessments were made using a kinetic communicator machine. The isometric power test of the ratios of quadriceps muscle at 30 and 60 degrees of flexion between donor and normal thighs revealed no significant difference (p > 0.05). The isokinetic peak torque ratio of the quadriceps and hamstring muscles, including concentric and eccentric contraction tests, showed no significant difference (p > 0.05), except the concentric contraction test of the quadriceps muscle, which revealed mild weakness of the donor thigh (p < 0.05). In summary, the functional impairment of the donor thighs was minimal after free anterolateral thigh myocutaneous flap transfer.

Microsurgical reconstruction of the buccal mucosa

This article addresses the reconstruction of the buccal mucosa, which is necessary after tumor resection and contracture release.

Mandibular reconstruction with fibula osteoseptocutaneous free flap and osseointegrated dental implants

The fibula osteoseptocutaneous free flap is ideal for reconstruction of composite mandible defects. Osseointegration is possible and advantageous. Primary osseointegration of dental implants is a safe and reliable procedure in selected groups of patients, promoting early total oral rehabilitation with restoration of both function and cosmesis. Further studies are necessary to assess the specific indications for osseointegration teeth in patients with malignant tumors and in those patients who have received radiation therapy.

Double-coping technique in prosthesis fabrication for osseointegrated teeth implantation: case report

Reconstruction of segmental mandibular defects resulting from trauma, infection, or tumor resection still remains difficult. Although cosmetic improvement was seen in patients who had immediate reconstruction of the mandibular continuity, normal mastication and deglutition could not be achieved by conventional removable dentures. Since 1988, the treatment protocol has been modified to use endosseous root-form implants to support dental prostheses instead of the conventional removable prostheses in these patients. There are 2 types of prostheses that can be constructed over dental implants: (1) a removable implant overdenture and (2) a fixed detachable prosthesis. Although the latter better meets in patients' psychological needs, it may present problems such as phonetic discrepancies, food impaction, difficult home care, and poor esthetics if the patient has a high lip line. In addition, it is not easy to fabricate accurately in the laboratory. To overcome these problems, a case is presented to illustrate the use of another fixed-type prosthesis, a double-coping technique, for fabricating dentures so that any discrepancy between the inner and outer copings can be filled by cement. The technique not only improves the shortcomings of fixed detachable prostheses but also satisfactorily meets patients' desire for normal mastication and deglutition. Follow-up after 4 years showed no significant changes around the implants by clinical and radiographic examinations.

Interposition of a pedicle fat flap significantly improves specificity of reinnervation and motor recovery after repair of transected nerves in adjacency in rats

Despite highest standards in nerve repair, functional recovery following nerve transection still remains unsatisfactory. Nonspecific reinnervation of target organs caused by misdirected axonal growth at the repair site is regarded as one reason for a poor functional outcome. This study was conducted to establish a method for preventing aberrant reinnervation between transected and repaired nerves in adjacency. Rat sciatic nerve was transected and repaired as follows: epineural sutures of the sciatic nerve (group A, n = 6), fascicular repair of tibial and peroneal nerves respectively (group B, n = 8), and, as in group B, separating both nerves using a pedicle fat flap as barrier (group C, n = 8). As control only, the tibial nerve was transected and repaired (group D, n = 5). Muscle contraction force of the gastrocnemius muscle was significantly higher in group C as compared with groups A and B after 4 months. Muscle weight showed significantly lower values in group A as compared with groups B, C, and D. Histologic examination in group C revealed little growth of axons from the tibial to the peroneal nerve and vice versa. This axon crossing was observed only when gaps between the fat cells were available. These findings were confirmed by a significantly lower rate of misdirected axonal growth as compared with groups A and B using sequential retrograde double labeling technique of the soleus motoneuron pool. We conclude that a pedicle fat flap significantly prevents aberrant reinnervation between repaired adjacent nerves resulting in significantly improved motor recovery in rats. Clinically, this is of importance for brachial plexus, sciatic nerve, and facial nerve repair.

Mimicking lip features in free-flap reconstruction of lip defects

This paper introduces a technique of lip reconstruction using free flaps in which recognisable landmarks are mimicked by strategic placement of flap junctions. The technique was applied in 15 patients undergoing reconstruction of combined cheek and lip defects using single (n= 9) or double (n= 6) free flaps. Attention to flap design and strategic placement of flap junctions successfully created the vermilion-cutaneous junction, oral commissure and labiomental groove. The presence of these distinguishing features improved the appearance of the reconstructed lip.

Lateral-dorsal neurovascular island flaps for pulp reconstruction

Finger pulp loss is often observed in daily practice. When the lateral and dorsal surfaces of the injured digit remain intact, a neurovascular island flap can be designed and raised from that part of the finger for pulp reconstruction. Two types of homodigital lateral-dorsal neurovascular island flaps were used in 17 patients (13 type I and 4 type II) for reconstruction of traumatic pulp loss on an emergent basis. The type I flap was used for the pulp defect less than 2.5 cm in length; the type II flap was designed for extensive pulp loss. The size of the pulp defect varied from 1.7 x 1.2 cm to 3.8 x 1.7 cm. All flaps survived completely without any partial loss. The mean follow-up was 17.7 months. The mean static two-point discrimination was 5.2 mm in type I flaps and 9.3 mm in type II flaps. All patients except five had full range of motion of the interphalangeal joint. These five patients (3 type I and 2 type II) had 10 to 20 deg reduction in flexion of the distal interphalangeal joints. The homodigital lateral-dorsal neurovascular island flap offers a durable, well-vascularized, sensate skin flap for one-stage pulp reconstruction in select patients. This technique is relatively simple, allows early postoperative mobilization, and has an acceptable surgical outcome.

Role of the target in end-to-side neurorrhaphy: reinnervation of a single muscle vs. multiple muscles

The authors examined the effects of end-to-side neurorrhaphy for reinnervation of the musculocutaneous nerve (Group A) which innervates the biceps muscle, compared to reinnervation of the median nerve which innervates multiple muscles in a rat model. Additionally, end-to-end neurorrhaphy to the musculocutaneous nerve using one-third of the median nerve (Group B) was investigated. End-to-end coaptation of the musculocutaneous nerve served as a control (Group C). In a grooming test, the biceps muscle function in Group A animals demonstrated a slower but nearly similar good recovery to Groups B and C. Biceps muscle contraction force investigated after 24 weeks demonstrated no statistically significant differences among all groups. In Groups A and B, no significant impairment of the donor median nerve function was found in a grasping test and the muscle contraction force of the flexor carpi radialis muscle, and histologic evaluation of the musculocutaneous nerve showed multiple regenerated axons distal to the coaptation site. Retrograde double-labeling in Group A animals showed reinnervation of the musculocutaneous nerve by median nerve axons located at the coaptation site. These results validate that end-to-side neurorrhaphy to a nerve innervating a single muscle is more efficient than to a nerve innervating multiple muscles, as demonstrated in an earlier study. The reason for this phenomenon is most likely that all sprouting axons are directed toward one target rather than toward multiple targets, with the latter situation resulting in a smaller number of axons and a variable distribution of axons per target. Since donor nerve sprouting axons were observed at the coaptation site, a relevance of the selected site for end-to-side neurorrhaphy is suggested. Both end-to-side neurorrhaphy and end-to-end neurorrhaphy, using one-third of the median nerve, led to useful functional recovery in this rat model, if an agonistic donor nerve is employed.

Nerve transfer to the median nerve using parts of the ulnar and radial nerves in the rabbit--effects on motor recovery of the median nerve and donor nerve morbidity

In this study, motor re-innervation of the median nerve by transfer of one-third, one-half, and two-thirds of either the agonistic ulnar nerve or the antagonistic radial nerve was investigated in both extremities of 20 rabbits. Recipient median nerve: Muscle contraction force of the flexor digitorum sublimus muscle after a one-third and a one-half of the ulnar nerve transfer achieved an average of 75 and 97% muscle power respectively as compared to conventional end-to-end neurorrhaphy. Muscle contraction force after one-third or one-half of the radial nerve transfer was significantly lower (36%). Donor nerves: Extensor carpi radialis muscle or flexor carpi ulnaris muscle contraction force 6 months postoperatively demonstrated a significant decrease after a one-half ulnar nerve and a two-thirds ulnar or radial nerve transfer, but not after a one-third transfer of either radial or ulnar nerves. Histologically, the number of axons in the re-innervated median nerve and both donor nerves distal to the coaptation site seemed to follow variable patterns. It was concluded that in the rabbit use of one-third of the agonistic ulnar nerve for re-innervation of the median nerve results in useful motor recovery with negligible donor site morbidity. Clinically, this technique may offer an alternative option for proximal nerve injuries or for free functioning muscle transplantations.

Microcirculatory changes following reperfusion insult in diabetic rat skeletal muscles

We investigated the microcirculatory changes of ischemia/reperfusion injury in the diabetic rat cremaster muscle as well as the therapeutic effect of insulin. Streptozotocin-induced diabetic rats were maintained hyperglycemic for up to 8 weeks or were treated with insulin in the diabetic period. The rat cremaster muscle was prepared as an island flap and subjected to 2-h clamp ischemia followed by 1-h reperfusion. In nonischemic conditions, effective concentrations for 50% response (EC50) of serial orders of arterioles to norepinephrine were higher in diabetic muscles. Ischemia/reperfusion insult significantly decreased the EC50 of arterioles in the normal group, but not in the diabetic group. Light microscopy showed that the diabetic cremasters had more collapsed capillaries and smooth muscle-disarranged arterioles. Insulin therapy showed significant improvement in the diabetes-caused reduction of perfused capillary density, but not in the contractility of the diabetic arterioles. These results indicate that diabetes mellitus may damage the skeletal muscle microvasculature irreversibly and make it less responsive to autonomic regulation. Insulin therapy can improve capillary perfusion, but not the microvascular reactivity of diabetic muscles.

Free flaps for reconstruction of the lower back and sacral area

Free flap reconstruction of the lower back and sacrum is complicated by a paucity of recipient vessels and difficulties in postoperative care. From 1983 to 1997, six patients with intractable wounds of the lower back and sacral area were treated with free flaps. The flaps used were latissimus dorsi (three), combined latissimus dorsi and serratus anterior (one), and filleted leg tissue (two). The recipient vessels were the deep femoral vessels, the perforator vessels of the deep femoral system, the inferior epigastric vessels, and the superior gluteal and inferior gluteal vessels. The patients were observed in the intensive care unit for 1 week and kept in prone position for 4 weeks. All flaps survived and wounds healed primarily. For large or multiple defects of the lower back and sacrum, free tissue transfer is effective in achieving primary healing, particularly when local flaps are inadequate or have failed.

An outcome study of thumb reconstruction using microvascular toe transfer

The purpose of this study was to evaluate outcomes following microvascular toe to thumb transfer in a cohort study using the Michigan Hand Outcomes Questionnaire, the 36-item Short-Form Health Survey, the Lower Limb Function Questionnaire, and standardized hand function tests. Twenty-one patients who had unilateral, isolated thumb amputations at the metacarpophalangeal joints were studied: 16 patients had toe transfer and 5 patients did not have reconstruction. The mean follow-up period was 7.2 years (range, 3-13 years). Toe transfer patients showed statistically significantly better overall hand function (effect size = 1.4), ADL (effect size = 3.4), work performance (effect size = 2.1), aesthetics (effect size = 1.9), and satisfaction (effect size = 1.1). Functional testing showed that strength and dexterity of the toe transfer hands were comparable to the opposite normal hands. Foot donor site morbidity was minimal. No significant difference was found in the mean Lower Limb Function Questionnaire scores between the toe transfer patients (1.4) and the amputation patients who did not undergo reconstruction (1.6). The results of our study showed that patients with toe transfer have better hand function than patients with thumb amputations at the level of the metacarpophalangeal joints.

Comparison of skeletal muscle microcirculation between clamp ischemia and microsurgical ischemia

We compared ischemia reperfusion injury-associated vasospasm and perfused capillary density (PCD) at the microcirculatory level between clamp ischemia and microsurgical ischemia in rat skeletal muscle. Rat cremaster muscle was prepared as an island flap, attached only with pudic-epigastric vessels branching from external iliac vessels. Two types of ischemia, with clamping only or with microvascular anastomosis, were applied at the external iliac vessels for 2 hours followed by 1-hour reperfusion before in vivo microscopic examination for hemodynamic changes. At the end of observation, small segments of the vessels at the clamping site and microsurgical anastomoses site were also harvested for histological examination. It was found that the first- and second-order arterioles had about 12-15% diameter reductions in both groups, whereas diameter reductions of the third-order arterioles were up to 37.8% in the microsurgical ischemia group, much greater than that in the clamp ischemia group (2.3%). There was also no significant difference in PCD reduction between the two groups, although the red blood cell velocity was much slower in the microsurgical ischemia group. Histological examination of the anastomosis site showed massive accumulation of polymorphonuclear neutrophils on the venous endothelium. These results suggested a different degree of endothelial damage and local leukocyte activation between microsurgical ischemia and clamp ischemia. Therefore, we conclude that clamp ischemia cannot replace microsurgical ischemia for studying microcirculatory changes in free tissue transfer.

Limiting donor site morbidity by suprafascial dissection of the radial forearm flap

A technique of suprafascial flap elevation to prevent donor site problems is described, based on careful intraoperative observation of the anatomical relations of all involved structures in a series of over 400 free forearm flaps used in various reconstructive procedures.

Sensory recovery and Meissner corpuscle number after toe-to-hand transplantation

This study investigated the possible relationship between sensory recovery and receptor number after toe-to-hand transplantation. Moving two-point discrimination was measured after a course of sensory re-education. Meissner corpuscle number was then quantified by light microscopic examination of multiple sections of glabrous skin obtained at pulp reduction and from site-matched normal toe and fingertip skin. Meissner corpuscle number per millimeter was 0.94 in normal toe skin (n = 4), and 0.37 after toe-to-hand transplantation (n = 34). A significant correlation existed between moving two-point discrimination and Meissner corpuscle number (r = -0.62; p < 0.001). No significant relationship was found between moving two-point discrimination and patient age or interval from injury to reconstruction. The results suggest that despite sensory re-education, there may be a level of receptor reinnervation below which good sensory recovery may not be obtained.

Indications and limitations of angiography before free-flap transplantation to the distal lower leg after trauma: prospective study in 36 patients

The necessity for routine angiography in evaluation of the vasculature of recipient legs prior to microsurgical free-tissue reconstruction still remains controversial. This prospective study was designed to determine the indications and limitations of angiography pertinent to this issue. The protocol consisted of palpation of dorsalis pedis and posterior tibial artery pulsation and lower-limb angiography prior to surgery, as well as intraoperative observation of the posterior tibial, anterior tibial, and peroneal arteries. Thirty-six patients were included who were treated from November, 1993 to December 1998. In five patients either the posterior tibial pulse (1), the dorsalis pedis pulse (3), or both pedal pulses, including the popliteal pulse (1) were not palpable preoperatively. These clinical findings correlated with the vascular lesion images on angiography. In two patients, pedal pulse palpation could not clearly be evaluated because of the injury. Among the 29 patients with both pedal pulses palpable, three patients angiographically presented an injury of the peroneal artery, and one patient a pseudoaneurysm of the anterior tibial artery. In none of the cases with at least one palpable pedal pulse (33), did preoperative angiography add relevant information which led to a plan change in the free-flap transfer. However, in two cases, severe scarring and fibrosis required an intraoperative change of the recipient vessel in one case, and a change of the anastomosis level and use of a vein graft, in the other case, although the angiography had demonstrated normal vascularity in both. The authors conclude that preoperative angiography is indicated only when both pedal pulses are not palpable, and that normal preoperative angiography does not guarantee the presence of vessels suitable for anastomosis.

Filleted toe flap for chronic forefoot ulcer reconstruction

Chronic plantar and dorsal forefoot ulcer may result from injury, structural deformity, and abnormal sensation or circulation. It is not uncommon that the distal portion of the affected toes is deficient functionally in these patients. A filleted toe flap from the expendable functionless toe can provide a durable, stable, and sensate skin flap of 4 to 5.5 cm for coverage of the forefoot defect. In this report, five cases of dorsal forefoot defects and four cases of plantar forefoot defects due to ischemia (N = 3), trophic change (N = 2), and diabetes (N = 4) were treated with filleted toe flaps. One flap failed due to postoperative deep infection. The other eight filleted toe flaps survived but 2 patients underwent secondary amputations 7 months and 2 two years later because of secondary diabetic foot infections.

Devices for ischemic preconditioning of the pedicled groin flap

BACKGROUND

Early division of the pedicled groin flap can be achieved by using ischemic preconditioning. The goal of this study was to investigate the devices available for ischemic preconditioning and determine which device is the most effective and results in lowest patient discomfort.

METHODS

Rubber bands, custom-made Orthoplast sheets, long-nose locking pliers, intestinal clamps, and a pneumatic tourniquet device were used for ischemic preconditioning on 13 patients who sustained severe hand injuries with reconstruction of pedicled groin flaps. The devices were compared by using laser Doppler flowmetry and the patient's local pain levels.

RESULTS

Twelve of 13 flaps were successfully divided at a mean period of 8.3 days by using a custom-made Orthoplast sheet or a pneumatic tourniquet device. All devices except the rubber bands could result in a biologic zero flow level.

CONCLUSION

The pneumatic tourniquet device is the most desirable ischemic preconditioning device, having the advantages of excellent ischemic effect, easy application, and minimal discomfort.

Selection of donor nerves--an important factor in end-to-side neurorrhaphy

We have examined the effects of end-to-side neurorrhaphy on peripheral nerve regeneration using the median nerve as recipient nerve and either the antagonistic radial nerve or the agonistic ulnar nerve as donor nerves in rat upper limbs. A perineural window was created in all cases. Motor recovery up to 16 weeks postoperation was tested with the grasping test. No recovery of motor function was evident after end-to-side neurorrhaphy of the median nerve to the antagonistic radial nerve, whereas six of eight rats with end-to-side neurorrhaphy to the agonistic ulnar nerve achieved 367 g +/- 47 g grasping power as compared to 526 g +/- 6 g in end-to-end coapted control animals. No significant difference in flexor digitorum sublimus-motor nerve conduction velocity was found among all three groups. Radial nerve stimulation produced simultaneous contraction of both extensor and flexor muscles of the lower arm that disabled any coordinated movement of the paw. Histology (toluidine blue, acetylcholinesterase-stain) showed multiple regenerated (motor)-axons distal to the coaptation site in the median nerve. Reinnervation of the median nerve solely by the respective donor nerve was demonstrated by a retrograde double labelling technique. These results show that averaged 70% muscle power as compared to end-to-end neurorrhaphy with well coordinated muscle function can be achieved by axonal sprouting through end-to-side neurorrhaphy if an agonistic nerve is used as donor nerve. However, satisfying results are unpredictable. Antagonistic nerves show the ability to induce axonal regeneration, but no useful function can be expected.

Immediate Camitz opponensplasty in acute thenar muscle injury

Thenar function impairment or destruction is not uncommon in hand crush injury or thumb avulsion injury. Although complete evaluation of thenar muscle function is difficult during an emergency setting because of skeletal instability and pain, if left untreated the injured hand may result in deficiency of opposition and may require secondary reconstruction. When the palmaris longus tendon is available from the open wound, a Camitz opponensplasty can be performed in the emergency operation setting even as an augmentation procedure for opposition if there is any suspicion of thenar muscle impairment. Seven patients with such injuries who underwent immediate Camitz opponensplasty were assessed to have an 80% angle of separation, a 90% angle of circumduction, and an 88% Kapandji test of the normal opposite hand. An emergency Camitz procedure provided a reliable, immediate one-stage reconstruction of thenar function.

Widely split latissimus dorsi muscle flaps for reconstruction of long soft-tissue defects in lower extremities

Although the latissimus dorsi is one of the largest and longest muscles in the human body, it is still sometimes inadequate for reconstruction of a soft-tissue defect of extensive length and dimension. Eight patients with such lower limb defects were treated with latissimus dorsi muscles split into two hemiflaps sequentially linked, one after the other like a chain. Six transfers were completely successful, one required reexploration for arterial occlusion, and two hemiflaps had a partial loss that could be managed by touching up the skin graft. The average split sequential-link muscle was 42 cm in length. Although two patients had a partial loss, we consider that the widely split single latissimus dorsi muscle can still be used reliably to reconstruct a long slender defect, or two separate, longitudinally located, medium-sized defects in the same leg.

Conventional versus endoscopic free gracilis muscle harvest

Compared with conventional techniques, the endoscopically assisted harvest of free tissue has advantages such as minimal interference with cosmesis and reduced donor-site morbidity. However, the procedure also requires training and has an extensive learning period. In this series of 22 patients, the initial gracilis muscle flaps were harvested using a conventional method; the subsequent flaps were harvested with the aid of endoscopic instrumentation. Endoscopically assisted gracilis muscle harvest in 16 patients was compared with open method harvest in six patients. The endoscopically assisted group had an average incision length of 6.5 cm; that of the conventional group was 15.5 cm. There was one reexploration in the endoscopically assisted group, but all flaps were transferred successfully. Using this minimally invasive technique of vascular and muscular dissection, assisted by endoscopic instruments designed for distal muscle dissection and transection, the gracilis muscles can be harvested within 40 minutes. We consider endoscopically assisted harvest of free gracilis muscle to be safe, relatively simple, and cost-effective.

Free colon transfer for pharyngo-oesophageal reconstruction

This report describes free transfer of transverse colon for reconstruction of the hypopharynx and cervical oesophagus. The transverse colon based on the middle colic vessels was used in three patients following laryngo-pharyngo-oesophagectomy for hypopharyngeal squamous carcinoma. There were no flap failures or intra-abdominal complications. Solid diet was well tolerated. Transverse colon is easy to harvest, has a long vascular pedicle, wide diameter and good ischaemic tolerance. Contrast studies showed it to be a wide bore passive conduit. Compared with currently available options these features may allow better outcome in pharyngo-oesophageal reconstruction and warrant further evaluation.

The versatile anterolateral thigh flap: a musculocutaneous flap in disguise in head and neck reconstruction

In search of an alternative soft tissue free flap donor site to radial forearm flap and rectus abdominis flap in head and neck reconstruction, we used the anterolateral thigh flap for reconstruction of various defects in the head and neck in 59 patients. The aim was to demonstrate the versatility of this donor site and propose a new approach to achieve a safer flap dissection. With the exception of three cases, all defects resulted from excision of malignant tumours. The defects were categorised as full thickness defects of the mandible (33.9%), full thickness defects of the cheek (52.5%) and others (13.6%). During the flap dissection a direct septocutaneous pedicle was observed in 12% of the cases. In the remaining cases there were only musculocutaneous perforators and the flaps were raised either as a split vastus lateralis musculocutaneous flap (72%) or as a perforator flap (16%), depending on the required thickness. Total flap survival was 96.7% with one total and one partial failure and two re-explorations (3.3%). The mean follow-up time was 7.1 months (range: 1-12 months). In conclusion, the anterolateral thigh flap is a versatile and dependable flap that can be adapted to any type of defect by modifying the flap design and composition. It should be considered to be a musculocutaneous flap of the vastus lateralis muscle that can also be raised as a perforator flap. When harvested and used in this context, the flap dissection becomes very safe and consistent, nullifying the only major disadvantage associated with this donor site.

Microsurgical combined scapular/parascapular flap for reconstruction of severe neck contracture: case report and literature review

OBJECTIVE

The reconstruction for severe neck contracture is difficult, because it may include not only the necessity the use of a large flap but also the ability for three-dimensional movement of the neck.

METHODS

A 41-year-old woman sustained a severe neck contracture with retraction of the lower lip and limited range of neck motion after a chemical burn. We used the combined scapular/parascapular flap to reconstruct the soft-tissue defect in the neck after excision of hypertrophic scar and release of contracture. The scapular portion was transferred to cover the defect vertically, and the parascapular portion was transferred to cover the transverse portion of the neck. This kind of design would allow the patient to move her neck more easily.

RESULTS

Postoperatively, the range of motion of the neck was full in the vertical and horizontal directions after 6 months of rehabilitation. Also, the patient was satisfied with the final aesthetic results.

CONCLUSION

The microsurgical combined scapular/parascapular flap, providing a large area of tissue for coverage in three dimensions with a reliable blood supply by only one pedicle anastomosis during surgery, is a good option for reconstruction of the severe neck contracture. We classify the inset of the combined scapular/parascapular flap into three types with six subtypes, according to the location of defects and the relation of the parascapular flap to the scapular flap.

Effects of Systemically Applied IGF-1 on Motor Nerve Recovery After Peripheral Nerve Transection and Repair in the Rat - A Functional Study

The trophic effects of systemically applied Rh insulin-like growth factor-1 (rhIGF-1) on peripheral motor nerve regeneration following transection and epineural repair in rats median nerve have been examined. RhIGF-1 (0.5 mg/kg/rat) was administered subcutaneously to the neck region of the repaired side for 14 days post-operation. Motor recovery was tested with the grasping test that is an objective quantitative behavioural assessment of regeneration of the rats median nerve. Muscle twitch tension and muscle weight were measured in the flexor digitorum sublimus muscle. No significant differences between experimental and control animals regarding onset of muscle function, recovery of muscle power, and muscle weight were found. These results demonstrate that subcutaneously applied rhIGF-1 cannot improve functional motor recovery after nerve transection and repair in the rat as has been demonstrated after nerve crushing injury. This is regarded as a consequence of specificity failure during reinnervation, which occurs after nerve transection and repair, whereas after crushing injury specific reinnervation is a common feature.

Prefabrication of jejunum for challenging reconstruction of cervical esophagus

A significant benefit exists for a jejunal replacement of the cervical esophagus, if indicated. The absence of available recipient vessels may impede free tissue transfer. If vascular induction between a vascular carrier and the selected jejunal segment is done as a kind of flap prefabrication, the jejunal interposition flap can be used without the need for complex microsurgery.

Effects of insulin-like growth factor-1 in motor nerve regeneration after nerve transection and repair vs. nerve crushing injury in the rat

Despite highest standards in nerve repair, functional recovery following nerve transection still remains unsatisfactory. Non-specific re-innervation of target organs are regarded as one reason for a poor functional outcome. Insulin-like growth factor-1 (IGF-1) has demonstrated promoting effects on sciatic nerve regeneration after crushing injury. Similarly, IGF-1 has shown a direct inductive effect on motoneuron growth associated protein-43 (GAP-43) which is believed to play a role in axon guidance during development. Based on this fact we have examined the trophic effects of recombinant human IGF-1 on peripheral motor nerve regeneration following transection and epineural repair in rats median nerve. RhIGF-1 (0.5 mg/kg/rat) was administered subcutaneously to the neck of the repaired side for 14 days postoperation. Accuracy of re-innervation of the flexor carpi radialis muscle motoneuron pool was studied by sequential retrograde double labelling technique. Motor recovery was tested with the grasping test. No significant differences between experimental and control animals in accuracy of re-innervation and in recovery of muscle power could be demonstrated. Non-specific re-innervation of the flexor carpi radialis muscle was found in 23.2% in the experimental group and in 24.2% in the control group. These results demonstrate that systemically applied rhIGF-1 failed to improve functional motor recovery after nerve transection and repair in the rat as it was demonstrated after nerve crushing injury in several studies. Furthermore, systemically applied IGF-1 did not improve accuracy of re-innervation after axotomy and repair in adult rats.

Reconstruction of bilateral metacarpal hands with multiple-toe transplantations

Bilateral metacarpal hands, if not treated properly, leave a patient without prehensile ability in both hands. Since 1990, six patients with bilateral metacarpal hands caused by accidents have undergone reconstruction with multiple-toe transplantations. Four or five toes were used for each patient, with a total of 27 toes transplanted to the hands. There was no toe loss. One nonunion in a middle-finger reconstruction was treated successfully with bone grafting. Secondary operations for functional improvement included one joint fusion and one flexor tendon tenolysis. Only one patient required excision of a plantar callus 42 months postoperatively, whereas the other five patients reported no major donor-site problems in an average 57 months of follow-up time. The six patients continue all their daily activities independently. Although their jobs were changed, all adult male patients were able to return to regular work. Principles of reconstruction to achieve satisfying prehensile function combined with minor donor-site morbidity in bilateral metacarpal hands include an adequate soft-tissue coverage before toe transplantations, selection of digits to be reconstructed based on functional and individual requirements, selection of toes and number of toes to be harvested based on consideration of usefulness for the hands and of foot morbidity, and consideration of thenar function in planning the sequence of transplantations. In conclusion, given thorough planning, multiple toe-to-hand transplantations can provide adequate prehensile function in reconstructed bilateral metacarpal hands with acceptable donor-site morbidity.

Strategies in multiple toe transplantation for bilateral type II metacarpal hand reconstruction

Multiple toe transplantation has been established as an effective means of restoring prehensile function in the metacarpal hand. The attainable outcome, however, must be weighed against potential donor site morbidity. Restoration of prehensile function in bilateral type II metacarpal hands can be achieved by reconstructing three opposable digits in the dominant hand and two opposable digits in the nondominant hand. This article outlines the strategy for optimizing functional outcome and discusses the rationale behind toe selection to reduce donor morbidity.

Salvage of the distal foot using the distally based sural island flap

The authors describe their additional experience with the distally based sural island flap for reconstruction of the whole foot, including the forefoot area in 8 patients. The flap is vascularized by the lowermost perforating branches of the peroneal artery. The skin flap can be elevated, based on the lesser saphenous vein and its accompanying arteries, in all parts of the sural region. This modification allows a farther reach of the flap for coverage of the distal foot and sole. All flaps, innervated by the lateral sural cutaneous nerves, were able to provide protective sensation in the distal soles. In 7 patients the flaps survived completely, and only 1 patient had partial necrosis of the flap. The advantage of this flap is its constant and reliable blood supply without sacrifice of the major artery. Elevation of the flap is simple and rapid. This flap is a versatile alternative that should be considered prior to a free flap transfer.