Surgically Implanted Electrodes Enable Real-Time Finger and Grasp Pattern Recognition for Prosthetic Hands.

Currently available prosthetic hands are capable of actuating anywhere from five to 30 degrees of freedom (DOF). However, grasp control of these devices remains unintuitive and cumbersome. To address this issue, we propose directly extracting finger commands from the neuromuscular system via electrodes implanted in residual innervated muscles and regenerative peripheral nerve interfaces (RPNIs). Two persons with transradial amputations had RPNIs created by suturing autologous free muscle grafts to their transected median, ulnar, and dorsal radial sensory nerves. Bipolar electrodes were surgically implanted into their ulnar and median RPNIs and into their residual innervated muscles. The implanted electrodes recorded local electromyography (EMG) with Signal-to-Noise Ratios ranging from 23 to 350 measured across various movements. In a series of single-day experiments, participants used a high speed pattern recognition system to control a virtual prosthetic hand in real-time. Both participants were able to transition between 10 pseudo-randomly cued individual finger and wrist postures in the virtual environment with an average online accuracy of 86.5% and latency of 255 ms. When the set was reduced to five grasp postures, average metrics improved to 97.9% online accuracy and 135 ms latency. Virtual task performance remained stable across untrained static arm positions while supporting the weight of the prosthesis. Participants also used the high speed classifier to switch between robotic prosthetic grips and complete a functional performance assessment. These results demonstrate that pattern recognition systems can use the high-quality EMG afforded by intramuscular electrodes and RPNIs to provide users with fast and accurate grasp control. SUMMARY: Surgically implanted electrodes recorded finger-specific electromyography enabling reliable finger and grasp control of an upper limb prosthesis.

Chronic recording of hand prosthesis control signals via a regenerative peripheral nerve interface in a rhesus macaque.

OBJECTIVE: Loss of even part of the upper limb is a devastating injury. In order to fully restore natural function when lacking sufficient residual musculature, it is necessary to record directly from peripheral nerves. However, current approaches must make trade-offs between signal quality and longevity which limit their clinical potential. To address this issue, we have developed the regenerative peripheral nerve interface (RPNI) and tested its use in non-human primates. APPROACH: The RPNI consists of a small, autologous partial muscle graft reinnervated by a transected peripheral nerve branch. After reinnervation, the graft acts as a bioamplifier for descending motor commands in the nerve, enabling long-term recording of high signal-to-noise ratio (SNR), functionally-specific electromyographic (EMG) signals. We implanted nine RPNIs on separate branches of the median and radial nerves in two rhesus macaques who were trained to perform cued finger movements. MAIN RESULTS: No adverse events were noted in either monkey, and we recorded normal EMG with high SNR (>8) from the RPNIs for up to 20 months post-implantation. Using RPNI signals recorded during the behavioral task, we were able to classify each monkey's finger movements as flexion, extension, or rest with >96% accuracy. RPNI signals also enabled functional prosthetic control, allowing the monkeys to perform the same behavioral task equally well with either physical finger movements or RPNI-based movement classifications. SIGNIFICANCE: The RPNI signal strength, stability, and longevity demonstrated here represents a promising method for controlling advanced prosthetic limbs and fully restoring natural movement.

Conduction Properties Of Decellularized Nerve Biomaterials.

The purpose of this study is to optimize poly(3,4,-ethylenedioxythiophene) (PEDOT) polymerization into decellular nerve scaffolding for interfacing to peripheral nerves. Our ultimate aim is to permanently implant highly conductive peripheral nerve interfaces between amputee, stump, nerve fascicles and prosthetic electronics. Decellular nerve (DN) scaffolds are an FDA approved biomaterial (Axogen ) with the flexible tensile properties needed for successful permanent coaptation to peripheral nerves. Biocompatible, electroconductive, PEDOT facilitates electrical conduction through PEDOT coated acellular muscle. New electrochemical methods were used to polymerize various PEDOT concentrations into DN scaffolds without the need for a final dehydration step. DN scaffolds were then tested for electrical impedance and charge density. PEDOT coated DN scaffold materials were also implanted as 15-20mm peripheral nerve grafts. Measurement of in-situ nerve conduction immediately followed grafting. DN showed significant improvements in impedance for dehydrated and hydrated, DN, polymerized with moderate and low PEDOT concentrations when they were compared with DN alone (a ≤ 0.05). These measurements were equivalent to those for DN with maximal PEDOT concentrations. In-situ, nerve conduction measurements demonstrated that DN alone is a poor electro-conductor while the addition of PEDOT allows DN scaffold grafts to compare favorably with the "gold standard", autograft (Table 1). Surgical handling characteristics for conductive hydrated PEDOT DN scaffolds were rated 3 (pliable) while the dehydrated models were rated 1 (very stiff) when compared with autograft ratings of 4 (normal). Low concentrations of PEDOT on DN scaffolds provided significant increases in electro active properties which were comparable to the densest PEDOT coatings. DN pliability was closely maintained by continued hydration during PEDOT electrochemical polymerization without compromising electroconductivity.

Terminolateral neurorrhaphy: a review of the literature.

Terminolateral neurorrhaphy (TLN) is an experimental technique for repairing peripheral nerves, when the proximal cut nerve stump is not available for traditional end-to-end repair. Over the past 7 years, the efficacy of TLN, its ability to preserve donor nerve function, the necessity of disrupting donor nerve connective tissue layers during the procedure, the mechanism by which TLN affords reinnervation, and the definition of the procedure, have been debated. In this critical review of TLN literature, the authors attempt to demonstrate 1) that a TLN in which the surgeon deliberately transects donor nerve axons is an effective method for peripheral nerve repair; the mechanisms by which axons innervate target muscles following this procedure are well-defined, and there is adequate experimental and clinical evidence to support its clinical application; and 2) that a TLN procedure in which the surgeon attempts to leave the donor nerve intact is neither mechanistically distinct from a TLN with deliberate donor nerve axotomy, nor is it as efficacious. Future studies should assess the degree of donor nerve transection that will maximize reinnervation via the TLN graft, without incurring functionally significant donor nerve deficits.

Endoscopically assisted pectus excavatum repair.

We present an endoscopic approach for the reconstruction of pectus excavatum with a custom silicone implant. The procedure incorporates endoscopic techniques to facilitate dissection of an extensive subcutaneous pocket through a 6-cm Chevron skin incision 8 cm below the level of the xiphoid. The incision is designed based on the size, shape, and flexibility of the custom implant and the configuration of the chest wall deformity. A superiorly based rectus abdominis anterior fascial sheath flap then is elevated up to the caudal-most margin of the implant, creating a sling below the implant, thus stabilizing its position and preventing direct communication with the overlying skin incision. In our patient, the endoscope permitted insertion of the custom implant while minimizing the length of incision. The cosmetic result using a minimally invasive approach to assist with the dissection was acceptable, and the morbidity and scarring were minimized.

Motor unit properties of nerve-intact extensor digitorum longus muscle grafts in young and old rats.

Impaired reinnervation has been implicated as the cause of the threefold disparity in the recovery of maximum force (P0) of standard muscle grafts in old compared with young rats. The specific, null hypothesis of this study is that compared with age-matched control extensor digitorum longus (EDL) muscles, nerve-intact EDL muscle grafts in young and old rats show no evidence of an age-related impairment in reinnervation. Nerve-intact grafts were performed in 3-month-old and 23-month-old rats and were evaluated 60 days postoperatively. Compared with age-matched control EDL muscles, nerve-intact grafts in young and old rats showed no difference in muscle mass or motor unit numbers. The mean motor unit P0 for nerve-intact graft muscles in both age groups was significantly lower than that of age-matched control muscles. These data support our hypothesis that if axons are allowed to regenerate in an endoneurial environment, there is no evidence of an age-related impairment in muscle reinnervation.

"Donor" muscle structure and function after end-to-side neurorrhaphy.

End-to-end nerve coaptation is the preferred surgical technique for peripheral nerve reconstruction after injury or tumor extirpation. However, if the proximal nerve stump is not available for primary repair, then end-to-side neurorrhaphy may be a reasonable alternative. Numerous studies have demonstrated the effectiveness of this technique for muscle reinnervation. However, very little information is available regarding the potential adverse sequelae of end-to-side neurorrhaphy on the innervation and function of muscles innervated by the "donor" nerve. End-to-side neurorrhaphy is hypothesized to (1) acutely produce partial donor muscle denervation and (2) chronically produce no structural or functional deficits in muscles innervated by the donor nerve. Adult Lewis rats were allocated to one of two studies to determine the acute (2 weeks) and chronic (6 months) effects of end-to-side neurorrhaphy on donor muscle structure and function. In the acute study, animals underwent either sham exposure of the peroneal nerve (n = 13) or end-to-side neurorrhaphy between the end of the tibial nerve and the side of the peroneal nerve (n = 7). After a 2-week recovery period, isometric force (F(0) was measured, and specific force (sF(0) was calculated for the extensor digitorum longus muscle ("donor" muscle) for each animal. Immunohistochemical staining for neural cell adhesion molecule (NCAM) was performed to identify populations of denervated muscle fibers. In the chronic study, animals underwent either end-to-side neurorrhaphy between the end of the peroneal nerve and the side of the tibial nerve (n = 6) or sham exposure of the tibial nerve with performance of a peroneal nerve end-to-end nerve coaptation approximately 6), to match the period of anterior compartment muscle denervation in the end-to-side neurorrhaphy group. After a 6-month recovery period, contractile properties of the medial gastrocnemius muscle ("donor" muscle) were measured. Acutely, a fivefold increase in the percentage of denervated muscle fibers (1 +/0 0.7 percent to 5.4 +/-2.7 percent) was identified in the donor muscles of the animals with end-to-side neurorrhaphy (p < 0.001). However, no skeletal muscle force deficits were identified in these donor muscles. Chronically, the contractile properties of the medial gastrocnemius muscles were identical in the sham and end-to-side neurorrhaphy groups. These data support our two hypotheses that end-to-side neurorrhaphy causes acute donor muscle denervation, suggesting that there is physical disruption of axons at the time of nerve coaptation. However, end-to-side neurorrhaphy does not affect the long-term structure or function of muscles innervated by the donor nerve.

Recurrence of pyoderma gangrenosum within a chronic wound following microvascular free-tissue transfer.

The authors present a 29-year-old woman with a chronic foot wound that failed to heal, despite extensive medical and surgical therapy. The diagnosis of pyoderma gangrenosum was ultimately made, and the patient was started on systemic cyclosporine therapy. In the absence of apparent active disease, surgical debridement and microvascular free flap reconstruction were performed to achieve wound closure. Six weeks postoperatively, recurrence of the pyoderma gangrenosum was identified in the free flap, resulting in partial, superficial, flap necrosis. Laboratory evaluation at that time demonstrated subtherapeutic cyclosporine levels. Once the cyclosporine level was increased to the therapeutic range, the wound healed, and the microvascular free flap was salvaged. Because of the relative lack of precision in both the clinical and pathologic determination of acuity level, as well as the tendency toward pathergy, surgical treatment of any form poses many potential risks for these patients. For this reason, surgery should serve only as an adjunct to medical therapy, which remains the mainstay for treatment of pyoderma gangrenosum.

Prospective analysis of psychosocial outcomes in breast reconstruction: one-year postoperative results from the Michigan Breast Reconstruction Outcome Study.

In the past decade, changing attitudes toward breast reconstruction among both patients and providers have led a growing number of women to seek breast reconstruction after mastectomy. Although investigators have documented the psychological, social, emotional, and functional benefits of breast reconstruction, little research has evaluated the effects of procedure choice on these outcomes. The current study prospectively evaluated and compared psychosocial outcomes for three common options for mastectomy reconstruction: tissue expander/implant, pedicle TRAM, and free TRAM techniques. In a prospective cohort design, patients undergoing postmastectomy reconstruction for the first time with expander/implant, pedicle TRAM, or free TRAM procedures were recruited from 12 centers and 23 plastic surgeons in the United States and Canada. Before reconstruction and at 1 year after reconstruction, patients were evaluated by a battery of questionnaires consisting of both generic and condition-specific surveys. Outcomes assessed included emotional well-being, vitality, general mental health, social functioning, functional well-being, social well-being, and body image. Baseline (preoperative) scores and the change in scores (the difference between postoperative and preoperative scores) were compared across procedure types using t tests and analysis of covariance. Preoperative and 1-year postoperative surveys were obtained from 273 patients. Procedure type was reported in 250 patients, of whom 56 received implant reconstructions, 128 pedicle TRAM flaps, and 66 free TRAM flaps. A total of 161 immediate and 89 delayed reconstructions were performed. Among women receiving immediate reconstruction, significant improvements were observed in all psychosocial variables except body image. However, no significant effects of procedure type on these changes over time existed. Similarly, delayed reconstruction patients had significant increases in emotional well-being, vitality, general mental health, functional well-being, and body image. Although the choice of reconstructive technique did not significantly impact most of these outcomes, significant differences existed among procedure types for three psychosocial subscales. Patients undergoing delayed expander/implant reconstructions reported greater improvements in vitality and social well-being relative to women receiving delayed TRAM procedures. By contrast, delayed TRAM patients noted significantly greater gains in body image compared with women choosing delayed expander-implant reconstruction. The authors conclude that both immediate and delayed breast reconstructions provide substantial psychosocial benefits for mastectomy patients. Although the choice of reconstructive procedure does not seem to significantly affect improvements in psychosocial status with immediate reconstruction, our data suggest that procedure type does have a significant effect on gains in vitality and body image for women undergoing delayed reconstruction.

Skeletal muscle reinnervation by reduced axonal numbers results in whole muscle force deficits.

Patients sustaining a peripheral nerve injury will frequently experience residual muscle weakness after muscle reinnervation, even if the nerve repair is performed under optimal circumstances to allow rapid muscle reinnervation. The mechanisms responsible for this contractile dysfunction remain unclear. It is hypothesized that after peripheral nerve injury and repair, a reduced number of axons are available for skeletal muscle reinnervation that results in whole muscle force and specific force deficits. A rat model of peroneal nerve injury and repair was designed so that the number of axons available for reinnervation could be systematically reduced. In adult rats, the peroneal nerve to the extensor digitorum longus muscle was either left intact (sham group, n = 8) or divided and repaired with either 50 percent (R50 group, n = 7) or 100 percent (R100 group, n = 8) of the axons in the proximal stump included in the repair. Four months after surgery, maximal tetanic isometric force was measured and specific force was calculated for each animal. Mean tetanic isometric force for extensor digitorum longus muscles from R50 rats (2765.7 +/- 767.6 mN) was significantly lower than sham (4082.8 +/- 196.5 mN) and R100 (3729.0 +/-370.2 mN) rats (p < 0.003). Mean specific force calculations revealed significant deficits in both the R100 (242.1 +/- 30 kN/m2) and R50 (190.6 +/- 51.8 kN/m2) rats compared with the sham animals (295.9 +/- 14 kN/m2) (p < 0.0005). These data support our hypothesis that after peripheral nerve injury and repair, reinnervation of skeletal muscle by a reduced number of axons results in a reduction in tetanic isometric force and specific force. The greater relative reduction in specific force compared with absolute force production after partial nerve repair may indicate that a population of residual denervated muscle fibers is responsible for this deficit.

Termino-lateral neurorrhaphy: the functional axonal anatomy.

The goal of this study was to determine the functional axonal anatomy of a termino-lateral neurorrhaphy (TLN). We hypothesize that axons populating a TLN must relinquish functional connections with their original targets prior to establishing new connections via the TLN. Two-month-old F344 rats underwent a TLN between the left peroneal nerve and a nerve graft tunneled to the contralateral hindlimb. Three months postoperatively, an end-to-end neurorrhaphy was performed between the nerve graft and the right peroneal nerve. Four months after the second operation, contractile properties and electromyographic (EMG) signals were measured in the bilateral hindlimbs. Left peroneal nerve stimulation proximal to the TLN site resulted in bilateral extensor digitorum longus (EDL) and tibialis anterior (TA) muscle contractions, with significantly lower forces on the side reinnervated by TLN. Evoked EMGs demonstrated that the right and left hindlimb musculature were electrically discontinuous following TLN. These data support our hypothesis that axons can form functional connections via a TLN, but they must first relinquish functional connections with their original targets.

Mechanical function of muscle reinnervated by end-to-side neurorrhaphy.

End-to-side neurorrhaphy is a surgical technique for peripheral nerve reconstruction when end-to-end neurorrhaphy is not an option. To define the effectiveness of end-to-side neurorrhaphy as a method of nerve repair, the authors tested the null hypothesis: there is no difference in the mechanical function of skeletal muscle denervated and reinnervated by end-to-side versus end-to-end neurorrhaphy. Adult Lewis rats underwent either transection and end-to-end epineurial repair of the left peroneal nerve (n = 9) or end-to-side repair of the distal stump of the peroneal nerve to the side of the tibial nerve (n = 8). After a 6-month recovery period, isometric force (Fo) was measured, and specific force (sFo) was calculated for the extensor digitorum longus muscle of each animal. Immunohistochemical staining for neural cell adhesion molecule (NCAM) was performed to identify populations of denervated muscle fibers. The mean extensor digitorum longus muscle mass in the end-to-end group (195 +/- 32 g) was significantly greater than that of the end-to-side group (146 +/- 55 g) (p < 0.05). A significantly greater percentage of denervated fibers was identified in the extensor digitorum longus muscles of animals in the end-to-side group (9.4 +/- 3.2 percent) than in those in the end-to-end group (3.8 +/- 1.0 percent) (p < 0.05). Despite a lower muscle mass and a higher percentage of denervated fibers, neither Fo nor sFo was significantly different in the two groups. These data support the null hypothesis that, under appropriate circumstances, there is no difference in the recovery of whole muscle force and specific force production in muscles reinnervated by end-to-side versus end-to-end neurorrhaphy.

The effect of reinnervation on force production and power output in skeletal muscle.

Failure to fully restore contractile function after denervation and reinnervation of skeletal muscle engenders significant disability in patients suffering peripheral nerve injuries. This work tested the hypothesis that skeletal muscle denervation and reinnervation result in a deficit in normalized power (W/kg), which exceeds the deficit in specific force (N/cm2), and that the mechanisms responsible for these deficits are independent. Adult Lewis rats underwent either transection and epineurial repair of the left peroneal nerve (denervation-reinnervation, n = 13) or SHAM exposure of the peroneal nerve (SHAM, n = 13). After a 4-month recovery period, isometric force, peak power, and maximum sustained power output were measured in the left extensor digitorum longus (EDL) muscle from each animal. Isometric force measurements revealed a specific force deficit of 14.3% in the reinnervated muscles. Power measurements during isovelocity shortening contractions demonstrated a normalized peak power deficit of 25.8% in the reinnervated muscles, which is accounted for by decreases in both optimal velocity (10.5%) and average force during shortening (13.7%). Maximum sustained power was similar in both groups. These data support our working hypothesis that both whole muscle force production and power output can be impaired in reinnervated muscle and that the relative deficits in power output exceed the deficits in force production. The mechanisms responsible for the deficits in force production appear to be independent of those that result in changes in peak power output. The measurement of muscle power output may represent a clinically relevant variable for studies of the recovery of mechanical function after motor nerve injury and repair.

Melkersson-Rosenthal syndrome: reduction cheiloplasty utilizing a transmodiolar labial suspension suture.

Melkersson-Rosenthal syndrome is a rare condition which consists of progressive and recurrent orofacial edema, intermittent facial palsy, and lingua plicata. Labial swelling is the most common feature of this syndrome complex. The lips may enlarge up to three times their normal size, resulting in aesthetic deformity and functional disability. Traditional medical interventions are only marginally successful in treating this syndrome. We present a case of Melkersson-Rosenthal syndrome with massive lower lip enlargement, which was successfully treated by combining a fleur-de-lis resection with a transmodiolar labial suspension suture. Five-year follow-up photographs are presented.

The effect of the delay phenomenon on the vascularity of rabbit abdominal cutaneous island flaps.

The beneficial effects of the delay phenomenon have been evaluated extensively and are widely known. However, no study has quantified the vascular changes seen in an abdominal cutaneous island flap following a surgical delay by vascular pedicle ligation. We evaluated the effect of unilateral superficial inferior epigastric and deep inferior epigastric pedicle ligation on the vascularity of a rabbit abdominal cutaneous island flap. Thirty rabbits underwent a left superficial inferior epigastric and deep inferior epigastric pedicle ligation as a delay procedure. A 19 x 15 cm abdominal cutaneous island flap was elevated at the time of sacrifice, based solely on the right superficial inferior epigastric pedicle. The flap vasculature was then evaluated by methylene blue injection and lead oxide microangiography at 0, 5, 10, 15, 21, and 27 days following the delay procedure. Methylene blue studies revealed perfusion of only the right (nonligated) side of the flap on day 0 and perfusion of the entire flap by day 15. This "capture" of the left (ligated) superficial inferior epigastric artery angiosome by day 15 could only have been achieved through enhanced cross-midline perfusion. Lead oxide microangiography revealed an increase in the number of vessels from day 0 to day 27 on both the ligated and nonligated sides in all the following: the number of large "choke" vessels (> 0.5 mm) crossing the flap midline, total number of vessels (all sizes) crossing the flap midline, and total number of vessels (all sizes) at the medial aspect of the right and left superficial inferior epigastric artery angiosomes. A statistically significant increase in these vessels was not seen until day 21. The effect of the delay phenomenon was significantly greater on the ligated side compared with the nonligated side. The areas of the flap that were relatively more ischemic following left superficial inferior epigastric pedicle ligation (medial aspect of the caudad half of the left superficial inferior epigastric artery angiosome) showed greater increases in vascularity with the delay procedure than did areas of lesser ischemia (medial aspect of the cephalad half of the right superficial inferior epigastric artery angiosome).

The effect of the delay phenomenon on the vascularity of rabbit rectus abdominis muscles.

The transverse rectus abdominis muscle (TRAM) flap has become the "gold standard" for autogenous breast tissue reconstruction. Complications are reported in 10 to 40 percent of patients undergoing this procedure, and many are related to soft-tissue necrosis secondary to ischemia. Various methods have been proposed to improve TRAM flap survival, including surgical delay of the flap. The beneficial effects of the delay phenomenon have been well established in laboratory studies and clinical evaluations. Many investigators agree that the delay phenomenon will enhance arterial inflow and venous outflow from the TRAM flap. No study has quantified the changes seen in the rectus abdominis muscle following a delay procedure. In this prospective, controlled, and blinded experiment, we evaluate the effect of a unilateral superficial inferior epigastric and deep inferior epigastric artery and vein ligation on the vascularity of the rectus abdominis muscles in rabbits. Thirty-eight rabbits underwent a left superficial inferior epigastric and deep inferior epigastric pedicle ligation as a delay procedure. The rectus abdominis muscle vasculature was then evaluated by lead oxide microangiography at 0, 5, 10, 15, 21, and 27 days following the delay procedure. Magnification (x 2) was used to count the number of vessels at the periphery of the deep inferior epigastric artery angiosomes in the microangiograms. An increase in the number of vessels from day 0 to day 27 was seen on both the ligated and nonligated sides in all the following: the number of large (> 0.5 mm) "choke" vessels and total number of vessels (all sizes) crossing the abdominal wall midline and the total number of vessels (all sizes) at the medial, superior, and lateral aspects of the right and left deep inferior epigastric artery angiosomes. A statistically significant increase in these vessels was not seen until day 21. The effect of the delay phenomenon was significantly greater on the ligated side compared with the nonligated side. The areas of the rectus abdominis muscles that were relatively more ischemic following left deep inferior epigastric pedicle ligation (medial aspect of the left deep inferior epigastric artery angiosome) showed greater increases in vascularity with the delay procedure than did areas of lesser ischemia (lateral aspect of the right deep inferior epigastric artery angiosome).

Clinical and pathological features of pediatric dermatofibrosarcoma protuberans.

Dermatofibrosarcoma protuberans (DFSP) is an uncommon malignant mesenchymal tumor characterized by local invasion and recurrence. Fewer than 50 cases have been reported in the pediatric population. We reviewed our experience in the treatment of children with DFSP to define clinical and pathological characteristics. Seven pediatric patients were included in the study (mean age, 11.7 yr). Clinically, the tumors were described as firm nodules fixed to the skin but mobile over the deep fascia, with slow, progressive growth. Diagnosis was made by excisional biopsy in 6 patients and punch biopsy in 1 patient. Six of 7 patients had positive margins after the diagnostic procedure. Pathologically, diagnosis was based on histology, with confirmation by CD34 staining. Definitive surgical therapy consisted of wide local excision (1-3 cm margins) in 5 patients and Moh's micrographic resection in 2 patients. There have been no local recurrences or distant metastases, with a mean follow-up of 15.1 months. Pathological and clinical diagnostic criteria for the pediatric population are reviewed, and treatment options are discussed.

Postmastectomy reconstruction: comparative analysis of the psychosocial, functional, and cosmetic effects of transverse rectus abdominis musculocutaneous flap versus breast implant reconstruction.

Over 40,000 postmastectomy breast reconstructions are performed annually. In this study, we investigated the psychosocial, functional, and cosmetic effects of transverse rectus abdominis musculocutaneous (TRAM) flap versus breast implant reconstruction. Thirty-three women who had undergone postmastectomy breast reconstruction were contacted by telephone and agreed to participate in the study. Twenty-two women completed the self-assessment questionnaires regarding their quality of life, psychological symptoms, functional status, body image, and global satisfaction. The TRAM and implant groups contained 8 and 14 patients, respectively. The groups were well matched for age, employment status, marital status, race, religion, and severity of medical and surgical illnesses. The average follow-up was 36 months. Statistical analysis of the responses revealed that women who had undergone TRAM flap reconstruction were more satisfied with how their reconstructed breast felt to the touch (p = .01), and there was a trend toward greater satisfaction with the appearance of their reconstructed breast (p = .08). However, these same patients identified more difficulties as far as functioning at work or school, performing vigorous physical activities, participating in community or religious activities, visiting with relatives, and interacting with male friends (p < .04). There were no statistically significant differences in body image or overall satisfaction. In this small cohort study, both the TRAM flap group and the implant group were satisfied with the results of their breast reconstruction, but the TRAM flap group was more satisfied with how their breast felt and tended to be more satisfied with the cosmetic result. The TRAM flap group reported greater psychological, social, and physical impairments as a result of their reconstruction.

Blood flow in the gluteus maximus of seated individuals during electrical muscle stimulation.

Blood flow was measured under the ischial tuberosites of seated individuals during electrical stimulation of the gluteus maximus muscles. Eight able-bodied and six spinal cord injured subjects were studied. Muscle blood flow was measured via radioactive tracer (133xenon) clearance. Retention of xenon in adipose tissue prevented accurate measurement of blood flow in cutaneous and subcutaneous tissue. Average muscle blood flow for both subject groups was increased during stimulation as compared to rest. All subjects showed an increase in muscle blood flow during stimulation. The statistical significance from a paired student t-test was greater for able-bodied subjects (p less than .05) than for spinal cord injured subjects (p = .12). The increase in muscle blood flow produced by electrical muscle stimulation in seated individuals supports the hypothesis that electrical muscle stimulation can help prevent pressure sores.

Electric muscle stimulation for pressure sore prevention: tissue shape variation.

This study measured changes in tissue shape and deformation at the seating interface produced by electric muscle stimulation (EMS) of the gluteus maximus. The purpose of the study was to investigate the application of EMS for pressure sore prevention. Limitations of pressure measurements for analysis of load distribution are discussed and a rationale developed for using tissue shape and deformation to further characterize the seating interface. Ultrasonic imaging of the seating interface is described under three conditions: buttocks suspended, external load applied with no EMS, and external load applied with bilateral EMS of the buttocks. Results show that low level stimulation of the gluteus maximus produces substantial changes in the shape of the loaded buttocks and an external contour more nearly shaped like the suspended buttocks. It is concluded that EMS produces buttock tissue undulation and shape reconfiguration which may assist in preventing pressure sores over the seating surface.