Aesthetic abdominal deformities: a personal approach to the posterior rectus sheath and rectus muscles

We have detailed our experience with abdominoplasty. The technique is based on undermining of the rectus abdominis muscle, treatment of the posterior sheath, and limited resection of the medial edge of the rectus muscle. The fatty and muscular redundancy in the epigastric region has been eliminated by resection of the muscle edge or local suction lipectomy.     

Extended transverse rectus abdominis musculocutaneous flap

Blood circulation within the conventional TRAM flap is not generous, and the contralateral random portion of the flap may result in fat or skin necrosis. However, this random portion can be extended safely and used for reconstruction by including the superficial epigastric vessels and the superficial circumflex iliac vessels and by anastomosing either of these to the recipient vessels. We have experienced this extended TRAM flap in two patients without any complications.     

Transverse rectus sheath plication in abdominoplasty

The standard abdominoplasty technique uses a wide, vertically oriented plication of the rectus sheath to narrow the waistline. This reduces the contribution of the rectus sheath to the anterior abdominal wall from more than 50 percent to 25 percent or less and creates an unnaturally flat appearance. No amount of exercise can restore the native form of the rectus sheath. For the past 3 years, the authors have performed a transverse plication of the rectus sheath, to address vertical laxity, complemented by a bilateral crescent-shaped plication of the external oblique fascia, to address waistline contour. Six consecutive patients who underwent the transverse rectus plication technique were compared with a similar group of patients who underwent vertical rectus plication. Comparison was made via preoperative and postoperative photographic analysis by two impartial judges. Although the overall result was excellent in both groups, the global score was significantly higher in the transverse plication group (4.5 versus 3.9, p = 0.044). Scores for anterior abdominal contour (4.7 versus 4.2, p = 0.029) and definition of the linea semilunaris (4.6 versus 3.7, p = 0.008) were also significantly higher for the transverse plication group. The difference for waistline contour (4.5 versus 3.8, p = 0.067), definition of the linea alba (4.4 versus 3.9, p = 0.067), and hip-waist transition (4.4 versus 3.7, p = 0.067) did not reach statistical significance. The outline of the rectus sheath is a significant portion of what is perceived as an aesthetic abdomen. Transverse plication of the rectus sheath with bilateral crescent-shaped plications of the external oblique fascia retains this native form. The result is improved anterior abdominal contour and definition of the rectus sheath with a comparable or better improvement in waistline contour and transition from the hips to the waist when compared with wide, vertical rectus plication.     

Uses of the rectus femoris myocutaneous flap.

The rectus femoris myocutaneous flap is quite useful for definitive immediate coverage of complex wounds within its territorial arc. We describe 4 cases to illustrate the capabilities of this flap. The indications for, the anatomy of, and the surgical technique for transfer, as well as the functional sequelae in two nonparaplegic patients are discussed.     

Configurations of the rectus abdominis muscle of anuran tadpoles

Configurations of the rectus abdominis in tadpoles of 60 anuran species in 13 families were examined. This muscle is present by Gosner stage 25 and does not change until late in metamorphosis. The anterior terminus of the r. abdominis usually is a straight, transverse front or fan-shaped array only loosely associated with the rectus cervicis. In some suspension feeders (Rhinophrynus, Xenopus, but not microhylids), macrophagous suction feeders (Lepidobatrachus) and bromeliad inhabitants (Hyla bromeliacia) the r. abdominis is contigous with the r. cervicis which continues anterolaterally and dorsally from the wall of the spiracular cavity. Suctorial forms (Scutiger), those that live in confined spaces (burrowers, Centrolenella; bromeliad inhabitants, Hyla bromeliacia), and the taxa that have the r. cervicis and r. abdominis contiguous all have closed myosepta; the myosepta of other taxa; except for ones with large tadpoles (e.g., Rana catesbeiana), have large gaps between at least anterior myotomes. These initial data suggest that the configurations of the r. abdominis have responded to selection based on ecomorphological function and convergence among lineages are noted. © 1992 Wiley-Liss, Inc.     

Clinical applications of the posterior rectus sheath-peritoneal free flap

Soft-tissue injuries involving the dorsum of the hand and foot continue to pose complex reconstructive challenges in terms of function and contour. Requirements for coverage include thin, vascularized tissue that supports skin grafts and at the same time provides a gliding surface for tendon excursion. This article reports the authors' clinical experience with the free posterior rectus sheath-peritoneal flap foil dorsal coverage in three patients. Two patients required dorsal hand coverage; one following acute trauma and another for delayed reconstruction 1 year after near hand replantation. A third patient required dorsal foot coverage for exposed tendons resulting from skin loss secondary to vasculitis. In all three patients, the flap was harvested through a paramedian incision at the lateral border of the anterior rectus sheath. After opening the anterior rectus sheath, the rectus muscle was elevated off of the posterior rectus sheath and peritoneum. When elevating the muscle, the attachments of the inferior epigastric vessels to the posterior rectus sheath and peritoneum were preserved while ligating any branches of these vessels to the muscle. Segmental intercostal innervation to the muscle was preserved. The deep inferior epigastric vessels were then dissected to their origin to maximize pedicle length and diameter. The maximum dimension of the flaps harvested for the selected cases was 16 X 8 cm. The anterior rectus sheath was closed primarily with non-absorbable suture. Mean follow-up was 1 year, and all flaps survived with excellent contour and good function in all three patients. Complications included a postoperative ileus in one patient, which resolved after 5 days with nasogastric tube decompression.     

Reconstruction of ablated rat rectus abdominis by muscle regeneration

Skeletal muscle regeneration is a powerful, naturally occurring process of tissue reconstruction that follows myofiber damage secondary to myotoxic injury that does not normally affect the tissue circulation and scaffold. The ablated tissue, in traumatology and free muscle grafts, is frequently replaced by scars. The final outcome is poor even after in situ myoblast seeding of the harvested muscle. The goal of this study was to identify protocols to reconstruct muscle tissue, even in such adverse environments. The authors applied a step-by-step approach to identify factors favoring the survival of autologous satellite cells and, thus, muscle regeneration. In a rat model of full-thickness rectus abdominis muscle ablation, autologous myoblasts were isolated from the explanted rectus abdominis and seeded in a homologous acellular matrix immediately after wall reconstruction (group 1, five animals). In group 2 (five animals), the ablated rectus abdominis was autografted in situ. In a third group of five rats, Marcaine was injected into both the autograft and the surrounding abdominal wall muscle. Three weeks after surgery, serial cross-sections of the reconstructed abdominal wall were stained with hematoxylin and eosin or embryonic myosin antibody, a well-characterized molecular marker of early myogenesis in development and regeneration. Percentages of the patch area covered by regenerated myofibers were determined by morphometry. When autologous myoblasts were seeded in a homologous acellular matrix, the only myofibers observed to regenerate were those along the border of the patch. Autografting of the middle third of the rectus abdominis muscle similarly resulted in scar formation. The few muscle cells in the graft core were scanty myoblasts that could be detected only by monoclonal embryonic myosin antibody. Although negative for myofiber regeneration, the results in both cases confirmed the mechanical patency of the patches with regard to abdominal organ support. Myofibers were successfully regenerated in the graft by injecting Marcaine into both the autograft and the surrounding muscles. Three weeks after surgery, the patch was paved with young, centrally nucleated myofibers intermixed with young myofibers and myotubes expressing embryonic myosin. The difference in percentage of patch area covered by regenerated myofibers in group 3 (Marcaine injection around the patch, 81.6 +/- 3.0 percent) (mean +/- SD) versus either group 1 (Myoblast-seeded acellular patch, 18.0 +/- 3.0 percent) or group 2 (Autograft, 25.8 +/- 7.0 percent) was statistically significant on independent t test analysis (p < 0.0001). Even an acellular matrix showed some myofiber regeneration after surrounding muscles had been injected with Marcaine. This is the first successful evidence of muscle reconstruction after full-thickness ablation of the middle third of the rectus abdominis. Muscle regeneration seems to be the result of successive waves of migration of angioblasts and then satellite cell-derived myoblasts from the muscles surrounding the patch. The results strongly suggest that vascularization of the scaffold and successive coordinate proliferation of the seeded cells are required for myoblasts to be able to migrate into the patch and differentiate up to myofiber stage.     

Importance of preswing rectus femoris activity in stiff-knee gait

Stiff-knee gait is characterized by diminished and delayed knee flexion during swing. Rectus femoris transfer surgery, a common treatment for stiff-knee gait, is often recommended when a patient exhibits prolonged activity of the rectus femoris muscle during swing. Treatment outcomes are inconsistent, in part, due to limited understanding of the biomechanical factors contributing to stiff-knee gait. This study used a combination of gait analysis and dynamic simulation to examine how activity of the rectus femoris during swing, and prior to swing, contribute to knee flexion. A group of muscle-actuated dynamic simulations was created that accurately reproduced the gait dynamics of ten subjects with stiff-knee gait. These simulations were used to examine the effects of rectus femoris activity on knee motion by eliminating rectus femoris activity during preswing and separately during early swing. The increase in peak knee flexion by eliminating rectus femoris activity during preswing (7.5+/-3.1 degrees ) was significantly greater on average (paired t-test, p=0.035) than during early swing (4.7+/-3.6 degrees ). These results suggest that preswing rectus femoris activity is at least as influential as early swing activity in limiting the knee flexion of persons with stiff-knee gait. In evaluating rectus femoris activity for treatment of stiff-knee gait, preswing as well as early swing activity should be examined.     

Properties of Two Homologous Alkaline Proteases from Streptomyces rectus

Some physicochemical properties of two thermostable proteases from Streptomyces rectus are described. The enzymes were judged to be identical with respect to molecular weight, inactivation with serine protease inhibitors, and in primary structure by peptide analysis. Amino acid analysis indicated the enzymes had identical compositions except for their amide content. The molecular weights of the enzymes were judged to be 28,000 by sedimentation equilibrium, 26,200 by sedimentation diffusion, and 29,100 from amino acid analysis. Titration of the proteases with diisopropylfluorophosphate and phenylmethane sulfonylfuoride indicate equivalent weights of 28,500 and 32,800 g, respectively, for the proteins. The pentapeptide around the serine residue reacting with diisopropylfluorophosphate was isolated and had the composition: Asx(1), Gly(1), Thr(1), Ser(1), Met(1).     

Donor-site morbidity of the pedicled rectus femoris muscle flap

The rectus femoris muscle flap is well known for its reliable anatomy, the ease with which it can be harvested, and its great versatility. As a pedicled or free flap, it is used to cover soft-tissue defects and to recreate motor function. Although the muscle is very reliable, it is not well respected because of its assumed donor-site morbidity, such as weakened knee extension force and decreased range of motion of the knee. To date, these clinical assumptions have only rarely been quantified in terms of objective scores, concerning force deficit and functional or aesthetic outcome. From 1995 to 2002, the authors treated 24 patients with pedicled rectus femoris muscle flaps. Fourteen patients were followed up. Follow-up time ranged from 3 to 56 months postoperatively. The results were evaluated by a standard questionnaire in which pain in relation to walking distance, subjective feeling of weakness, sensibility disorders, everyday function, and aesthetic aspects were assessed. Range of motion in the hip and the knee was measured. For objective verification of a decrease of maximal voluntary contraction force of the remaining quadriceps muscle and for detecting differences in true muscular capacity and voluntary activation, 10 patients with unilateral rectus femoris flaps were tested using the twitch interpolation technique. The authors' patients assessed the remaining function and the aesthetic result of the thigh as at least satisfactory. Two patients complained about pain and weakness in the thigh. Eight patients reported hypesthesia in the lateral suprapatellar region. The maximal voluntary contraction and true muscular capacity values were reduced by 21.8 percent and 18 percent, respectively, when compared with the healthy leg. The range of motion in the knee and hip was not influenced by muscle harvesting. The twitch interpolation technique revealed a mild voluntary activation deficit, probably caused by inhibitory regulation in the spinal cord. In conclusion, donor-site morbidity of the rectus femoris muscle flap is evident but well compensated. There is no decrease in active range of motion in the knee and hip. Patient satisfaction with the functional and aesthetic outcome was high.     

Abdominal wall function after rectus abdominis transfer.

The abdominal wall function of 57 patients who have undergone TRAM flap breast reconstructions using the whole rectus muscle, on one side (33 patients) or both (24 patients), was evaluated 6 months to 2 years after surgery. The defect was repaired with a Teflon mesh buried in the rectus sheath. There was a perfect tolerance to the mesh, and no hernia or bulging of the abdominal wall developed. Patients had less back pain after (10 patients) than before (18 patients) the operation and found their sit-up and sport possibilities about the same as before. Detailed assessment of the abdominal muscles by the physiotherapist showed, however, a decreased function, more evident in bilateral cases. CT scans demonstrated a medialization of the lateral muscles, leaving only a small medial portion of the abdominal wall devoid of muscles. On the whole, no problem of clinical significance was encountered, and patients showed a high degree of satisfaction with the operation.