Comparison of angiogenic activities after urethral reconstruction using free grafts in rabbits

OBJECTIVE: To determine the most suitable type of graft-free penile skin grafts or mucosal grafts from bladder or buccal regions - for urethral reconstruction in an animal model, as evaluated on the basis of angiogenic activity. METHODS: Twenty-two male White New Zealand rabbits were randomly divided into four groups. In the control group (group O, n=4) a simple urethrotomy and closure was performed, whereas a ventral urethral defect was created in groups A, B, and C and then bridged using the following onlay patches: free penile skin (group A, n=6), buccal mucosal graft (group B, n=6), and bladder mucosal graft (group C, n=6). On the 21st postoperative day, the animals were sacrificed and the retrieved implants were subjected to macroscopic and microscopic analysis. The angiogenic activity was assessed with immunohistochemistry, using the anti-CD31 MoAb and the phosphatase antialkaline phosphatase procedure. The native vascularity of penile skin as well as buccal and bladder mucosa was assessed in rabbits from group O (n=3). Statistical analysis was performed using the one-way ANOVA. RESULTS: The angiogenesis in a magnification of x200 in groups O, A, B, and C was 34.1+/-4.1 (mean+/-SD), 61.7+/-6.4, 94.3+/-6.4, and 91.5+/-7.2 vessels per optical field, respectively. There were, statistically significant differences (p<0.001) between groups A and B and between groups A and C, but not (p>0.05) between groups B and C. The native vascularity of penile skin, buccal mucosa and bladder mucosa was 23.3+/-3.0, 24.6+/-3.7 and 17.0+/-2.6 vessels per optical field, respectively. CONCLUSION: The viability of mucosal grafts from bladder or buccal regions is better than that of a free penile graft because of higher angiogenic activity. Although the mucosal grafts showed the same angiogenic activity, the buccal mucosa graft is preferable because of its easier harvesting.     

New frontiers in urethral reconstruction: injectables and alternative grafts

Contemporary management of anterior urethral strictures requires both endoscopic as well as complex substitution urethroplasty, depending on the nature of the urethral stricture. Recent clinical and experimental studies have explored the possibility of augmenting traditional endoscopic urethral stricture management with anti-fibrotic injectable medications. Additionally, although buccal mucosa remains the gold standard graft for substitution urethroplasty, alternative grafts are necessary for reconstructing particularly complex urethral strictures in which there is insufficient buccal mucosa or in cases where it may be contraindicated. This review summarizes the data of the most promising injectable adjuncts to endoscopic stricture management and explores the alternative grafts available for reconstructing the most challenging urethral strictures. Further research is needed to define which injectable medications and alternative grafts may be best suited for urethral reconstruction in the future.     

Foot reconstruction using free microvascular muscle flaps with skin grafts

Free muscle flap transfer with skin graft coverage for extensive foot defects can be a successful form of foot reconstruction in well-selected patients who have overall normal foot innervation and deep pressure sensibility. Cutaneous sensibility does not appear to be necessary to maintain a functional or well-healed foot. The major reconstructive goal in plantar foot reconstruction is the restoration of weight-bearing during normal ambulation using regular foot apparel. Based on this reconstructive goal, the authors present their current approach in the reconstruction of extensive defects of the foot using free microvascular muscle flaps with skin grafts.     

Beard reconstruction using hair grafts in a free flap

Hair transplantation using micrografts or minigrafts is a standard procedure used for hair restoration in androgenic, burn scar and cicatricial alopecia. These grafts have also been used to reconstruct the eyebrow, eyelash, mustache, beard and pubic escutcheon. A patient who underwent successful micrograft and minigraft hair transplantation into a free osteocutaneous mandibular flap reconstruction is presented. The patient was very satisfied with his reconstruction, and the hair transplants provided excellent camouflage for the flap.     

Skin grafts used in combination with free flaps for intraoral oncological reconstruction

Surgeons have relied less on skin grafts for intraoral reconstruction by extending free flap tissue onto adjacent areas that could be potentially skin grafted. Split-thickness skin grafts provide thin, reliable epithelial coverage to tissue beds that can be grafted without requiring additional flap tissue. The combined use of split-thickness skin grafts with free tissue transfer may be advantageous in select situations. Four patients underwent intraoral tumor resection with immediate reconstruction using free tissue transfer and split-thickness skin grafts. Skin grafting the tongue component of combined hemiglossectomy and floor-of-mouth (FOM) defects rather than spanning the tongue-FOM junction with flap tissue may prevent excessive bulk, improve tongue mobility, and reduce the size requirement of the flap. A split-thickness skin graft can be applied to the intraoral surface of free flaps used to reconstruct through-and-through orocutaneous defects, reducing the complexity of flap design and inset. Maxillectomy defects reconstructed with muscle flaps can be epithelialized immediately with the application of a split-thickness skin graft to provide a stable obturator cavity. In select cases, the combination of split-thickness skin grafts and free tissue transfer may have advantages over the use of flap tissue alone to cover the adjacent areas of a complex defect capable of being grafted.     

Long anterior urethral reconstruction using a jejunal free flap

We report the case of a transgender patient who was referred to our department for management of chronic strictures of his neophalloplasty. We successfully used a free jejunal flap for a long anterior urethral reconstruction. He achieved a patent and functional urethra with satisfactory urinary control and was happy with the cosmetic outcome.     

The successful reconstruction of thoracic tracheal defects with free periosteal grafts

A defect was created in the thoracic trachea in nine piglets (10 kg) by excising a segment from the entire thoracic trachea proximal to the right upper lobe bronchus (3 to 3.5 cm in length) and 30% of the circumference in width (1 to 1.5 cm). The defect was repaired with a free tibial periosteal graft (FPG) and in four piglets an omental pedicle graft (OPG) was applied to the surface of the FPG. An internal tracheal splint was inserted for 12 to 16 days to support the repair and prevent air leak. The splints were removed bronchoscopically. None of the pigs developed signs of airway obstruction at any stage following the repair. Eight were killed 3 months postoperatively when four to six times their original weight. One pig died on the 18th postoperative day of unknown cause. The tracheas were removed, x-rayed, and examined grossly and histologically. The results demonstrated normal tracheal growth with absence of either stenosis, collapse, or granulation tissue. All grafts were viable, bone formation was present, and the lumenal surfaces were lined with columnar and respiratory epithelium. The OPG did not improve vascularization of the FPG. This model suggests that tracheal stenosis in children may be surgically corrected by simply incising the stenotic segment longitudinally and enlarging the tracheal diameter by inserting a FPG into the defect.     

Experience with fibrin glue in bulbar urethral reconstruction using dorsal buccal mucosa graft

Buccal mucosa dorsal onlay graft urethroplasty represents a widespread method for bulbar urethral stricture repair. We describe a modified procedure with the use of fibrin glue applied on the receiving bed before graft location.     

Mandibular reconstruction: Experience with the free vascularized fibula transfer

Mandibular resection, following surgery for tumor or osteoradionecrosis, leaves a patient with a swallowing, speech, and cosmetic disability. Repair of the oromandibular defect is difficult and various prostheses and grafts have been used and reported. The most popular form of mandibular reconstruction is the use of the free, vascularized bone transfer. We report our experience with the free vascularized fibula bone transfer in eight patients. © 1993 Wiley-Liss Inc.     

The use of free periosteal grafts in extensive lower lid reconstruction

We describe using a scaffold of free periosteum as a posterior lamella replacement in the reconstruction of large defects involving the lower lid. Although the tarsoconjunctival flap is the treatment of choice in lower lid defects, the technique we describe is especially useful in cases in which it is best not to cover the eye for an extended period, and in cases involving defects extending beyond those of the lower lid.     

Experience with urethral stent explantation

PURPOSE: We examined the timing, causes and results of the explantation of UroLume (American Medical Systems, Minnetonka, Minnesota) urethral stents. MATERIALS AND METHODS: The North American Study Group enrolled 465 patients in a trial of UroLume stent placement, including 69 (14.8% of the series) who required removal of a total of 73 stents (15.6% of stents) in 7 years. The time of explantation, reason for stent removal and local histological findings were determined from patient charts and reviewed in relation to the indication for stent placement. RESULTS: In patients treated for bladder outlet obstruction secondary to benign prostatic hyperplasia 23% of the stents were removed, as were 5% of those implanted in patients with bulbar urethral stricture and 22% of those in patients with detrusor-sphincter dyssynergia (see figure). Of the explantations 43.8% were done during year 1. Migration and/or inappropriate placement was the cause in 38.4% of cases. The most common stent site tissue finding was focal inflammation with a hyperplastic tissue response. Stent specific malignant changes were not observed. Stent removal was feasible with no sequelae. CONCLUSIONS When used appropriately, the UroLume endoprosthesis has a low incidence of failure. Stent removal is technically feasible and options are available for subsequent therapy. Local tissue reaction is minimal.