Recipient wound bed characteristics affect scarring and skin graft contraction

The use of autograft skin is essential in the treatment of full thickness burns and large cutaneous defects. Both autograft thickness and condition of the wound bed modulate aesthetic and functional outcomes. Thicker autografts contract less and maintain greater functionality as the scar matures. The presence of hypodermis can also positively affect the eventual appearance and functionality of the wound site by modulating contraction and alleviating inflammation and cellular stress responses. In this study, we characterize wound‐site physical and cellular characteristics following split‐thickness skin grafting onto hypodermis vs. onto fascia. Compared to autografts grafted onto fascia, identical thickness autografts grafted onto fat demonstrated reduced contraction, enhanced mobility and vascularity, and reduced topographical variability. Grafts onto fat also showed reduced levels of myofibroblasts and leukocytic infiltration. The status of the wound bed prior to engraftment is an important contributor of skin quality outcome. The presence of hypodermis is associated with improved functional and aesthetic qualities of split thickness skin grafts, which are correlated with reduced presence of myofibroblasts and leukocytic infiltration.     

A prospective comparison of two split-skin graft donor site dressings

Adjacent split-skin graft donor sites were dressed with polyurethane foam (Lyofoam) and the occlusive dressing normally used in this unit. The findings are discussed.     

Single-stage dorsal inlay split-skin graft for salvage anterior urethral reconstruction

OBJECTIVE

To report our initial experience and extended follow‐up of single‐stage dorsal inlay skin‐graft urethroplasty for salvaging recurrent anterior urethral stricture (AUS), as urethral reconstruction remains a challenge, particularly in patients with recurrent AUS after previous surgery, and a paucity of local skin frequently requires free graft reconstruction techniques.

PATIENTS AND METHODS

In all, 27 patients (mean age 48.12 years, range 17–79) with recurrent AUS had a dorsal inlay urethroplasty using extragenital split‐thickness skin grafts. An electrical dermatome was used for graft harvesting. All patients had contraindications for buccal mucosal grafting (e.g. radiotherapy, leukoplakia). The assessment before repair comprised a clinical investigation, urine analysis, uroflowmetry, retrograde and voiding cystogram, urethral ultrasonography and endoscopy. The follow‐up was based on an assessment of flow rate and postvoid residual volume. Success was defined by the absence of symptoms and stable maximum flow rate, while any further instrumentation was considered a failure.

RESULTS

The mean (range) stricture length was 8.35 (3–14) cm. The overall complication rate was 7%, with no complications during surgery. During the mean (range) follow‐up of 32.43 (5–46) months, 25 (93%) of the patients were successfully cured in one operation. Two patients required further treatment for recurrence and fistula. No long‐term complications were noted at the graft donor sites. There was no case of intraurethral hair growth during the extended follow‐up.

CONCLUSION

If there are contraindications for buccal mucosal grafting, a split‐thickness skin can be used for dorsal inlay urethroplasty in recurrent AUS. A well‐vascularized recipient bed on the corpora cavernosa is required for reliable graft take. Intra‐urethral hair growth is avoided by using split‐skin grafts. Although the complication rates are equivalent to those of buccal mucosa, we await the longer follow‐up to assess the ultimate value of this alternative single‐stage technique.     

The use of split-skin mesh graft in the management of urethral strictures

In the last 3 years 268 patients with urethral strictures have attended this unit. We treat most strictures by urethrotomy and consider an open operation only after two recurrences or in patients whose strictures are considered unsuitable for urethrotomy. Open operations have been performed on 42 patients. Although several types of operation have been used, most comprised an end-to-end anastomosis or Blandy's scrotal flaps. In the last few years a split-skin mesh graft has been used to replace the posterior urethra and the advantage of this technique is that the new urethra is soft and hairless. We present our experience with this method and our overall results.     

Influence of decortication of the recipient graft bed on graft integration and tissue neoformation in the graft-recipient bed interface

The objective of the present study was to assess the influence of decortication of the posterior elements of the vertebra (recipient bed) and the nature of the bone graft (cortical or cancellous bone) on graft integration and bone, cartilage and fiber neoformation in the interface between the vertebral recipient bed and the bone graft. Seventy-two male Wistar rats were divided into four experimental groups according to the presence or absence of decortication of the posterior vertebral elements and the use of a cortical or cancellous bone graft. Group I—the posterior elements were decorticated and cancellous bone used. Group II—the posterior elements were decorticated and cortical graft was used. Group III—the posterior elements were not decorticated and cancellous graft was used. Group IV—the posterior elements were not decorticated and cortical graft was used. The animals were killed 3, 6 and 9 weeks after surgery and the interface between the posterior elements and the bone graft was subjected to histomorphometric evaluation. Mean percent neoformed bone was 40.8% in group I (decortication and cancellous graft), 39.13% in group II (decortication and cortical graft), 6.13% in group III (non-decorticated and cancellous graft), and 9.27% in group IV (non-decorticated and cortical graft) for animals killed at 3 weeks (P = 0.0005). For animals killed at 6 weeks, the mean percent was 38.53% for group I, 40.40% for group II, 10.27% for group III, and 7.6% for group IV (P = 0.0005), and for animals killed at 9 weeks, the mean was 25.93% for group I, 30.6% for group II, 16.4% for group III, and 18.73% for group IV (P = 0.0026). The mean percent neoformed cartilage tissue was 8.36% for group I, 7.46% for group II, 11.1% for group III, and 9.13% for group IV for the animals killed at 3 weeks (P = 0.6544); 6.6% for group I, 8.07% for group, 7.47% for group III and 6.13% for group IV (P = 0.4889) for animals killed at 6 weeks, and 3.13% for group I, 4.06% for group II, 10.53% for group III and 12.07% for group IV (P = 0.0006) for animals killed at 9 weeks. Mean percent neoformed fibrous tissue was 11% for group I, 6.13% for group II, 26.27% for group III and 21.87% for group IV for animals killed at 3 weeks (P = 0.0008); 7.67% for group I, 7.1% for group II, 9.8% for group III and 10.4% for group IV (P = 0.7880) for animals killed at 6 weeks, and 3.73% for group I, 4.4% for group II, 6.67% for group III and 6.8% for group IV (P = 0.0214) for animals killed at 9 weeks. The statistically significant differences in percent tissue formation were related to decortication of the posterior elements. The use of a cortical or cancellous graft did not influence tissue neoformation. Ossification in the interface of the recipient graft bed was of the intramembranous type in the decorticated animals and endochondral type in the non-decorticated animals.     

The morbidity of split-skin graft donor sites in the elderly: the case for mesh-grafting the donor site

An impression that the healing of split-skin donor sites in the elderly is significantly prolonged compared with that in younger patients was confirmed by retrospective and prospective clinical studies. Possible explanations are discussed. In a prospective clinical trial of 20 consecutive patients over the age of 60 part of the donor site was covered with a meshed skin graft leaving the remaining unmeshed area as a control. In all patients the mesh-grafted area was healed in 10 days while the control "unmeshed" area demonstrated the same morbidity we had noted in patients over 60 in our retrospective study. It is suggested that the mesh grafting of small split-skin donor sites in the elderly can accelerate the rate of healing and significantly reduce the demands on hospital and community resources.     

Avulsion injuries of the nail bed do not need nail bed graft

From 1985 to 1992, 12 cases of severe avulsion injuries of the nail bed were treated by allowing the nail bed to regenerate naturally, without a nail bed graft irrespective of the extent of nail bed loss. This involved simply covering the residual nail bed with the nail splint for a period of approximately 6 weeks or until the nail bed was observed to be fully regenerated. The patients were then followed up until full nail growth. It was observed that the nail bed regenerated spontaneously, followed by a normal nail growth identical to the contralateral uninjured nail.Proper coverage of the nail bed protected the culture milieu conducive to natural nail bed regeneration, and nail bed grafting was not necessary irrespective of the extent of tissue loss.     

Free nail bed graft for treatment of nail bed injuries of the hand

Free full-thickness grafts of nail bed of the lesser toes or an amputated fingertip were successfully performed on 11 fingers of 10 patients since 1979. In nine patients in whom the nail beds had been severely crushed or lost, but the nail matrix was intact, the end results of this technique were excellent. In one patient in whom both the nail bed and matrix had been lost, free grafting of the toenail bed and matrix was performed, with a good result. The procedure can be used when restoring the length of the tip in fingertip amputation if used in combination with local skin flaps such as V-Y advancement or local rotation flaps.     

Bone graft incorporation after cortical perforations of the host bed

A fundamental issue in onlay bone graft persistence is the unpredictable extent of incorporation and volumetric maintenance of the graft. The purpose of this study was to evaluate the effects on integration of onlays, with either their cancellous or cortical portion facing toward the host bed, positioned over cortical perforations at the recipient site. Tibial or femoral unicortical bone grafts were harvested from isogeneic donors and positioned subperiostally on each tibia of 22 adult Lewis rats. On the experimental side, the recipient outer cortical bone surface received multiple perforations, 0.25 mm in diameter. The contralateral side served as a control (no cortical perforations). The findings were assessed after 4 and 20 weeks using routine histologic and immunohistochemistry techniques. Cortical perforations induced a migration of the recipient bone marrow into the graft as well as a reduced size diminution. More cortical bone remodeling and marginal lamellar bone apposition were observed after orientating the cortical portion of the graft toward the recipient site. These observations may be useful clinically to improve long-term success after autogeneic bone grafting. (Otolaryngol Head Neck Surg 1997;117:664-70.)     

Depth of subchondral perforation influences the outcome of bone marrow stimulation cartilage repair

Subchondral drilling and microfracture are bone marrow stimulation techniques commonly used for the treatment of cartilage defects. Few studies to date have examined the technical variants which may influence the success of the cartilage repair procedures. This study compared the effect of hole depth (6 mm vs. 2 mm) and hole type (drill vs. microfracture) on chondral defect repair using a mature rabbit model. Results from quantitative histomorphometry and histological scoring showed that deeper versus shallower drilling elicited a greater fill of the cartilage defect with a more hyaline character in the repair matrix indicated by significant improvement (p = 0.021) in the aggregate measure of increased cartilage defect fill, increased glycosaminoglycan and type II collagen content and reduced type I collagen content of total soft repair tissue. Compared to microfracture at the same 2 mm depth, drilling to 2 mm produced a similar quantity and quality of cartilage repair (p = 0.120) according to the aggregate indicator described above. We conclude that the depth of bone marrow stimulation can exert important influences on cartilage repair outcomes. © 2011 Orthopaedic Research Society Published by Wiley Periodicals, Inc. J Orthop Res 29: 1178–1184, 2011     

Alteration of split skin graft contraction with a synthetic dressing

Summary In a rat model, covering a split skin graft with a synthetic dressing for only one week alters the subsequent contraction characteristics of the underlying wound so that the graft increases in size in a manner similar to a full thickness skin graft.     

A useful method of fixing split-skin grafts

An n-butyl ester of cyanoacrylate monomer which polymerizes in 10 seconds when in contact with OH ions has been used for fixing skin grafts. It can be used for gluing graft to skin, or graft to graft. It is easy and rapid to apply, both in the theatre and on the ward, and has caused no side effects in 18 burn cases. It gives a stronger join than suturing in thin skin grafts.     

Absorption of lignocaine through split-skin donor sites

Seventeen patients undergoing split-skin grafting each received 3 mg/kg of a sterile 1% lignocaine gel applied to an area of the donor site equal to 3 sq cm/kg. Serial venous blood samples were taken for one hour following application and analysed for serum lignocaine concentration by high pressure liquid chromatography. The concentrations in all the patients were well below those associated with systemic toxicity. Clinical assessment included haemodynamic monitoring during the procedure, and postoperative evaluation of possible central nervous effects and of the degree of donor site analgesia obtained. No untoward effects were noted and the degree of analgesia, although difficult to assess, appeared good.     

外用罂粟碱抑制植皮片术后挛缩的实验研究

目的探讨外用罂粟碱霜对自体游离植皮片术后晚期挛缩的影响。方法在每头小型猪背部两侧皮肤制备10个2cm×2cm创面,从动物腹部正中取2cm×2cm的断层皮片并植于背部创面上,术后2周拆线,取同一动物身上100%成活且位置恰好左右侧相对的植皮片共12对,按左右侧分成A(罂粟碱治疗组)、B(空白霜剂对照组)2组,自拆线之日起,A组每日在植皮片表面外涂2%罂粟碱霜2次,B组仅涂抹空白对照霜剂,最后观察两组植皮片成活后1、2、3、4、5、6个月收缩率及植皮片成活后6个月时的组织学差异。结果A组植皮片收缩率较B组明显降低,两组之间差异有显著性意义(P<005)。组织切片显示A组植皮片成纤维细胞较B组明显减少,微血管数量较B组数量多,两组之间差异有显著性意义(P<005)。结论外用罂粟碱霜剂能够抑制自体游离植皮片术后挛缩,提高植皮效率。