Surgical Management of Large and Giant Congenital Pigmented Nevi of the Lower Extremity:

Refinements in the Preexpanded Distant Flap for Giant Melanocytic Nevi of the Upper Extremity in Pediatric Patients

BACKGROUND

Surgical treatment of large and giant congenital melanocytic nevi (GCMN) of the upper extremity is challenging because of limited options for reconstruction. A preexpanded distant flap is considered an important option in upper extremity reconstruction, where the soft tissue available for use is limited. The authors aimed to refine the preexpanded distant flap after excision of the GCMN in the upper extremity.

METHODS

Large (>10 cm) and giant (>20 cm) congenital melanocytic nevi of the upper extremities treated with tissue expansion and distant flaps over 10 years were retrospectively reviewed, and the authors describe in detail the surgical strategies for reconstruction of the upper extremity with a distant flap.

RESULTS

From March of 2010 to February of 2020, 13 patients (mean age, 2.87 years) treated with 17 preextended distant flaps were included. The mean flap dimension was 154.87 cm 2 , ranging from 15 × 5 to 26.5 × 11 cm. All procedures were successfully completed except for one, in which partial flap necrosis occurred. Preconditioning was performed before flap transfer in 5 patients with larger rotation arcs and flap dimensions. The mean duration of postoperative follow-up was 51.85 months. A new reconstructive protocol was proposed that combined the 3 elements, including a distant flap, tissue expander, and preconditioning.

CONCLUSIONS

In the treatment of GCMN in the upper extremities, careful planning and multiple stages are required. For pediatric patients, the preextended distant flap with preconditioning is useful and effective for reconstruction.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, IV.

Updates in the Management of Congenital Melanocytic Nevi

Congenital melanocytic nevi (CMN) carry an increased risk of melanoma and may be disfiguring, and consensus regarding treatment recommendations is lacking. While clinical monitoring is the standard of care, many caregivers are interested in its removal to prevent psychosocial burden or to decrease risk. Although melanoma can occur regardless of CMN removal, there are a variety of treatments that may offer improved cosmesis or local symptom control, including surgical excision, laser therapy, and other superficially destructive techniques. Regardless of the selected management, these patients are monitored for ongoing melanoma risk. An extensive discussion with families regarding the risks and benefits of observation versus active intervention is essential. To facilitate these discussions, we herein summarize current CMN management strategies and considerations.

Lower Extremity Pediatric Tissue Expansion: A Single Surgeon's 16-Year Experience

BACKGROUND

Tissue expansion is a well-established approach to soft tissue reconstruction in the pediatric population for lower extremity pathologies. Unfortunately, complication rates range from 19% to 40% in literature, including infection and implant extrusion, leading to delays in reconstruction. These challenges have prompted investigation toward categorizing risk factors for lower extremity tissue expander placement.

METHODS

A retrospective study of pediatric patients who underwent lower extremity tissue expander placement by the senior author (R.J.R.) was performed over a 16-year period. Patient charts were reviewed to categorize baseline and operative characteristics. Primary outcome variables were surgical-site infection, expander extrusion, and expander deflation. Univariate and multivariate logistic regressions were performed ( α < 0.05).

RESULTS

There were 59 tissue expanders in our cohort. The overall complication rate was 27.1% with a 77.2% successful reconstruction rate. Greater number of expanders placed during 1 operation is associated with 2.5 increased odds of having any complication and is associated with 0.4 decreased odds of having a successful reconstruction. Incisions made in scar tissue for expander placement appear to be associated with a greater than 7 times increased odds of readmission.

CONCLUSIONS

Reconstruction of soft tissue pathologies using lower extremity tissue expanders in the pediatric population is an effective yet challenging technique. This study identified that the number of expanders inserted during 1 operation, incisions made over scar tissue, and expanders placed in the anterior thigh were correlated with having a negative impact on reconstructive outcomes. Extra care should be taken with patients who require multiple expanders during 1 operation and with choosing the location and incision of expander placement.

3D Printing and Surgical Simulation for Management of Large and Giant Congenital Melanocytic Nevi

Tissue expansion with subsequent adjacent tissue transfer is often the preferred and sometimes the only option for reconstruction of large and giant congenital melanocytic nevi. Successful reconstruction with maximal efficiency and optimal aesthetic outcome requires careful planning of the tissue transfer, which itself requires careful selection of the tissue expander size and positioning. Unfortunately, there is little opportunity to gain experience in these skills due to the rarity of this condition. In situations where there is a rare condition that requires a complex technical procedure with much interoperative decision-making, surgical experience can be supplemented with the use of surgical simulation. In this article, we report on the use of three-dimensional patient imaging, three-dimensional printing, and surgical simulation for planning the reconstruction of large and giant congenital melanocytic nevi. We describe how this technology allows us to simulate multiple different approaches to expander placement and adjacent tissue transfer. We also describe how these simulations can be used to create cutting guides to guide final incision design and reduce intraoperative decision-making. Finally, we discuss how these models can be used to educate patients and families about the process and outcomes of nevus excision and reconstruction.

Safety and effectiveness of surgical excision of medium, large, and giant congenital melanocytic nevi: A systematic review and meta-analysis

BACKGROUND

Treatment indications of congenital melanocytic naevi (CMN) have shifted from the prevention of malignant transformation more towards the improvement of appearance and psychosocial health. Surgical excision is often preferred, but its safety and effectiveness remain unclear.

OBJECTIVE

To assess the outcomes of surgical excision of medium-to-giant CMN.

PRIMARY OUTCOME

safety (complications).

SECONDARY OUTCOME

effectiveness (satisfaction and CMN core outcomes).

METHODS

PubMed, EMBASE, and CENTRAL were searched for studies on the excision of medium-to-giant CMN and/or CMN requiring reconstruction or serial excision. Meta-analyses of safety per patient were conducted, and pooled outcomes of safety and effectiveness were presented in summary-of-findings tables.

RESULTS

A total of 1444 studies were found, of which 22 were included, evaluating 643 eligible patients. Study quality varied, and reporting of baseline characteristics and outcomes was heterogeneous. Pooled proportions were overall 9.8% for major wound-related complications, 1.2% for minor wound-related complications, 1.2% for scar-related complications, and 4.3% for anatomical deformities. For large/giant CMN, complication rates were, respectively, 23.1%, 2.9%, 12.9%, and 2.4%; and for CMN with eyelid involvement, 0.5%, 3.3%, 0.4%, and 54.2%. Patients rated their satisfaction with the cosmetic outcome as 24.4% excellent, 71.0% good, and 4.6% poor/moderate. Physicians rated this as 18.3% excellent, 70.1% good, and 11.7% poor/moderate. Thirty-five other outcomes of effectiveness were summarized. However, many were rarely reported.

CONCLUSIONS

Surgical excision of CMN appears to be safe and effective in many cases, depending on CMN size and location. Major wound-related complications and scar-related complications occurred more frequently with large/giant CMN, whereas anatomical deformities occurred with the majority of CMN with eyelid involvement.

[The complications of skin expansion in paediatrics: Diagnostic, taking over and prevention]

Skin expansion is a difficult and long process in which can occur more or less serious complications. Overall complications rates describe in the literature vary between 13 and 37%. We can categorize them in major complications, which can lead to a failure maybe even an aggravation of the anterior status, and in minor complications that do not compromise the expansion process but can alter it. The main major complications are infection, skin suffering and necrosis which can lead to prosthesis exposition, leaks and technical problems with equipment dysfunctions that may cause difficulties or a failure of the inflations. The main minor complications are hematomas, seromas, valve or tube exposition, pains with paraesthesias caused by neighbouring organs compression, pathologic and unsightly scares and can lead to an important psychological impact. These complications can be due to a precarious skin's state, a material dysfunction or unpredictable technical problems but also by an inappropriate preoperative indication or planning. The emerging of a complication, however, is not synonymous to a failure of the procedure; a satisfactory reconstruction may still be obtained in 75% of all cases. The purpose of this article is to help to identify the situations at risk of complications in order to prevent, detect and treat them early.

Management of challenging congenital melanocytic nevi: outcomes study of serial excision

BACKGROUND

Large congenital melanocytic nevi (CMN) cause significant deformity and are at risk for malignant degeneration. Techniques used to remove difficult CMN include serial excision, skin grafting, or tissue expansion. Some authors prefer skin grafting or tissue expansion if several stages would be required to serially resect the CMN. The purpose of this study was to determine the efficacy of serial excision for CMN requiring ≥3 procedures.

METHODS

Medical records and clinical images of patients with CMN treated between 2007 and 2013 were reviewed. Inclusion criteria were: (1) lesions that required ≥3 serial excisions to remove and (2) CMN that could have been treated reasonably with skin grafting or tissue expansion. Patient age, gender, location of the lesion, size of the CMN, number of serial excisions, and complications were recorded.

RESULTS

The study included 21 patients. Lesions were located on the lower extremity (38.1%), head/neck (33.3%), upper extremity (14.3%), or trunk (14.3%). Nevus size was 2.2%±1.2% total body surface area. The age during the first operation was 4.3 years (range 3 months to 15 years). The number of excisions was 3.5±0.7, spaced 8.2±4.3 months apart. Partial suture line dehiscence occurred after 2/72 operations and seroma resulted after 1/72 operations; there were no infections.

CONCLUSION

Challenging CMN amenable to serial excision can be removed effectively and safely using this technique. Children are left with a favorable linear scar, do not have donor or recipient site morbidity from skin grafting, and are not subjected to potential tissue expander complications and injections required for expansion.

The shifting paradigm in the management of giant congenital melanocytic nevi: review and clinical applications

SUMMARY

Congenital melanocytic nevi remain a subject of controversy with respect to risk of malignant transformation and recommended management. Recent studies indicate a lower malignant risk (0.7 to 2.9 percent) than had previously been estimated. Surgery has not been proven to reduce malignant risk or improve quality of life, and may result in undesirable aesthetic and functional outcomes. In this article, the authors review key controversial issues in the management of congenital melanocytic nevi and re-evaluate indications for surgical treatment. An updated review of controversial topics in the management of congenital melanocytic nevi is presented, and clinical applications are demonstrated through clinical cases. Updates regarding the risks and outcomes of congenital melanocytic nevi patients open a renewed debate with respect to the indications for surgery as well as the extent of surgery that may be suitable. Treatment should be tailored to achieve optimal aesthetic results whereby complete nevus excision is not the goal. As such, nonsurgical management and incomplete nevus excision should be integrated as legitimate parts of any treatment algorithm.

Skingineering I: engineering porcine dermo-epidermal skin analogues for autologous transplantation in a large animal model

BACKGROUND

Extended full thickness skin defects still represent a considerable therapeutic challenge as ideal strategies for definitive autologous coverage are still not available. Tissue engineering of whole skin represents an equally attractive and ambitious novel approach. We have recently shown that laboratory-grown human skin analogues with near normal skin anatomy can be successfully transplanted on immuno-incompetent rats. The goal of the present study was to engineer autologous porcine skin grafts for transplantation in a large animal model (pig study = intended preclinical study).

MATERIALS AND METHODS

Skin biopsies were taken from the pig's abdomen. Epidermal keratinocytes and dermal fibroblasts were isolated and then expanded on culture dishes. Subsequently, highly concentrated collagen hydrogels and collagen/fibrin hydrogels respectively, both containing dermal fibroblasts, were prepared. Fibroblast survival, proliferation, and morphology were monitored using fluorescent labelling and laser scanning confocal microscopy. Finally, keratinocytes were seeded onto this dermal construct and allowed to proliferate. The resulting in vitro generated porcine skin substitutes were analysed by H&E staining and immunofluorescence.

RESULTS

Dermal fibroblast proliferation and survival in pure collagen hydrogels was poor. Also, the cells were mainly round-shaped and they did not develop 3D-networks. In collagen/fibrin hydrogels, dermal fibroblast survival was significantly higher. The cells proliferated well, were spindle-shaped, and formed 3D-networks. When these latter dermal constructs were seeded with keratinocytes, a multilayered and partly stratified epidermis readily developed.

CONCLUSION

This study provides compelling evidence that pig cell-derived skin analogues with near normal skin anatomy can be engineered in vitro. These tissue-engineered skin substitutes are needed to develop a large animal model to establish standardized autologous transplantation procedures for those studies that must be conducted before "skingineering" can eventually be clinically applied.

Tissue engineering of skin

The engineering of skin substitutes and their application on human patients has become a reality. However, cell biologists, biochemists, technical engineers, and surgeons are still struggling with the generation of complex skin substitutes that can readily be transplanted in large quantities, possibly in only one surgical intervention and without significant scarring. Constructing a dermo-epidermal substitute that rapidly vascularizes, optimally supports a stratifying epidermal graft on a biodegradable matrix, and that can be conveniently handled by the surgeon, is now the ambitious goal. After all, this goal has to be reached coping with strict safety requirements and the harsh rules of the economic market.

[Giant congenital naevus : Indications and techniques for surgical treatment]

According to current knowledge the term giant congenital naevus is generally applied to skin alterations which consist of naevus cells, that are already conspicuous at birth and reach a diameter of at least 20 cm or more in adulthood. Surgical removal of such alterations is fundamentally indicated because there is high potential for degeneration. The surgical challenge is the functional and aesthetic reconstruction after removal. This article presents the incidence, natural course and pathology of such giant congenital naevus alterations. The advantages and disadvantages of various reconstruction procedures are presented together with an algorithm for management of these potentially malignant alterations.