The halo split skin graft in the management of non-melanoma skin cancer of the leg: a retrospective study

Background: The purpose of this study was to compare the results of the halo split skin graft (HSSG) by two primary care skin cancer practitioners at one clinic at the Gold Coast, Queensland, Australia, to the results of the only previous study while adding to the body of evidence regarding use of the HSSG following excision of non-melanoma skin cancer on the leg. Method: A retrospective review of the notes (Jan 2010–Aug 2012) was performed of all cases of nonmelanoma skin cancer (NMSC) excisions in which split skin graft (SSG) closure with the HSSG was utilized on the leg. Results: There were a total of 68 HSSGs included over the 31 months of the study. Average lesion size was 19.4 mm (range 9–75 mm) and the average age of patients was 78 years (range 49–95 years) with 49% of patients being male. The average healing time was 4 weeks with 35/68 (51%) healing within 14 to 21 days. The overall infection rate was 8/68 (11.8%), which decreased to 4/53 (7.5%) when the ankle grafts were excluded. The graft failure rate was 7/68 (10%) with 3/68 (4.4%) having both infection and graft failure. Limitations: This was a retrospective study. Conclusion: The HSSG confines the surgical wounds to a single site, does not require specialized equipment and it is an economical and effective option for managing NMSC on the leg in situations where skin graft is indicated.


Introduction
The halo split skin graft (HSSG) was first described by Sharad Paul in 2010, with a series of 28 procedures, as a novel method for surgically managing non-melanoma skin cancer (NMSC) lesion defects on the leg (lower limb below the knee to the ankle) [1]. This technique eliminated the need for two separate surgical sites, both requiring local anesthetic and The actual size of the lesions was included for the purpose of this study and where size had not been recorded in the notes it was determined from the histopathology report.
Surgical margins were marked prior to excision of the lesions according to those recommended in the clinical guidelines [6] with a minimal margin of 3 mm for clinically favorable BCCs and keratoacanthomas and 5 mm for clinically favorable SCCs. Pre-operative biopsy was routinely performed to establish the diagnosis and histological characteristics.
All cases of HSSG included had healed within the time period of the study.

The HSSG Protocol
The practitioners followed a similar protocol to Paul [1] with some minor modifications with respect to the harvest-  The procedures included in this study were on NMSC on the leg (from below the knee to the ankle) as well as on NMSC that were sited both at the ankle and just distal to the ankle including the Achilles tendon area and also the dorsum of the foot immediately adjacent to the ankle. This group of lesions both at and just distal to the ankle were grouped together and allocated to the 'ankle' for the purpose of this study.
annulus (see Figure 1B). For the majority of the study time, small bleeding areas in both the donor site and the wound bed were electrically cauterized, however a change was made later in the study period to using aluminum chloride 35% for hemostasis to the donor area only, while still using cautery to achieve hemostasis in the wound bed. No aluminum chloride was used on the wound bed at any time. The

Results
There were a total of 76 HSSG performed on the leg and ankle during the 31 months of the study. Eight were excluded due to lack of clarity in the notes or because the patients were lost to follow up leaving 68 cases of HSSG which were included in the study (SCC=45, BCC=16, KA=7). All analyzed details of all of the 68 cases are displayed in Table 1.
Overall, 36/68 (51%) of the patients were female and the average age of patients was 78 years (range 49-95 years). The average age for females was 79 years and for males 77 years.
All lesions in this study were excised down to at least the subcutaneous tissue plane. There were 2/68 (2.9%) cases in which the histopathology report stated that a margin was positive for tumor and 3/68 (4.4%) where margins were ner graft than that of the No. 22 scalpel blade that was used by Paul [1].
The protocol adopted required that patients wash at home in triclosan 1% (Phisohex-Sanofi-Aventis, Paris, France) body wash for 1 week prior to the surgery. At the time of presentation for surgery, the lesion and the clinical surgical margins were marked on the skin after which the annulus, from which the graft would be harvested, was marked around the central lesion (see Figure 1A). This was measured slightly differently to the method described by Paul [1].   The overall infection rate was 8/68 (11.8%) and this consisted of 4/15 (26.7%) ankle grafts and 4/53 (7.5%) leg grafts.
The graft failure rate was 7/68 (10%) and three of these were co-infected. Five of the infected grafts did not fail (see Table 1). Post-operative bleeding on the first day occurred in 4/68 (5.9%), but bleeding did not result in infection or graft failure in any of these cases.
ciency and diabetes. The older population of this study may be relevant in that regard.
Graft failure was declared in any wound that took more than 8 weeks to heal or which was described in the notes as having had a graft failure. While the infection rate was 8/68 and the graft failure rate similar at 7/68, there were 5 infected grafts that did not fail. Ankle HSSG however were over-represented with five of the graft failures involving ankle grafts. Post-operative bleeding, which occurred in 4/68 cases, was not associated with either infection or graft failure (see Table 1). It is not known whether the slight deviations in surgical method or the difference in dressing protocol to that described by Paul [1], contributed to the graft failure rate. However it is clear that the HSSG at the ankle were not always successful. was smaller, the color and texture match to surrounding skin was superior and the reported patient pain levels were less [1]. Objective measurement of these characteristics is an area of potential future research.
A major limitation of this study is that it was retrospective. It was totally reliant on the comprehensiveness of the notes that were taken by the practitioners and the nursing staff at the time of treatment and the subsequent interpretation of those notes by the researcher.
Overall, this study highlights a number of areas in which more research is desirable. A prospective randomized study of patients allocated to a traditional SSG procedure or a HSSG procedure, would be a useful future study.

Conclusion
The results of this study suggest that the HSSG is a reasonable choice for wound management after excision of NMSC on the leg when primary closure or skin-flap closure is not pos-These cases were not routinely re-excised but were assessed on an individual basis taking into account the patient's morbidity at the time and in fact they were both managed by ongoing surveillance. In addition, margins assessed as inadequate according to current guidelines [6] occurred in another 3/68 (4.4%) of the cases (all SCCs) and similarly these cases were managed by observation rather than re-excision.
It is acknowledged that the HSSG procedure is unique in that the skin from the surgical margin is placed over the defect in contrast to traditional SSG procedures where the skin from a remote site is used. It is also acknowledged that this is done in a non-oriented manner. For this reason it would appear to be advisable to respond to a positive margin with a HSSG procedure by total removal of the graft, in contrast to the situation where a traditional skin graft or skin flap procedure has been employed where orientation of the specimen permits targeted re-excision if a margin is positive.
Although there was no clear protocol followed for positive or inadequate margins in the practice, which is the subject of this retrospective observational study, there is a good argument for establishing a protocol for dealing with these in the future. One such protocol could include delaying SSG closure of wounds by 24-48 hours while awaiting pathology results regarding histological margins, in order to establish that clear margins have been obtained. While Mohs surgery would be optimal prior to closure, it is not affordable for most patients.
The average time taken for wound healing was longer in this study compared to that of Paul (28 days compared to 17).
It is acknowledged that the deviation from the protocol of Paul may have influenced slower healing rates although this is not the explanation in the opinion of the authors. The estimation of healing time on a weekly basis using a surrogate marker as described is likely to have produced an overestimation but it was the only method available in this retrospective study.
The infection rate was higher in this study (11.8% of all leg and ankle HSSGs compared to 0% by Paul [1]), which may have also contributed to the overall increased time taken to heal. It is known that wounds on the lower leg have a higher rate of infection than wounds on some other sites of the body, with an increased infection rate with a more distal location from the knee [9,10]. This is reflected in this study with the infection rate for ankle grafts being proportionately higher than that for the leg (26.7% vs. 7.5%). It is also possible that the infection rate in this study was overestimated by the researcher due to the methods used to collect the data, by which all instances of antibiotic prescribing were classified as due to wound infection if they occurred after the time of surgery and if an alternative reason for the prescription was not clear. Other potential causes of the higher wound infection rate and slower healing times are the warmer and more humid climate of the region [10] and patient co-morbidities such as peripheral vascular disease, chronic venous insuffi-sible. It allows patients to remain out of hospital, to continue to mobilize and to convalesce at home. It also confines the surgical wounds, and thus local anesthetic infiltration, surgical healing and wound dressing to a single site. The authors of this study agree with Paul that the HSSG is a technique that does not require specialized equipment and that it is an economical and effective procedure for managing NMSC on the leg when SSG is indicated.