UNASSIGNED: The large resection area of perianal tumor makes the skin defect hard to reconstruct. The keystone flap has demonstrated a growing application in skin defects. Herein, we aimed to explore the efficacy of keystone flap in the repair of skin defect after perianal tumor resection.
UNASSIGNED: This study is a retrospective review of patients diagnosed with perianal tumor from January 2010 to November 2021. A standardized data collection template was used to collect variables. The detailed process of the reconstructive surgery is carefully described in this article. After surgery, the healing process was closely observed.
UNASSIGNED: Twenty patients underwent keystone flap repair. The average wound size before closure measured 3.5 × 4.9 cm2. Primary wound healing was achieved, and the flap survived during the follow up period, which ranged from 6 to 24 months. No severe complications occurred; slight edema was noticed in one patient.
UNASSIGNED: The application of keystone flap is a promising way to repair skin defect after tumor removal, and the complications rate was low after surgery. It can be concluded that this method is an effective and reliable way to repair perianal skin defect.

BACKGROUND: The aim of this study was to evaluate the treatment outcomes of patients with trunk defects reconstructed by Keystone Design Perforator Island Flap (KDPIF).
METHODS: A total of 37 eligible cases with trunk defects were reconstructed by KDPIF from January 2017 to June 2020. Data were collected from electronic medical records, including aetiology, defect size and location, and type of KDPIF applied. Postoperative complications were recorded, and patient satisfaction was evaluated at the last clinical visit.
RESULTS: There were 23 males and 14 females, and the average defect was 8.16 × 4.94 cm. Etiologies included decubitus ulcer (n = 12), oncologic resection (n = 11), infection (n = 9) and others (n = 5). Type III was applied in 19 cases, Type IIa in 13 cases, type IV in two cases and modified KDPIF in three cases. There were no major complications except delayed healing or wound dehiscence in three cases, which were managed by regular dressing or secondary surgical intervention. The average postoperative satisfaction score was 8.68 ± 1.13 points and all patients were satisfied with their cosmetic appearance and function at the last follow-up.
CONCLUSIONS: Trunk defects can be successfully reconstructed by KDPIF, which results in satisfactory cosmetic and functional outcomes without major complications.

Facial defect coverage is a common subject in the field of reconstructive surgery. There are many methods for facial defect reconstruction, and reconstructive surgeons should choose the most appropriate method on a case-by-case basis to achieve both functional and aesthetic improvement. Among various options for facial reconstruction, the local flap technique is considered the best reconstructive modality to provide good tissue matches of color and texture, which is consistent with the ideal goal of reconstruction (replacement of like-with-like). Keystone design perforator island flap (KDPIF), devised by Behan in 2003, has been applied to various fields of reconstructive surgery in the past decade due to its design simplicity, robust vascular supply, and reproducibility. Several studies have reported KDPIF reconstruction of facial defects, such as large parotid defects, small-to-moderate nasal defects, and eyelid defects. However, KDPIF has been used relatively less in facial defects than in other body regions, such as the trunk and extremities. The purpose of this review is to provide an organized overview of facial KDPIF reconstruction including the classification of KDPIF, modifications, physiology, mechanism of flap movement, consideration of facial relaxed skin tension lines and aesthetics, surgical techniques, clinical applications, and precautions for successful execution of KDPIF reconstruction.

OBJECTIVE: The keystone design perforator island flap (KDPIF) is often used to cover defects in reliable blood supply and similar skin patterns, but its mobility is limited, especially when the wound is large or occurs around joints. Here, we describe a modified KDPIF, boat-shaped flap. We added a V shape along the lateral arc, forming a V-Y flap on KDPIF\'s outer arc shapes like a sail. This paper also describes a clinical study to evaluate this method.
METHODS: From September 2014 to March 2017, 31 patients were operated on using the boat-shaped flap in our department and were followed up annually with clinical evaluation. The wound locations included joints (n = 11), trunk (n = 18), and face (n = 2). Fifteen defects were ≥5 × 5 cm2 .
RESULTS: After 6 to 24 months of follow-up, 29 patients had first-intention healing and were satisfied with the morphology and function. Secondary healing was observed in two patients, and the wounds were closed after dressing treatment for 2 weeks.
CONCLUSIONS: The boat-shaped flap enhances the mobility and achieves strong resistance to tension. The modified curvilinear shape prevents the joint activity from being restricted, with visually concealed scars. It is particularly applicable for repairing large wounds and defects around joints.

OBJECTIVE: We aimed to explore the efficacy of keystone flap combined with vacuum-assisted closure (VAC) in the repair of sacrococcygeal wounds.
METHODS: This study is a retrospective review of patients undergoing keystone flap reconstruction between January 2014 and January 2018. A standardized data collection template was used to collect related variables. The detailed process of the reconstructive surgery is carefully described in this study. The postoperative healing process was closely observed.
RESULTS: Twelve patients underwent keystone flap repair between January 2014 and January 2018. The average wound size before closure measured 7.83 ± 1.93 × 5.28 ± 0.91 cm. All the patients achieved primary wound healing and the flaps survived during the follow-up period, which ranged from 1 to 24 months. No severe complications and obvious scar appeared, and the patients were satisfied with both appearance and function.
CONCLUSIONS: The application of keystone flap combined with VAC is a promising way to repair wounds in the sacrococcygeal region with little postoperative complication and similar soft-tissue thickness to the surrounding tissue.

We have previously reported a small series on the closure of large myelomeningocele (MMC) defects with a keystone design perforator island flap (KDPIF) in a paediatric neurosurgical centre in Australia. We are now presenting an updated longer term follow-up of an expanded series demonstrating longer term durability of this vascularized flap for large myelomeningocele defects.
The prospective data from the Monash Neurosurgical Database were used to select all cases of MMC between December 2008 and September 2016. Retrospective analysis of the neurosurgical database revealed an additional three patients who underwent KDPIF closure at the Monash Medical Centre for MMC repair at birth.
Wound healing was satisfactory in all six cases. With delayed follow-up, there was no associated skin flap separation, skin flap dehiscence, skin flap necrosis, cerebro-spinal fluid leak, however two infections were encountered, both resolved with conservative management including antibiotics and simple washout.
In this expanded case series with increased longevity of follow-up, the keystone design perforator island flap remains a robust alternative for closure of large myelomeningocele defects.