A systematic review of the keystone design perforator island flap in the reconstruction of trunk defects

The Keystone Flap: A Game Changer That Promises New Horizons in Reconstructive Surgery

BACKGROUND

Since its first description emerged in 2003, the keystone flap has garnered the attention of the international scientific community due to its high safety profile and the suitably low complication rate associated with the reconstructive process.

MATERIALS AND METHODS

In this study, data were obtained from the performance of 72 keystone flaps to cover soft-tissue defects after the excision of neoplastic processes, excisions, and injuries occurring in polytrauma. The study was conducted in the Department of Plastic Surgery, "Bagdasar-Arseni" Emergency Hospital, Bucharest, and two plastic surgeons in the department performed the surgical procedures.

RESULTS

The statistical analysis revealed a remarkably low complication rate (3.22%), excellent functional and esthetic results, and a short hospitalization time. No intraoperative complications were identified during this study. The degree of satisfaction obtained after reconstructive surgery was exceptionally high, with a score of 9.47 on a 10-point rating scale (0 = poor results, 10 = excellent results) from the patient's perspective and 9.51 out of 10 for the surgical team.

CONCLUSIONS

The keystone flap is the optimal solution for reconstructing soft-tissue defects of variable sizes and shapes. It is associated with a low length of hospitalization, a low complication rate, and high patient satisfaction.

The Keystone Perforator Island Flap: Review of Utility and Versatile Clinical Applications

Background

The keystone perforator island flap (KPIF) was described almost a decade ago. However, this flap has only recently been recognized for its advantages in various clinical applications in plastic surgery. A better understanding of the versatility of KPIFs can help promote the widespread adoption of this technique for complex wounds in various anatomical regions.

Methods

A retrospective chart review was conducted of patients undergoing KPIFs from December 2018 to March 2022 at the authors' home institution. The indications, surgical approaches, patient characteristics, and outcomes were extracted for review and analysis.

Results

A total of 12 patients (ages 13-86 years) underwent reconstruction with KPIFs for oncologic and nononcologic defects. By anatomic region, three cases involved the upper back, six involved the lumbosacral region, one involved the perineum, and two involved the midfoot. Half of the patients (n = 6) had failed previous attempts at wound closure. The mean defect size was 13.8 × 10.0 cm for the upper back lesions, 13.7 × 4.8 for the lumbosacral defects, and 3.5 × 2.0 for the metatarsal wounds. Median follow-up time for all patients was 7.5 months (IQR: 4-10.5). On follow-up, there was 100% flap survival.

Conclusion

KPIFs are a simple, safe, and suitable option for reconstructive closure of defects in many anatomical areas, including wounds complicated by previous failed closure attempts, with low complication risk profile.

A bipedicled keystone perforator island flap: Pedicle division technique with enhanced advancement potential for chronic wound coverage

Since the first description of the keystone perforator island flap (KPIF) in 2003, several modifications have been suggested to enhance its coverage ability. However, locoregional flaps have limited its use in chronic wounds due to decreased elasticity around the defect. We investigated the use of a bipedicled KPIF (bKPIF), which covers a defect while completely elevating the median part of the flap from the fascia. A retrospective chart review of 20 consecutive patients who underwent classical type I KPIF (n = 10) or bKPIF (n = 10) reconstruction from June 2020 to December 2022 was performed. Baseline characteristics, indications, operative details, healing time, and complications were analyzed and compared between the two groups. The average defect size was 30 cm2 in type I KPIF and 36.6 cm2 in bKPIF, and an average flap size of 86.5 cm2 was covered in type I KPIF, larger than bKPIF at 73.8 cm2. The flap/defect ratio was significantly lower in the bKPIF group (p < 0.02), with an average of only 55% pedicular area. The average advancement distance in the bKPIF group was 1.85 cm (standard deviation 0.78) greater than that in the type 1 KPIF group. There was no significant difference between the groups in terms of operation time, complete healing time, and complications. All ten bKPIFs were successful without any flap necrosis. Even though the mean pedicular area in the bKPIF group was nearly half compared with that in the type I KPIF group, it was sufficient to perfuse the entire flap without any major complications. This novel technique using bKPIF has potential clinical relevance, as evidenced by the enhanced ability to cover chronic defects with severe scarring. Lateralizing the hotspots to the bilateral corners of the flap is the mechanism that facilitates this potential.

Current Controversies in Melanoma Treatment

LEARNING OBJECTIVES

After reading this article and viewing the videos, the participant should be able to: 1. Discuss margins for in situ and invasive disease and describe reconstructive options for wide excision defects, including the keystone flap. 2. Describe a digit-sparing alternative for subungual melanoma. 3. Calculate personalized risk estimates for sentinel node biopsy using predictive nomograms. 4. Describe the indications for lymphadenectomy and describe a technique intended to reduce the risk of lymphedema following lymphadenectomy. 5. Offer options for in-transit melanoma management.

SUMMARY

Melanoma management continues to evolve, and plastic surgeons need to stay at the forefront of advances and controversies. Appropriate margins for in situ and invasive disease require consideration of the trials on which they are based. A workhorse reconstruction option for wide excision defects, particularly in extremities, is the keystone flap. There are alternative surgical approaches to subungual tumors besides amputation. It is now possible to personalize a risk estimate for sentinel node positivity beyond what is available for groups of patients with a given stage of disease. Sentinel node biopsy can be made more accurate and less morbid with novel adjuncts. Positive sentinel node biopsies are now rarely managed with completion lymphadenectomy. Should a patient require lymphadenectomy, immediate lymphatic reconstruction may mitigate the lymphedema risk. Finally, there are minimally invasive modalities for effective control of in-transit recurrences.

Vulvar Reconstruction Using Keystone Flaps Based on the Perforators of Three Arteries

Various flaps are used to reconstruct skin and soft tissue defects of the vulva following resection of malignancies. Whenever possible, reconstruction using local flaps is the standard treatment. Here, we describe vulvar defect reconstruction using keystone flaps. Standard keystone flaps are based on randomly located vascular perforators. However, we designed a keystone flap that includes perforators of three named arteries (the anterior labial artery of the external pudendal artery, cutaneous branches of the obturator artery, and posterior labial artery of the internal pudendal artery) and the pudendal nerve, which accompanies the internal pudendal artery. Four patients with squamous cell carcinoma and extramammary Paget's disease of the vulva underwent radical vulvectomy and keystone flaps including perforators of three arteries. Depending on the morphology of the defects, keystone flaps were used with different designs. For elliptical and unilateral vulvar defects, a standard keystone flap was designed, and for defects on both sides of the vulva, a double opposing keystone flap was used. For oval defects, the omega variant keystone flap was designed, and when the morphology of the defect needed rotation of the flap, a rotational keystone flap was designed. All the patients showed good function and sensation, with an acceptable cosmetic appearance.

Customized reconstruction with rotation Hemi-Keystone flap

INTRODUCTION

The keystone perforator flap has become a versatile alternative for reconstruction of cutaneous defects of various etiologies and in all age groups. However, it demands a notable incision area proportional to defect size and is more prone to excessive tension during defect closure. We present a novel modified rotation Hemi-keystone flap that reveals its excellence in flap survival.

METHODS

Between March and December 2021, a retrospective chart review was conducted of 40 patients who received rotation Hemi-keystone flap for coverage of cutaneous defects by a single surgeon. The primary outcome was successful flap survival.

RESULTS

We performed a total of 45 modified rotation Hemi-keystone flaps for reconstruction of cutaneous wound defects. The location of the wound defects was in the head and neck (38%), extremities (35.7%), and trunk (26.2%). The most common cause of wound defect is tumor resection (45.2%). The mean wound defect dimensions were 3.5 cm × 3 cm. The mean follow-up time was 6 months. There were no significant complications, with only one patient (2.4%) having minor wound dehiscence, which was treated by local wound care.

CONCLUSIONS

The current series presents a simple, reliable, and versatile modification of the traditional keystone flap that minimizes morbidity at the reconstruction site along with improvement of flap mobility for successful reconstruction of cutaneous defects in a tension-free manner. The favorable outcome of this technique contributes to the inclusion of the rotation Hemi-keystone flap as an excellent surgical option in the reconstruction of various soft tissue defects.

HOW WE DO IT: the Keystone flap for large skin defects: our experience with 30 consecutive cases

BACKGROUND

The keystone perforator-based fasciocutaneous island flap is a method of locoregional skin defect reconstruction, consisting of two conjoined V to Y advancement flaps. In this article, we report a series of 30 consecutive cases in various body parts with the aim to demonstrate the versatility of the keystone flap in the reconstruction of various skin defects after removal of a suspected malignant skin lesion and evaluate our clinical experience while maintaining oncological safety and good aesthetic results.

METHODS

Patients who underwent keystone flap reconstruction between January 2016 and January 2021 were retrospectively reviewed. Their demographics, operative details, oncological data and postoperative details were obtained from the institution's internal electronic patient records system.

RESULTS

The majority of the skin defects were the result of an oncologic resection (97%, n = 29) and were located in the pretibial region (47%, n = 14). In five cases (17%) there was a need for a double keystone flap to cover the skin defect. One or more risk factors (hypertension, smoking, anticoagulation, …) were identified in 22 patients (73%). Minor complications (partial wound dehiscence, effusion or surgical site infection) occurred in ten cases (33%) which were resolved with conservative wound management or systemic antibiotics. There were no major postoperative flap-related complications such as flap failure or need for re-surgery.

CONCLUSION

In our experience, the keystone island flap is an effective and reliable technique to attain a single stage tension-free closure of large skin defects. Due to its low technical complexity and high success rate, we consider it a feasible alternative to other reconstructive flaps and grafts for direct closure of secondary defects.

Vessel Loop Shoelace Technique followed by Keystone Flap to Treat a Large Mid-back Defect

The keystone design perforator island flap has been gaining popularity for reconstructing large cutaneous defects with sufficient soft tissue laxity. However, for a defect with insufficient local tissue and tense laxity such as upper to mid-back, a single keystone flap may not be so suitable for advancement and mobilization. Instead of an additional flap or double-opposite-designed keystone flaps, we attempted to apply the vessel loop shoelace technique for external expansion before proceeding with only one keystone flap reconstruction for a 15 × 15 cm skin and soft tissue defect on the mid-back. The outcome was a viable flap, with no ischemic flap edge, wound dehiscence, or infection. In our opinion, external expansion with vessel loops followed by a keystone flap might yield fairly good results for the reconstruction of mid-back defects; furthermore, this method may be ideal for defects located in regions lacking sufficient skin laxity.

The Use of Color Duplex Ultrasound for Local Perforator Flaps in the Extremity

BACKGROUND

 The local flaps, especially perforator and keystone flaps, are used as first-line treatment option in reconstruction of small tomoderate-sized defect of the extremity. However, the high complication rate associated with these flaps may hinder this usage.

METHODS

 This article reviews the technical and clinical aspect of using color duplex ultrasound )CDU) in the preoperative, intraoperative, and postoperative period for propeller and keystone flaps.

RESULTS

 CDU allows the surgeon to understand the anatomical aspect of the perforator such as the location, point of penetration on the deep fascia, subcutaneous pathway )axiality) and physiological aspect such as velocity and flow volume. Understanding and utilizing this information will allow accurate preoperative design, intraoperative decision making, and postoperative monitoring, leading to better outcome.

CONCLUSION

 Carefully designed local perforator flaps based on anatomy and physiology using CDU will be a powerful armamentarium for reconstruction of the lower extremity.

Comparison of the Keystone flap and the Limberg flap technique in the surgical treatment of pilonidal sinus disease

Pilonidal sinus (PS) disease is a chronic inflammatory disease of the sacrococcygeal region. Although various methods have been described for surgical treatment, there is no consensus on the best surgical technique. The aim of this study was to present the results of a new advancement flap technique named the "Keystone flap (KSF)" and compared with the Limberg flap (LF) technique in pilonidal sinus surgery. A retrospective review was made of 124 consecutive patients surgically treated for PS disease with KSF and LF procedures. Baseline characteristics, operation time, volume of excised specimen, duration of hospitalization, duration of drainage, duration of healing, time to return to work, local complications and recurrence were evaluated and compared between the two procedures. Operation time, healing time, and time to return to work were significantly shorter in the KSF group. Partial wound dehiscense and prolonged wound healing were more common in the LF group. An additional intervention in the operating room was required by 21.1% of the LF group and was a significantly lower rate in the KSF group at 7.5%. There was no significant difference between the groups in terms of recurrence. The KSF procedure seems promising for treating pilonidal sinus disease, with the advantages of shorter operation, healing, and return to work times. It also provides lower partial wound dehiscence and necrosis rates.

Outcomes of the keystone perforator island flap for oncologic reconstruction of the back

BACKGROUND

Coverage of posterior trunk defects after tumor resection can be challenging due to the intricate anatomy. The keystone perforator island flap (KPIF) provides coverage of the defect without the need for distant flap coverage or microsurgery, matches the recipient's skin color and contour, and requires a short operative time.

METHODS

A retrospective review of all oncological back reconstructions with KPIF was performed at our institution. The patient comorbidities and surgical outcomes were collected.

RESULTS

A total of 17 patients underwent 20 KPIF (15 single and 2 double) for back reconstruction. Surgical indications were sarcoma (n = 12) and melanoma (n = 5). The mean age at surgery was 47.3 years (SD 23.3). The flaps were located in the upper back (n = 8), paraspinal (n = 4), middle back (n = 6), and lower back (n = 2). The average wound size after sarcoma and melanoma excision were 231.6 ± 297.4 and 156.7 ± 269.7 cm² , respectively. Four patients required an additional planned skin graft and one patient underwent a simultaneous myocutaneous latissimus dorsi flap. The mean operative time, including tumor resection, was 256 min (SD 118). The median length-of-hospital stay was 3 days (Q1-3: 1-6.5) and the median follow-up time was 35.3 months (Q1-3: 13.3-53.1). All flaps survived with minor surgical complications which included hematoma (n = 1), surgical site infection requiring debridement (n = 1), superficial wound dehiscence (n = 1), cellulitis (n = 1), and seroma (n = 1). The reconstructions were successful in 100% of patients.

CONCLUSIONS

The KPIF is a reliable and safe option for reconstruction of oncological back defects with minimal perioperative complications. This flap option avoids the use of free flaps and myocutaneous flaps for moderate-sized back defects.