Safety and efficacy of the keystone and rhomboid flaps for immediate reconstruction after wide local excision of non-head and neck melanomas

The Versatility of Keystone Flaps for Skin Cancer Reconstruction of the Nose

Nasal reconstruction has been a challenging problem for even the most experienced surgeon to provide excellent esthetic and functional outcomes. Although the bilobed flap offers distinct advantages for reconstructing these defects using an adjacent tissue with similar esthetic qualities, this flap has several potential limitations. The authors hypothesized that the conventional keystone flap and its variants provide a versatile and easily reproducible reconstructive option for nasal reconstruction after wide skin cancer excision. The authors retrospectively reviewed 12 consecutive soft tissue reconstruction data using 3 types of keystone flaps between May 2021 and July 2023. The authors reviewed all patients who underwent reconstruction with the keystone flap or its modification to repair cutaneous nasal defects following wide skin cancer excision. The authors reconstructed small- to medium-sized nasal defects ranging from 1×1 to 2.5×2.5 cm2 with a mean size of 1.2×1.1 cm2 using either a conventional keystone flap or its modification, including the Omega variant and rotation Hemi-keystone flap. All patients were satisfied with the esthetic outcomes. Keystone flaps are a versatile option for reconstructing the nose after cancer surgery. This strategy obviates the need for a bilobed flap after cancer removal in the nose.

Outcomes of the Keystone Island Perforator Flap: A Systematic Review

BACKGROUND

 The Keystone Design Perforator Island Flap (KDPIF), first described by Behan in 2003, has been demonstrated as a versatile, safe, and straightforward reconstructive option for various soft tissue defects. The purpose of this systematic review is to evaluate the indications, variations, and overall complication profile of the keystone flap in reconstructive surgery.

METHODS

 A literature review was conducted in accordance with PRISMA guidelines using MeSH term "surgical flaps" with the keyword "keystone flap." Empirical studies with at least 15 patients who underwent keystone flap reconstruction were assessed for quantitative analysis. Outcomes of interest included patient demographics, indications, anatomic location, flap design, and complications.

RESULTS

 Database search produced 135 articles, of which 25 were selected for full-text review. Out of 23 studies selected qualitative analysis and 22 met criteria for quantitative analysis. Overall success rate of this flap was 98%. Wound complications were highest in extremity flaps. Several modifications of this flap were described.

CONCLUSION

 Keystone reconstruction demonstrates excellent success rates and versatility. However, further studies with more standard reporting are needed to determine guidelines for patient specific surgical planning.

Keystone Flaps: Physiology, Types, and Clinical Applications

The keystone perforator flap (KPF) was first introduced in 2003 by Behan et al for use in reconstruction after skin cancer excision. Since its initial description, KPF use has been expanded to complex defects of various etiologies and disorders throughout the body. At its most basic, the KPF is a perforator-type flap designed with a 1:1 flap-to-defect width ratio. Keystone perforator flaps are specifically raised on pedicles arising from musculocutaneous or fasciocutaneous perforator vessels. Major advantages of the KPF derive from the maintenance of perforator vascular territories, perforosomes, permitting increased flap viability. In turn, this allows for more aggressive undermining in sites away from perforators when greater skin mobilization is necessary. Furthermore, the KPF is relatively easy to perform leading to shorter operative times and no postoperative monitoring period. There are basically 4 different types of keystone flaps in order of increasing undermining and disturbance of underlying fascia. These different classifications of KPFs may be used in different anatomical locations over the entire body based on skin laxity and defect size/depth. Numerous advancements and modifications have been documented adapting the KPF to specific conditions, including myelomeningoceles, and scrotal and lower eyelid defects. The purpose of this article is to provide an organized review of the KPF with emphasis on different classifications, applications, and limitations as well as an overview of the surgical technique. We have additionally included a discussion on KPF physiology and review of current literature.

Giant keystone type III perforator flaps for dermatofibrosarcoma protuberans defect reconstruction

INTRODUCTION

Dermatofibrosarcoma protuberans (DFSP) is a relatively rare malignant tumor, with important local aggressiveness.

CASE REPORT

We present a case of a 59-years-old man with a history of Psoriasis and viral hepatitis C presented in our department with a giant lesion on the posterior trunk, of 24/36 cm, with pus and local bleeding, causing important anemia. The tumor was excised, creating an elliptical defect of around 34 × 42 cm down to fascial level, which was covered by two lateral flaps - modified Keystone type III.

RESULTS

The flaps were completely viable and integrated with small dehiscence, which were assisted to heal secondarily.

CONCLUSION

Our paper presents a reliable alternative to skin grafting for a very large defect on the posterior trunk, the modified type III keystone flap, to our knowledge, for the first time presented for such a wide defect and on adult.

Keystone Flap: Overcoming Paradigms

Background:

The physiology and geometry of the keystone flap (KF) are the main factors that support its development. This study reports our experience using the KF and proposes the concept of pedicular area.

Methods:

A prospective cohort study was conducted from October 2014 to December 2016, in which 112 KF procedures were performed with an average follow-up time of 10 months. The conclusions drawn from clinical observations were compared with the findings of a literature review.

Results:

One hundred twelve flaps were performed in 89 patients (45 men and 44 women) with an average age of 64 years (range, 3–89 years). The flap survival rate was 100%. The term pedicular area (PA) was coined to describe a flap segment that remains attached to its bed without vascular detriment and whose location can be randomly selected. In this study, the PA could be reduced up to a 10%, which means that over 90% of each flap was dissected without any harm.

Conclusions:

The KF is a safe, cost-effective technique with better results when compared with other reconstructive procedures. Although research is still needed to better understand the physiological adaptations of KF, the clinical evidence supports its use in many reconstructive scenarios.

The rule of 10s versus the rule of 2s: High complication rates after conventional excision with postoperative margin assessment of specialty site versus trunk and proximal extremity melanomas

Specialty site melanomas on the head and neck, hands and feet, genitalia, and pretibial leg have higher rates of surgical complications after conventional excision with postoperative margin assessment (CE-POMA) compared with trunk and proximal extremity melanomas. The rule of 10s describes complication rates after CE-POMA of specialty site melanomas: ∼10% risk for upstaging, ∼10% risk for positive excision margins, ∼10% risk for local recurrence, and ∼10-fold increased likelihood of reconstruction with a flap or graft. Trunk and proximal extremity melanomas encounter these complications at a lower rate, according to the rule of 2s. Mohs micrographic surgery (MMS) with frozen section melanocytic immunostains (MMS-I) and slow Mohs with paraffin sections decrease complications of surgery of specialty site melanomas by detecting upstaging and confirming complete tumor removal with comprehensive microscopic margin assessment before reconstruction. This article reviews information important for counseling melanoma patients about surgical treatment options and for developing consensus guidelines with clear indications for MMS-I or slow Mohs.

The Keystone Flap in Dermatology: Clinical Experience with 18 Patients

INTRODUCTION AND OBJECTIVES

The keystone flap is a fasciocutaneous flap supplied by perforating arteries. It is used in dermatology to repair surgical defects in areas with low skin extensibility (the upper and lower limbs and the back). We review the clinical experience gained with keystone flap reconstruction at our hospital and report on the surgical outcomes.

MATERIAL AND METHODS

Descriptive retrospective study of patients with malignant skin tumors on the lower limbs who underwent keystone flap reconstruction.

RESULTS

Eighteen patients (mean age, 77.83 years) underwent keystone flap reconstruction using the Behan technique in 17 cases and the modified Moncrieff technique in one. Basal cell carcinomas accounted for 38.8% of the tumors excised, squamous cell carcinomas 33.3%, and malignant pigmented tumors 27.7%. Cardiovascular risk factors were observed in 72.2% of patients. Minor complications occurred in 38.8% of patients, and there were no cases of partial or total flap necrosis.

CONCLUSIONS

We consider the keystone flap to be a good alternative to other flaps and grafts for the surgical reconstruction of lower limb defects. The success rate was high, and the cosmetic and functional outcomes were good.