Felix C. Behan

The Keystone Design Perforator Island Flap in reconstructive surgery

Background:  A surgical technique for closing skin defects following skin cancer (particularly melanoma) removal is described in the present paper. Its use is illustrated in five patients. The technique has been used in 300 cases over the past 7 years and is suitable for all areas of the body from scalp to foot.

Keystone island flap : An alternative reconstructive option to free flaps in irradiated tissue

Background:  The Keystone Flap is an island flap that is very useful for repairing skin defects of the integument. Described as a keystone, this arc‐shaped flap in fact consists of a schematically designed, perforator‐based reconstructive unit which serendipitously resembles two conjoined VY flaps. This facilitates closure because of the multiple VY points at the extremes, where the surrounding tissue is advanced to close the defect while the flap size remains basically static.

The cervico-submental keystone island flap for locoregional head and neck reconstruction

BACKGROUND Locally advanced head and neck cancer often requires wide resections of the cheek and parotid gland, and in an ageing population preferred reconstructive options aim to avoid lengthy operating times or high risk surgery. While most large parotid defects traditionally require free flap reconstruction, we describe a new and versatile locoregional flap that has been shown to be reliable, simple and safe. METHODS We describe the cervico-submental (CSM) keystone-design perforator island flap for head and neck reconstruction, including an analysis of 33 consecutive patients with a range of head and neck defects. The flap was raised based on perforators of the external carotid artery and its branches, and designed to overlay the C2/C3 dermatomes (an aide memoire for flap design). The indications, and surgical technique are described. RESULTS In 33 consecutive patients, no major complications were encountered. Five patients developed superficial infections, one developed post-operative bleeding and one patient developed partial tip necrosis. Theatre time was considerably shorter than our alternative reconstructive options. CONCLUSION The CSM keystone-design perforator island flap is a novel and versatile flap, which can be used in a range of advanced cheek and parotidectomy defects, and may enable improved surgical management in an increasingly elderly and high-risk population.

Keystone island flap reconstruction of parotid defects.

Background: Skin cancers of the face and scalp have a propensity to metastasize to the parotid group of lymph nodes. The resection of these secondary tumors and other primary tumors in the parotid region often results in defects requiring flap reconstruction. Pectoralis major flaps are reliable and free flaps are arguably the criterion standard. However, we have found keystone island flaps to be a simple and robust alternative, with low donor-site and patient morbidity. The aim of this article is to share our surgical technique, experience, and outcomes of reconstructing parotid defects with keystone island flaps. Methods: The authors retrospectively reviewed 62 patients who had 63 parotid defect reconstructions at a single institution from 2004 to 2009 (5-year period). Results: The diseases involved were squamous cell carcinoma (52 cases), melanoma (five cases), basal cell carcinoma (four cases), and others (two cases). Nine patients presented with a previous history of radiotherapy and 33 patients required adjuvant radiotherapy. Seven patients (11 percent) suffered postoperative complications necessitating a return to the operating room. Conclusions: Keystone island perforator-based flaps present an alternative to free tissue transfer. From the series presented, it can be seen that reliable and reproducible results are achievable. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV.

Re: The ‘keystone concept’: time for some science

1. Behan FC. The Keystone Design Perforator Island Flap in reconstructive surgery. ANZ J. Surg. 2003; 73: 112–20. 2. Douglas CD, Low NC, Seitz MJ. The keystone flap: not an advance, just a stretch. Ann. Surg. Oncol. 2013; 20: 973–80. 3. Pelissier P, Santoul M, Pinsolle V, Casoli V, Behan F. The keystone design perforator island flap. Part I: anatomic study. J. Plast. Reconstr. Aesthet. Surg. 2007; 60: 883–7.

The omega - Ω - variant designs (types A and B) of the keystone perforator island flap.

Dumb-bell tumours of the sciatic notch are rare. They usually present with buttock pain, sciatica with or without neurological dysfunction, or a buttock mass. Because their symptoms are similar to more common causes of sciatica, these tumours are often diagnosed late and can grow extremely large before surgical intervention is undertaken. Their characteristic dumb-bell appearance is due to constriction of the tumour within the sciatic notch (Fig. 1). They are mostly composed of neurofibromas, lipomas and soft tissue sarcomas, but it is also often difficult to preoperatively determine their malignant potential, thus, optimal treatment is complete excision as a single unit rather than piecemeal extraction, which could potentially seed malignancy. However, radical excision is undesirable because of significant morbidity associated with vascular and nerve injury in this region. Because of their rarity and complicated anatomy, management protocols have not been clearly established. We propose that optimal treatment is provided by a combined transgluteal and transperitoneal approach, performed by two different surgical disciplines experienced in operating within designated regions. Our surgical approach involves draping the abdomen, buttock and leg to allow the patient to be alternately positioned supine and lateral. A lower midline abdominal incision allows access to the pelvic cavity with the vascular team expertise freeing the tumour from within the pelvis. A transgluteal incision performed by the orthopaedic team allows delivery of the tumour through the sciatic notch while protecting the sciatic nerve and performing pelvic osteotomies as required. We have successfully utilized this approach in the removal of a lipoma and a malignant fibrous histiocytoma with resolution of symptoms and 10-year survival without recurrence. We propose that the utilization of two different surgical disciplines optimizes intraoperative expertise and anatomical familiarity, thereby optimizing operative success.

Use of the keystone island flap for advanced head and neck cancer in the elderly — a principle of amelioration

Traditional management strategies of advanced head and neck cancer in the elderly include palliation and radical resection with microsurgical reconstruction. The keystone flap approach is an alternate reconstructive technique with a range of benefits for the aging population. This publication presents a series of elderly patients with head and neck cancer who underwent resection and reconstruction using the keystone flap principles. The aim is to demonstrate the value of this reconstructive technique in the various anatomical regions of the head and neck. Various operative sequences are accompanied by illustrations and discussions of the underlying principles.

EVOLUTION OF THE FASCIOCUTANEOUS ISLAND FLAP LEADING TO THE KEYSTONE FLAP PRINCIPLE IN LOWER LIMB RECONSTRUCTION

I have been asked to comment on the article by Sham et al.1 In any such perspective of lower limb flap reconstruction, one should examine the historical background, the clinical presentation, the scientific evidence and finally one’s own personal experience in relation to such flap reconstructions of the lower limb. I myself have published some material on this and related topics and this synopsis is the distillate of more than 30 years of reconstructive work, seeking optimal surgical solutions in this area. From a historical viewpoint, the use of flaps in the lower limb has been plagued with difficulties. From the time of Gillies, repetitive complications generally led practitioners to limit flap design length · breadth dimensions to a 1:1 ratio for security. My earliest findings came from my research at the Royal College of Surgeons in London in the 1970s on the vascularity of flaps. I used two clinical concepts, which have stood me in good stead in clinical practice throughout my career (reinforcing the value of such research opportunities) – the reliability of fascially based flaps and the clinical principles that govern the efficacy of island flaps. Acceptance was slow, and I myself even experienced criticism from Benny Rank in the early 1980s. Reviewing on an accident victim for a medico-legal report he commented on my reconstruction technique to the patient. I had successfully repaired a large defect over the exposed lower third of the tibia with a fasciocutaneous transposition flap. He said to the patient ‘What’s he doing this for – you never do flaps in the lower limb’. Her own response as reported back to me was ‘What’s wrong with it, sir? It worked’. In essence, these clinical concepts recognize the significance of a fascial base to a flap supported by axial and random vasculature, providing a reliable substrate for flap reconstruction. The second of these concepts involves the angiotome2 – flap extensions created by linking axial vascular systems (I drew this description from Dorland’s Dictionary, which defines angiotome as a ‘vascularised segment’). This provides the basis for increased reliability in flap design, particularly in the lower limb. From a historical publication viewpoint, Ponten (1981) was the first to describe a large series of cases using the fasciocutaneous principle, subsequently taken up by Hallock in his work on the lower limb. These flaps still retained dermal plexus supply (prevailing thought still maintained that dermal bridges were required to ensure flap reliability). The next notable advancement in the use of the island flap came in 1987 when Morrison and Shen documented the anterior tibial artery perforator flap based on tibial perforators.3 In the same year Taylor and Palmer described the concepts of angiosome and choke vessels in relation to adjacent vascular territories in cadaver injection studies.4 In the same year Masquelet presented his work with lateral supra-malleolar flaps, supplied through a cutaneous branch of the perforating division of the peroneal artery and successfully established this technique in providing cover to the ankle joint and its environs.5 Thus, 1987was a seminal year in reconstructive surgical advancement. Building on the findings drawn from the cadaver injection studies, Taylor et al. used the Doppler probe in clinical trials to establish guidelines for successful flap reconstruction in the lower limb.6 In my own clinical experience it has not been my practice to resort to the Doppler localization technique for defining perforator supply, but rather to use the multiple random perforator sites available (named, unnamed, random or axial), using the dermatomes as an aide memoire or road map for localization. The use of a wide architectural design (keystone or Bezier island flaps) incorporates more possible perforators while retaining any neurovascular supports on a fascial base and also where possible any cutaneous sensory nerves in the vicinity of the flap. An intrinsic feature of island flap design is improved vascular reliability, with improved healing and reduced complication rates. In 1994 I published the first large series of cases using fasciocutaneous island (FCI) flaps in the Journal7 (reviewed by Wayne Morrison) bringing together these principles of perforator supply and fascial support, with island flaps designed or located where possible in the longitudinally orientated dermatomal precincts and advanced, rotated or transposed to cover compound tibial defects of the lower limb, replacing a circumferential design basis with this longitudinal approach along neurovascular channels. These flap designs are raised without skeletonizing the perforator source, as is discussed in the Sham article, which reflects almost universal present practice. My own conviction here is that if these FCI flaps are raised with a blunt dissection technique using the digit (retaining a substantial attachment in the vicinity of the recognized perforator locations and precluding any obvious vascular kinking, which may otherwise occur if the axis is thin and attenuated), then teased and dissected to facilitate defect closure, a reliable clinical result retaining neurovascular support (long and short saphenous veins) can be achieved in a shorter time frame without the use of Doppler localization. This can be particularly beneficial in the elderly, where extended devascularization/ tourniquet time frames may significantly exacerbate postoperative morbidity. Another important technical point is that where a tourniquet has been used, it is necessary to release the pressure once the flap is raised over the definitive side to assess vascular perfusion. Metal clips are used to achieve fascial haemostasis. To date I have not had to replace a flap because of unreliable vascular input. In 2003 the concept of the keystone design first appeared in the Journal.8 This advanced the random perforator-based fascially lined island flap principle and enabled limited defects of the lower limb, ankle and plantar and dorsal aspects of the foot to be covered reliably. This was further reinforced in 2007 with the publication of Pelissier’s clinical and research findings in BAPRAS.9 Ongoing clinical/vascular studies regarding the keystone design are now the subject of further research, particularly focusing on the hyperaemic flare observed on raising these perforator-based island flaps. This obviously supplements the predicted perforatorbased hydrostatic input. The closest analogy in clinical practice is my recollection of the effects of lumbar sympathectomy on the diabetic foot, with the subsequently pink reaction indicating improved vascularity, frequently with resolution of any intractable ulceration. The ‘red dot’ sign is another apparent indicator of increased vascular perfusion (not an indicator of any cyanotic change, except in extreme circumstances). In clinical practice ANZ J. Surg. 2008; 78: 116–117 doi: 10.1111/j.1445-2197.2007.04382.x

Yin-Yang flaps: the mathematics of two keystone island flaps for reconstructing increasingly large defects.

and management of blunt internal carotid artery injury. Eur. J. Vasc. Endovasc. Surg. 2004; 27: 577–84. 3. van Heurn LW, Hamerlijnck RP, de la Rivière AB, Suttorp MJ, Ernst SM, Vermeulen FE. Combined traumatic avulsion of the aortic valve and rupture of the left common carotid artery. Ann. Thorac. Surg. 1992; 54: 157–8. 4. Dubose J, Recinos G, Teixeira PG, Inaba K, Demetriades D. Endovascular stenting for the treatment of traumatic internal carotid injuries: expanding experience. J. Trauma 2008; 65: 1561–6.

The interpretation of vascular changes observed in keystone island flaps: a hypothesis.

The pathogenesis of augmented vascular perfusion observed in keystone island flaps remain unexplained. In this setting, we refer to excerpts from Baker’s textbook Local Flaps in Facial Reconstruction regarding routine skin flap physiology: ‘Both cutaneous and sympathetic nerves are severed in the process of flap elevation. When a sympathetic nerve is divided, catecholamines are released from the nerve terminal and the mechanism of catecholamine reuptake is eliminated. A local ‘hyperadrenergic state’ exists, which produces vasoconstriction mediated by a-adrenergic receptors in the cutaneous vasculature. The vasoconstricting effect of sympathectomy further reduces the total flap blood flow,