Tips on Raising Reliable Local Perforator Flaps.

From early on in the development of plastic surgery, it was quickly realized that utilizing locally adjacent tissue, or "matching like with like," yielded superior aesthetic reconstructions to those in which the tissue was derived from a distant location. In many cases, the use of a local perforator flap is a simpler procedure with less patient morbidity and a quicker recovery from surgery. The difficulty with local perforator flaps has been locating the supplying perforators, ensuring that the flap has a robust and reliable blood supply, and that sufficient tissue is able to be transferred. The recent reappraisal of our understanding of the blood supply of the integument has allowed, for the first time, the capacity to accurately and inexpensively, without the need for "high tech equipment," locate perforators, as they emerge from the deep fascia into the overlying integument, and through a better understanding of the interconnecting anastomotic vessels between perforators reliably predict how much tissue can be safely raised on a single perforator, before surgery. Further, through the use of strategic "delay," it is possible to manipulate the interconnecting vessels between the selected perforator and its surrounding neighbors to design a flap of tissue of any dimension, composed of whatever tissue we require, and safely transfer that tissue locally, or if required, distantly, as a free flap. This article will highlight these advances, explain their relevance in raising reliable local perforator flaps, and will, where possible, call attention to any pearls and pitfalls, and how to avoid complications.

Increasing Perfusion Pressure Does Not Distend Perforators or Anastomoses but Reveals Arteriovenous Shuntings.

BACKGROUND: It has been proposed that hyperperfusion of perforators and distension of anastomotic vessels may be a mechanism by which large perforator flaps are perfused. This study investigates whether increasing perfusion pressure of radiographic contrast in cadaveric studies altered the radiographic appearance of vessels, particularly by distending their anastomotic connections. METHODS: From 10 fresh cadavers, bilateral upper limbs above the elbow were removed. Three cadavers were excluded. Seven pairs of limbs were injected with lead oxide solutions via the brachial artery while distally monitoring intravascular pressure in the radial artery using a pressure transducer. One limb was injected slowly (0.5 mL/s) and the other rapidly (1.5 mL/s) to produce low and high perfusion pressures, respectively. Skin and subcutaneous tissue were then removed and radiographed. RESULTS: The filling of perforators and their larger caliber branches appeared unchanged between low- and high-pressure injections, with no significant increase in true anastomoses (P = 0.32) and no association between maximum perfusion pressure and number (P = 0.94) or caliber (P = 0.10). However, high-pressure injections revealed arteriovenous shunting with filling of the tributaries of the major veins. CONCLUSIONS: This study demonstrated that increased perfusion pressure of the cutaneous arteries (1) did not change the caliber of vessels; (2) did not convert choke to true anastomoses; and (3) revealed arteriovenous shunting between major vessels with retrograde filling of venous tributaries as pressure increased. This suggests that it is not possible to distend anastomotic connections between vascular territories by increasing perfusion alone.

The Functional Anatomy of the Ophthalmic Angiosome and Its Implications in Blindness as a Complication of Cosmetic Facial Filler Procedures.

BACKGROUND: Blindness following facial filler procedures, although rare, is devastating, usually acute, permanent, and attributed to an ophthalmic artery embolus. However, blindness may be delayed for up to 2 weeks, sometimes following injection at remote sites, suggesting alternative pathways and pathogenesis. METHODS: Seeking solutions, fresh cadaver radiographic lead oxide injection, dissection, and histologic studies of the orbital and facial pathways of the ophthalmic angiosome, performed by the ophthalmic artery and vein, both isolated and together, and facial artery perfusions, were combined with total body archival arterial and venous investigations. RESULTS: These revealed (1) arteriovenous connections between the ophthalmic artery and vein in the orbit and between vessels in the inner canthus, allowing passage of large globules of lead oxide; (2) the glabella, inner canthi, and nasal dorsum are the most vulnerable injection sites because ophthalmic artery branches are anchored to the orbital rim as they exit, a plexus of large-caliber avalvular veins drain into the orbits, and arteriovenous connections are present; (3) choke anastomoses between posterior and anterior ciliary vessels supplying the choroid and eye muscles may react with spasm to confine territories impacted with ophthalmic artery embolus; (4) true anastomoses exist between ophthalmic and ipsilateral or contralateral facial arteries, without reduction in caliber, permitting unobstructed embolus from remote sites; and (5) ophthalmic and facial veins are avalvular, allowing reverse flow. CONCLUSION: The authors' study has shown potential arterial and venous pathways for filler embolus to cause blindness or visual field defects, and is supported clinically by a review of the case literature of blindness following facial filler injection.

The quadriceps Femoris allograft as an extension of the Angiosome concept: A cadaveric-based anatomical feasibility study.

BACKGROUND: Vascularised composite allo-transplantation (VCA) is emerging as a tailored approach for complex tissue reconstruction. This study focuses on the quadriceps VCA as a potential solution for tissue repair, following trauma, necrotising fasciitis/myositis, or tumor ablation. METHODS: Dissections were undertaken in 10 adult cadaveric lower limbs to characterize the blood supply to the quadriceps femoris for en bloc muscle allo-transplantation. A mock cadaveric transplantation was performed to (a) define the best neurovascular VCA design and (b) test the feasibility of the procedure. A review of 54 archival radiograph studies from the institution was also performed to further evaluate the muscle vasculature. RESULTS: In two lower limbs, the quadriceps VCA was harvested designed on the common and superficial femoral vessels and nerve, which revealed a lengthy and bloody dissection, especially of the veins, which could increase clinically with the inability to use a tourniquet for most of the dissection. However, review of our previous archival studies showed that all four quadriceps muscles are supplied within the lateral circumflex femoral angiosome. In a further eight lower limbs, the quadriceps femoris muscle group consistently received its blood supply from the lateral circumflex femoral angiosome, verified by selective lead oxide injections of this artery. The vastus medialis appeared to have a more tenous blood supply distally based on this angiosome. A successful mock cadaveric transplant was performed based on this data. CONCLUSIONS: We suggest that the best neuromuscular quadriceps VCA should be (a) designed on the lateral circumflex femoral pedicle, (b) should be raised from distal to proximal, and (c) should include the descending genicular vessels as a potential supplemental supply to vastus medialis, should all four muscles be required.

The Role of Anastomotic Vessels in Controlling Tissue Viability and Defining Tissue Necrosis with Special Reference to Complications following Injection of Hyaluronic Acid Fillers.

BACKGROUND: Most target areas for facial volumization procedures relate to the anatomical location of the facial or ophthalmic artery. Occasionally, inadvertent injection of hyaluronic acid filler into the arterial circulation occurs and, unrecognized, is irreparably associated with disastrous vascular complications. Of note, the site of complications, irrespective of the injection site, is similar, and falls into only five areas of the face, all within the functional angiosome of the facial or ophthalmic artery. METHODS: Retrospective and prospective studies were performed to assess the site and behavior of anastomotic vessels connecting the angiosomes of the face and their possible involvement in the pathogenesis of tissue necrosis. In vivo studies of pig and rabbit, and archival human total body and prospective selective lead oxide injections of the head and neck, were analyzed. Results were compared with documented patterns of necrosis following inadvertent hyaluronic acid intraarterial or intravenous injection. RESULTS: Studies showed that the location of true and choke anastomoses connecting the facial artery with neighboring angiosomes predicted the tissue at risk of necrosis following inadvertent intraarterial hyaluronic acid injection. CONCLUSION: Complications related to hyaluronic acid injections are intimately associated with (1) the anatomical distribution of true and choke anastomoses connecting the facial artery to neighboring ophthalmic and maxillary angiosomes where choke vessels define the boundary of necrosis of an involved artery but true anastomoses allow free passage to a remote site; or possibly (2) retrograde perfusion of hyaluronic acid into avalvular facial veins, especially in the periorbital region, and thereby the ophthalmic vein, cavernous sinus, and brain.

The Functional Angiosome: Clinical Implications of the Anatomical Concept.

BACKGROUND: The angiosome is a three-dimensional block of tissue supplied by a source vessel with its boundary outlined either by an anastomotic perimeter of reduced-caliber choke vessels or by true anastomoses with no reduction of vessel caliber. This article focuses on the role of these anastomotic vessels in defining flap survival or the necrotic pattern seen in fulminating meningococcal septicemia. METHODS: Experiments in pigs, dogs, guinea pigs, and rabbits over the past 46 years were reviewed, focusing on the necrosis line of flaps, the effects of various toxins in vivo, and correlating these results in the clinical setting. RESULTS: Experimentally, choke anastomoses are functional and control flow between perforator angiosomes. They (1) permit capture of an adjacent angiosome when the flap is raised on a cutaneous perforator in 100 percent of cases, with the necrosis line occurring usually in the next interperforator connection; (2) confine flow to the territory of the involved artery when a toxin is introduced by spasm around its perimeter; and (3) lose this property of spasm when choke vessels are converted to true anastomoses following surgical delay, or where true anastomoses occur naturally, thereby allowing unimpeded blood flow and capture of additional angiosome territories. Clinical experience supports these observations. CONCLUSIONS: The functional angiosome is the volume of tissue that clinically can be isolated on a source vessel. The area extends beyond its anatomical territory to capture an adjacent territory if connections are by choke anastomoses, or more if they are by true anastomoses.

Angiosome-Based Allografts: Vascularized Composite Allotransplantation for Tailored Subunit Reconstruction with Volkmann Ischemic Contracture as a Case in Point.

BACKGROUND: As we enter an age with new approaches to tissue reconstruction, the emphasis on the adage "like for like" has become even more relevant. This study illustrates the potential for several tailored vascularized composite allotransplantation reconstructive techniques and, in particular, for the management of Volkmann contracture. METHODS: Twenty fresh cadaver dissections and 30 archival lead oxide radiographic studies were examined to (1) identify potential upper limb vascularized composite allotransplantation donor sites (i.e., elbow, forearm, and flexor tendon complex) and (2) demonstrate a "mock transplant" of the vascularized volar forearm allograft for a severe Volkmann ischemia defect. They were designed without skin to reduce antigenicity. RESULTS: The elbow joint was supplied within the brachial angiosome and the flexor tendon complex of the flexor digitorum superficialis and flexor digitorum profundus by the superficial palmar arch of the ulnar angiosome. The forearm allograft of flexor muscles, median, ulnar, and anterior interosseous nerves, when harvested on the brachial vessels, was supplied within the radial, ulnar, and anterior interosseous angiosomes but could be based on the ulnar artery alone because of intramuscular connections with the other territories. A mock transplant was performed with a distal-to-proximal dissection of the allograft, facilitating the best and fastest technique. CONCLUSIONS: This application of the angiosome concept highlights the anatomical feasibility of the volar forearm vascularized composite allotransplantation donor site focusing on a complex subunit problem in the upper limb-severe Volkmann ischemic contracture. It demonstrates the potential use and immunologic advantage of subdivided and modified nonskin variations of vascularized composite allotransplantation in reconstructive transplantation surgery. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, V.

The Relationship of Superficial Cutaneous Nerves and Interperforator Connections in the Leg: A Cadaveric Anatomical Study.

BACKGROUND: The lower limb is a source of many flaps both for closure of local defects and for free transfer. Fasciocutaneous flap techniques have been progressively refined, although the vascular basis for their success needs clarification. METHODS: Archival studies of 48 lower limbs were reviewed and combined with 20 studies of lower limbs from fresh cadavers, making a total of 68 investigations. Lower limbs were injected with a dilute lead oxide solution; the integument was removed and radiographed; and the cutaneous nerves were dissected, tagged with wire, radiographed again, and their paths traced on the original images. RESULTS: The major cutaneous nerves in the leg are paralleled by a longitudinal vascular axis often comprising long branches with large-caliber true anastomotic connections between perforators. The most highly developed vascular axes followed the medial sural cutaneous and saphenous nerves, together with their accompanying veins, immediately superficial to the deep fascia. The intervening areas were characterized by shorter branches usually connected by small-caliber choke anastomotic connections. CONCLUSIONS: These findings provide the anatomical basis for the observed reliability of longitudinal flaps in the leg. The superficial cutaneous nerves of the leg, especially the saphenous and medial sural cutaneous nerves, are paralleled by a vascular axis on or beside the nerve comprising long perforator branches connected usually but not always by large-caliber true anastomotic connections. This emphasizes the importance of understanding the characteristics of interperforator anastomoses when designing and raising flaps.

The Lymphatic Anatomy of the Lower Eyelid and Conjunctiva and Correlation with Postoperative Chemosis and Edema.

BACKGROUND: There are minimal data in the literature regarding the lymphatic drainage of the conjunctiva and lower eyelid and the relationship with postoperative chemosis and edema. METHODS: Injection, microdissection, and histologic and radiologic studies were conducted on 12 hemifacial fresh cadaver specimens. Indocyanine green lymphography was conducted in five volunteers. RESULTS: Histology identified lymphatic vessels superficial and deep to the orbicularis oculi. Cadaveric dissection, injection, and radiographic studies identified interconnecting superficial and deep facial lymphatic systems and a conjunctival lymphatic network draining through the tarsal plate to the deep lymphatic system. The superficial lymphatic collectors traveled in subcutaneous fat within the lateral orbital and nasolabial fat compartments. The lateral deep lymphatic collectors traveled beneath orbicularis oculi, then through the superficial orbicularis retaining ligament, and into the sub-orbicularis oculi fat in the roof of the prezygomatic space. These vessels descended to preperiosteal fat at the level of zygomaticocutaneous ligaments to travel adjacent to the facial nerve into preauricular nodes. Indocyanine green lymphography identified correlating draining pathways laterally to the parotid nodes and medially to submandibular nodes. CONCLUSIONS: The authors have found that the lower eyelid and conjunctiva are drained by interconnecting superficial and deep lymphatic systems of the face. The superficial system is vulnerable to damage in incisions and dissection in the infraorbital area. The deep system is vulnerable to damage in dissection around the orbicularis retaining ligament and the zygomaticocutaneous ligaments. The authors suggest that concurrent damage to both the superficial and deep lymphatic systems, especially laterally, may be responsible for postoperative chemosis and edema.

Long-Term Patency of Lymphovenous Anastomoses: A Systematic Review.

BACKGROUND: With advancements in technology and microsurgical techniques, lymphovenous anastomosis has become a popular reconstructive procedure in the treatment of chronic lymphedema. However, the long-term patency of these anastomoses is not clear in the literature. METHODS: A systematic review of the MEDLINE and EMBASE databases was performed to assess the reported long-term patency of lymphovenous anastomoses. RESULTS: A total of eight studies satisfied the inclusion criteria. Pooled data from four similar experiments in normal dogs showed an average long-term (≥5 months) patency of 52 percent. The only experiment in dogs with chronic lymphedema failed to show any long-term patency. CONCLUSIONS: The creation of peripheral lymphovenous anastomoses with a moderate long-term patency rate has become technically possible. However, the long-term results in chronic lymphedema are limited.

The Evolution of Free Vascularized Bone Transfer: A 40-Year Experience.

BACKGROUND: The first successful free vascularized bone flap was performed on June 1, 1974 (and reported in 1975), using the fibula. This was followed by the iliac crest based on the superficial circumflex iliac artery in 1975 and then the deep circumflex iliac artery in 1978. METHODS: A total of 384 transfers using fibula (n = 198), iliac crest (n = 180), radius (n = 4), rib (n = 1), and metatarsal (n = 1) were used between June of 1974 and June of 2014 for reconstruction of the mandible (n = 267), maxilla (n = 20), clavicle (n = 1), humerus (n = 8), radius and ulna (n = 21), carpus (n = 3), pelvis (n = 2), femur (n = 11), tibia (n = 47), and foot bones (n = 4). Indications were tumor ablation (n = 286), trauma (n = 84), osteomyelitis (n = 2), and the congenital deformities hemifacial microsomia (n = 2) and pseudarthrosis of the tibia (n = 9) and ulna (n = 1). RESULTS: Successful transfer was achieved in 95 percent of patients. Union varied with the recipient bone, from 6 to 8 weeks in the jaw, 2 to 3 months in the upper limb, and 3 to 4 months in the femur and tibia. Union was fastest with iliac crest. The fibula provided easier dissection; it could be raised on either peroneal or anterior tibial vessels; the skin flap could be designed distally; it could be placed centrally in the medullary cavity of long bones; and hairline stress fracture in the lower limb frequently preceded rapid subperiosteal hypertrophy. The fibula lacks sufficient height for osseointegration, whereas iliac crest is ideal. Osteotomies of either bone are possible to straighten or increase curvature. CONCLUSIONS: The fibula is best for long bone or angle-to-angle jaw reconstruction, especially in edentulous patients. Iliac crest is best for hemimandible, curved bones (pelvis, carpus, and metacarpus), and as an alternative for short, straight, 6- to 8-cm-long bone defects.

Vascularized Lymph Node Transfer: A Review of the Current Evidence.

Over the past decade, lymph node transfer has rapidly gained popularity among plastic surgeons for the treatment of chronic lymphedema because of the initial promising results and its unique technical advantages compared with the other reconstructive options. However, its functional mechanism is still a matter of great debate, and some concerning reports have emerged regarding the safety of this procedure in patients with chronic lymphedema. The authors review the literature on the experimental and clinical evidence for lymph node transfer, discuss its proposed functional mechanisms, review the potential risk of iatrogenic lymphedema following this procedure, and discuss the suggested strategies to avoid this complication.

The Microvascular Basis of the Superior Thyroid Artery Perforator Flap.

BACKGROUND: The superior thyroid artery perforator flap has been presented previously in this Journal as a locoregional flap that provides an excellent tissue match with minimal donor morbidity for lateral face and temple defects. In the current study, the authors aimed to describe the microvascular anatomy of this flap. METHODS: The authors used in vivo computer tomographic angiography, cadaveric dissection, and ex vivo angiography in order to improve surgical safety and application of this technique. RESULTS: The authors provide a detailed map of the microvasculature that is critical to success in this technique, in addition to useful surface anatomical landmarks for ready application in the clinical scenario. Further, the authors discuss the anatomical basis of this flap with reference to the angiosome concept and the critical presence of true anastomoses. CONCLUSION: The superior thyroid artery perforator flap has been shown to be an excellent technique for reconstruction of lateral face and temporal soft tissue defects, providing a thin, pliable, hair-bearing tissue with minimal donor morbidity.

Scarpa Fascia Preservation in Abdominoplasty: Does It Preserve the Lymphatics?

BACKGROUND: The course of the cutaneous lymphatic collectors of the abdominal wall in relation to the Scarpa fascia is unclear in the literature. Preserving the Scarpa fascia in the lower abdomen to reduce the seroma rate following abdominoplasty has been suggested based on the assumption that the lower abdominal lymphatics run deep to this layer along their entire course. METHODS: Using the previously described technique, the superficial lymphatic drainage of eight hemiabdomen specimens from four fresh human cadavers was investigated. RESULTS: The upper and lower abdominal collectors originated at the umbilical and midline watershed areas in a subdermal plane by the union of precollectors draining the dermis. In the lower abdomen, the depth of the collectors gradually increased in the subcutaneous fat as they coursed toward the groin. They eventually pierced the Scarpa fascia before draining into the superficial inguinal nodes located deep to this layer. The transition from the supra- to the infra-Scarpa fascia plane occurred within 2 to 3 cm of the inguinal ligament in 95 percent of the collectors. CONCLUSION: In the four cadavers studied, preserving the Scarpa fascia during abdominoplasty would not preserve the lower abdominal collectors.

Current evidence for postoperative monitoring of microvascular free flaps: a systematic review.

BACKGROUND: Despite a plethora of monitoring techniques reported in the literature, only a small number of studies directly address clinical relevant end points, such as the flap salvage rate and false-positive rate. METHOD: We conducted a systematic review of current evidence regarding the postoperative monitoring of microvascular free-tissue transfer via extensive electronic and manual search and perusing databases, such as PubMed, Cochrane, American College of Physicians (ACP) Journal Club, Cumulative Index of Nursing and Allied Health Literature (CINAHL), Excerpta Medica Database (EMBASE), and Ovid MEDLINE. The included literature (n = 184 publications) was critically appraised using March 2009 Oxford Centre for Evidence-Based Medicine definitions, focusing on the evidence for the efficacy of each technique in improving the flap salvage rate of compromised flaps. RESULT: There is a paucity of outcome-based studies, with only implanted Doppler probes, near-infrared spectroscopy, laser Doppler flowmetry, quantitative fluorimetry, and digital photography assessment using smartphones having been demonstrated in comparative studies to improve flap salvage rate. Currently, the implantable Doppler probe is the technique with the largest number of comparative studies and case series to demonstrate its effectiveness compared with clinical monitoring. CONCLUSIONS: Future studies need to evaluate the most promising monitoring techniques further with a focus on assessing clinically relevant outcomes, such as the flap salvage rate and the false-positive rate, and not simple clinical series reporting patient and physician satisfaction.

Understanding the three-dimensional anatomy of the superficial lymphatics of the limbs.

BACKGROUND: There are minimal data in the current literature regarding the depth of the superficial lymphatic collectors of the limbs in relation to the various subcutaneous tissue layers. METHODS: Injection, microdissection, radiographic, and histologic studies of the superficial lymphatics and the subcutaneous tissues of 32 limbs from 15 human cadavers were performed. RESULTS: Five layers were consistently identified in the integument of all the upper and lower limb specimens: (1) skin, (2) subcutaneous fat, (3) superficial fascia, (4) loose areolar tissue, and (5) deep fascia. Layer 2 was further divided into superficial (2a) and deep (2c) compartments by a thin, transparent, horizontal septum (layer 2b). The main superficial veins and the superficial nerves coursed in layer 4. The lymphatic collectors were found at layer 2c and layer 4. CONCLUSIONS: The use of consistent nomenclature to describe the subcutaneous tissue layers facilitates a greater understanding and discussion of the anatomy. In lymphovenous anastomosis for the treatment of lymphedema, indocyanine green lymphography is an unreliable method for identification of the superficial collectors of the thigh. The medial proximal leg, the dorsum of the wrist over the anatomical snuffbox, and the volar proximal forearm provide suitable areas for locating superficial collectors with nearby matching size veins. In vertical medial thigh lift, choosing a dissection plane superficial to the great saphenous vein is unlikely to preserve the collectors of the ventromedial bundle.