Biomedical subjects
Geoffrey G Hallock
Publications and source records attributed to Geoffrey G Hallock.
Devastating massive knee defect reconstruction using the cornucopian chimera flap from the subscapular axis: two case reports.
Two cases of successful reconstruction of massive defects around the knee with multiple-island combined flaps based on the subscapular axis are reported. Both defects resulted from aggressive debridement for acute osteomyelitis after open fixation of high-energy fractures around the knee. In Case 1, a four-island combined flap consisting of the scapular flap, the lattissimus dorsi muscle flap, the serratus anterior muscle flap, and the scapular osseous flap, based on the same subscapular axis, was used. Partial bone transport using the Ilizarov apparatus was added as reinforcement of arthrodesis. In Case 2, a five-island combined flap, consisting of the scapular, parascapular flap, the lattissimus dorsi muscle flap, the serratus anterior fascial flap, and the scapular osseous flap, was used. Consequent ankylosis of the knee joint afforded the patient painless full weight bearing without secondary arthrodesis. Multiple-island combined flaps based on the subscapular axis can provide three-dimensional reconstruction of destructive knee defects.
Further clarification of the nomenclature for compound flaps.
LEARNING OBJECTIVES: After studying this article, the participant should be able to: 1. Understand the attributes and unique niche for compound flaps and their limitations. 2. Comprehend a proposed schema for further clarifying the classification of all types of compound flaps that is differentiated on the basis of the distinct vascular supply to each flap subtype. 3. Appreciate that minor technical modifications of known flaps of any type in general do not necessarily create a new category of flap. BACKGROUND: A unique niche exists for compound flaps because of their extraordinary capability to allow repair of massive defects where the simultaneous restoration of multiple missing tissue components is demanded. The guidelines from the previous "simplified" classification schema need to be updated to allow a more complete clarification and further standardization of this concept. METHODS: Compound flaps can be partitioned into two major classes that in turn are further differentiated into various subtypes according to their inherent pattern of circulation. RESULTS: The subdivisions of compound flaps are those with a solitary source of vascularization and those with combinations of sources of vascularization. Those with a solitary source include composite flaps, defined as multiple tissue components all served by the same single vascular supply, and thereby consisting of dependent parts. Those flaps with combinations of sources of vascularization include (1) conjoined flaps, defined as multiple flap territories, dependent because of some common physical junction, yet each retaining its independent vascular supply; and (2) chimeric flaps, defined as multiple flap territories, each with an independent vascular supply, and independent of any physical interconnection except where linked by a common source vessel. CONCLUSIONS: Although many technical modifications have improved and will improve the reliability and versatility of compound flaps, these maneuvers alone should not be confused with creating distinct flap types but rather acknowledged to be only important variations. With this understanding, this revised nomenclature system for compound flaps is intended to be a means of standardizing communication and to facilitate research agendas on a common ground, fully realizing its primary role still only to serve as a convenient guideline.
Why not indirect nonmuscle perforator flaps?
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The propeller flap version of the adductor muscle perforator flap for coverage of ischial or trochanteric pressure sores.
Recidivism after flap coverage of ischial and trochanteric pressure sores is predictably common. Available local flap options are limited in number and must be cautiously preserved as long as possible for these patients who are destined to have a lifelong vulnerability for recurrence. Muscle perforator flaps have been introduced as another set of alternatives to solve this conundrum. Since the posteromedial thigh often has been previously unviolated by the usual workhorse flaps selected for this problem, the adductor perforator flap will then usually still be available as an important "backup" option. If designed as a propeller flap, this version after rotation will cover the defect and simultaneously allow direct donor-site closure to avoid the need for a skin graft.
Scrotal reconstruction following fournier gangrene using the medial circumflex femoral artery perforator flap.
Fournier gangrene can have devastating consequences. Often in the male, the testicles become exposed and demand both a functional and esthetic coverage. Local medial thigh cutaneous flaps usually still are available and have evolved to become a preferred solution. The medial circumflex femoral artery perforator (MCFAP) flap based on musculocutaneous perforators of the gracilis muscle represents yet another one of these options. As with all muscle perforator flaps, no muscle need be expended. A case report illustrates the role of the MCFAP flap for creation of a neoscrotum.
The old, the young, and the computer or musings of a plastic surgery curmudgeon.
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Medial suralGASTROCNEMIUS muscle perforator free flap: an immediate cross-leg flap?
The advantage of the medial sural (GASTROCNEMIUS) muscle perforator free flap is that it is relatively thin, even in most obese individuals, and the donor site can be acceptable, if morbidity must preferably be restricted to the lower extremities. Unfortunately, anatomic anomalies of both the arterial and venous circulation are not infrequent, making this a somewhat less than perfect donor site in the author's total experience using this flap. Nevertheless, the contralateral calf skin was successfully used, as shown in a clinical example, to cover a transmetatarsal amputation stump. This allows the conclusion that, at least as a technical exercise, the medial sural (GASTROCNEMIUS) muscle perforator free flap as a microsurgical transfer can be used as an "immediate" cross-leg flap. This is reminiscent of bygone eras, where such a feat required multiple stages over many weeks.
Free-flap monitoring using a chimeric sentinel muscle perforator flap.
Muscle perforator flaps have become an important resource for the creation of cutaneous flaps based on musculocutaneous perforators, but without inclusion of the involved muscle. As a chimeric flap with or without the muscle, the cutaneous perforator flap can specifically serve as a sentinel or monitoring flap to allow the early detection of anastomotic compromise involving the common source vessel, without the need for direct observation of the major free-flap component. This can be a valuable adjunctive use of muscle perforator flaps for the continuous assessment of free muscle flaps or as an exteriorized flap for the monitoring of buried free flaps.
The Venus de Milo: an icon of reconstructive surgery and the American Society of Plastic Surgeons.
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Efficacy of venous supercharging of the deep inferior epigastric perforator flap in a rat model.
BACKGROUND: An insidious risk with the use of muscle perforator flaps is the possibility of venous outflow compromise. Congestion in deep inferior epigastric perforator (DIEP) flaps in particular is not infrequent. On an empiric basis, their salvage has been accomplished by augmenting venous drainage through alternative outflow tracts. The validity of this clinical maneuver can now best be tested in a rat DIEP flap model. METHODS: The rat DIEP flap is a modification of the rat ventral abdomen flap. Flap perfusion can be based on a single rectus abdominis musculocutaneous perforator. No muscle is included with the flap. Three groups of five male Sprague-Dawley rats each were used. The conventional DIEP flap group had only a solitary perforator artery and venae comitantes and served as the control. The contralateral superficial inferior epigastric vein was included with the flap in the other two groups as a distinctly separate venous outflow tract. The latter two groups differed in that the perforator venae comitantes were either retained or deleted. RESULTS: Mean flap survival in the control DIEP flap group was 80.8 +/- 16.3 percent. Retention of the contralateral superficial inferior epigastric vein resulted in a statistically significant enhancement in flap viability (p < 0.027) whether the perforator venae comitantes were left intact (99.8 +/- 0.4 percent) or had been intentionally ablated (99.6 +/- 0.5 percent). CONCLUSIONS: Venous supercharging of the rat DIEP flap ensures greater flap survival. As a corollary, this supports the efficacy of prior anecdotal experiences in which an alternative venous outflow tract, preferably from the superficial system, had been used to overcome venous congestion. It is advisable for any muscle perforator flap to always try to retain a second outflow source to allow the potential for venous supercharging, if later indicated.
Top ten reasons to hate the "V.A.C.".
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The superior epigastric(RECTUS ABDOMINIS) muscle perforator flap.
The concept of the muscle perforator flap has been proven valid repeatedly, now including the territories of almost all known musculocutaneous flap donor sites. It is well known that the rectus abdominis muscle has a dual vascular supply from 2 dominant source vessels. Yet only the deep inferior epigastric vessels have been used for a relatively long time to supply the well-known DIEP muscle perforator flap. Logically, as previously predicted in this journal, a muscle perforator flap utilizing the cephalic pedicle to the rectus abdominis muscle should also be possible. This prophecy has now become a reality in this first report where a superior epigastric(RECTUS ABDOMINIS) muscle perforator flap was used successfully as a local flap to close a chest defect.
The proximal pedicled anterolateral thigh flap for lower limb coverage.
Although primarily considered as a versatile free-flap donor site, the anterolateral thigh can also be a source of a local muscle perforator flap. This attribute has previously been rarely considered for lower limb coverage. This small series of 3 additional cases demonstrates the usefulness of a proximal pedicled anterolateral thigh flap for medial and lateral thigh wounds. This flap can also be part of a combined flap, in particular when transferred with the vastus lateralis muscle as a local chimeric flap. The peninsular version of the anterolateral thigh local flap avoids venous congestion and is very reliable. The orthograde pedicled anterolateral thigh muscle perforator flap should be considered as another useful alternative for any upper thigh wound if a flap is essential.
The complete classification of flaps.
Whereas the permutations and combinations in our arsenal of free flaps continue to increase exponentially, the lack of a coherent nomenclature system has caused this often to appear as only a haphazard array of bewildering possibilities. A simplified nomenclature schema is essential to enhance the acceptance and universal application of, as well as accurately describe, many of these new flap options. A minor modification of prior anatomical systems that incorporates all possible distinguishing characteristics in describing any given flap is an intrinsic part of the system, but the primary focus in flap identification is centered around its vascular supply. Several examples are given to illustrate how the complete classification of every free flap can be possible in a reproducible and highly interpretable fashion.
On "Management of significant venous discrepancy with microvascular venous coupler" (J Reconstr Microsurgery 2003;19:377-380).
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Further experience with the medial circumflex femoral(GRACILIS) perforator free flap.
The microsurgical transfer of the medial groin skin territory previously required this to be part of a transverse-oriented gracilis musculocutaneous free flap. As the concept of muscle perforator flaps has evolved, avoidance of muscle bulk and/or retention of muscle function here is also possible with the careful intramuscular dissection of the gracilis musculocutaneous perforators back to the usual medial circumflex femoral source vessel. This so-called medial circumflex femoral (GRACILIS) [MCF (GRACILIS)] perforator free flap has been successfully used seven times in six patients with minimal complications. The MCF (GRACILIS) muscle perforator flap may well represent the ideal skin flap: no muscle function is sacrificed; a reliable skin territory of large size is available; the dominant vascular pedicle is consistent in location; the flap may be harvested with the patient in a supine position; a combined conjoint flap including the gracilis muscle is optional; closure of the donor site leaves a medial groin scar that can be readily concealed; and flap dissection in this region is already very familiar to most microsurgeons.
The conjoint medial circumflex femoral perforator and gracilis muscle free flap.
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