Muscle-splitting approach to superior and inferior gluteal vessels: versatile source of recipient vessels for free-tissue transfer to sacral, gluteal, and ischial regions

The superior gluteal vessel has been reported as a recipient in free-tissue transfer for the coverage of complex soft-tissue defects in the lumbosacral region, where a suitable recipient vessel is difficult to find. The characteristics of proximity, vessel caliber, and constancy make the superior gluteal vessel preferable to previously reported recipient vessels. However, there are technical difficulties in microsurgery (e.g., short pedicle length and deep location) and muscle injury (transection of the muscle) associated with use of the superior gluteal vessel. The purpose of this article is to present a modification of an approach to the gluteal vessel to alleviate technical difficulties and minimize muscle injury. From August of 1997 to January of 1999, six patients received microvascular transfer of the latissimus dorsi muscle or myocutaneous flap to the sacral (4) and ischial (2) regions. The causes of defects were tumor (1), trauma (1), and pressure sores (4). A muscle-splitting approach was used on the superior gluteal vessel and was later applied to the inferior gluteal vessel. The gluteus maximus muscle was split as needed in the direction of its fibers, and the perforators were dissected down to the superior or inferior gluteal artery and vein deep into the muscle. The follow-up period ranged from 6 to 22 months, and all of the flaps survived with complete recovery of the lesion. The major drawbacks of using the superior and inferior gluteal vessels can be overcome with the muscle-splitting approach, which provides increased accessibility and additional length to the vascular pedicle while causing minimal injury to the muscle itself. It also proves to be an easy, safe, and reliable method of dissection. When free-tissue transfer to sacral, gluteal, and ischial regions is indicated, the muscle-splitting approach to the superior and inferior gluteal vessels is a recommended option in the selection of a recipient vessel.     

Superiority of the deep circumflex iliac vessels as the supply for free groin flaps. Clinical work.

In this paper we present 16 cases of free transfer of compound flaps from the groin, 11 using the deep circumflex iliac vessels as a stem and 5 using the superficial circumflex iliac vessels as a stem. We found the deep vessels superior in many ways to the superficial vessels for this purpose; they are larger, permitting greater ease in anastomoses and providing more reliable blood flow. We believe that larger osteocutaneous or myocutaneous flaps can be transferred on the deep vessels than on the superficial ones-and that the deep circumflex iliac flap may supplant the conventional free going flap in most situations. The method evolved in response to patient need, not for surgical éclat.     

Microvascular free transfer of human testes.

This clinical study was undertaken to demonstrate the feasibility of free transfer of undescended human testes with microvascular anastomoses. We have performed 4 microvascular free transfers of such testes in children aged 5, 6, and 8 years, with follow-up periods of one to three years. All 4 testes have remained clinically viable. The final proof of functional viability will have to await puberty, of course.     

Microvascular free tissue transfer for treatment of osteoradionecrosis of the maxilla

Head and neck tumors often require radiotherapy as part of the treatment protocol. Although it improves the survival rate in cancer patients, it may cause osteoradionecrosis, especially in the mandible and maxilla. Twelve patients with osteoradionecrosis of the maxilla were treated with microsurgical free tissue transplantations between April of 1996 and August of 2002. There were 10 male and two female patients, with a mean age of 60.2 years. The mean radiotherapy dose was 6674 cGy. The radiation dose could not be traced in three patients because radiotherapy was performed elsewhere. Radical sequestrectomy, soft-tissue debridement, and pathologic proof of no tumor recurrence were performed before microsurgical reconstruction. Free flaps used included the following: anterolateral thigh (n = 7), radial forearm (n = 2), rectus femoris musculocutaneous (n = 2), and supracondylar chimeric (n = 1) flaps. All flaps survived completely and reconstruction succeeded. During a mean 25-month follow-up period, ectropion, plate exposure, and mild infection were encountered in three patients and treated successfully. Radical debridement and obliteration of dead space with well-vascularized tissue are essential for successful treatment of maxillary osteoradionecrosis. The anterolateral thigh flap is most versatile for almost all types of soft-tissue defect reconstruction in the head and neck region.     

Selection of the recipient vessel in the free flap around the knee: the superior medial genicular vessels and the descending genicular vessels

In reconstructions around the knee, the use of a free flap is indicated in a limited number of cases, but it plays a critical role in cases of extensive defects or unavailability of local flaps. The selection of the recipient vessel is an essential and challenging step for a successful free tissue transfer. Popliteal vessels and other small vessels around the knee have been reported to be used as recipient vessels, but the choice of recipient vessels around the knee has not been established. In this study, after a thorough investigation of the vascular anatomy at the knee region, the superior medial genicular vessels and the descending genicular vessels were considered to be the proper recipient vessels, and a clinical application was tried. From July of 1997 to July of 1999, a total of seven cases of soft-tissue defects around the knee-four cases in the posterior region and three cases in the anterior region-were reconstructed with free flaps, using the superior medial genicular vessels and the descending genicular vessels, respectively. All flaps survived completely, with no flap loss. The advantages of these vessels are their proximity to the knee and their reliability, versatility, simplicity, and size match. The outstanding characteristic of this combination of vessels is their versatility, because the combination can cover all defects around the knee. The clinical application and the versatility of the combination of the superior medial genicular vessels and the descending genicular vessels as the recipient vessels was confirmed for the reconstruction of posterior and anterior knee defects.     

The vascular anatomy of the lower anterior abdominal wall: a microdissection study on the deep inferior epigastric vessels and the perforator branches

The deep inferior epigastric artery provides the main blood supply to the lower abdominal wall. Microdissection of the artery, its main branches, and the perforator vessels was undertaken in 20 cadavers. The artery was found to be associated with two veins in most of the cases (90 percent). The lateral division of the deep inferior epigastric artery and the perforator vessels it gives are more dominant (80 percent of cases) than the medial perforators (20 percent of cases). The lateral perforators were greater in number (80) and more consistent than those that arose from the medial division (28). The musculocutaneous perforators are the most important perforators supplying the anterior abdominal wall. An average of 5.4 large perforators (>0.5 mm in diameter) were dissected in each case. These perforators are mostly contained in the area lying laterally and below the umbilicus, with an average distance of 4 cm from the umbilicus. The musculocutaneous perforators may have a direct or indirect course. Larger perforators (>0.5 mm in diameter) were found to have a direct course through the subcutaneous fat to the skin. Smaller perforators do not reach the skin but terminate at the level of the deep fat layer by branching after piercing the rectus sheath. The direct perforator vessels with their associated veins (microdissection) keep a consistent diameter before dividing at the subdermal level and end by contributing to the subdermal plexus.     

Venous valves in the large branches of superior vena cava

In 97 human cadavers the valves of the following blood vessels were investigated with regard to their cusps and their sizes and positions: the internal jugular veins, the subclavian veins, the brachiocephalic veins, and the superior vena cava. The cusps of each of the valves, which consist of two or three parts, are neither always of equal size nor obligatorily sufficient. Unipartite valves may be sufficient as well as insufficient. Internal jugular veins: The inferior bulb of the internal jugular vein is provided with valves which in 6% of the cases consist of three parts, in 66% of two parts, and in 15% of only one cusp. The concave margins of most of them go down as far as the venous angle. The convex edges attached to the wall of the vein extend to a higher level on the right side than on the left. In 13% there do not exist any valves. Varieties are described separately in this paper. Subclavian veins: Valves are found along the length of the vessel. Only few of them reach the venous angle. In rare cases there exist two valves: one at the beginning, the other at the end of the subclavian vein. In 4% of the cases the valves consist of three, in 75% of two cusps. In 12% they are unipartite. In 9% there are no valves to be found. The right side is more often without valves than the left. Brachiocephalic veins: Only a minority of these vessels is provided with valves. Most of these consist of one cusp, are insufficient, and are situated in the left innominate vein.(ABSTRACT TRUNCATED AT 250 WORDS)     

The vascular anatomy of rectus abdominis musculocutaneous flaps based on the deep superior epigastric system

Radiographic studies of the deep superior epigastric artery (DSEA) and its connections within the soft tissues of the abdominal wall were performed in 64 fresh cadavers. The patterns of anastomosis between the deep superior epigastric artery and the deep inferior epigastric artery (DIEA) were noted. Type I (29 percent) revealed a single deep superior epigastric artery and deep inferior epigastric artery, type II (57 percent) revealed a double-branched system of each vessel, and type III (14 percent) revealed a system of three or more major branches. In each case, the two systems were united by choke vessels in the segment of muscle above the umbilicus. The supply to the various transverse and vertical skin flaps from the deep superior epigastric artery was defined as a series of captured anatomic territories bounded by choke vessels. The upper transverse and vertical flaps had the best supply, and the TRAM flap had the most tenuous supply. Midline crossover occurs predominantly in the subdermal plexus and on the surface of the rectus sheath. Modifications of the design of the TRAM flap, the case for a delay procedure, the wisdom of including a strip of anterior rectus sheath, and the risks of splitting the muscle with respect to its nerve supply and vascular patterns are discussed on an anatomic basis.     

Small free vascularized iliac crest bone grafts in reconstruction of the scaphoid bone: a retrospective study in 60 cases.

Carpal instability may result in progressive degenerative arthritis of the wrist. The surgical goal of the reconstruction of scaphoid nonunion is to achieve bone union and to restore the scaphoid. Many procedures are described to treat scaphoid nonunion for different indications. This retrospective study reports on the anatomical fundamentals, the operative procedure, and the results of 60 patients (21 with recalcitrant scaphoid nonunion that lasted longer than 4 years, 26 with an avascular pole fragment, and 13 with scaphoid nonunion after previous surgery) who were treated by a small free vascularized iliac crest bone graft. All 60 patients have routinely been followed up clinically and with magnetic resonance imaging. Union was achieved in 91.7 percent by improvement of stability and the compromised vascularity of the scaphoid. The bone flap loss rate and persisting nonunion was 8.3 percent, leading to progressive arthritis and carpal collapse. Complaints concerning discomforts caused by the scar were heard from 40.1 percent of the patients, and 31.7 percent complained of discomforts caused by the bony deformity. Bone deformations on the donor site were detected radiologically in 63.3 percent of the patients. In 31.7 percent, an impairment of the lateral femoral cutaneous nerve was noted. Reconstruction of the scaphoid by means of implantation of a vascularized iliac bone graft proved efficient to treat avascular recalcitrant scaphoid nonunion and pseudarthrosis with avascular proximal pole fragments.     

Sinusoids of the bone marrow stroma in the human iliac bone

Results of histological and ultramicroscopic investigations of sinusoid vessels are presented. Interrupted structure of the basal membrane and continuous endothelial lining are revealed. Endotheliocytes of two types are described. At places of blood cells migration functional activity of endothelium is increased and the basal membrane is absent. A suggestion is made that the endothelial cells directly influence hemopoiesis.     

Patient-specific bone modelling and remodelling simulation of hypoparathyroidism based on human iliac crest biopsies

We previously developed a load-adaptive bone modelling and remodelling simulation model that can predict changes in the bone micro-architecture as a result of changes in mechanical loading or cell activity. In combination with a novel algorithm to estimate loading conditions, this offers the possibility for patient-specific predictions of bone modelling and remodelling. Based on such models, the underlying mechanisms of bone diseases and/or the effects of certain drugs and their influence on the bone micro-architecture can be investigated. In the present study we test the ability of this approach to predict changes in bone micro-architecture during hypoparathyroidism (HypoPT), as an illustrative example. We hypothesize that, apart from reducing bone turnover, HypoPT must also lead to increased osteocyte mechanosensitivity in order to explain the changes in bone mass seen in patients. Healthy human iliac crest biopsies were used as the starting point for the simulations that mimic HypoPT conditions and the resultant micro-architectures were compared to age-matched clinical HypoPT biopsies. Simulation results were in good agreement with the clinical data when osteocyte mechanosensitivity was increased by 40%. In conclusion, the results confirm our hypothesis, and also demonstrate that patient-specific bone modelling and remodelling simulations are feasible.