The Gracilis Myocutaneous Free Flap: A Quantitative Analysis of the Fasciocutaneous Blood Supply and Implications for Autologous Breast Reconstruction

BACKGROUND: Mastectomies are one of the most common surgical procedures in women of the developed world. The gracilis myocutaneous flap is favoured by many reconstructive surgeons due to the donor site profile and speed of dissection. The distal component of the longitudinal skin paddle of the gracilis myocutaneous flap is unreliable. This study quantifies the fasciocutaneous vascular territories of the gracilis flap and offers the potential to reconstruct breasts of all sizes. METHODS: Twenty-seven human cadaver dissections were performed and injected using lead oxide into the gracilis vascular pedicles, followed by radiographic studies to identify the muscular and fasciocutaneous perforator patterns. The vascular territories and choke zones were characterized quantitatively using the 'Lymphatic Vessel Analysis Protocol' (LVAP) plug-in for Image J® software. RESULTS: We found a step-wise decrease in the average vessel density from the upper to middle and lower thirds of both the gracilis muscle and the overlying skin paddle with a significantly higher average vessel density in the skin compared to the muscle. The average vessel width was greater in the muscle. Distal to the main pedicle, there were either one (7/27 cases), two (14/27 cases) or three (6/27 cases) minor pedicles. The gracilis angiosome was T-shaped and the maximum cutaneous vascular territory for the main and first minor pedicle was 35 × 19 cm and 34 × 10 cm, respectively. CONCLUSION: Our findings support the concept that small volume breast reconstructions can be performed on suitable patients, based on septocutaneous perforators from the minor pedicle without the need to harvest any muscle, further reducing donor site morbidity. For large reconstructions, if a 'T' or tri-lobed flap with an extended vertical component is needed, it is important to establish if three territories are present. Flap reliability and size may be optimized following computed tomographic angiography and surgical delay

Lymphatic drainage of the nasal fossae and nasopharynx : preliminary anatomical and radiological study with clinical implications

Background: The lymphatic pathways of the nasal cavity are of enormous clinical importance. To date there has been no accurate radiographic record of these pathways. Methods: Four halves of the head and neck from 2 fresh human cadavers were studied. Results: The capillary network arises from the mucous membrane of the atrium, the turbinates, the floor of the nasal cavity, and the nasopharynx. They drain into the lateral pharyngeal and retropharyngeal lymph nodes. There is 1 lymphatic communication at the junction of the lateral posterior wall of the turbinates and the nasopharynx and another communication between 2 groups of lymph nodes situated between the origin of the facial artery and the bifurcation of the carotid artery. Conclusions: A rich avalvular lymph capillary network exists in the mucous membrane and 2 major lymph collecting vessels course through the parapharyngeal space to multiple first tier lymph nodes.6 page(s

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

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

The lumbar artery perforators: a cadaveric and clinical anatomical study

Background: The lumbar region has been scarcely explored as a donor site for free tissue transfer or as a free flap recipient site. The lumbar integument provides a versatile prospective flap site, with a potentially well-concealed scar. Similarly, defects of this region can require recipient vessels that may be difficult to identify. Although lumbar artery perforators have been described, the reliability of perforators in this region remains questionable.\ud \ud Methods: An anatomical study was undertaken combining both cadaveric and in vivo analysis of the lumbar vessels. The cadaveric component comprised both dissection and angiographic studies in fresh and embalmed cadavers (36 lumbar regions in 18 cadavers), and the clinical study comprised a computed tomographic angiographic study (44 sides in 22 patients) and an operative case report.\ud \ud Results: Perforators were shown to arise from all eight lumbar arteries to enter the lumbar integument, with their size, location, and course described. Lower lumbar perforators were more often septocutaneous and of larger caliber. A case in which the fourth lumbar artery and concomitant vein were used as free flap recipient vessels is described, the first such reported case in the literature.\ud \ud Conclusions: Improving the incidence of identifying lumbar perforators of large caliber and with a septocutaneous course can be achieved by selecting lower lumbar vessels, or with the use of preoperative computed tomographic angiography. Computed tomographic angiography can successfully identify the location, size, and course of lumbar artery perforators and can aid flap design. Lumbar artery perforators are highly useful for both donor and recipient vessels in free flap surgery

The DIEA branching pattern and its relationship to perforators : the importance of preoperative computed tomographic angiography for DIEA perforator flaps

Background: Abdominal donor-site flaps based on the deep inferior epigastric artery (DIEA) are the most common flaps used in autologous breast reconstruction. With significant variation in the vascular anatomy of the DIEA, preoperative imaging is desirable. Computed tomographic angiography, recently described for this purpose, uniquely demonstrates the branching pattern of the DIEA. The authors sought to correlate the DIEA branching pattern to the location and course of perforators as a preoperative planning tool for perforator flaps. Methods: Forty-five cadaveric hemi–abdominal walls were used for contrast injection of the DIEA with subsequent radiographic imaging. The branching pattern on radiography was thus correlated to the location and intramuscular course of perforators, from the main DIEA trunk to the point of the penetrating rectus sheath. Results: The DIEA branching pattern correlated closely with the course of perforators. A bifurcating (type II) branching pattern demonstrated a reduced transverse distance traversed by each perforator, whereas a trifurcating (type III) branching pattern demonstrated significantly greater transverse distances (p = 0.0002). Type I vessels were intermediate. Vessel branching type, however, displayed no significant correlation with the number of perforators (p = 0.56). Conclusions: The distances traversed by perforators were significantly reduced with a bifurcating branching pattern of the DIEA, particularly those originating from the lateral branch, and were greatest with a trifurcating branching pattern. Increased transverse distances correlate with greater rectus muscle sacrificed during perforator flap surgery. As computed tomographic angiography is the optimal modality for demonstrating this pattern preoperatively, the authors suggest its use for preoperative assessment in transverse rectus abdominis musculocutaneous and DIEA perforator flaps.7 page(s

Anatomical variations in the harvest of anterolateral thigh flap perforators: a cadaveric and clinical study

Background: The anterolateral thigh (ALT) flap has become increasingly popular due to its versatility and minimal donor site morbidity. Its major limitation has been uncertainty in predicting perforator anatomy, with the occasional absence of suitable perforators and high variability in their size and course. The variability of this anatomy has not been adequately explored previously.\ud \ud Methods: A cadaveric study was undertaken, in which 19 thighs (from 10 fresh cadavers) underwent contrast injection and angiographic imaging. Anatomical variations of the vasculature were recorded. A clinical study of 44 patients undergoing ALT flap reconstruction was also undertaken. Perforator anatomy was described in the first 32 patients, and the subsequent 12 patients underwent computed tomography angiography with a view to predicting individual anatomy and improving operative outcome.\ud \ud Results: Cadaver angiography was able to highlight and classify the variations in arterial anatomy, with four patterns observed and marked variability between cases. In 32 patients undergoing ALT flaps without preoperative CT angiography (CTA), five patients (16%) did not have any suitable perforators from the descending branch of the lateral circumflex femoral artery. By selecting the limb of choice with preoperative CTA, the incidence of flap unsuitability was reduced to 0%. Comparing CTA with Doppler, CTA was more accurate (sensitivity 100%) and provided more information.\ud \ud Conclusion: The perforators supplying the ALT flap show significant variability in location and course, with the potential for unsuitable perforators limiting flap success. Preoperative CTA can demonstrate the vascular anatomy and can aid perforator selection and operative success

Angiogram of a cadaveric gracilis musculocutaneous flap showing the intramuscular arterial branching pattern of each pedicle.

<p>(Green: Main pedicle, Blue: First minor pedicle, Pink: Second Minor Pedicle, Yellow: Third minor pedicle.).</p

(A) A ‘screen grab’ image demonstrating the process of quantifying a radiographic injection study of the gracilis muscle and overlying fasciocutaneous tissues.

<p>Image was opened in Image J<b>®</b> and ‘initialized’ in the LVAP ‘Lymphatic Vessel Analysis Protocol’ (LVAP) plug-in. The image was then overlayed with two grids (see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0036367#s2" target="_blank">methods</a>) to allow systematic quantification of vessel density. Each yellow dot represents a counting point. (B) Graphical representation of the quantified average vessel density in both the muscle and skin specimens, in each one third of the flap.</p

(A) A ‘screen grab’ image of a radiographic injection study of the gracilis muscle and overlying fasciocutaneous tissue demonstrating the relative perfusion for each one third of the tissues.

<p>Image opened in Image J<b>®</b> and ‘initialized’ in the LVAP ‘Lymphatic Vessel Analysis Protocol’ (LVAP) plug-in. (B) Graphical representation of the relative perfusion for each one third of the tissues of the gracilis muscle and overlying fasciocutaneous tissues.</p