Ex vivo intraoperative angiography for rectus abdominis musculocutaneous free flaps

Deep Inferior Epigastric Perforators Topography for "Island Transverse Rectus Abdominis Musculocutaneous Flap" in Breast Reconstruction

Background  The Island transverse rectus abdominis musculocutaneous (TRAM) flap is well vascularized with very reliable blood flow, because all perforators of the zone I are included when it is harvested. The number of perforators, topographic mapping, and their relationship with reconstructed outcomes were investigated. Methods  Fifty patients with Island TRAM breast reconstruction from September 2021 to August 2022 were investigated. The zone I was divided into a total of eight sections. Under the loupe magnification, all perforators larger than 0.5 mm in zone I were counted with fine dissection, and photographs were taken in background of vessel loops. Complications like flap necrosis, seroma, and hematoma were also investigated. Result  There are 12 ideal perforators on average in zone I such as one perforator in section I, II, IV, V, VI, VIII, and three perforators in section III and VII. However, two perforators (M6 and L6) below arcuate line were sacrificed in the time of flap harvest to prevent hernia. Island TRAM included 10 perforators on average (5 perforators in each side) above arcuate line to be transferred to the recipient site. Only minor complications were identified. Conclusion  The Island TRAM flap includes 10 perforators to get the vigorous blood flow. The periumbilical to upper medial perforators become more dominant in the perfusion of the flap after deep inferior epigastric artery division. Well preserved perforators will guarantee the satisfactory breast reconstruction with the least complication.

Rezoning Free Muscle-Sparing Transverse Rectus Abdominis Myocutaneous Flaps Based on Perforasome Groupings and a New Understanding of the Vascular Architecture of the Deep Inferior Epigastric Artery-Based Flaps

BACKGROUND

We compare the vascular territory of free muscle-sparing transverse rectus abdominis myocutaneous (MS-TRAM) flaps, deep inferior epigastric perforator (DIEP) flaps, and crossover anastomosis (CA) flaps using intraoperative ex vivo angiography. We also use ex vivo angiography to analyze the vascular architecture of the MS-TRAM flap.

METHODS

Our study includes 84 lower abdominal free flaps: MS-TRAM, DIEP-1 (1 perforator), DIEP-2 (2 perforators), and CA. We compare the arterial perfusion area and vascular territory pattern in each group. We also analyze the vascular architecture in MS-TRAM flaps and determine the number and location of their dominant perforators and the direction of the axial arteries connecting them.

RESULTS

The CA's arterial perfusion area is the largest, and the DIEP-1's, the smallest of our groups; there is no statistically significant difference between MS-TRAM and DIEP-2. In all groups, average arterial perfusion area in the vascular pedicle's ipsilateral side is larger than in its contralateral side. The MS-TRAM and DIEP-2 flaps have homologous perfusion patterns and the same arterial perfusion areas. The DIEP-1 perfusion pattern varies with perforator location. Ex vivo angiograms show the MS-TRAM flap's axial arteries heading laterally to be larger and longer than those heading medially.

CONCLUSIONS

Two dominant perforators are preferable in DIEP flap breast reconstruction. Lateral perforators play a more important role in flap perfusion than do medial ones. Crossover anastomosis is an effective technology for increasing arterial perfusion areas. Our rezoning shows which areas are better for surgery and which have a high risk of complications-valuable information for a surgeon designing a flap for breast reconstruction.

Computed tomographic angiography: assessing outcomes

Perforator flaps are preferable for breast reconstruction after mastectomy in many patients. Preoperative imaging of the perforators and source vessels is desirable to reduce surgeon stress, limit donor and recipient site complications, and minimize operative time and associated costs. Computed tomographic angiography (CTA) has been shown to provide highly accurate representations of vascular anatomy with excellent spatial resolution. A critical review of the currently available literature was performed to identify the benefits of preoperative imaging (specifically CTA) in perforator flap reconstruction.

Extended vertical rectus abdominis myocutaneous flap for pelvic reconstruction: three-dimensional and four-dimensional computed tomography angiographic perfusion study and clinical outcome analysis

BACKGROUND

The extended vertical rectus abdominis myocutaneous (eVRAM) flap includes skin and subcutaneous fat extending from the costal margin to the anterior axillary line. The reliability and vascularity of this distal extension have been questioned. The authors hypothesized that the eVRAM flap would have adequate perfusion throughout the extended portion and be reliable for pelvic reconstruction. To evaluate this, the authors conducted a perfusion study on eVRAM flaps from cadavers and a retrospective clinical study of outcomes in patients.

METHODS

In the perfusion study, seven eVRAM flaps were harvested from fresh cadavers. Iodinated contrast material was injected into the deep inferior epigastric artery of each flap, and three- and four-dimensional computed tomography (three-dimensional and four-dimensional computed tomography) angiography was performed. In the clinical study, the surgical outcomes of all patients who underwent repair of pelvic defects with a pedicled eVRAM flap between 2004 and 2008 were retrospectively evaluated.

RESULTS

Three-dimensional and four-dimensional computed tomography demonstrated connections between adjacent intercostal and superior epigastric artery vascular territories that provided a robust blood supply to the flap extension. In the eight patients included in the clinical study, all flaps demonstrated excellent vascularity and survived completely. Two minor complications occurred: a lateral perineal dehiscence and hypertrophic scarring of the abdomen.

CONCLUSIONS

Four-dimensional computed tomography angiography demonstrated vascular perfusion throughout the eVRAM flaps. Low rates of donor-site and recipient-site complications and good distal flap perfusion were observed when a pedicled eVRAM flap was used for pelvic reconstruction. The eVRAM flap is a reliable option for pelvic reconstruction requiring large tissue volume and/or additional flap reach.

Improving outcomes in autologous breast reconstruction

Autologous breast reconstruction can often provide a more aesthetic outcome than other options for breast reconstruction because breast volume and shape can be extensively modified based on individual need, the texture of the reconstructed breast is a closer match to the native breast, and complications such as capsular contracture are avoided. However, with these benefits come the potential for complications unique to autologous tissue transfer. While overall complications are low, there are ways to maximize operative success and minimize the risk of complications. Deep inferior epigastric artery perforator (DIEP) flaps, the current mainstay in choice of autologous reconstruction, provide generally good outcomes. However, improvements in outcomes can still be achieved with a better understanding of individual anatomy. Perforator size, location, intramuscular and subcutaneous course, and association with motor nerves are all factors that can significantly affect operative technique, length of operation, and operative outcomes. With significant variation between individuals, preoperative imaging has become an essential element of DIEP flap surgery. Computed tomography angiography (CTA) is currently the gold standard but evolving techniques such as magnetic resonance angiography (MRA) and image-guided stereotaxy are rapidly contributing to improved outcomes.

Muscle sparing-2 transverse rectus abdominis musculocutaneous flap for breast reconstruction: a comparison with deep inferior epigastric perforator flap

Breast reconstruction using free transverse rectus abdominis musculocutaneous (TRAM) flap can be divided into 4 muscle-sparing (MS) types: conventional TRAM flap containing full width muscle as MS-0, while deep inferior epigastric perforator (DIEP) flap containing absolutely no muscle as MS-3. We include only the muscle portion between the medial row and lateral row perforator vessels in TRAM flap, which is designated as MS-2. Between October 1999 and April 2006, the same surgeon performed 82 breast constructions using MS-2 free TRAM flaps in 79 patients. All the flaps survived. Postoperative complications included partial fat necrosis in 8 cases, all corresponding to zone IV or zone II. Bulging of donor site occurred in 5 patients, 4 of whom were obese and 1 had bilateral flap harvest. Compared with our own reconstructions using DIEP flap (30 cases), there were no significant differences in operative time and blood loss between the two techniques. In conclusion, MS-2 free TRAM flap is a useful technique for breast construction considering the easy surgical techniques, length of the vascular pedicle that can be harvested, and the degree of freedom of the flap.

The versatility of the SIEA flap: a clinical assessment of the vascular territory of the superficial epigastric inferior artery

Following the TRAM and the DIEP the SIEA flap is the next logical step to reduce the donor site morbidity in autologous breast reconstruction. The vascular axis of the SIEA flap, however, is completely different from the deep epigastric pedicle, on which previous lower abdominal flaps were based. Therefore, a mapping of the vascular territory, which can be reliably harvested on this pedicle, seems mandatory before this new technique can become established.

AIM

To chart the angiosome of the superficial inferior epigastric artery with regard to breast reconstruction and to evaluate the random extension of the vascular territory, which can be reliably raised on this pedicle.

STUDY DESIGN

Clinical, prospective study in a university-affiliated department of plastic surgery.

PATIENTS

Ten patients undergoing autologous breast reconstruction with the superficial inferior epigastric perforator flap and five patients undergoing aesthetic abdominoplasty with isolation of the abdominal flap on the superficial epigastric vessels.

MATERIAL AND METHODS

After isolation of the abdominal panniculus on a single superficial inferior epigastric artery pedicle, the flap was divided in the four conventional zones according to Hartrampf. Perfusion in each of the four zones was measured on the table using the technique of dynamic laser-fluorescence videoangiography.

RESULTS

Perfusion of Hartrampf Zone III occurred first (25s post-injection) and the perfusion index amounted median 89% of reference. Perfusion of Zone I occurred median 5s later and the relative perfusion was 80%. Perfusion of the contralateral zones II and IV was dramatically reduced to 8% and zero, respectively, and this reduction was statistically significant (p<0.0001).

CONCLUSION

The true angiosome of the superficial epigastric artery is located laterally on the ipsilateral hemiabdomen. Its random extension is unreliable and ranges most frequently only to the midline. Based on the results of this study, survival of the skin and subcutaneous fat taken laterally to the border of the contralateral rectus sheath seems questionable. Therefore, the versatility of the SIEA flap for autologous breast reconstruction seems limited when compared with the conventional methods based on the deep inferior epigastric system.

The Cutaneous Arteries of the Anterior Abdominal Wall: A Three-Dimensional Study

BACKGROUND

Abdominal perforator flaps represent a natural progression in the quest to minimize abdominal wall morbidity. Their one disadvantage is the significant rate of vascular complications to which they are subject in some series. The authors examined the vascular anatomy of the abdominal integument, to determine why such complications occur and how they may be prevented.

METHODS

In 10 fresh cadavers, major arteries supplying the abdominal wall were injected with a lead-based contrast medium. The abdominal integument of each cadaver was imaged using a 16-slice spiral computed tomography scanner, to produce three-dimensional reconstructions of the arterial anatomy. Reconstructions were observed for orientation, course, and morphology of the major perforators within the abdominal integument.

RESULTS

Perforators of the deep inferior epigastric artery (DIEA) varied markedly in their orientation, course, and morphology among specimens. By contrast, perforators of the superior epigastric artery (SEA) were relatively consistent in their morphology and orientation. In eight of 10 specimens, SEA perforators with extensive anatomical "territories" orientated toward the umbilicus were present. These SEA perforators pierced the rectus sheath within 4 cm of the costal margin and were present bilaterally in seven of eight specimens.

CONCLUSIONS

The unpredictable orientation and course of DIEA perforators indicate that the blood supply of abdominal perforator flaps, raised without clear knowledge of their unique vascular anatomy, may often be more random than axial. This may account for much of the ischemia-related morbidity observed with DIEA-based perforator flaps. Preservation of SEA perforators adjacent to the costal margin during abdominoplasty will likely improve abdominal wall perfusion and reduce donor-site morbidity.

Analyzing the Vascular Architecture of the Free TRAM Flap Using Intraoperative Ex Vivo Angiography

BACKGROUND

Using ex vivo intraoperative angiography to analyze 14 flaps from 12 breast reconstruction patients, the authors investigated the vascular architecture of free transverse rectus abdominis musculocutaneous (TRAM) flaps nourished by the deep inferior epigastric artery.

METHODS

Contrast medium was injected through the deep inferior epigastric artery and flaps were radiographed to observe their vascular patterns.

RESULTS

TRAM flaps showed one or two segmental arteries stained on their ipsilateral side (zones 1 and 3) and serving as the flap's axial artery. These segmental arteries directly connect to the large perforators (axial perforators) and emerge not only from the paraumbilical perforators but also from the caudal branches of the deep inferior epigastric artery. Arterial density is always lower in the contralateral area (zones 2 and 4) than in the ipsilateral area (zones 1 and 3).

CONCLUSIONS

Because the cephalic half of zone 2 and all of zone 4 remain unstained, these areas are prone to skin or fat necrosis, especially in high-risk patients. Ex vivo angiography, by providing specific information about the individual flap and by reflecting its flow physiology, enables one to observe and to chart the vascular architecture of free TRAM flaps nourished by the deep inferior epigastric artery.