The "limited rectus sheath incisions" technique for DIEP flaps using preoperative CT angiography.

The abdominal wall donor site has become popularized for autologous breast reconstruction, with low donor site morbidity one of its key attributes. Further improvements in donor site outcomes have been facilitated through muscle sparing techniques, such as the use of the deep inferior epigastric artery (DIEA) perforator (DIEP) flap, and the use of modifications to closing the rectus sheath following muscular dissection, such as the use of endoscopic techniques and the use of mesh. We describe a new and unique method for potentially minimizing donor site damage during DIEP flap harvest: the "limited rectus sheath incisions" technique. This approach is only possible in select cases, the choice of which can be aided with the use of preoperative computed tomography angiography (CTA). In select patients, there may be an extended segment of DIEA that does not give any musculocutaneous perforators, and thus does not require open exposure. In such cases, limited incision to the rectus sheath may be made: one to access the periumbilical perforators and a separate incision to access the pedicle near its origin on the external iliac artery. This incision may then be made in a muscle-splitting fashion, in the line of external oblique fibers. This approach may reduce damage to the anterior rectus sheath, and may contribute to improving donor site morbidity. (c) 2009 Wiley-Liss, Inc. Microsurgery, 2009.

Image-guided, stereotactic perforator flap surgery: a prospective comparison of current techniques and review of the literature.

BACKGROUND: Image-guided stereotaxy is a recent advancement in imaging technology, allowing computer guidance to aid surgical planning and accuracy. Despite the use of multiple techniques for patient registration in several surgical specialities, only fiducial marker registration has been described for use in soft tissue reconstructive surgery. The current study comprises an evaluation of the current techniques available for this purpose. METHODS: A cohort of nine consecutive patients planned for elective free flaps were recruited, with the first five patients (four for the abdominal wall and one anterolateral thigh donor site) undergoing fiducial marker registration with a variable number of fiducial markers in order to determine the optimal number of fiducial markers to be used. Four subsequent patients undergoing perforator flap surgery underwent registration using three available registration modalities: fiducial marker registration, surface matching pointer/landmark and surface matching laser registration. RESULTS: For the abdominal wall, registration was not able to be achieved with five fiducial markers, and was successfully achieved in all cases with either six or seven fiducial markers. For the anterolateral thigh, registration was achieved with either nine or ten markers. The four patients who also underwent surface-landmark registration and 'Z-touch' laser surface matching registration all failed the registration process. CONCLUSION: Stereotactic navigation is a useful adjunct to the preoperative imaging of perforator flaps. Fiducial marker registration was able to be achieved in all cases, can be successfully achieved with a low and predictable number of fiducial markers, is highly accurate, and was the only reliable registration process in our experience.

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.

The cutaneous course of deep inferior epigastric perforators: implications for flap thinning.

BACKGROUND: The deep inferior epigastric artery (DIEA) perforator flap is frequently used for autologous breast reconstruction following mastectomy. Thinning of the flap is often performed to debulk the flap of excess fatty tissue, such as in partial mastectomy defects. Thinning may disrupt the blood supply to the flap and compromise viability, however adequate guidelines for thinning are lacking from the literature. METHODS: Clinical and anatomical studies were concurrently undertaken to explore the cutaneous course of perforators as a guide to flap thinning. Twenty consecutive patients undergoing DIEA perforator flap breast reconstruction underwent preoperative computerised tomography angiography (CTA), and a cadaveric study was also undertaken, in which six fresh, whole abdominal walls underwent CTA. All perforators greater than 2 mm were analysed for their cutaneous course. RESULTS: In all cases, perforators emerged from the anterior rectus sheath and traversed an oblique, but direct course through the deep layer of adipose tissue, before reaching Scarpa's fascia. Branching of perforators occurred in two planes of the superficial adipose layer: just superficial to Scarpa's fascia (the fascial plexus) and in the subdermal plexus. CONCLUSION: Thinning of DIEA perforator flaps can only be performed safely deep to Scarpa's fascia. Thinning performed superficial to Scarpa's fascia threatens the intrinsic blood supply to the flap.

Advanced imaging technologies for mapping cadaveric lymphatic anatomy: magnetic resonance and computed tomography lymphangiography.

Lymphatic anatomy has become increasingly clinically important as surgical techniques evolve for investigating and treating cancer metastases. However, due to limited anatomical techniques available, research in this field has been insufficient. The techniques of computed tomography (CT) and magnetic resonance (MR) lymphangiography have not been described previously in the imaging of cadaveric lymphatic anatomy. This preliminary work describes the feasibility of these advanced imaging technologies for imaging lymphatic anatomy. A single, fresh cadaveric lower limb underwent lymphatic dissection and cannulation utilizing microsurgical techniques. Contrast materials for both CT and MR studies were chosen based on their suitability for subsequent clinical use, and imaging was undertaken with a view to mapping lymphatic anatomy. Microdissection studies were compared with imaging findings in each case. Both MR-based and CT-based contrast media in current clinical use were found to be suitable for demonstrating cadaveric lymphatic anatomy upon direct intralymphatic injection. MR lymphangiography and CT lymphangiography are feasible modalities for cadaveric anatomical research for lymphatic anatomy. Future studies including refinements in scanning techniques may offer these technologies to the clinical setting.

Stereotactic image-guided navigation in the preoperative imaging of perforators for DIEP flap breast reconstruction.

Preoperative imaging is sought prior to DIEA (Deep Inferior Epigastric Artery) perforator flaps due to the potential for maximizing operative success and minimizing operative complications. Recent advances include the use of computed tomography (CT) angiography (CTA) and magnetic resonance angiography. Image-guided stereotactic surgery is a recent technique that has been used with success in several fields of surgery. The variability of perforator anatomy makes DIEA perforator flap surgery a suitable candidate for such technology, but as yet this has not been described. A study was undertaken to determine the feasibility of CT-guided stereotaxy technique in DIEA perforator flap surgery and to compare findings with both conventional CTA and operative findings. Five consecutive patients planned for an elective DIEA perforator flap were recruited. Each patient underwent preoperative imaging of the anterior abdominal wall vasculature with both conventional CTA and CT-guided stereotactic imaging. Imaging findings were compared to operative findings. In all cases, all the major perforators were accurately localized with stereotactic imaging and with conventional CTA. Stereotactic navigation demonstrated a slightly better (nonsignificant) correlation with perforator location than conventional CTA. As such, CT-guided stereotactic imaging is an accurate method for the preoperative planning of DIEA perforator flaps, providing additional and potentially more accurate data to conventional CTA. With no additional scanning required, the method described in this paper allows the combined use of both methods for preoperative planning.

Establishing the case for CT angiography in the preoperative imaging of abdominal wall perforators.

Preoperative imaging of the donor site vasculature for deep inferior epigastric artery (DIEA) perforator flaps and other abdominal wall reconstructive flaps has become more commonplace. Abdominal wall computed tomography angiography (CTA) has been described as the most accurate and reproducible modality available for demonstrating the location, size, and course of individual perforators. We drew on our experience of 75 consecutive patients planned for DIEA-based flap surgery undertaking CTA at a single institution. Seven of these cases have been reported to highlight the utility of CTA for preoperative planning, emphasizing the unique information supplied by CTA that may influence operative outcome. Among all cases that underwent preoperative imaging with CTA, there was 100% flap survival, with no partial or complete flap necrosis. We found that in three of the cases described, the choice of operation was necessarily selected based on CTA findings (DIEA perforator flap, transverse rectus abdominis myocutaneous flap, and superficial superior epigastric artery flap). In addition, three cases demonstrate that CTA findings may dictate the decision to operate at all, and one case demonstrates the utility of CTA for evaluating the entire abdominal contents for comorbid conditions. Our experience with CTA for abdominal wall perforator mapping has been highly beneficial. CTA may guide operative technique and improve perforator selection in uncomplicated cases, and in difficult cases it can guide the most appropriate operation or indeed if an operation is appropriate at all. This is particularly the case in the setting of comorbidities or previous abdominal surgery.

Refining the course of the thoracolumbar nerves: a new understanding of the innervation of the anterior abdominal wall.

Previous descriptions of the thoracolumbar spinal nerves innervating the anterior abdominal wall have been inconsistent. With modern surgical and anesthetic techniques that involve or may damage these nerves, an improved understanding of the precise course and variability of this anatomy has become increasingly important. The course of the nerves of the anterior abdominal is described based on a thorough cadaveric study and review of the literature. Twenty human cadaveric hemi-abdominal walls were dissected to map the course of the nerves of the anterior abdominal wall. Dissection included a comprehensive tracing of nerves and their branches from their origins in five specimens. The branching pattern and course of all nerves identified were described. All thoracolumbar nerves that innervate the anterior abdominal wall were found to travel as multiple mixed segmental nerves, which branch and communicate widely within the transversus abdominis plane (TAP). This communication may occur at multiple locations, including large branch communications anterolaterally (intercostal plexus), and in plexuses that run with the deep circumflex iliac artery (DCIA) (TAP plexus) and the deep inferior epigastric artery (DIEA) (rectus sheath plexus). Rectus abdominis muscle is innervated by segments T6-L1, with a constant branch from L1. The umbilicus is always innervated by a branch of T10. As such, identification or damage to individual nerves in the TAP or within rectus sheath is unlikely to involve single segmental nerves. An understanding of this anatomy may contribute to explaining clinical outcomes and preventing complications, following TAP blocks for anesthesia and DIEA perforator flaps for breast reconstruction.

Developments in perforator imaging for the anterolateral thigh flap: CT angiography and CT-guided stereotaxy.

INTRODUCTION: The anterolateral thigh flap is an increasingly popular reconstructive option despite uncertainty in its perforator anatomy. Perforators are not always present, vary in size and intramuscular course, and have variable cutaneous courses and supply. As such, preoperative imaging has become favored. METHODS: The current study describes the preliminary use of two new modalities for preoperative imaging: computed tomography (CT) Angiography and CT-guided stereotaxy. These have been utilized in the preoperative imaging of two patients undergoing ALT flap reconstruction. Each patient underwent each of these techniques combined with Doppler ultrasound, the previous standard modality. The size, location, and course of perforators were explored and compared with operative findings. RESULTS: Both techniques are technically feasible, highly accurate, and provide more information to the surgeon than ultrasound. CONCLUSION: CT Angiography and CT-guided stereotaxy are useful adjuncts to Doppler ultrasound for imaging perforators prior to ALT flaps. A larger study is suggested to quantify the accuracy of these techniques.

Reviewing the vascular supply of the anterior abdominal wall: redefining anatomy for increasingly refined surgery.

The abdominal wall integument is becoming the standard donor tissue for postmastectomy breast reconstruction, with its vascular supply of key importance to the reconstructive surgeon. Refinements in tissue transfer, from pedicled to free flaps and musculocutaneous to perforator flaps, have required increasing understanding of finer levels of this vascular anatomy. The widespread utilization of the deep inferior epigastric artery (DIEA) perforator flap, particularly for breast reconstruction, has rekindled clinical interest in further levels of anatomical detail, in particular the location and course of the musculocutaneous perforators of the DIEA. Advances in operative techniques, and anatomical and imaging technologies, have facilitated an increase in this understanding. The current review comprises an appraisal of both the anatomical and clinical literature, with a view to highlighting the key anatomical features of the abdominal wall vasculature as related to reconstructive flaps.

Fasciocutaneous island flaps for orthopaedic management in lower limb reconstruction using dermatomal precincts.

This paper describes a technique of fasciocutaneous island flaps used in reconstruction of the lower limb. It is very versatile and some 26 individual flaps in 22 patients have been used to reconstruct skeletal and soft tissue problems from the popliteal fossa to the ankle joint. These longitudinally designed flaps made up of a trilaminate of skin, subcutaneous fat and fascia are aligned within the dermatomal precincts. The most important location for such flap design is along the peroneal compartment sitting within the L5 dermatome and incorporating the superficial peroneal nerve. It can be lengthened as far as the lateral malleolus and is an excellent reconstructive method to close defects over the lower third of the tibia. The medial compartment of the leg employing the saphenous nerve (L4 dermatome) is another area for fasciocutaneous island flap reconstruction, but use is restricted to the upper two-thirds of the tibial area. Posteriorly the island flap design sits along the S2 dermatome, this time incorporating the sural nerve to reconstruct defects of the calf and can be extended to include problems of the popliteal fossa. In the overall flap technique, the age of the patient is not a contraindication and cases with peripheral vascular disease have been treated successfully. The flaps may extend up to a 5:1 ratio in dimension. The operating time can be considerably shortened.