Computerized Tomographic and Magnetic Resonance Angiography for Perforator-Based Free Flaps: Technical Considerations

MRA for Preoperative Planning and Postoperative Management of Perforator Flap Surgeries: A Review

Perforator flap magnetic resonance angiography (MRA) has emerged as a widely accepted and preferred modality for perforator flap mapping at several institutions. Autologous perforator flaps are a type of reconstructive microsurgical technique that involves transferring skin and fat from one part of the patient's body to another to replace tissue lost due to trauma, cancer resection, or other reasons. Autologous perforator flaps are based on a specific perforating blood vessel perfusing the transferred tissue. Hence, the surgery relies on the precise identification and mapping of perforating vessels to ensure successful outcomes. With its superior soft tissue contrast and multiplanar imaging capabilities, MRA has shown great potential in providing accurate and detailed visualization of perforator anatomy, size, and course. This review article summarizes the current literature on perforator flap MRA, including its technical considerations, imaging protocols, postprocessing, and reporting, specifically for autologous breast reconstructions. The advantages and limitations of MRA in evaluating perforator flaps are discussed, including its role in preoperative planning, intraoperative guidance, and postoperative assessment. Anatomy, brief surgical technique, specific technical modifications, and reporting of most commonly performed autologous breast flaps are described. Recent advancements in Perforator flap surgery and MRA techniques are discussed. Additionally, we examine the emerging role of artificial intelligence and machine learning in improving the accuracy and efficiency of perforator flap MRA interpretation. LEVEL OF EVIDENCE: 5 TECHNICAL EFFICACY: Stage 5.

Alternative flaps in autologous breast reconstruction

The gold standard for autologous reconstruction in the post-mastectomy patient remains the deep inferior epigastric artery perforator flap, although many women may not be candidates for abdominally based free tissue transfer. In this scenario, there are several other donor site options based from the thigh (transverse and diagonal upper gracilis flaps, profunda artery perforator flap, lateral thigh flap) and trunk (lumbar artery perforator flap, superior and inferior gluteal artery perforator flaps). This study will review the history, relevant anatomy, surgical technique and outcomes for alternative flaps in autologous reconstruction. Additionally, preoperative imaging (CTA, MRA) and novel applications (stacking flaps, neurotization) in breast reconstructive microsurgery will be discussed.

Pedicled Peroneal Artery Perforator Flap for Knee Defect Reconstruction: Case Presentation and Literature Discussion

There have been very limited data on the use of pedicled peroneal artery perforator flaps in knee soft-tissue reconstruction, especially for anterior and medial defects. Here, we present a case of proximally based peroneal artery perforator flap for knee soft-tissue reconstruction in a defect that included lateral, anterior, and medial surfaces of the knee presenting the technical challenges associated with this flap. A 15-year-old girl presented with extruded knee implant after osteosarcoma resection of femur. The defect involved the whole knee with the anterior and mostly the lateral knee surfaces. Her medical condition precluded the use of free tissue transfer. During her previous surgery, gastrocnemius muscles were detached with injured vascular pedicled and posterior tibial artery. Successful single-stage coverage was achieved using a large proximally based pedicled peroneal artery perforator flap. There are only few reports that described the use of peroneal artery flaps for knee soft-tissue coverage. The reach of a proximally based flap can be increased when it is raised on a distal perforator or when peroneal artery has a proximal takeoff. Furthermore, removing the fibula can facilitate the dissection and the reach of the flap till the most medial aspect of the knee. Pedicled peroneal artery perforator flap provides superior soft-tissue coverage with limited morbidity for knee soft-tissue reconstruction; however, flap reach is usually affected by anatomic variation. Preoperative planning can help to determine the reach of the flap and ease the dissection.

MRA of the skin: mapping for advanced breast reconstructive surgery

Autologous breast reconstruction using muscle-sparing free flaps are becoming increasingly popular, although microvascular free flap reconstruction has been utilised for autologous breast reconstructions for >20 years. This innovative microsurgical technique involves meticulous dissection of artery-vein bundle (perforators) responsible for perfusion of the subcutaneous fat and skin of the flap; however, due to unpredictable anatomical variations, preoperative imaging of the donor site to select appropriate perforators has become routine. Preoperative imaging also reduces operating time and enhances the surgeon's confidence in choosing the appropriate donor site for harvesting flaps. Although computed tomography angiography has been widely used for preoperative imaging, concerns over excessive exposure to ionising radiation and poor iodinated contrast agent enhancement of the intramuscular perforator course has made magnetic resonance angiography, the first choice imaging modality in our centre. Magnetic resonance angiography with specific post-processing of the images has established itself as a reliable method for mapping tiny perforator vessels. Multiple donor sites can be imaged in a single setting without concern for ionising radiation exposure. This provides anatomical information of more reconstruction donor site options, so that a surgeon can design a flap of tissue centralised around the best perforator, as well as a back-up perforator, and even a back-up flap option located on a different region of the body. This information is especially helpful in patients with a history of scar tissue from previous surgeries, where the primary choice perforator is found to be damaged or unsuitable intraoperatively. In addition, chest magnetic resonance angiography evaluates recipient site blood vessel suitability including vessel diameters, course, and branching patterns. In this article we provide a broad overview of various skin flaps, clinical indications, advantages and disadvantages of each of these flaps, basic imaging technique, along with advanced sequences for visualising tiny arteries in the groin and in the chest. Post-processing techniques, structure of the report and how automation of the reporting system improves workflow is described. We also describe applications of magnetic resonance angiography in postoperative imaging.

Photo Epilation with Intense Pulsed Light for Thinning of Anterior Hairline after Hairline Correction Surgery in East Asians

Background

Thin hairs are critical to achieve natural result in female hairline correction surgery. However, there are few studies on the usefulness of hair thinning by intense pulsed light (IPL) after hairline correction surgery in East Asian females.

Methods

Hair thinning using IPL was performed in 54 women who had complained about thick hairs along the frontal hairline after hairline correction surgery. Patient mean age was 31.2 years old and patients were an average of 2.1 years post-hairline correction surgery. Initial treatment used 10 J, while second and third sessions were conducted with 10 to 15 J according to responsiveness to treatment.

Results

Mean thickness of individual hairs assessed before the procedure was 78.86 µm. The mean number of procedures was 1.6 per patient. Forty of 54 subjects (74%) achieved satisfactory hair thinning with only one procedure from 78.01 to 66.14 µm after treatment. The measured thickness was 66.43 µm at the end of the first year in patients who were satisfied after one procedure. Thirteen cases achieved satisfactory hair thinning after two sessions. Mean thickness was 74.44 µm and 67.51 µm, before and after the second session. One case required a third session with 15J, thinning from 89.00 to 66.50 µm.

Conclusions

Hair thinning by IPL is a very useful method to provide a natural look after hairline correction surgery in East Asians, who have naturally thick hair.

Peroneal Flap: Clinical Application and Cadaveric Study

Background

The goal of this study was to investigate the anatomy of the peroneal artery and its perforators, and to report the clinical results of reconstruction with peroneal artery perforator flaps.

Methods

The authors dissected 4 cadaver legs and investigated the distribution, course, origin, number, type, and length of the perforators. Peroneal artery perforator flap surgery was performed on 29 patients.

Results

We identified 19 perforators in 4 legs. The mean number of perforators was 4.8 per leg, and the mean length was 4.8 cm. Five perforators were found proximally, 9 medially, and 5 distally. We found 12 true septocutaneous perforators and 7 musculocutaneous perforators. Four emerged from the posterior tibia artery, and 15 were from the peroneal artery. The peroneal artery perforator flap was used in 29 patients. Retrograde island peroneal flaps were used in 8 cases, anterograde island peroneal flaps in 5 cases, and free peroneal flaps in 16 cases. The mean age was 59.9 years, and the defect size ranged from 2.0 cm×4.5 cm to 8.0 cm×8.0 cm. All the flaps survived. Five flaps developed partial skin necrosis. In 2 cases, a split-thickness skin graft was performed, and the other 3 cases were treated without any additional procedures.

Conclusions

The peroneal artery perforator flap is a good alternative for the reconstruction of soft tissue defects, with a constant and reliable vascular pedicle, thin and pliable skin, and the possibility of creating a composite tissue flap.