Distal anastomosis patterns of the descending branch of the lateral circumflex femoral artery

Morphological study of branches of lateral femoral circumflex artery based on digital subtraction angiography

In this study, the digital subtraction angiography (DSA) data were used to describe the number, course, and distribution of the branches of the lateral circumflex femoral artery (LCFA), in order to provide an imaging basis for the application of the anterolateral thigh flap pedicled with each branch of the LCFA. The number, location, direction, and distribution of the branches of the LCFA were analyzed by selective DSA angiography in 113 patients who needed an anterolateral thigh flap to repair the wound. LCFA usually originates from the deep femoral artery or femoral artery and routinely sends out four main branches: ascending branch, transverse branch, oblique branch, and descending branch. The ascending branch is about 45 °outward and upward with the horizontal axis of the body; the transverse branch is roughly parallel to the horizontal axis of the body to the outside of the thigh or slightly upward or downward; the oblique branch is about 45 °outward and downward to the body's long axis or horizontal axis and gradually turns parallel to the body's long axis; the 5∼10 cm at the beginning of the descending branch is parallel to the long axis of the body, and the internal and external branches are separated near the midpoint of the line between the anterior superior iliac spine and the lateral edge of the patella. It is of high reference value to use DSA technology to analyze the morphological characteristics of LCFA.

Knee Defect Reconstruction Using the Distally Based Anterolateral Thigh Flap Based on the Reverse Flow from the Oblique Branch of the Lateral Circumflex Femoral Artery

Reconstruction of soft tissue defects around the knee is challenging, and the most common solution is to use various locoregional flaps or, in some difficult cases, a free flap. The distally based anterolateral thigh (dALT) flap is a commonly used flap that relies on reverse blood flow from the descending branch of the lateral circumflex femoral artery (d-LCFA). Here, we present the case of an anteromedial knee reconstruction using a dALT flap after resection of a pleomorphic undifferentiated sarcoma. The tumor resection resulted in a 14 × 7 cm defect, and a dALT flap, measuring 20 × 8 cm was elevated. During the surgery, we found a robust oblique branch of the LCFA (o-LCFA) sending off two sizable perforators to the anterolateral thigh region, whereas the d-LCFA was relatively small with no usable perforators. Therefore, we harvested a dALT flap relying on reverse flow from the o-LCFA. The patient's postoperative course was uneventful, and the flap survived without complications. This report demonstrates that reverse flow from the o-LCFA may be an alternative to nourish a dALT flap in cases where the d-LCFA is hypoplastic or suitable perforators from the d-LCFA are unavailable.

"Reverse tensor fascia latae perforator flap for reconstruction of knee defect: Anatomic study by computed tomographic angiography and a case report"

BACKGROUND

Reverse anterolateral thigh perforator (ALTp) pedicle flap can be used to reconstruct perigenicular defect thanks to the anastomoses between the descending branch of the lateral circumflex femoral artery (LCFA) and the perigenicular network. In a few cases, however, patients do not present any ALTp. We hypothesized that, in such cases, an adjacent perforator, the tensor fascia latae perforator (TFLp), emerging from the LCFA ascending branch, could be used instead. To assess the feasibility of this technique, a radiological study was conducted. A first patient was treated using this option.

METHODS

Sixty lower limb computed tomography were analyzed. The first treated patient was a 50-years-old man suffering from a 5-mm chronic bone exposure and osteomyelitis. Other reconstructive options were not indicated since he presented a multiscarry leg, severe arteriopathy, and no ALTp. A TFLp flap was raised, and the LCFA ascending and descending branches were dissected in continuity. After ligation of the LCFA, the blood flow reversed in the descending branch to irrigate the flap through the ascending branch.

RESULTS

A TFL perforator was observed in all the cases of the radiological study. The LCFA branching pattern was compatible with achieving a reverse TFL perforator flap in 43 cases (72%). The average pedicle length was 32 cm (22-38 cm). In the first clinical case, the flap covered the defect easily. After three months, the patient showed no evidence of infection recurrence and recovered a painless walk.

CONCLUSION

The reverse TFLp flap can be a suitable option for perigenicular reconstruction.

Collateral circulation of the femoral and genicular systems in human lower limbs is highly uncommon

The descending branch of the lateral circumflex artery is a septocutaneous vessel that is vital for free and pedicle thigh flap transfer surgeries when repairing tissue defects. It also forms an anastomosis with the superior lateral genicular artery to create a collateral pathway for circumventing occlusions in the superficial femoral artery (SFA). Many anatomical texts and atlases imply the persistence of this anastomosis. However, previous studies indicate variability in the source of the arteries that form the anastomosis, and have reported cases where an anastomosis does not exist. We hypothesized that variations from the conventional accepted pattern can be predicted by comparisons of arterial diameters, and that unconventional anastomoses may be present to facilitate collateral circulation to the limb. Fifty-one limbs were dissected and analyzed to establish the source of the descending branch of the lateral circumflex artery, classify the types of anastomoses, and compare the diameters of the descending branch of the lateral circumflex artery, the SFA and the profunda femoris artery to the common femoral artery (CFA). Vessel diameters were normalized to the diameter of the CFA to allow comparison of limbs from both sexes and to minimize the effects of cadaver size on correlating vessel size to the presence or absence of collateral circuits. We report that 62.7% of limbs (32/51) had typical branching patterns; however, only 27.4% of limbs (14/51) had any anastomosis to connect the proximal and distal regions of the thigh. Importantly, the SFA had a wider relative diameter in limbs without anastomoses than in limbs that had normal anastomoses, perhaps precluding the formation of a collateral pathway. Overall, collateral circulation of the lower limb was highly uncommon, in contrast to information inferred from anatomical texts. This study suggests the need for more thorough procedures for determining viable anastomoses prior to thigh flap surgeries to ensure flap survival.

Anatomic Variations of the Deep Femoral Artery and Its Branches: Clinical Implications on Anterolateral Thigh Harvesting

The deep femoral artery (DFA) is the largest branch of the common femoral artery (CFA), supplying with its branches, the medial circumflex femoral artery (MCFA) and lateral circumflex femoral artery (LCFA), the thigh muscles, the hip joint, and the femur. Their anatomical variations have a great impact on both interventional and surgical procedures. The anterolateral thigh (ALT) flap, a versatile soft tissue with highly increasing use in reconstructive surgery, is noticeably influenced by this variability. A total of 25 articles were incorporated into the review. Studies conducted after the year 2009 were included. After the assessment of all studies included, we concluded that the DFΑ arises from the CFA with a varying site of origin, the posterolateral being the prevalent one found in 51.32% of cases. Of all cases studied, the MCFA and the LCFA most often originated from the DFA in 63.125% and 74.92%, respectively, but the CFA constitutes another frequent source of origin in 27% and 12.12% of cases, respectively. The descending branch of the lateral circumflex femoral artery (dLCFA) is the prominent pedicle in the ALT flap, originating from the LCFA in 83.55% of cases. However, the presence of an oblique lateral circumflex femoral artery (oLCFA) branch with changeable origination was observed. Knowledge of the anatomical variants in the deep femoral artery is imperative both for interventional radiologists and surgeons. Especially in reconstructive surgery, the possibility for different sources supplying the skin and the pedicle compel surgeons to acquire an awareness of this subject.

Vascular coverage of the anterior knee region - an anatomical study

Descriptions of vessel angiosomes or perforasomes throughout the human body are quite frequent, and led to the development of flaps nowadays commonly used to surgically cover skin and soft tissue defects. In these procedures, the surgeon requires a profound anatomical knowledge of the respective blood vessels and the extent of the perfused area to define the size of the graft. In the region of the knee joint, descriptions of flaps based on the superior lateral genicular artery and descending genicular artery are quite frequent. In contrast, information regarding other popliteal branches is scarce or non‐existent. The aim of this study was to provide a concise and complete overview on the extent and variability of the perforator angiosomes of the femoral and popliteal arteries in the anterior knee region. Twenty lower extremities were dissected, the respective perforators identified and perfused with dye. All resulting angiosomes were marked and documented. A total of 84 angiosomes were identified in all specimens, with an average of 4.2 (3–6) angiosomes per specimen. The average size of the angiosomes was 97.04 ± 72.30 cm² (8.61–360.41 cm²), their source vessels had an average diameter of 1.42 ± 0.54 mm (0.60–3.25 mm). The complex and highly variable distribution of perforator angiosomes of the anterior knee region and especially of its less frequently investigated distal part was demonstrated. Based on these results, the planning of existing perforator flaps in this region and the development of flaps including the inferior medial or inferior lateral genicular arteries may be facilitated.