A Dynamic Anatomic Study of Parasacral Perforators: Mapping, Perforasome, and Applications for Buttock Enhancement.

BACKGROUND: Due to the lack of knowledge about parasacral artery perforators, flaps from this region cannot be used with complete confidence in their security and effectiveness. Knowledge of the clusters and perforasome of these perforators could help in the design of more reliable flaps and extend the range of applications. OBJECTIVES: This study aimed to identify the location, number, and density of perforators, and to subsequently analyze the perfusion flow and linking vessel distribution. METHODS: Five fresh cadavers were harvested and dissected. For the mapping, after injecting lateral sacral arteries with colored latex, perforators with a diameter of >0.5 cm were examined in 5 sacral regions. All data were collected on the suprafascial plane, with an orthonormal coordinate system placed on iliac crests and median lines. For perforasome analysis, 5 perforators and 3 three sacral flaps were injected with radiopaque dye. A dynamic (4-dimensional) computed tomographic angiography completed the analysis. RESULTS: A mean [standard deviation] of 8.4 [1.36] perforators per corpse, with a mean diameter of 0.72 [0.14] mm, were identified. There was a higher density of parasacral perforators close to the median line and 7.6 cm above the iliac crests. This pattern was not a random distribution (P < 0.05). The perfusion area was preferentially in the superior gluteal region. Perfusion flow was permitted by the dominant direct-linking vessels towards adjacent lumbar perforators, oriented diagonally upward and outward to the midline. CONCLUSIONS: Parasacral perforator flaps appear to be a useful procedure in reconstruction and in aesthetic surgery, especially in gluteal augmentation. Their reliability depends on sound anatomic knowledge, with accurate preoperative perforator mapping.

Flow-Through Arterialized Posterior Interosseous Nerve Grafts for Digital Neurovascular Bundle Defects: Anatomical Study.

BACKGROUND: Digital neurovascular bundle defects are often encountered during crush or avulsion injuries and require complex reconstruction. Use of an arterialized nerve graft (neurovascular graft) serving both as an interpositional arterial conduit and as a nerve graft could be a reconstructive option in these cases. In this anatomical study, the authors aimed to describe a neurovascular graft of the posterior interosseous nerve and a branch of the anterior interosseous artery for neurovascular bundle reconstruction of the fingers. METHODS: Eighteen forearms were injected with red latex in order to collect the anatomical characteristics of the posterior interosseous nerve and the artery running near it. RESULTS: In all cases, the posterior interosseous nerve was followed by a branch of the anterior interosseous artery: the distal dorsal branch of the anterior interosseous nerve. The origin of this artery was proximal to the radiocarpal joint, at an average of 56.5 ± 11.1 mm. The proximal and distal diameters of the branch of the anterior interosseous artery were 1.6 ± 0.2 and 1.1 ± 0.2 mm, respectively. The proximal and distal diameters of the posterior interosseous nerve were 1.2 ± 0.3 mm and 1.1 ± 0.3 mm, respectively. CONCLUSIONS: These results show that a potential free neurovascular graft using the posterior interosseous nerve as nerve graft and the anterior interosseous artery as an arterial bypass to reconstruct both the nerve and arterial tree of the finger could be a useful approach. The authors speculate that this graft could be used to reconstruct the neurovascular bundle of amputated or devascularized digits.

Does needle biopsy cause an increased risk of extracapsular extension in the diagnosis of metastatic lymph node in melanoma?

BACKGROUND: Needle biopsy is a rapid, reliable, and reproducible procedure for histological confirmation of metastatic melanoma localization. Nonetheless, this procedure presents a theoretical risk of a mechanical weakening of the lymph node capsule with perinodal tumor seeding. The objective of the study was to evaluate the incidence of extracapsular extension after needle biopsy in comparison with surgical adenectomy in patients suspected of metastatic lymph node of melanoma. METHODS: We conducted a retrospective study of 1056 patients who underwent lymphadenectomy for melanoma between 2000 and 2016 in our unit. Sixty-nine patients were clinically and/or radiologically suspected of metastatic lymph node of melanoma. Patients were divided according to external lymph node biopsy or surgical adenectomy before lymphadenectomy. The primary endpoint was the histopathological identification of extracapsular extension in analyzed lymph nodes. RESULTS: The two populations were comparable except for the mitotic index, which was more frequently > 1/mm2 in the group with surgical adenectomy (P = 0.005). The proportion of extracapsular extension was significantly greater in the needle biopsy group (28/37) than in patients who underwent surgical adenectomy (14/32) (P = 0.0067; OR = 4 [95% CI: 1.4-11]). CONCLUSION: Our results suggest an increased risk of extracapsular extension after external lymph node biopsy in cases of suspicion of metastatic lymph node of melanoma. Thus, this encourages us to prefer surgical adenectomy in patients with suspected adenopathy accessible surgically. In other cases, needle biopsy should be carried out under radiological guidance using devices limiting tumor seeding.