{'fraction_non_alphanumeric': 0.026262626262626262, 'fraction_numerical': 0.005555555555555556, 'mean_word_length': 5.3493589743589745, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Rare anomaly of the right subclavian artery and vein transposition: A case report

Although central venous catheterization (CVC) of the subclavian vein is a routine procedure in clinical practice, significant complications can occur in a certain proportion of patients during the procedure.1 Therefore, thorough understanding and intraoperative evaluation of the anatomy of the target vessels are essential for safe subclavian CVC. There are several studies regarding the anatomical considerations of subclavian vessels.2 However, there has been only one reported case of the subclavian artery and vein transposition, which is a critical anatomic anomaly for subclavian CVC.3 We report the case of a 75-year-old man, who came to our hospital complaining of anorexia and nausea and was diagnosed as having sigmoid colon cancer with peritoneal metastases. His past history was unremarkable. For the administration of chemotherapy, a central venous access port (CV-port; MicroNeedle Port, Cardinal Health, USA) was implanted via the right subclavian vein. Preoperative ultrasound (US) evaluation revealed that the right subclavian artery was located on the inferior side of the subclavian vein in the right mid-clavicular region (Figure 1(a)). Using the US-guided technique,4 the puncture of the right subclavian vein and CV-port implantation were successfully performed. Postoperative computed tomography (CT) images confirmed the severe tortuosity of the right subclavian artery and transposition of the artery and vein in the right mid-clavicular region (Figure 1(b)), whereas no anatomical anomalies were seen in the left subclavian vessels. The anatomy of the subclavian artery and vein has been described in detail.2 Lavallée et al.2 have described the anatomy of the subclavian and axillary vessels by conducting a prospective observational US study. In their report, the subclavian artery was anterior to the subclavian vein in the right mid-clavicular region in 4% of cases;