1 Thoracic Surgery Department, Basaksehir Çam ve Sakura City Hospital, 34480 Istanbul, Turkey
Correspondence to: Omer Yavuz, Thoracic Surgery Department, Basaksehir Çam ve Sakura City Hospital, 34480 Istanbul, Turkey (e-mail: omeryavuz@dr.com).
Editor: Andrea Zuin
Abstract
AIM: Totally implantable venous access port (TIVAP) placement is routinely recommended under ultrasound guidance to reduce complications. However, in low-resource settings, the anatomical landmark technique remains widely used. Data evaluating the learning curve of landmark-based TIVAP placement through formal statistical methods are limited.
METHODS: This retrospective single-center study analyzed 1285 consecutive TIVAP-related procedures, including port placement, revision, and removal, performed by a single surgeon between June 2022 and September 2025 using the anatomical landmark technique. The cohort comprised 1093 port catheter placements, 98 removals, and 67 revisions. Technical failure was defined as the inability to achieve venous cannulation or to advance the guidewire/catheter into the central venous circulation and was assessed only in procedures requiring venous access (placements and revisions), in which 27 failures occurred. Cumulative sum (CUSUM) analysis was restricted to procedures requiring venous access to evaluate performance based on technical failure rates; port removals were excluded from the failure-based CUSUM framework. Procedures were additionally stratified by technical complexity. The CUSUM inflection point was used to explore a potential transition in procedural performance.
RESULTS: Technical success was achieved in 1258 of 1285 TIVAP-related procedures (97.9%). A total of 27 cases resulted in technical failure (failure rate: 2.1%), primarily due to unsuccessful venous cannulation or guidewire advancement. CUSUM analysis identified an inflection point at the 422nd case, indicating a transition from the initial learning phase to a phase of performance stabilization. Among procedures requiring venous access, technical failure rates were significantly higher in Phase 1 (cases 1–422) compared with Phase 2 (cases 423–1187) (5.2% vs. 0.7%, p < 0.001). Procedural complexity showed only minimal variation across the series, and technical performance remained stable throughout the study period. No further technical failures were observed during the final 252 consecutive procedures. Pneumothorax occurred in 5 cases (0.39% [5/1285] of all procedures; 0.43% [5/1160] of venous access procedures).
CONCLUSIONS: Based on the observed learning curve, procedural stabilization in landmark-based TIVAP placement may require a higher case volume than reported previously for ultrasound-guided approaches. In this single-center, single-operator study, an inflection point at approximately 422 cases was associated with stabilization of procedural performance and a reduction in technical failure rates. These findings suggest that, in low-resource settings where ultrasound guidance is not routinely available, the landmark technique may be performed with an acceptable safety profile under standardized workflows and with adequate training and experience.
Keywords
- learning curves
- vascular access device
- anatomic landmark
- central venous catheter placement

