Venous Port implantation in persistent left superior vena cava with azygos vein variation: a case report and literature review

Abstract

Background

Persistent left superior vena cava catheterization for venous port is still sporadically reported, let alone combined with variations of the azygos.

Case presentation

During the implantation of a venous access port in a 73-year-old patient, who was planned to carry out postoperative chemotherapy, a persistent left superior vena cava was discovered. A review of the preoperative plain chest computed tomography further corroborated the existence of a double superior vena cavas. Besides, the right azygos vein was absent and a left azygos vein draining into the persistent left superior vena cava was evident. The diameter of the persistent left superior vena cava was greater than that of the right SVC. Consequently, the decision was made to insert the catheter into the persistent left superior vena cava for the subsequent implantation procedures. The surgery was successful and no complications related to the venous port occurred during the whole catheter days.

Conclusions

The rare persistent left superior vena cava with variant azygos vein should not be a contraindication for venous port implantation after a comprehensive evaluation.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12893-025-03144-9.

Background

Currently, the totally implantable venous access port (TIVAP) is widely utilized for intravenous chemotherapy in patients with tumors. Compared to the peripherally inserted central catheter (PICC), the TIVAPs have longer service lives, maintenance intervals, and lower complication rates. According to most clinical guidelines and expert consensus, the most common port location is the right chest wall, and the preferred venous access is the right internal jugular vein (IJV). However, the use of a left chest wall port is not uncommon, especially in patients with right breast cancer. One potential reason for the preference for right-sided ports may be related to the variation of thoracic veins, such as the persistent left superior vena cava (PLSVC), which is a rare anatomical venous aberration of the thoracic venous system with a prevalence of 0.3–0.5% and most cases are asymptomatic [1]. This type of venous anomaly, known as PLSVC, is found in 3–10% of patients with congenital heart disease [2]. However, most doctors who perform venous port implantation come from fields such as oncology, interventional radiology, and vascular surgery. As a result, they may not be as familiar with anatomical abnormalities like PLSVC compared to cardiothoracic surgeons. Therefore, it is crucial not to overlook PLSVC and to confirm its presence, especially during the venous port implantation [3].

The azygos venous system, which includes the azygos, hemiazygos, and accessory hemiazygos veins, is crucial in facilitating communication between the superior vena cava (SVC) and inferior vena cava (IVC). When the PLSVC coexists with azygos vein variations, this represents an even rarer anatomy, which is bound to have a certain impact on the venous port implantation [4, 5]. Herein, we present such a rare case, in which the PLSVC with a variant azygos vein system was occasionally diagnosed during a left chest port implantation. Although the inherent right SVC was considered the preferred venous access for TIVAP, the PLSVC seemed to be the proper vein on account of its size.

Case presentation

A 73-year-old male was admitted for postoperative adjuvant chemotherapy one month after a proctectomy with protective ileostomy. It’s crucial to note that the primary surgery was an emergency operation due to rectal cancer with strangulated intestinal obstruction, with the pathological stage being T4aN1bMx. His hemoglobin level was 124 g/L, and liver, kidney functions, B-type natriuretic peptide, troponin, and thyroid function were normal. In addition, his D-Dimer was 1.37 mg/L, the fecal occult blood test showed 1 + positivity, and he tested positive for hepatitis B surface antigen. He also presented with a small ground-glass nodule in the right lung, multiple liver hemangiomas, and atrial fibrillation with a normal ventricular rate. Echocardiography revealed the absence of congenital heart disease. The “XELOX” chemotherapy regimen was scheduled, and the patient opted for a TIVAP over a PICC for administration. Based on the examination results, the patient had no contraindications for the venous port implantation and he strongly requested to place the port on the left chest wall. The procedures for port implantation were consistent with our previous report [6] and the left axillary vein (AxV) approach was applied. The venous port was from Beijing Yuetong Medical Equipment Co., Ltd (ZS2-II-1.8/1.2–750). The catheter was observed running alongside the left mediastinum during port catheter insertion. Despite several attempts to adjust its position, the catheter remained in the same location. Due to the circumstances, the surgical team determined that angiography was essential for a clearer understanding of vascular anatomy. The angiography confirmed the presence of the PLSVC, with no contrast material flowing to the right mediastinum from the junction of the left IJV and subclavian vein (SCV)(Fig. 1). A review of the preoperative plain chest computed tomography (CT) further corroborated the existence of double SVCs. Furthermore, the right azygos vein was absent and a left azygos vein draining into the PLSVC was evident (Fig. 2). The diameter of the PLSVC (9.8 mm) was greater than that of the right SVC (3.3 mm). Consequently, the decision was made to insert the catheter into the PLSVC for the subsequent implantation procedures.

Fig. 1.

Intraoperative angiography. A The catheter is located in the left mediastinum. B Angiography confirmed the PLSVC. C Angiography confirmed the left brachiocephalic vein was absent. D Final fluoscopy

Fig. 2.

Review of the preoperative pulmonary CT. A Coronal plane. B Axial image

Notably, no complications arose during the first 2 cycles of chemotherapy. However, the patient couldn’t tolerate chemotherapy and finally came to the hospital for port removal after evaluation with no signs of tumor recurrence. Before the removal operation, an ultrasonic scan of the access vessels was performed. No venous thrombosis was found in the visible segments of the SCV/AxV (Fig. 3). The total number of catheter days was 139 without any complications related to the venous port.

Fig. 3.

Ultrasound examination of SCV-AxV before removal and no venous thrombosis was found. A Visible segment of the SCV/AxV. B Color Doppler flow imaging

Discussion and conclusions

To our knowledge, PSLVC catheterization for TIVAP was still sporadically reported [7–14], even though Jheengut et al. reported the largest number of cases [15]. According to the literature, there are three types of variations in the SVC based on chest radiographs. Type I represents normal anatomy, type II indicates the presence of only a PLSVC, and type III is characterized by the coexistence of right SVC and PLSVC. Type IIIa involves a connection between the two SVCs, whereas type IIIb does not [16]. Around 90% of patients fall into type III, and most of them do not display any clinical symptoms or hemodynamic changes unless there are other coexisting cardiovascular anomalies. As illustrated in Table 1, type III PLSVC is the most prevalent among the literature reports related to TIVAP implantation. Except for two reports in which doctors immediately removed the infusion port for fear of thrombosis risk [17, 18], all patients in the remaining literature received chemotherapy through the infusion port, except for one reported by Dinasarapu et al. [19], where the patient tolerated only two cycles before removing the port due to complications like infection. Although our case involved only two chemotherapy sessions, the port was maintained for 139 days without complications. This indicates the safety and efficacy of PLSVC venous port implantation, which aligns with most of the existing literature.

Table 1.

Literature review of venous Port implantation through PLSVC

Year	Author(s)	n	Age (years)	Gender	Diagnosis	Azygos Vein Variation	Port Duration	Port-a-Cath Related Complications	PLSVC Type
2003	Laurenzi et al. [3]	1	59	Male	Lung cancer	N/A	8 months	None	II
2010	Dinasarapu et al. [19]	1	52	Female	Right breast cancer	N/A	2 cycles of chemotherapy	Postoperative fever, leukopenia, and recurrent neurological symptoms associated with the use of the port-a-cath, considered to be related to microthrombus detachment or air embolism.	IIIb
2011	Povoski et al. [9]	1	53	Female	Bilateral breast cancers	N/A	about 7 months	None	IIIb
2016	Zhou et al. [10]	1	37	Female	Non-Hodgkin lymphoma	N/A	8 months	None	N/A
2016	Sarsenov et al. [11]	1	35	Female	Right breast cancer	N/A	N/A	None	IIIb
2016	Konstantinou et al. [17]	1	63	Male	Metastatic colon cancer	N/A	Removed after implantation	N/A	IIIb
2017	Evers et al. [16]	1	50	N/A	Adenocarcinoma of the esophagus	N/A	8 cycles of chemotherapy	None	IIIb
2018	Van Walleghem et al. [12]	1	74	Male	Lung cancer	N/A	N/A	None	IIIb
2021	Jheengut et al. [15]	8	average 44.8 (range 31–59)	6 females; 2 males	6 cases of breast cancer, 2 cases of non-small cell lung cancer	N/A	6–20 cycles of chemotherapy (varying for each patient)	None	N/A
2022	El-Helou et al. [13]	1	40	Male	Mixed Hodgkin lymphoma	N/A	9 months	None	IIIa
2022	Zhou et al. [14]	2	40 and 54	Female	40y-Bilateral breast cancers; 54y- Right breast cancer	N/A	Completion of chemotherapy	None	40y-IIIa; 54y-N/A
2023	Bonitto et al. [8]	1	5	Female	Long-chain L-3 hydroxyacylCoA dehydrogenase deficiency	N/A	3 years	Catheter dysfunction	N/A
2023	Masaki et al. [18]	1	85	Female	Dysphagia due to the after-effects of cerebral infarction	N/A	Removed after implantation	N/A	IIIb
2024	Hama et al. [7]	1	33	Female	Right breast cancer	N/A	8 months	Catheter dysfunction and malposition	IIIb

In this case, the azygos vein traveled up the left side of the descending thoracic aorta and connected to the PLSVC. This unique anatomy may be attributed to irregular embryonic development. According to Uemura M et al., the left common cardinal vein and anterior cardinal vein were retained, and the proximal part of the left posterior cardinal vein developed into the root of the left azygos vein in a 12-week-old fetus [20]. In our case, the diameter of the PLSVC was larger than that of the right SVC, likely due to the inflow from the azygos vein. Regrettably, previous literature (Table 1) regarding port-a-caths associated with the PLSVC has largely overlooked the significance of the azygos venous system.

When choosing the left SCV or AxV for different catheterization procedures, such as venous port and cardiac stimulator, it’s important to be aware of the presence of PLSVC. Although rare, severe complications such as deep vein thrombosis (DVT), malignant arrhythmias, perforation of the coronary sinus, or even death can occur [1]. Previous knowledge about thoracic vascular malformations mostly comes from autopsy. Since a chest CT scan is typically done for cancer patients, reviewing the preoperative imaging carefully can easily help identify PLSVC, as illustrated in the present case. Whether PLSVC is suitable for catheterization depends on several factors. It’s generally accepted that the catheter-to-vein ratio should not exceed 45% to reduce the risk of venous thromboembolism (VTE) [21]. Theoretically, a larger vessel used for catheterization carries a lower risk of VTE. If the PLSVC has a larger diameter than the right SVC, it is automatically suitable for catheterization. When the right SVC is absent, the PLSVC becomes the intrinsic access for SVC catheterization. Therefore, PLSVC should not be considered a contraindication for venous port implantation. Based on the lung CT of the present case, the PLSVC was larger than the right SVC, and the left azygos vein drained into the PLSVC. This meant the PLSVC (the catheter-to-vein ratio was 18%) was more suitable for catheterization, and the left AxV access for chest wall port seemed to be an accidental but correct decision.

The ideal location for the catheter tip is generally considered to be the cavoatrial junction (CAJ), which was considered two vertebral body units below the carina of the trachea. Besides, many guidelines also recommend placing the catheter tip in the lower third of the SVC [22]. However, the optimal catheter tip location remains unclear for catheterization of the PLSVC due to their rarity. One of the major concerns in determining the catheter tip position in PLSVC is the risk of catheter-related venous thrombosis and paradoxical arterial embolism [23]. A study by Jheengut et al. reported eight cases of PLSVC catheterization, where all catheter tips were placed in the lower part of PLSVC without any complications [15]. In the present case, the catheter tip position was ultimately determined to be in the lower part of PLSVC based on intraoperative angiography. No complications related to the venous port occurred during the whole catheter days.

In the context of venous port implantation, which is predominantly performed by clinicians from oncology, vascular surgery, interventional radiology, and breast surgery rather than cardiothoracic specialists, the clinical significance of this case extends beyond its anatomical description. As summarized in Table 1, existing literature on venous port implantation in PLSVC has consistently left the “Associated Azygos Vein Variation” as “Not mentioned”, indicating a lack of attention to this critical anatomical detail among practitioners in these fields. To our knowledge, our case, for the first time, explicitly documents the coexistence of PLSVC and left azygos vein (with absent right azygos vein) in venous port implantation, and highlights its impact on procedural decision-making—specifically, how the left azygos vein drainage may contribute to the larger diameter of PLSVC, thereby supporting its suitability for catheterization. This finding underscores a practical framework for relevant clinicians: preoperative chest CT should be meticulously reviewed to identify not only PLSVC but also associated azygos vein variations; intraoperative angiography can further confirm vascular anatomy when catheter placement deviates from expectations; and the catheter-to-vein ratio, in conjunction with anatomical features like azygos drainage, should guide final catheterization decisions. Such a structured approach, derived from our experience, provides actionable insights for improving procedural safety in similar rare anatomical scenarios.

Overall, the rare PLSVC with variant azygos vein should not be a contraindication for TIVAP implantation. Assessment of a patient’s primary diagnosis, treatment strategy, thoracic vascular anatomy, and vessel diameters is critical in evaluating the feasibility of performing catheterization on a PLSVC. Thoroughly examining the chest CT scan and identifying the condition during surgery is crucial. If a TIVAP is implanted through a PLSVC, it should be used carefully and monitored closely.

Abbreviations

TIVAP

Totally implantable venous access port

PICC

Peripherally inserted central catheter

IJV

Internal jugular vein

PLSVC

Persistent left superior vena cava

SVC

Superior vena cava

IVC

Inferior vena cava

SCV

Subclavian vein

AxV

Axillary vein

CT

Computed tomography

DVT

Deep vein thrombosis

VTE

Venous thromboembolism

CAJ

Cavoatrial junction

Authors’ contributions

Conceptualization: JW. Data curation: LZ. Formal analysis: LZ. Investigation: LZ. Methodology: JW. Validation: JW. Visualization: LZ. Writing - original draft: LZ. Writing - review & editing: JW.

Funding

Not applicable.

Data availability

No datasets were generated or analysed during the current study.

Declarations

Ethics approval and consent to participate

This case report’s ethical review and approval were obtained from the Ethics Committee of the Fourth Affiliated Hospital Zhejiang University School of Medicine (K2024242).

Consent for publication

We obtained written informed consent from the patient for the publication of this case report and any accompanying images.

Competing interests

The authors declare no competing interests.