Introduction
Totally implantable venous access ports have become a routine practice in modern medicine. Most oncology clinics have already accumulated extensive experience in their placement and clinical use, enabling a comprehensive retrospective analysis of adverse events and complications. Nevertheless, research publications on this topic remain limited. Currently, there is no recommended classification of complications, not to mention adverse events, so it is often used the classification of complications of central venous catheterization proposed by the Society of Interventional Radiologists in 2003. Following this system, complications are categorized as, early (up to 30 days) and late complications (more than 30 days after implantation) [1]. However, not all adverse events can be classified as complications, nor are they all attributable to medical errors.
Objectives
The aim of this retrospective observational study was to analyze the reasons for removal of implanted subcutaneous venous port systems (TIVAP) in two clinics in St. Petersburg.
Materials and methods
Patients undergone conventional TIVAP implantation from January 2022 to December 2024. Totally 2626 implantable venous access ports were installed in two centers - the Saint-Petersburg Oncology Center and the MEDSI St. Petersburg Clinic. The study included data from 218 patients, only cases with indwelling time exceeding 30 days were included in the study. A retrospective analysis of medical records was conducted, and the following indications for ISPPS removal were identified:
- “end of treatment”, including a few cases when chemotherapy treatment was replaced by radiotherapy, necessitating the removal of a functioning port;
- “necrosis” — epidermal breakdown, erosion, redness, thinning of the subcutaneous fat in the area of the port chamber without signs of infection;
- “infection” — local inflammation, abscess, purulent or serous discharge in the area of the port chamber;
- “catheter-related bloodstream infection (CRBI)” — bacteriologically confirmed bloodstream infection or clinical signs of CABI with negative cultures;
- “thrombosis” — the presence of a mural thrombus or complete occlusion of the catheter, confirmed by radiography or the statement "it is impossible to use the port" without any other possible cause;
- “discomfort” — the patient's request to remove a normally functioning port system;
- “catheter detachment from the port chamber”— pinch-off syndrome, confirmed by radiography, and requiring vascular interventional procedure;
- “migration” — displacement of the catheter from the vena cava into soft tissues;
- “rotation” — rotation the port chamber in the subcutaneous tissue.
For statistical processing, the Statistica 8.0 program and descriptive statistics methods were used: mean, standard deviation, median.
Results
The study included data from 218 patients aged 35 to 85 years who had their venous port system removed. The average age was 60.9 ± 10.5 years, there were 116 women and 102 men. The median duration of port system function before removal was 14.8 ± 8.2 months.
In this group, 49 TIVAP systems were removed due to the end of treatment, which amounted to 22.8 % of those explanted or 1.2 % of the installed during the study period; the median functioning time was 16.2 ± 8.4 months.
Among complications that led to the removal of the port system in 168 patients, the share of which was 77.2 % (3.9 % of the total number), the most common were: skin necrosis — 62 patients, 37.2 % of all complications (1.4 % of the total number of TIVAP), infection of the port chamber area – 46 patients, 27.45 % (1.1 % of the total number), including four cases where the infected port was removed and immediately re-implanted on the opposite side to ensure uninterrupted treatment. Less frequent but comparable in occurrence were observed: CABI – in 20 patients, 11.76 % of all complications (0.5 % of the total number) and thrombosis — 19 patients, 10.78 % of all complications (0.4 % of the total number), and relatively rarely: discomfort — 10 patients, 5.88 % of all complications (0.07 % of the total number), pinch-off syndrome — 6 patients, 3.92 % of all complications (0.15 % of the total number), migration — 3 patients, 1.96 % of all complications (0.08 % of the total number) and 2 cases of camera rotation, 1.05 % of all complications (0.06 % of the total number) (fig. 1).
Fig. 1. Totally implantable central venous port system complications
The average time to complication onset from the moment of implantation was following: skin necrosis — 6.2 ± 4.6 months, port chamber infection — 7.8±3.2 months, CABI — 7.1 ± 4.3 months, thrombosis — 9.9 ± 7.2 months, discomfort — 15.8±6.9 months, pinch-off syndrome — 28 ± 10.2 months, migration — 20.1 ± 4.8 months, rotation — 26.4 ± 2.0 months.
The microbiological profile of the cultures is presented in Fig. 2, of which in 25 % of cases there was no growth of any microorganisms was detected, and the most frequently isolated pathogen was Staphylococcus epidermidis – 29.2 %. Fig. 2.
Fig. 2. Causative agents of infectious complications
Discussion
In this retrospective study, we obtained results that are generally comparable with the data of other authors. In the majority of publications, the number of implantations significantly exceeds the number of removals. Thus, Ma L. et al. report that out of 2996 installed port systems, 82 were removed due to complications [2]. Similarly, Philomena C. D'Souza et al. provide data on removal for various reasons, including the end of treatment: 193 port systems out of 516 implantations [3]. On average, one port system is removed for every 12–15 implantations, with about a quarter of removals due to treatment completion and the majority related to adverse events. The rate of adverse events is not considered high, as studies report a 2–5 % incidence, confirmed by our study at 3.4 %. The relatively low number of port removals, compared to the total number implanted, reflects their specific use in oncology patients. Long and repeated courses of chemotherapy, which must be provided with reliable venous access, do not justify removal even in the case of a long remission. In many cases, we cannot track the port state because the patients lost to follow up due to death or other medical reasons.
It must be emphasized that operational lifespan of TIVAP is predominantly determined by the type of complication. Necrosis or local infection are detected fairly quickly, and the port system is removed as soon as possible. However, in conditions such as thrombosis and port chamber rotation, the real time of occurrence is difficult to establish, since they can only be detected by direct contact with the patient, often long after onset of the adverse event. Catheter migration and pinch-off syndrome in our study were incidental findings when patients had not received chemotherapy for a long time and presented for care months or even years after the last flush. The challenge of calculating IPVPS functional duration is likewise reflected in other centers' results. Some studies omit duration data entirely, while others only report complication rates within the first 3–12 months [4].
Skin necrosis was the most common reason of removal — 37.2 % of all complications and 1.4 % of all of all implanted port systems. The commonly used term “pressure ulcer” does not fully capture the complexity of the issue, which includes thinning and damage to skin and subcutaneous fat over the port chamber. We argue that "necrosis" is a more appropriate term, encompassing tissue breakdown from microcirculatory disturbances regardless of whether the cause is internal (e.g., cachexia, hypoproteinemia) or external (e.g., repeated needle trauma, extravasation). International literature rarely uses “decubitus” in this context, favoring “skin damage” or “erosion” [5]. Similar complication rates are reported: Tsuruta S. et al. – 1.5 %, Philomena C. D’Souza et al. – 1.2 % [3,6], though some studies report rates under 1 % [7,8].
Skin necrosis and port chamber prolapse are often associated with needle insertion at the same point with subsequent infection. Risk factors also include excessive tension in the chamber area [9], weight loss and cachexia, and extravasation.
Weight loss is a controllable but unpredictable factor. Since the pocket for the TIVAP camera is formed at a depth of 0.5 cm, the risk of necrosis exists even in patients with an initially high body mass index. To illustrate this, we examine a case when the port system was removed from the patient weighing 157 kg, 6.2 months after installation, due to the "cutting" of the camera against the background of a relatively insignificant loss of 10 kg.
Some authors consider skin necrosis as a result of extravasation of chemotherapeutic drugs or parenteral nutrition. Causes include needle misplacement, leakage due to port or catheter damage, and difficulty targeting the silicone membrane in obese patients, while lack of subcutaneous fat causes vascular compromise and skin erosion [10,11].
Use of anti-VEGF monoclonal antibodies, especially bevacizumab, may contribute to necrosis. Bevacizumab is often used for metastatic colorectal and NSCLC, but is associated with delayed wound healing [12,13]. In some of our patients, we observed skin damage without infection, suggesting conservative treatments like wound edge excision and port repositioning instead of removal. Surgery is usually postponed for 4–6 weeks after last bevacizumab dose, and treatment resumes 4 weeks post-surgery. Studies by Zawacki et al. and Erinjeri et al. showed high wound dehiscence rates when bevacizumab was started 10–14 days after the port implantation, though these involved dehiscence, and not necrosis [14, 15]. Port removal due to necrosis is widely debated. Some case reports describe successful port retention despite skin damage. Liu C. et al. reported a case where the port was externalized to the chest wall and functioned for six more months [16]. Steiert A. et al. described pocket irrigation upon early extravasation to prevent erosion [17].
Infection, both local and bloodstream-associated, were the second and third most common removal reasons. Local inflammation accounts for almost a third of all complications (27 %), significantly exceeding CRIC (12 %). If we correlate this data with the total number of port systems installed, it will amount to 1.07 % and 0.46 %, which generally corresponds to world date. Thus, port-associated infection was detected according to reports by Ma L. et al. in 1.84 % of cases, Philomena C. D'Souza et al. – 0.2 per 1000 catheter-days (12.2 % of all complications), Kim DH et al. — 0.6 %. Some of the authors do not consider catheter related infection complication separately and include in previous category, P. C. D'Souza et al. cite a rate of 3.7 % among all complications, while DH Kim et al. reported a rate of 0.8 % [2, 3, 5]. Of particular interest is the study of Mori Y. et al., who obtained similar rates of infectious complications, but with ports were installed on the inner surface of the shoulder — 3.7 % of cases [18].
Microbiological analyses showed that Staphylococcus epidermidis was most often detected in cultures (29.2 %), however, in a quarter of cases, cultures were negative. The profile of pathogens in our and other centers is usually similar, if we do not take into account specific strains. We believe that negative culture results in our study as a lack of laboratory diagnostics or a sampling defect, since the laboratories in both centers have international certification. In our opinion, a negative result is most often associated with an incorrect interpretation of clinical data when a patient is referred for removal of the port system due to signs of infection, which include such laboratory parameters as leukocytosis and neutropenia, especially in cases where they are associated with hyperthermia. Obviously, the clinician in such a situation decides to take extra precautions, vacillating between a systemic infection and the consequences of chemotherapy. Since the rate of “sterile” cultures in other studies is also quite high [3], this issue requires separate study in the future.
Removal of the port system in the presence of infection is the most common tactic, although it is also possible to prescribe antibacterial therapy, during which the use of port system is suspended [19].
Thrombosis — this group of complications consists of a number of problems that patients encounter with long-term use of port systems. This includes catheter occlusion by a thrombus or fibrin sleeve, superior vena cava syndrome, thrombosis of central and peripheral veins from the port system. Often, these complications are statistically combined into one group, the average frequency of these complications varies from 3 to 58 % [20–22], depending on the definitions used by certain authors, and in our study it was 10.78 %. Port-associated thrombosis most often occurs in the site where the catheter enters the vein and the point where catheter tip contacts the vessel wall. More than half of these thromboses remain asymptomatic and are detected only by computed tomography or chest X-ray.
In their discussion of upper extremity thrombosis, Tabatabaie O. et al. reported a 1.81 % incidence of this complication, along with standard risk factors common to all thromboses [23]. Important risk factors include a narrow vesel lumen where the catheter is placed, hypercoagulation, and displacement of the catheter into areas of low blood flow. Upper limb vein thrombosis is accompanied by a classic presentation of edema, erythema, pain, and corresponding changes in duplex imaging.
Catheter dysfunction may be due to kinking of the catheter (usually an early complication), formation of a fibrin sheath around the catheter, occlusion by a clot or precipitate, or occlusion by the vessel wall. Most often, the staff detects problems of venous return flow, which occurs in 0.5 %– 8 % of cases [11, 24] and is associated with the formation of a fibrin sheath around the tip of the catheter [25, 26]. As a rule, the complication develops asymptomatically and is characterized by increasing difficulties with blood sampling and only in 10 %– 5 % of cases does it have characteristic clinical manifestations [21, 27, 28].
The standard method of assessing blood flow is ultrasound and contrast venography, although the latter is rarely used, as it requires additional consumables, and according to some data, it can worsen the course of thrombosis. It is important to note that during our retrospective analysis of medical records, we were often unable to differentiate between “true thrombosis” and “fibrin sheath,” as these diagnoses require detailed radiological assessment. In some cases, the term “catheter thrombosis” was used in documentation, but more commonly, referring physicians simply noted that the port was “no longer usable.” The actual cause was often discovered intraoperatively — either through visual identification of a thrombus within the catheter or confirmed occlusion upon removal.
It is known that the placement of a central venous catheter increases the risk of thrombosis by 12 times. We register in average 10-11 cases of thrombosis per year in both centers. In two cases out of ten, the port system can be preservedstandard treatment primarily involves low molecular weight heparins (LMWH) [28], we have successfully achieved recanalization using apixaban, and these cases were not included in the statistics for port explantation. Oral anticoagulants are recommended for patients with deep vein thrombosis (DVT) during both initial and long-term therapy. Pharmacokinetic data suggest that oral administration of apixaban and rivaroxaban provides a rapid anticoagulant effect comparable to that of subcutaneous unfractionated heparin or LMWH. Therefore, Xa factor inhibitors may be recommended as initial therapy for DVT from the moment of diagnosis confirmation [29].
Is a rarely reported adverse event, including among our patients, where its incidence was only 0.07 %. We identified only one publication addressing this issue. In a study by Kim D.H. et al., only one patient (0.1 %) required port removal due to discomfort. Among our patients, complaints of discomfort are common immediately after implantation but rarely lead to decisive interventions. However, in later stages, when treatment involves significant breaks in the use of the implantable port system and regular flushing is required, some patients find the procedure so unpleasant that they choose to have the port removed. In our opinion, this accounts for the long median time from implantation to removal, which is comparable to the duration observed in cases of explantation due to treatment completion.
Spontaneous catheter migration following port placement is a rare complication, usually diagnosed incidentally during chest radiography performed for other reasons. Predisposing factors may include intrathoracic pressure changes related to heavy lifting, coughing, or forced exhalation. It has been suggested that body position changes, head movements, and high-pressure port flushing may also contribute to catheter dislocation [30–32].
Over the past three years, we have encountered this complication in 0.08 % of cases. In one case, an impaired blood backflow was noted and X-ray examination revealed migration of the catheter into the ipsilateral internal jugular vein, which required reinstallation of the port. In the second case, the catheter was inserted using the right axillary approach, and after 6 months, migration into the internal jugular vein on the right was detected. The correct position of the catheter was restored using a mobile C-arm type X-ray system without removing the port. In both cases, the initial verification of the catheter position was performed using intracardiac electrocardiography, one of the most reliable methods for verifying the location of the catheter tip in the vena cava superior. Additionally, radiographic imaging was performed within the first month after implantation, showing no abnormalities in the lungs or port chamber. According to some data, the incidence of this complication ranges from 0.9 % to 1.8 % [32], leading some authors to suggest confirming catheter position twice monthly if the port is not in use, and more frequently during active treatment [33]. However, these recommendations date back to the 1990s and clearly require revision in light of accumulated experience with port maintenance.
We also observed one early complication involving port chamber migration in a woman with a body mass index (BMI) of 53.3. The port was inserted via the right axillary vein, with the chamber fixed 4 cm below the clavicle. Catheter tip positioning was confirmed by ECG; the distance from the access point to the port chamber was 24 cm. Three weeks later, standing chest radiography revealed the catheter tip in the region of the right brachiocephalic vein. The port was replaced. During the port installation, the size of the patient's mammary glands and their mobility were not taken into account, which contributed to a significant displacement of the port chamber when changing position. In this regard, in obese patients, we recommend preliminary marking in a sitting position. We subsequently used this experience and at present, in patients with a high body mass index, we not only mark in advance, but also implant the system in a "semi-sitting position".
From 2022 to 2024, we recorded 6 cases of catheter detachment (5 ports were installed in other hospitals), and in all of them the subclavian approach was used. Obviously, we encountered a “pinch-off” syndrome. In three cases, the reason for additional examination was the absence of backflow, in two cases it was an incidental finding. In four cases, the catheter fragment was in the right ventricle, in one case in the right femoral vein, without any clinical manifestations. In one case, fragmentation was an incidental finding during port removal, when a 5 cm long fragment was found during opening of the capsule surrounding the reservoir, the second part of the catheter was in the right ventricle according to CT data. According to Surov et al., in 56.3 % of cases the first sign of catheter fragmentation was dysfunction, and in 11.6 % the diagnosis was made incidentally during radiography. According to this review, catheter fragments were most frequently located in the pulmonary arteries — 35 %, in the right atrium — 27.6 %, in the right ventricle — 22 %, and in the superior vena cava — 15.4 % [34]. Despite the lack of severe symptoms, catheter fracture is a potentially life-threatening condition. The patient must be referred to a specialized center with access to both interventional radiological diagnostics and tools for endovascular catheter fragment retrieval.
Port Chamber Rotation was the rarest cause of IPPS removal in our cohort, occurring in 0.06 % of cases. In similar studies, it was reported slightly more frequently — up to 0.5 % [18, 35]. Some authors have linked this complication to the failure to suture the port chamber to the fascial layer during implantation. However, this topic has not been thoroughly studied, and in studies that specifically assessed this connection, the authors concluded that fixation of the chamber may not be necessary [36].
The real reasons for the rotation of the port system chamber under the skin remain unclear. Our experience allows us to assume that one of the reasons may be incorrect use, in particular, abrupt removal of the needle, without manual fixation.
Conclusions
We have intentionally focused on late complications and adverse events, as we believe it is essential to raise awareness about them not only among oncologists, but also among physicians of other specialties and nursing staff. With the increasing use of implantable port systems, healthcare professionals in general hospitals—not only specialized oncology centers—are more likely to encounter such patients.
Based on our experience, we concur with our colleagues [23, 29] that improper use and inadequate care of IPPS are frequent causes of complications. Training for non-oncology personnel, patient and caregiver education, and awareness campaigns can significantly reduce the rate of complications requiring port explantation. There is a clear need for ongoing monitoring and analysis of adverse events. Future research directions may include: identifying the exact causes of skin necrosis and effective prevention strategies for this most common complication, developing targeted infection prevention programs, and creating tools for personalized thrombosis risk assessment specifically for patients with implantable port systems.
Disclosure. The authors declare no competing interests.
Author contribution. All authors according to the ICMJE criteria participated in the development of the concept of the article, obtaining and analyzing factual data, writing and editing the text of the article, checking and approving the text of the article.
Ethics approval. The study does not disclose personal data and does not apply any new methods of treatment, diagnosis or prevention. The study cannot pose an additional threat to patient safety.
Funding source. This study was not supported by any external sources of funding.
Data Availability Statement. Data supporting the findings of this study can be obtained from the corresponding author on reasonable request.
