The two most common surgical techniques for TIVAD implantation are the venous cutdown technique (CT) and the surface landmark method using Seldinger-Technique (ST). Reviewing the literature, ST gained in importance during the last 20 years and is nowadays preferred compared to a surgical preparation of the vein as is required for the cutdown-technique [5, 6]. Nocito et al. showed a higher success rate (90% vs 70%, p = 0.007) and a shorter time requirement (48.9 min. vs. 64.8 min, p < 0.001) for TIVAD implantation in ST compared to CT. There was no significant difference in TIVAD-related complication rate between both groups . Hsu et al. also showed a higher success rate for TIVAD implantation using ST and no difference in overall peri- and postoperative complication rates . As Blanco-Guzman described, the advantage of ST is the reduced need of surgical time and supportive equipment (e.g. ultrasound or X-ray machine), as the puncture of the vein is usually performed blind. However, intraoperative ultrasound could lead to a higher amount of correct implanted TIVADs with ST and could replace the routinely performed postoperative chest X-ray . However, another study showed disadvantages for ST compared to CT with a higher rate of TIVAD associated thrombosis (16.7 % in ST vs. 10.3 % in CT) and a higher rate of TIVAD dislocations (4.6 % in ST vs. 0.3 % CT) .
Though generally ST seems to be the more preferred method, CT could still be an adequate alternative depending on risk factors (e.g. obesity) and personal preferences of the surgeon.
In this study, postoperative infections were the most frequent complication (5.8%). Bassi et al. reported in 2012 a similar TIVAD-infection rate (6.17%) , whereas several other studies reported a higher rate of TIVAD-related infections up to 11 % [3, 10–11]. In contrast, Bow et al. reported in a study of 1999 no TIVAD-related infection  and some other studies also showed less TIVAD-related infections [5, 13] than ours. However, comparison of complications between different studies is challenging as observation periods are not congruent and thereby interpretation of the reported data is hindered. Depending on time of appearance, etiology of the complication “infection” could be totally different. In our study the observation period was not limited, and the longest observed duration between TIVAD implantation and explantation due to occurrence of an infection was 1187 days. This infection was most probably not caused by the surgical procedure itself but more likely related to improper long-term use of TIVAD. In contrast, the shortest reported duration between TIVAD implantation and explantation because of a port-associated infection was 6 days; in this case the infection was presumably caused by the implantation procedure itself.
The rate of TIVAD-related thrombosis found in this study (4.1%) is within the range of 1.5 up to 16.4% reported in the current literature [2, 5, 11, 13–18]. Likewise, the observed incidence of the complication “venous malposition” (3.1%) is in line with previous studies [13, 16–17]. In clinical routine, especially the development of a pneumothorax following TIVAD implantation by ST is feared, but the reported low incidence found in this study is reassuring. In total, pneumothorax occurred in only 1.9% of patients (n = 12), and in only 4 of these patients a thoracic drainage was required. Reviewing the literature showed similar low rates (between 0.4% and 3.4%) of pneumothoraces after TIVAD implantation in ST [2, 12–13, 16–17].
In a study with similar study population and design than our study, El-Balat et al. retrospectively assessed rate of complication for TIVAD implantation by gynecologists in breast cancer patients. However, the preferred method for catheter implantation was CT and ST was only used in case of a failed implantation by CT. The observed overall complication rate was 26% and thus considerably higher compared to our study (18%) .
In this study, a significant higher success rate for the implantation of TIVADs in the left subclavian vein compared to the right subclavian vein was found (98.2% vs. 95.3%, p = 0.036). This finding might be explained by anatomical circumstances, as the course of the left subclavian vein is flatter than on the right side, possibly facilitating puncture of the subclavian vein and subsequent protrusion of the wire. However, discrepant results are found in the literature for side-related success rates of port implantations. Lin et al. reported a higher rate of correct position of TIVAD-tubes (transition between right atrium and Vena cava superior) for the implantation by ST on the left side compared to the right side (p = 0.001) . In contrast, El-Balat et al. found no significant difference in success rates depending on the chosen implantation side (p = 0.43). However, in contrast to Lin et al. and this study, El-Balat et al. used the CT of the cephalican vein as preferred method . Another study from Ma et al. reported a higher success rate for the TIVAD implantation with ST in the right subclavian vein (95.6% vs. 81.8%), but, in difference to the studies before, the puncture was performed supraclavicular instead of infraclavicular .
We could show a significant higher rate for developing a TIVAD-related thrombosis for implantation in the left subclavian vein compared to the right subclavian vein (5.9% vs. 2.0%, p = 0.013). In contrast, Biacchi et al. found an association between postoperative thromboses and implantation of TIVADs via ST into the right subclavian vein. In addition, a correlation between diameter of the catheter system and the rate of thrombosis has been described . However, other studies showed no correlation between thrombosis and side of implantation [11, 14]; thus, the findings of our study with a higher rate of thrombosis after TIVAD implantation on the left side is not supported by present literature.
The results of this study showed a significant higher rate of venous misplacements in patients with obesity. Biffi et al. defined among other factors like scares within the localization of vein puncture especially obesity as an exclusion criterion for using ST for implantation of TIVADs . This recommendation is supported by our finding, which is to our knowledge the first study reporting an association between BMI and venous malposition of TIVADs for port implantation by ST.
Especially due to logistic reasons, local anesthesia is the preferred method of anesthesia for port-implantation not only at our institution as [3, 13–14, 17, 20]. Interestingly, we found a significantly lower overall complication-rate with general anesthesia (13.1%) compared to both local anesthesia and analgosedation (22.4% and 20.3%, respectively). These findings may be explained by the optimized surgical conditions in general anesthesia due to maximal relaxation of patient without any disturbance caused by incautious patient movements, pain or anxiety reactions.
Though our study showed a significant higher rate of pneumothoraces and impaired wound healing in patients with cervical cancer compared to patients with other gynecological tumor entities, no previous studies reporting similar findings were found. However, these results have to be interpreted carefully as the overall numbers are very small.
Even if the result was not significant, a trend favoring application of single-shot antibiotics to prevent postoperative infections was observed. However, there are several studies which could not show any benefit for perioperative antibiotics during surgery to prevent subsequent infections. A large meta-analysis including data from 2154 patients found no reduced rate of postoperative infections (within 30 days postoperative) following placement of subcutaneously implanted central venous access ports when prophylactic antibiotics were used . Di Carlo et al. also showed in a randomized study comprising oncological patients that perioperative antibiotics do not provide a benefit in terms of reduced infection rates after TIVAD implantation . For this study, it is important to mention that some patients received antibiotics during surgery not for port implantation but for the simultaneous surgical procedure (e.g. breast-conserving-therapy) that was combined with TIVAD implantation. In addition, infections as postoperative complications were considered independent of time of occurrence in this analysis. Thus, our findings on influence of intraoperative single-shot antibiotics on infection rates could be biased by delayed infections e.g. due to parenteral nutrition or other long-term use of the port device. Nevertheless, application of antibiotics should be considered carefully, because even if the above mentioned studies showed no benefit for perioperative antibiotics in the context of port implantations, several other studies proofed the benefit of antibiotics in surgeries using allogeneic materials (e.g. breast implants) [23–24].
A clear limitation of this study is the retrospective study design. No systemic follow up was available for the study population and data regarding date and reason of TIVAD explantation is missing for patients that had their TIVAD explanted at other clinics. In addition, information on complications which occurred after the last contact with our institution could have been missed. As another weakness it needs to be mentioned that complications were not further classified regarding degree of severity, e.g. by using the Clavien-Dindo classification. Although the total number of included patients is higher than in most other published studies on this topic, sample sizes for some complications or patients sub-cohorts were still rather small, and rare complications could not be observed in some of the smaller patient cohorts. Furthermore, because the significance level was not adjusted for multiple testing, results of the statistical analyses have to be interpreted carefully. Overall, more large studies with extended observational periods are essential to facilitate detection of both rare complication events and long-term complications such as TIVAD malfunction, thrombosis or infections that may occur several months after TIVAD implantation.
One of the major strengths of the study besides the large number of patients is that it comprises a clearly defined patient cohort including only female patients with gynecological malignancies. Thus, our results are not affected by a potential gender bias, as differences in anatomy between men and women may influence the success rate of TIVAD implantation via ST or the risk for specific complications. As a single-center analysis, this study also benefits from consistent standards in surgical technique, postoperative procedures and subsequent surveillance
Overall, the presented results provide a good basis for optimized counseling of female patients with planned TIVAD implantation regarding surgical procedures, success rate, and probability of suffering from complications.