Feasibility and Safety of the Craniocaudal Approach for Superior Sulcus Lesions of the Thorax

Purpose To evaluate the feasibility and safety of the craniocaudal approach for superior sulcus lesions of the thorax. Material and Methods Between October 2010 and December 2020, the data from 22 consecutive patients who underwent drainage or biopsy using a craniocaudal trajectory were retrospectively reviewed. The craniocaudal approach was applied for patients in which the fluid collection or tumor was limited to the superior thoracic sulcus lesion or otherwise inaccessible owing to intervening structures such as pleural dissemination. The indications for this procedure were drainage in 20 patients and biopsy in 2 patients. Technical success, procedure time, complications, and clinical success were evaluated. Results Technical and clinical success were achieved in all patients, and no major complications were found. The median procedure time was 25 min (range 15–40 min). This procedure was performed with fluoroscopic guidance in 11 patients and ultrasound guidance in 11 patients. The routes of needle passage were the first intercostal space (n = 16), the second intercostal space (n = 5), and between the clavicle and the first rib (n = 1). Conclusion The craniocaudal approach for superior sulcus lesions might be a safe and feasible option for patients in which the conventional intercostal approach is difficult. Level of Evidence Retrospective cohort study. Level 4.


Introduction
Pleural effusion and empyema are common conditions that may require thoracic drainage or pleurodesis [1]. An intercostal approach is most widely applied for percutaneous thoracic drainage with the trocar or Seldinger's technique [2,3]; however, thoracic superior sulcus lesions are sometimes difficult to access using the conventional intercostal approach because of the intervening structures, such as the subclavian artery and vein, scapula, and clavicle. Takizawa et al. [4] reported two cases of drainage in which the needle punctured the skin from just above the posterior third rib to the apical zone. That is called the axial puncture approach. Although this approach may be beneficial, the feasibility, safety, and efficacy have not been fully evaluated. Thus, this study aimed to evaluate the safety and feasibility of the craniocaudal approach.

Patients
This single-institution, retrospective, and observational study was performed in accordance with the Declaration of Helsinki and approved by the Institutional Ethics Committee. Informed consent for participation in this study was waived due to the retrospective nature of the study. Written informed consent for the procedure was obtained from all patients. Between October 2010 and December 2020, 22 consecutive patients (15 males and 7 females, median age 65.5 years, range 36-86 years) who underwent drainage or biopsy using the craniocaudal approach were included. The most common reason for employing the craniocaudal approach was difficulty with conventional intercostal access (n = 17). Difficulty with conventional intercostal approach was defined by the operator's subjective judgment. The demographic and clinical characteristics of the patients are summarized in Table 1.

Procedures
All procedures were performed by 10 interventional radiologists with 3-24 years of experience in interventional radiology in the angiography suite with a hybrid angiocomputed tomography (CT) system. Each procedure was performed under local anesthesia. In most patients (n = 16/ 22), hydroxyzine (Atarax-P; Pfizer, NY, USA) and pentazocine (Pentazine; Daiichi Sankyo, Tokyo, Japan) were administered as procedural sedation and analgesia. The patient was placed in the supine or 15°-45°semi-erect position in the case of dyspnea. For fluoroscopic puncture, the method described in Takizawa's article was primarily used [4]. A 17-gauge metallic Huber-point needle (PTC needle; Hakko, Chikuma, Japan) was inserted from the base of the neck to the superior sulcus lesion with fluoroscopic or ultrasound (US) guidance (TUS-300/Aplio300; Toshiba Medical Systems). The choice of modality was decided based on operator's preference. Before and during the puncture, CT scan was performed and utilized as a guidance for the puncture direction. The superior sulcus lesion was accessed mainly through the first or second intercostal spaces because of the low risk of injury to vessels or nerves. Lateral or oblique views under fluoroscopy were effective in inserting the needle through the intercostal space. In the drainage cases, a 0.035-inch J-shaped guide wire (Fixed Core Wire Guide; Cook, Bloomington, IN, USA) was advanced into the cavity after the puncture of the needle, followed by the placement of a drainage catheter (Fig. 1). Prior to the removal of drainage catheters, the shrinkage of the cavities was confirmed via chest CT or radiograph.

Study Outcomes
The primary outcome parameters was technical success, defined as the successful placement of the drainage catheter or successful collection of tissue samples with biopsy devices. Procedure time, complications, and clinical success were also evaluated. Clinical success was defined as the shrinkage of the drained cavity, followed by the removal of the catheter, or when the pathologists could make a diagnosis from the biopsy specimen. Complications were evaluated using the Cardiovascular and Interventional Radiological Society of Europe (CIRSE) classification system [5].

Technical and Clinical Success
Both the technical and clinical success rates were 100% (n = 22/22). The craniocaudal approach was performed with fluoroscopic guidance in 11 patients and US guidance in 11 patients. The most common needle trajectory was through the first intercostal space (n = 16/22). In the 20 drainage cases, 20 fluid collections have resolved in total.

Complications
Minor complications (CIRSE classification Grade 2) occurred in one case. In this patient, the normal lung parenchyma was mistakenly traversed. Transient hemoptysis occurred, but it disappeared in 24 h. The clinical outcomes and follow-up data are summarized in Table 2.

Discussion
All patients who underwent the craniocaudal approach were successful both technically and clinically. The median procedure time was 25 min; this was similar to the time reported by Takizawa et al. [4], which was within 20 min. Unlike their report, where all procedures were performed using fluoroscopic guidance, half of our procedures were performed using US guidance. In fact, poor visibility of superior sulcus lesion precluded the US-guided puncture and thus fluoroscopic puncture was used in 4 patients. Therefore, it might be preferable to prioritize fluoroscopic puncture. Possible approaches to the superior sulcus lesions other than the craniocaudal approach include the conventional intercostal approach and transscapular approach. Although the safety and efficacy of the conventional intercostal approach are established, reaching the superior sulcus lesion is sometimes difficult because of the existence of normal lung parenchyma [6]. The transscapular approach has been reported to reach the superior sulcus lesions [7]. However, this approach requires penetration of the bone and is thus more invasive than the craniocaudal approach. The craniocaudal approach has two advantages. The first one is the ability to achieve the procedure in the supine position. Therefore, this approach may be feasible for patients who are connected to ventilators, which can make changing their postures difficult. The second one is the effectiveness for the patients with diffuse subcutaneous metastases or pleural dissemination (Fig. 2). If the conventional intercostal approach is performed for such patients, it may induce needle tract seeding. Furthermore, it is extremely painful to place a drainage catheter through metastases because the local anesthesia is not very effective. Moreover, drainage tube fixation is difficult when passed through percutaneous metastases. For these reasons, it is unfavorable to puncture through the tumor.
There is no other contraindication for the craniocaudal approach than the conventional interventional radiology procedures, which includes severe thrombocytopenia or bleeding tendency.
No major complications were observed in this study, although the craniocaudal approach poses the risk of vascular injury. The needle passes through the trapezius, serratus anterior, and levator scapulae muscles, followed by the first or second intercostal space to finally reach the thoracic cavity. Therefore, injury to the small branches of the subclavian artery might occur [8].
Regarding nerve injuries, C5 and C6 of the brachial plexus are located near the needle tract. However, these structures typically run between the anterior and middle scalene muscles, which are anterior to the needle tract of the axial puncture approach [9,10]. Thus, the possibility of injuring the brachial plexus is considered low. This study was subject to several limitations. First, it included a limited number of patients from a single center. Second, it was retrospective study and thus might have the inherent biases. Third, inferior visibility with US might be caused by old US equipment, but it was difficult to collect enough information about the specification of US at that time.

Conclusion
We reported on the findings from the use of a craniocaudal approach for superior sulcus lesions. For patients unsuitable for the conventional intercostal approach, the craniocaudal approach could be a feasible and safe option. Consent for Publication For this type of study, consent for publication is not required.
Ethical Approval All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki Declaration and its later amendments or comparable ethical standards. For this type of study formal, consent is not required. This retrospective study was approved by the Institutional Ethics Committee. A Postoperative left breast cancer. The conventional intercostal approach is not feasible because of diffuse pleural dissemination and subcutaneous metastases (white arrow). B, C The needle is passed through the first intercostal space and a 16-Fr trocar catheter is placed Informed Consent This study has obtained IRB approval from the Institutional Ethics Committee and the need for informed consent was waived.
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