This retrospective, single-center study was approved by our Institutional Review Board. The requirement of written informed consent was waived.
Study design
From January 2014 to September 2020, a total of 152 patients with PNs underwent CT-guided CL prior to VATS-guided WR. Among them, 14 patients (9.2%) had the SBPNs and underwent TSCL procedure.
Inclusion criteria were as follows: (a) a definite SBPN on CT; (b) PNs with the diameter ≤ 3 cm (sub-solid PNs ≤ 30 mm; solid PNs ≤ 15 mm); (c) the PN-pleura distance ≤ 20 mm; and (d) PNs lacking a definite pathological diagnosis.
Exclusion criteria were as follows: (a) a PN diameter < 5 mm; (b) a PN which decreased in size during CT follow-up; and (c) any abnormal coagulation activity, active bleeding, active infection, or limited cardiopulmonary reserve.
Puncture of the scapular
An interventional radiologist with more than 5 years of experience conducting CT-guided interventions performed all procedures using a 64-row CT (GE Healthcare, Milwaukee, WI). Patients were placed in the prone position and were administered local anesthesia.
A preoperative CT scan was used to ensure the needle pathway (Fig. 1a). A 17G needle (DuoSmart, Modena, Italy) was used to puncture the scapula. When the needle contacted the scapula, it was punctured using a drill and the application of steady pressure. Repeat CT scan was performed to observe the location of needle tip and the procedure-related complications (Fig. 1b). When the 17G needle passed across the scapula, the needle tip was pushed near the lung. However, the needle tip did not enter the lung.
Localization procedure
When the 17G needle passed through the scapula, an 18G needle (Precisa, Roma, Italy) was inserted from the 17G needle and was smoothly pushed to the lung to within approximate 10 mm of the PN (Fig. 1c). Next, a coil (5-cm-length and 0.038-inches-diameter, Cook, Bloomington, IN) was partially placed into the pulmonary parenchyma, after which the needle was smoothly retracted so that the coil tail remained above the visceral pleura (Fig. 1d). Repeat CT scan was performed to observe the location of coil and the procedure-related complications.
VATS procedure
VATS-guided WR was routinely performed within 24 h of localization. The coil tail was used to guide this procedure. When the coil tail was detected under the thoracoscope, the WR was performed with the cutting margin > 20 mm from the coil tail. If the coil tail was invisible, the coil was considered to be completely inserted into the pulmonary parenchyma, then palpation of the coil was performed in order to conduct the WR. When this was still unsuccessful, the lobectomy should be performed.
The resected lesions were sent for a rapid pathological examination. If the pathological diagnosis indicated the results of benign, carcinoma in situ, mini-invasive carcinoma, or metastatic PN, the VATS could finish. Further lobectomy and lymph node dissection should be performed if the PN was diagnosed as invasive carcinoma.
Definitions
SBPN was defined as the PN with the lesion-pleura vertical line striding across the scapula. Technical success of TSCL was defined as that if coil tail could be detected under the thoracoscope. Technical success of WR was defined as that if the PN was found in the resected wedge tissue.
The primary endpoint was technical success of TSCL. The secondary endpoints included localization-related complications, technical success of VATS-guided WR, and final diagnoses of the PNs.
Statistical analysis
All statistical analyses were conducted by SPSS 16.0 (SPSS Inc., Chicago, IL). Continuous variables were presented with mean ± standard deviation. Categorical data were presented as a percentage (number/total).