Virtual-assisted lung mapping is a preoperative bronchoscopic multi-spot dye-marking technique. This study aimed to examine the efficacy of virtual-assisted lung mapping for obtaining sufficient surgical margins in sublobar lung resection. The multicenter, prospective, single-arm study was conducted from September 2016 to July 2017 in 19 registered centers. Patients who required sublobar lung resection and careful determination of resection margins underwent virtual-assisted lung mapping followed by thoracoscopic surgery. Successful resection was defined as resection of the lesion with margins greater than the lesion diameter or 2 cm using the preoperatively planned resection without additional resection. We defined the primary goal of the study as achieving successful resection in 95% of lesions. The resection of 203 lesions (average diameter, 9.6 ± 5.3 mm) was intended in 153 patients. The lesions included pure and mixed ground-glass nodules (75 [35.9%] and 36 [17.2%], respectively), solid nodules (91 [43.5%]), and others (7 [3.3%]). Surgical procedures included wedge resection (131, 71.2%), segmentectomy (51, 27.7%), and others (2, 1.1%). Successful resection was achieved in 178 lesions (87.8% [95% confidence interval, 82.4-91.9%]), and virtual-assisted lung mapping markings successfully aided in the identification of 190 lesions (93.6% [95% confidence interval, 89.3-96.5%]). Multivariable analysis showed that the most significant factor affecting resection success was the depth of the necessary resection margin (P = .0072). This study showed that virtual-assisted lung mapping has reasonable efficacy, although the successful resection rate did not reach the primary goal. The depth of the required margin was the most significant factor leading to resection failure.

Chronic lung allograft dysfunction post-lung transplantation: The era of bronchiolitis obliterans syndrome and restrictive allograft syndrome

OBJECTIVES: Virtual-assisted lung mapping (VAL-MAP) is a preoperative bronchoscopic multispot dye-marking technique using virtual images. The purpose of this study was to evaluate the safety, efficacy and reproducibility of VAL-MAP among multiple centres. METHODS: Selection criteria included patients with pulmonary lesions anticipated to be difficult to identify at thoracoscopy and/or those undergoing sub-lobar lung resections requiring careful determination of resection margins. Data were collected prospectively and, if needed, compared between the centre that originally developed VAL-MAP and 16 other centres. RESULTS: Five hundred patients underwent VAL-MAP with 1781 markings (3.6 ± 1.2 marks/patient). Complications associated with VAL-MAP necessitating additional management occurred in four patients (0.8%) including pneumonia, fever and temporary exacerbation of pre-existing cerebral ischaemia. Minor complications included pneumothorax (3.6%), pneumomediastinum (1.2%) and alveolar haemorrhage (1.2%), with similar incidences between the original centre and other centres. Marks were identifiable during operation in approximately 90%, whereas the successful resection rate was approximately 99% in both groups, partly due to the mutually complementary marks. The contribution of VAL-MAP to surgical success was highly rated by surgeons resecting pure ground glass nodules (P < 0.0001), tumours ≤ 5 mm (P = 0.0016), and performing complex segmentectomy and wedge resection (P = 0.0072). CONCLUSIONS: VAL-MAP was found to be safe and reproducible among multiple centres with variable settings. Patients with pure ground glass nodules, small tumours and resections beyond conventional anatomical boundaries are considered the best candidates for VAL-MAP. Clinical Trial Registration Number: UMIN 000008031. University Hospital Medical Information Network Clinical Trial Registry (http://www.umin.ac.jp/ctr/).

Bronchiolitis obliterans syndrome (BOS) had been considered to be the representative form of chronic rejection or chronic lung allograft dysfunction (CLAD) after lung transplantation. In BOS, small airways are affected by chronic inflammation and obliterative fibrosis, whereas peripheral lung tissue remains relatively intact. However, recognition of another form of CLAD involving multiple tissue compartments in the lung, termed restrictive allograft syndrome (RAS), raised a fundamental question: why there are two phenotypes of CLAD? Increasing clinical and experimental data suggest that RAS may be a prototype of chronic rejection after lung transplantation involving both cellular and antibody-mediated alloimmune responses. Some cases of RAS are also induced by fulminant general inflammation in lung allografts. However, BOS involves alloimmune responses and the airway-centered disease process can be explained by multiple mechanisms such as external alloimmune-independent stimuli (such as infection, aspiration and air pollution), exposure of airway-specific autoantigens and airway ischemia. Localization of immune responses in different anatomical compartments in different phenotypes of CLAD might be associated with lymphoid neogenesis or the de novo formation of lymphoid tissue in lung allografts. Better understanding of distinct mechanisms of BOS and RAS will facilitate the development of effective preventive and therapeutic strategies of CLAD.