Ultrasonographic localization of occult pulmonary nodules during video-assisted thoracic surgery

Intraoperative lung ultrasound improves subcentimetric pulmonary nodule localization during VATS: Results of a retrospective analysis

BACKGROUND

Video-assisted thoracoscopic surgery (VATS) resection of deep-seated lung nodules smaller than 1 cm is extremely challenging. Several methods have been proposed to overcome this limitation but with not neglectable complications. Intraoperative lung ultrasound (ILU) is the latest minimally invasive proposed technique. The aim of the current study was to analyze the accuracy and efficacy of ILU associated with VATS to visualize solitary and deep-seated pulmonary nodules smaller than 1 cm.

METHODS

Patients with subcentimetric solitary and deep-seated pulmonary nodules were included in this retrospective study from November 2020 to December 2022. Patients who received VATS aided with ILU were considered as group A and patients who received conventional VATS as group B (control group). The rate of nodule identification and the time for localization with VATS alone and with VATS aided with ILU in each group were analyzed.

RESULTS

A total of 43 patients received VATS aided with ILU (group A) and 31 patients received conventional VATS (group B). Mean operative time was lower in group A (p < 0.05). In group A all the nodules were correctly identified, while in group B in one case the localization failed. The time to identify the lesion was lower in group A (7.1 ± 2.2 vs. 13.8 ± 4.6; p < 0.05). During hospitalization three patients (6.5%; p < 0.05) in group B presented air leaks that were conservatively managed.

CONCLUSION

Intracavitary VATS-US is a reliable, feasible, real-time and effective method of localization of parenchymal lung nodules during selected wedge resection procedures.

Beyond the Frontline: A Triple-Line Approach of Thoracic Surgeons in Lung Cancer Management-State of the Art

Non-small cell lung cancer (NSCLC) is now described as an extremely heterogeneous disease in its clinical presentation, histology, molecular characteristics, and patient conditions. Over the past 20 years, the management of lung cancer has evolved with positive results. Immune checkpoint inhibitors have revolutionized the treatment landscape for NSCLC in both metastatic and locally advanced stages. The identification of molecular alterations in NSCLC has also allowed the development of targeted therapies, which provide better outcomes than chemotherapy in selected patients. However, patients usually develop acquired resistance to these treatments. On the other hand, thoracic surgery has progressed thanks to minimally invasive procedures, pre-habilitation and enhanced recovery after surgery. Moreover, within thoracic surgery, precision surgery considers the patient and his/her disease in their entirety to offer the best oncologic strategy. Surgeons support patients from pre-operative rehabilitation to surgery and beyond. They are involved in post-treatment follow-up and lung cancer recurrence. When conventional therapies are no longer effective, salvage surgery can be performed on selected patients.

Intraoperative Contrast-Enhanced Ultrasonography (Io-CEUS) in Minimally Invasive Thoracic Surgery for Characterization of Pulmonary Tumours: A Clinical Feasibility Study

BACKGROUND

The intraoperative detection of solitary pulmonary nodules (SPNs) continues to be a major challenge, especially in minimally invasive video-assisted thoracic surgery (VATS). The location, size, and intraoperative frozen section result of SPNs are decisive regarding the extent of lung resection. This feasibility study investigates the technical applicability of intraoperative contrast-enhanced ultrasonography (Io-CEUS) in minimally invasive thoracic surgery.

METHODS

In this prospective, monocentric clinical feasibility study, n = 30 patients who underwent Io-CEUS during elective minimally invasive lung resection for SPNs between October 2021 and February 2023. The primary endpoint was the technical feasibility of Io-CEUS during VATS. Secondary endpoints were defined as the detection and characterization of SPNs.

RESULTS

In all patients (female, n = 13; mean age, 63 ± 8.6 years) Io-CEUS could be performed without problems during VATS. All SPNs were detected by Io-CEUS (100%). SPNs had a mean size of 2.2 cm (0.5-4.5 cm) and a mean distance to the lung surface of 2.0 cm (0-6.4 cm). B-mode, colour-coded Doppler sonography, and contrast-enhanced ultrasound were used to characterize all tumours intraoperatively. Significant differences were found, especially in vascularization as well as in contrast agent behaviour, depending on the tumour entity. After successful lung resection, a pathologic examination confirmed the presence of lung carcinomas (n = 17), lung metastases (n = 10), and benign lung tumours (n = 3).

CONCLUSIONS

The technical feasibility of Io-CEUS was confirmed in VATS before resection regarding the detection of suspicious SPNs. In particular, the use of Doppler sonography and contrast agent kinetics revealed intraoperative specific aspects depending on the tumour entity. Further studies on Io-CEUS and the application of an endoscopic probe for VATS will follow.

Intraoperative Lung Ultrasound (ILU) for the Assessment of Pulmonary Nodules

Background: The primary aim of this study was to confirm the validity of intraoperative lung ultrasound (ILU) as a safe and effective method of localization for difficult to visualize pulmonary nodules during Video-Assisted Thoracoscopic Surgery (VATS) and open thoracotomy. The secondary aim was to enhance knowledge on the morphological patterns of presentation of pulmonary nodules on direct ultrasound examination. Materials and methods: 131 patients with lung nodule and indication for surgery were enrolled. All patients underwent pre-operative imaging of the chest, including Chest Computed Tomography (CT) and Transthoracic Ultrasound (TUS), and surgical procedures for histological assessment of pulmonary nodules (VATS or open thoracotomy). Results: The identification of 100.00% of lung nodules was allowed by ILU, while the detection rate of digital palpation was 94.66%. It was not possible to associate any specific ILU echostructural pattern to both benign or malignant lesions. However, the actual histological margins of the lesions in the operating samples were corresponding to those visualized at ILU in 125/131 (95.42%) cases. No complications have been reported with ILU employment. Conclusions: In our experience, ILU performed during both open surgery and VATS demonstrated to be a reliable and safe method for visualization and localization of pulmonary nodules non previously assessed on digital palpation. In addition, ILU showed to allow a clear nodule’s margins’ definition matching, in most cases, with the actual histological margins.

Perioperative identifications of non-palpable pulmonary nodules: a narrative review

Early detection of lung cancer is the key to improving treatment and prognosis of this disease, and the advent of advances in computed tomography (CT) imaging and national screening programs have improved the detection rate of very small pulmonary lesions. As such, the management of this sub-centimetric and often sub-solid lesions has become quite challenging for clinicians, especially for choosing the most suitable diagnostic method. In clinical practice, to fulfill this diagnostic yield, transthoracic needle biopsy (TTNB) is often the first choice especially for peripheral nodules. For lesions for which TTNB could present technical difficulties or failed, other diagnostic strategies are needed. In this case, video-assisted thoracic surgery (VATS) is the gold standard to reach the diagnosis of lung nodules suspect of being malignant. Nonetheless it’s often not easy the identification of such lesions during VATS because of their little dimensions, non-firm consistency, deep localization. In literature various marking techniques have been described, in order to improve intraoperative nodules detection and to reduce conversion rate to thoracotomy: CT-guided hookwire positioning, methylene blue staining, intra-operative ultrasound and electromagnetic navigation bronchoscopy are the most used. The scientific evidence on this matter is weak because there are no randomized clinical trials but only case series on single techniques with no comparison on efficacy, so there are no guidelines to refer. From this standing, in this article we conducted a narrative review of the existing literature on the subject, with the aim of outlining a framework as complete as possible. We analyzed strengths and weaknesses of the main techniques reported, so as to allow the clinician to orient himself with greater ease.

Intrathoracic use of a small ultrasonic probe for localizing small lung tumors in thoracoscopic surgery: Empirical results and comparison with preoperative CT images

OBJECTIVE

To evaluate the use of a small mobile ultrasound probe to localize small lung tumors during thoracoscopic surgery under thoracic CO₂ insufflation.

METHODS

We prospectively enrolled 20 patients (26 tumors) scheduled to undergo thoracoscopic pulmonary wedge resection between April 2016 and October 2018. Ultrasonographic tumor detection was performed with an ARIETTA 850 and L51K probe (Hitachi, Tokyo, Japan). Ultrasonography was repeated after achieving adequate lung collapse under a positive intrathoracic pressure of 8-15 mmHg. The appearance on preoperative CT versus the ultrasonographic localization was compared for each tumor. The receiver operating characteristic curves were compared for the tumor dimension of the lung window, consolidation dimension of the lung window, tumor dimension of the mediastinal window (MD), and tumor depth from the lung surface.

RESULTS

The average age was 62 years (range 42-79 years), average pathological tumor size was 9 mm (range 3-22 mm), and average tumor depth was 6 mm (range 1-25 mm). Although no tumors could be visualized before lung collapse, 22 tumors (85%) were detectable with ultrasonography after lung collapse. Of these 22 tumors, 16 were well-depicted, while six were poorly delineated. MD showed the largest area under the receiver operating characteristic curve (0.81), and tumors with a MD of ≤ 6 mm had a high risk of difficult localization using ultrasonography.

CONCLUSION

This ultrasonographic method obtained high tumor detection rates, especially for tumors with a MD > 6 mm. Tumors with a MD ≤ 6 mm may require another localization method.

CLINICAL REGISTRATION NUMBER

University Hospital Medical Information Network Clinical Trials Registry (UMIN000036921).

Intraoperative Detection and Assessment of Lung Nodules

Lung cancer is the most frequent cause of cancer-related death worldwide. Despite advances in systemic therapy, the 5-year survival remains humbling at 4% to 17%. For those diagnosed early, surgical therapy can yield potentially curative results. Surgical resection remains a cornerstone of medical care. Success hinges on sound oncologic resection principles. Various techniques can be used to identify pulmonary nodules. A challenge is intraoperative assessment of the surgical specimen to confirm disease localization and ensure an R0 resection. The primary tool is frozen section. Understanding the options available enhances the arsenal of thoracic surgeons and leads to better patient care.

Planting Seeds into the Lung: Image-Guided Percutaneous Localization to Guide Minimally Invasive Thoracic Surgery

Image-guided localization materials are constantly evolving, providing options for the localization of small pulmonary nodules to guide minimally invasive thoracic surgery. Several preoperative methods have been developed to localize small pulmonary lesions prior to video-assisted thoracic surgery. These localization techniques can be categorized into 4 groups according to the materials used: localization with metallic materials (hook-wire, microcoil, or spiral coil), localization with dye (methylene blue or indigo carmine), localization with contrast agents (lipiodol, barium, or iodine contrast agents), and radiotracers (technetium-99m). However, the optimal localization method has not yet been established. In this review article, we discuss the various localization techniques and the advantages and disadvantages of localization techniques as well as the available safety and efficacy data on these techniques.

Pulmonary nodules precision localization techniques

The advent of helical high-resolution CT scanners, the application of screening programs and the follow-up of patient with oncological history, led to an increasing number of diagnosis of small pulmonary nodule (less than 10 mm in maximum diameter), partially solid nodule or completely ground glass ones. Their management is controversial. Excisional biopsy by mean of video-assisted thoracic surgery is often a viable choice but to locate these lesions intraoperatively can be impossible without the aid of preoperative or intraoperative localization techniques. In this brief review we will analyze the benefit of adopting localization techniques prior to pulmonary resection for small pulmonary lesions and face the advantages and problems with the main techniques described in the literatures.

Ultrasound location of pulmonary nodules in video-assisted thoracoscopic surgery for precise sublobectomy

BACKGROUND

We investigated the clinical value of accurate sublobectomy of pulmonary nodules using video-assisted thoracoscopy (VATS). In June 2017 to June 2019, single lung nodule patients who accepted thoracoscopic resection were included. Palpation and intraoperative ultrasound (IU) were used to localize lung nodules, and the success rate, location time and safety compared. Performance of lung nodule ultrasound was assessed. The success rate of IU localization of pulmonary nodules with different properties was studied.

RESULTS

A total of 33 cases with single pulmonary nodules were included in the study, and 32 cases (97%) were successfully located by IU as opposed to 16 cases (48.5%) located by palpation (P < 0.05). Clear hypoechoic ultrasound images of nodules were obtained in all 32 cases, and the diameter of pulmonary nodules on ultrasound and CT were found to have a significant correlation (R = 0.860, P = 0.000). The average positioning time of IU was lower than that of the palpation group (P < 0.05). No complications occurred during ultrasound examination. The success rate of intraoperative ultrasonic localization between the pure ground-glass opacity (p-GGO) group and the mixed-ground-glass opacity (m-GGO) group was 90%, 100% (P = 0.526).

CONCLUSIONS

In thoracoscopic surgery, IU can locate pulmonary nodules accurately, efficiently and safely, and also has a high degree of accuracy in locating different types of pulmonary nodules.

VATS-US1: Thoracoscopic ultrasonography for the identification of nodules during lung metastasectomy

Open thoracotomy during pulmonary metastasectomy allows lung palpation and may discover unexpected further nodules. We assess the validity of intraoperative lung ultrasonography via thoracoscopy in identifying lung nodules. A first surgeon will perform an ultrasonographic investigation on the deflated lung by thoracoscopy. A second surgeon will then perform a manual exploration of the organ by thoracotomy. Data on number and localization of nodules will be matched and compared with final histology report. Sensitivity and specificity will be assessed. Concordance will be assessed with Cohen K test. Calculated sample size is 89 patients. This study might have an important role in shifting the surgical practice towards a less invasive approach, with consequent benefits for the patient. Protocol is registered on clinicaltrials.gov. Protocol registration number: NCT03864874.

A simple and efficient method to perform preoperative pulmonary nodule localization: CT-guided patent blue dye injection

OBJECTIVE

To assess the efficacy of computed tomography (CT)-guided localization with the injection of a low dose of patent blue dye (PBD) for the thoracoscopic resection of pulmonary nodules.

MATERIALS AND METHODS

Overall, 125 consecutive patients underwent CT-guided localization with injection of a lower dose of PBD between June 2015 and June 2016. The total injection dose relative to the distance between nodules and the visceral pleura was recorded. The clinical and radiological characteristics, technical details, pathological results and procedure-related complications were reviewed.

RESULTS

A total of 137 indeterminate pulmonary nodules were identified. The mean nodule size was 9.5 (3.0-22.0) mm. The mean injection dose of PBD relative to the distance between nodules and the visceral pleura was classified as follows: 0.07 ml: <1 cm, 0.1 ml: 1-2 cm and 0.18 ml: >2 cm. The mean time of CT-guided localization was 16.5 (10-50) min. The mean time interval from localization to surgery was 188 (24-1440) min. Pneumothorax developed in 50 patients (40%), and focal parenchymal hemorrhage occurred in 16 patients (12.8%) after localization. No patient required chest tube placement or emergent resuscitation. The success rate of dye marking was 98.5% (135/137). Malignancies, including 82 lung cancers, were diagnosed in 97 nodules (70.8%).

CONCLUSION

The injection of a lower dose PBD based on the distance to the visceral pleura can be successful with nodular localization and may facilitate thoracoscopic surgery, even in cases with a long interval from localization to surgery.

Computed Tomography-Guided Wire-Marking for Thoracoscopic Resection of Small Lung Nodules in Children

Introduction: In pediatric patients, thoracoscopic wedge-resection of pulmonary nodules is an established therapy. However, intraoperative localization of small lesions is still challenging. Purpose of this study was to evaluate the efficacy of preoperative computed tomography (CT)-guided wire-marking of small lung nodules. Materials and Methods: Between 2012 and 2017 a total of six cases receiving thoracoscopic resection of CT-marked lung nodules were analyzed. The nodules were preoperatively tagged by a wire, which was attached to the thoracic wall by sterile dressing. Characteristics of interest were stability of wire, complete resection, and prevention of open thoracotomy. Results: Six procedures were performed on five patients, including four men and one woman. Median age at intervention was 16 years (range 11-19 years). All patients had a history of primary malignancies, including osteosarcoma (n = 4) and synovial sarcoma (n = 1). A total of 10 nodules were visualized in CT of which 9 were marked by wire. The median expected size of nodules was 6 mm (range 2-23 mm). Two patients had bilateral, two left-sided and two right-sided lung lesions. There was no wire slippage. In five procedures wedge resection was possible; one case needed a near total lobe resection. In one case a mini-thoracotomy at port insertion site was performed to extract the specimen. There was no conversion to thoracotomy. Histopathology showed R0 resection in all patients. Malignancy was found in all specimens. In one patient postoperative hemorrhagic anemia necessitated transfusion. Conclusions: Preoperative wire-localization of small lung nodules is a safe and effective tool to enable thoracoscopic resection in children and to avoid thoracotomic interventions.

The use of ultrasound in detecting and defining ground-glass opacities: results of an ex vivo evaluation

OBJECTIVES

To evaluate the role of ultrasound in detecting and defining ground-glass opacities (GGOs) in surgical specimens of patients undergoing thoracoscopic diagnostic resection.

METHODS

We performed an observational single-centre study of all consecutive patients undergoing thoracoscopic diagnostic resection of GGOs. In each patient, the specimen was scanned with ultrasound; then, a needle was inserted into the lesion to facilitate its detection by the pathologist. We evaluated the rate of detection with ultrasound, compared the size and depth measurements of the lesions as determined from ultrasound scans with those from the histological specimens and correlated the ultrasound findings with the histological subtypes of adenocarcinomas.

RESULTS

We reviewed 17 tissue samples. The final diagnoses were 1 (6%) atypical adenomatous hyperplasia, 5 (29%) adenocarcinomas in situ, 4 (24%) minimally invasive adenocarcinomas and 7 (41%) invasive adenocarcinomas. All tumours were successfully identified using ultrasound. The size (P = 0.87) and depth (P = 0.25) of the lesions measured with ultrasound did not significantly differ from the measurements obtained from the histological specimens. In addition, ultrasound size (r = 0.945; P < 0.0001) and depth (r = 0.588; P = 0.013) were significantly correlated with the pathological measurements. All lesions with hyperechoic findings (n = 6) were pure GGOs, whereas lesions with mixed echoic (n = 11) patterns were mixed GGOs. We were unable to differentiate the histological subtypes of adenocarcinomas using the ultrasound scans.

CONCLUSIONS

Detection of GGOs on ultrasound scans is feasible, but differentiation of the histological subtypes of adenocarcinomas is not possible. The next step is to evaluate the intraoperative reproducibility of our results.

[Preoperative Computed Tomography-guided Microcoil Localization for Multiple Small Lung Nodules before Video-assisted Thoracoscopic Surgery]

背景与目的

肺内多发小结节微创手术的成功与否有赖于术前定位，然而目前缺乏针对肺内多发小结节术前定位的临床研究。本研究旨在与同期肺内单发小结节定位相比，探讨行电视胸腔镜手术（video-assisted thoracoscopic surgery, VATS）术前电子计算机断层扫描（computed tomography, CT）引导下留置微弹簧圈定位肺内多发小结节的临床价值。

方法

回顾性分析术前行肺内小结节微弹簧圈定位者235例的临床资料。根据结节是否为单发分为：单发结节组184例（single nodule group），多发结节组51例（multiple nodules group）。单发结节组常规方式CT引导下定位，多发结节组在CT引导下分级、分批次留置微弹簧圈定位，统计分析两组定位成功率、并发症、病理结果及定位操作相关数据等。

结果

多发结节组定位成功率达90.2%，与同期单发结节组成功率相比无统计学差异（90.2% vs 94.6%, P=0.205），多发结节组气胸发生率与单发结节组亦无统计学差异（21.6% vs 14.1%, P=0.179），然而多发结节组的操作时间明显长于单发结节组的操作时间[(30.6±6.6) min vs (19.9±7.4) min, P=0.000]。两组均无大咯血、空气栓塞及血胸发生等严重并发症。两组均无因术中无法定位结节而中转开胸者；手术方式以亚肺叶切除为主；术后病理以非浸润性病变为主。

结论

对于需行胸腔镜手术的肺部多发小结节，按照一定策略，术前CT引导下分级、分批次留置微弹簧圈的定位方法安全、有效，值得推广。

Doppler Ultrasound-Visible SignalMark Microspheres are Better Identified than HydroMARK® Clips in a Simulated Intraoperative Setting in Breast and Lung Tissue

BACKGROUND

Preoperative breast and lung markers have significant drawbacks, including migration, patient discomfort, and scheduling difficulties. SignalMark is a novel localizer device with a unique signal on Doppler ultrasound.

OBJECTIVE

We aimed to evaluate intraoperative identification of SignalMark microspheres compared with HydroMARK^® clips. We also assessed the safety and efficacy of SignalMark in the lung.

METHODS

Twelve breasts of lactating pigs were injected with SignalMark or HydroMARK^® by a breast radiologist, and subsequently identified using a standard ultrasound machine by three surgeons blinded to marker location. Time to identification of each marker was recorded, with a maximum allotted time of 300 s. To further demonstrate efficacy in lung parenchyma, a second cohort of pigs underwent lung injections.

RESULTS

A total of eight SignalMark markers and four HydroMARK^® clips were placed in pig breasts. Overall, the surgeons correctly identified SignalMark 95.8% of the time (n = 23/24) and HydroMARK^® clips 41.7% of the time (n = 5/12) within 300 s (p < 0.001). The mean time to identification was significantly faster for SignalMark, at 80.8 ± 20.1 s, than for HydroMARK^®, at 209.4 ± 35.2 s (p < 0.002). For the lung injections, all 10 SignalMark markers were visible on Doppler ultrasound at the time of placement, and at the 7- and 21-day time points.

CONCLUSIONS

Surgeons identified SignalMark in significantly less time than HydroMARK^® clips in a simulated intraoperative setting, and SignalMark was easily viewed in the lung. These results suggest that SignalMark is a feasible option for efficient intraoperative localization of non-palpable breast and lung tumors using ultrasound guidance.

Intraoperative fluorescence imaging in thoracic surgery

Intraoperative fluorescence imaging (IFI) can improve real-time identification of cancer cells during an operation. Phase I clinical trials in thoracic surgery have demonstrated that IFI with second window indocyanine green (TumorGlow^® ) can identify subcentimeter pulmonary nodules, anterior mediastinal masses, and mesothelioma, while the use of a folate receptor-targeted near-infrared agent, OTL38, can improve the specificity for diagnosing tumors with folate receptor expression. Here, we review the existing preclinical and clinical data on IFI in thoracic surgery.

Image-guided techniques for localizing pulmonary nodules in thoracoscopic surgery

Low-dose computed tomography (LDCT) screening has increased the detection rate for small pulmonary nodules with ground-glass opacity (GGO) in the peripheral lung parenchyma. Minimally invasive thoracoscopic surgery for these lung nodules is challenging for thoracic surgeons, and image-guided preoperative localization is mandatory for their successful resection. Image-guided localization methods primarily include two imaging tools: computed tomography (CT) and bronchoscopy. These different methods may use different localized materials, including hookwires, dyes, microcoils, fiducial markers, contrast media, and radiotracers. Ultrasonography and near-infrared imaging are also used for intraoperative localization of lung lesions. In this article, we review different localization techniques and discuss their indications and limitations.

CT-guided microcoil VATS resection of lung nodules: a single-centre experience and review of the literature

BACKGROUND

Video-assisted thoracoscopic surgery (VATS) is standard of care for small lung resections at many centres. Computed tomography (CT)-guided insertion of microcoils can aid surgeons in performing VATS resections for non-palpable lung nodules deep to the lung surface.

METHODS

Retrospective analysis of CT-guided microcoil insertions prior to VATS lung resection at a single institution from October 2008 to January 2014.

RESULTS

A total of 63 patients were included (37% male, mean age 61.6±11.4 years). Forty-two patients (67%) had a history of smoking, with 10 current smokers. Sixty one (97%) patients underwent wedge resection and 3 (5%) patients had segmentectomy. Three (5%) patients required intra-operative staple line re-resection for positive or close margins. Eleven (17%) patients had a completion lobectomy, 5 of which were during the same anaesthetic. The average time between the CT-guided insertion and start of operation was 136.6±89.0 min, and average operative time was 84.0±53.3 min. The intra-operative complication rate was 5% (n=3), including 1 episode of hemoptysis, and 2 conversions to thoracotomy. The post-operative complication rate was 8% (5 patients), and included 2 air leaks, 1 hemothorax (drop in hemoglobin), 1 post chest tube removal pneumothorax, and one venous infarction of the lingula after lingula-sparing lobectomy requiring completion lobectomy. . Average post-operative length of stay was 2.2 days. A diagnosis was made for all patients.

CONCLUSIONS

CT-guided microcoil insertion followed by VATS lobectomy is safe, with short operative times, short length of stay and 100% diagnosis of small pulmonary nodules. This technique will become more important in the future with increasing numbers of small nodules detected on CT as part of lung cancer screening programs.

Hybrid theatre and alternative localization techniques in conventional and single-port video-assisted thoracoscopic surgery

Management of pulmonary nodules in terms of diagnosis and intraoperative localization can be challenging, especially in the minimal invasive video-assisted thoracoscopic surgery (VATS) approach, and may be even more difficult with single port VATS with limited access. The ability to localize small lesions intraoperatively is particularly important for excisional biopsy for diagnostic frozen section, as well as to guide sublobar resection. Some of the common techniques to aid localization include preoperative percutaneous hookwire localization, colour dye or radio-dye labelling injection of the nodule or adjacent site to allowing visualization or detection by radioactive counter intraoperatively. The use of hybrid operating room (OR) for intraoperative localization of lung nodules was first reported in 2013, and was called image guided VATS (iVATS). Subsequently, we have expanded the iVATS application for single port VATS major lung resection of small or ground-glass opacity lesions. By performing an on-table cone-beam CT scan, real-time and accurate assessment of the pulmonary lesion can be made, which can aid the localization process. Other types of physical or colour marker that can be deployed percutaneously in the hybrid OR immediate before surgery can enhance haptic feedback and sensitivity of digital palpation, as well as provide a radiopaque nidus for radiological confirmation. In the past decade, the electromagnetic navigation bronchoscopy (ENB) technology had developed into a useful adjunct technology for the localization of peripheral lung nodules by injection of marking agent or deployment of fiducial to the lesion through the endobronchial route causing much lower marking agent diffusion and artefacts. Recently, the combination of hybrid OR and ENB for lung nodule localization and marking has further increased the accuracy and applicability of the technology. The article will be exploring the latest development of the above approaches to lung nodule localization, and discuss some of the techniques' advantages and flaws.

Novel Methods of Intraoperative Localization and Margin Assessment of Pulmonary Nodules

Lung cancer screening has lead to frequent diagnosis of solitary pulmonary nodules, many of which require surgical biopsy for diagnosis and intervention. Subcentimeter and central nodules are particularly difficult to visualize or palpate during surgery, thus nodule localization can be a difficult problem for the thoracic surgeon. Although minimally invasive techniques including transthoracic computed tomography and bronchoscopic-guided biopsy may establish a diagnosis, these methods do not help locate nodules during surgery and can lead to inadequate tissue sampling. Therefore, surgical biopsy is often required for diagnosis and management of solitary pulmonary nodules. Additionally, after an excision, intraoperative margin assessment is important to prevent local recurrence. This is important for bronchial margins following lobectomy or parenchymal margins following sublobar resection. First, we examine methods of preoperative lesion marking, including wire placement, dye marking, ultrasound, fluoroscopy, and molecular imaging. Second, we describe the current state of the art in intraoperative margin assessment techniques.

Ex vivo pulmonary nodule detection with miniaturized ultrasound convex probes

BACKGROUND

The intraoperative localization of small and deep pulmonary nodules is often difficult during minimally invasive thoracic surgery. We compared the performance of three miniaturized ultrasound (US) convex probes, one of which is currently used for thoracic endoscopic diagnostic procedures, for the detection of lung nodules in an ex vivo lung perfusion model.

METHODS

Three porcine cardiopulmonary blocks were perfused, preserved at 4°C for 6 h and reconditioned. Lungs were randomly seeded with different patterns of echogenicity target nodules (9 water balls, 10 fat, and 11 muscles; total n = 30). Three micro-convex US probes were assessed in an open setting on the pleural surface: PROBE 1, endobronchial US 5-10 MHz; PROBE 2, laparoscopic 4-13 MHz; PROBE 3, fingertip micro-convex probe 5-10 MHz. US probes were evaluated regarding the number of nodules localized/not localized, the correlation between US and open specimen measurements, and imaging quality.

RESULTS

For detecting target nodules, the sensitivity was 100% for PROBE 1, 86.6% for PROBE 2, and 78.1% for PROBE 3. A closer correlation between US and open specimen measurements of target diameter (r = 0.87; P = 0.0001) and intrapulmonary depth (r = 0.97; P = 0.0001) was calculated for PROBE 1 than for PROBES 2 and 3. The imaging quality was significantly higher for PROBE 1 than for PROBES 2 and 3 (P < 0.04).

CONCLUSIONS

US examination with micro-convex probes to detect pulmonary nodules is feasible in an ex vivo lung perfusion model. PROBE 1 achieved the best performance. Clinical research with the endobronchial US micro-convex probe during minimally invasive thoracic surgery is advisable.

Localization of nonpalpable pulmonary nodules using CT-guided needle puncture

Background

Surgical resection of small pulmonary nodule is challenging via thoracoscopic procedure. We describe our experience of computed tomography (CT)-guided needle puncture localization of indeterminate pulmonary nodules prior to video-assisted thoracoscopic surgery (VATS).

Methods

From January 2011 to July 2014, 78 consecutive patients underwent CT-guided marking for the localization of 91 small pulmonary nodules. We retrospectively reviewed the clinical data, technical details, surgical findings and pathologic results, and complications associated with CT-guided localization.

Results

Seventy-eight consecutive patients (36 men and 42 women) underwent CT-guided marking localization of 91 indeterminate pulmonary nodules (62 pure ground-glass opacity nodules, 27 part-solid nodules, and 2 solid nodules). The mean size of the nodules was 8.6 mm (3.0–23.0 mm). The mean pleural distance between the nodule and lung surface was 11.5 mm (3.0–31.3 mm). The mean procedure time of CT-guided localization was 15.2 min (8–42 min). All patients stood the procedures well without requiring conversion to open thoracotomy. Twenty-four patients (30.77 %) developed pneumothorax after the procedures. Only one patient required retention of the puncture needle introducer for air drainage. The mean visual assessment pain score was 1.7 (0–3). Fifty-seven nodules (62.63 %) were confirmed as malignances, including 45 primary lung cancer, and 34 nodules (37.37 %) were confirmed as benign lesions.

Conclusions

CT-guided needle puncture can be an effective and safe procedure prior to VATS, enabling accurate resection and diagnosis of small pulmonary nodules.

A new technique combining virtual simulation and methylene blue staining for the localization of small peripheral pulmonary lesions

Background

Quickly and accurately localizing small peripheral pulmonary lesions can avoid prolonged operative time and unplanned open thoracotomy. In this study, we aimed to introduce and evaluate a new technique combining virtual simulation and methylene blue staining for the localization of small peripheral pulmonary lesions.

Methods

Seventy four (74) patients with 80 peripheral pulmonary lesions <20 mm in size on computer tomography (CT) were virtually punctured using a radiotherapy planning simulator on the day before operation. Under general anaesthesia, methylene blue dye was injected to the virtually identified point according to the surface point, angle and depth previously determined by the simulator. The wedge resection of the marked lesion was performed under video-assisted thoracoscopic surgery (VATS) and the specimens were sent for immediate pathologic examination. According to pathology results, appropriate surgical procedures were decided and undertaken.

Results

The average lesion size was 10.4±3.5 mm (range: 4-17 mm) and the average distance to the pleural surface was 9.4±4.9 mm. Our preoperative localization procedure was successful in 75 of 80 (94%) lesions. Histological examination showed 28 benign lesions and 52 lung cancers. The shortest distance between the edges of the stain and lesion was 5.1±3.1 mm. Localization time was 17.4±2.3 min. All patients with malignant lesions subsequently underwent lobectomy and systematic lymph node dissection. No complications were observed in all participants.

Conclusions

The novel technique combining the preoperative virtual simulation and methylene blue staining techniques has a high success rate for localizing small peripheral pulmonary lesions, particularly for those tiny lesions which are difficult to visualise and palpate during VATS.

[Advance in lung cancer surgery]

近年来微创技术在各期肺癌的检测、诊断和治疗中的应用出现爆发。这些技术的应用提高了手术的风险-收益比，并且使考虑肺癌手术治疗的患者更易接受手术。同时它们为晚期肺癌患者综合治疗的实施提供了便利。该综述总结了代表肺癌胸外科手术前沿的现有外科技术。

Indication for VATS sublobar resections in early lung cancer

When dealing with early non-small cell lung cancer (NSCLC) sublobar resections still remain part of the surgical armamentarium. In selected patients with lung cancer, the combination of the potential benefits of parenchyma sparing procedures to the limited trauma provided by Video Assisted Thoracic Surgery (VATS) techniques can become very appealing. Two main groups are included: non-anatomical (wedges) and anatomical (segmentectomies) excisions. We describe the techniques, results and potential indications of both of these techniques.

Ultrasound-guided Thoracoscopic Dental Extraction

Recurrent pneumonias in children may be from an unrecognized aspirated foreign body. Our patient was a 10-year-old neurologically impaired child with an aspirated tooth in the right lower lobe segmental bronchus that was inaccessible to extraction using flexible bronchoscopy because of its extremely distal location. We used intraoperative ultrasound during thoracoscopy to locate the foreign body, a tooth, and to facilitate a wedge resection of the involved lung. This combined approach with ultrasound and thoracoscopy can be useful in managing an aspirated foreign body that cannot be extracted from the airway using conventional rigid or flexible bronchoscopy.

Thoracoscopic resection of computed tomography-localized lung nodules in children

PURPOSE

Detection and treatment of small lung nodules are important in managing pediatric cancer. We studied the effectiveness of preoperative localization of pulmonary nodules by CT-guided needle hook wire placement followed by thoracoscopic resection in children with cancer.

METHODS

We reviewed records of patients who underwent thoracoscopic resection of lung nodules localized preoperatively with CT-guided needle and hook wire placement at our hospital between March 1999 and April 2010 for nodule characteristics and outcomes of procedure.

RESULTS

Thirty-seven patients (median age, 14years) with osteosarcoma or other cancers underwent thoracoscopic resection of needle-localized lung nodules. Lesion (median nodule size, 4mm) location was left lung (n=11), right lung (n=19), and bilateral (n=7). The procedure was successful in 36 (97.3%) patients. Five patients had a pneumothorax after localization but none required chest tube placement before thoracoscopy. All patients underwent thoracoscopy, but 4 required conversion to open thoracotomy. During thoracoscopic inspection, the hook wire slipped out of the lesion in 6 patients, of whom 1 needed thoracotomy to locate nodule. Lesions (malignant in 13 patients) were removed in all patients. Five patients with benign lesions had recurrent malignant lung nodules.

CONCLUSIONS

Thoracoscopic resection of preoperatively localized small lung nodules is a safe and effective procedure in children.

Videothoracoscopic identification of chondromatous hamartoma of the lung

Introduction

The main disadvantage of a videothoracoscopic procedure is the lack of touch sensation. The probability of easily finding the lesion is usually estimated according to computed tomography (CT).

Aim

To find useful parameters of location of chondromatous hamartoma of the lung parenchyma in relation to its size to assess the probability of successful search via a videothoracoscopic approach only.

Material and methods

A group of 55 patients operated on for chondromatous hamartoma of the lung at the First Department of Surgery in Olomouc from January 2006 to June 2011 was analyzed. Initially, the tumor's longest diameter and its nearest distance to the pleural surface were measured on CT scans. Subsequently, the surgery began using the videothoracoscopic approach. A short thoracotomy with direct palpation followed when videothoracoscopy failed.

Results

No significant differences in age, sex and side of localization between the group with and without successful videothoracoscopic detection were found. A significant difference was found in the median size (p = 0.026) and the depth of the tumor (p < 0.0001) and in the calculated index “tumor size/depth” (p < 0.0001). Deeper analysis revealed that the parameters “depth” and “index size/depth” are considered to be good predictors but the parameter “size” is not a suitable predictor.

Conclusions

The main predictors of successful videothoracoscopic detection of lung chondromatous hamartoma are considered to be the depth of the tumor in the lung parenchyma with a cut-off value ≤ 7.5 mm and the index “size/depth” with a cut-off value ≥ 1.54; the tumor size is not considered to be a good predictor.

Advances in lung cancer surgery

The last few years have witnessed an explosion of the use of minimally invasive techniques for the detection, diagnosis, and treatment of all stages of lung Cancer. The use of these techniques has improved the risk-benefit ratio of surgery and has made it more acceptable to patients considering lung surgery. They have also facilitated the delivery of multi-modality therapy to patients with advanced lung cancer. This review article summarizes current surgical techniques that represent the “cutting edge” of thoracic surgery for lung cancer.

In patients undergoing video-assisted thoracoscopic surgery excision, what is the best way to locate a subcentimetre solitary pulmonary nodule in order to achieve successful excision?

A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was 'In patients undergoing video-assisted thoracoscopic surgery (VATS) excision, what is the best way to locate a subcentimetre solitary pulmonary nodule (PN) in order to achieve successful excision?' Altogether, 107 papers were found using the reported search, of which 19 represented the best evidence to answer the clinical question. The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results of these papers were tabulated. The hook-wire technique showed a varied success rate ranging from 58 to 97.6% and a relatively higher failure rate due to wire dislodgement. The most common complication of this method was pneumothorax. CT-guided spiral-wire localization displayed a success rate of 86% with the added advantage of providing more stability than the hook-wire technique and permitting manipulation. Radio-guided localization techniques and fluoroscopic-aided methods using contrast media displayed consistently high sensitivities with few complications. The radio-guided technique had the benefit of allowing a longer time-period between the staining of the nodule and the operation. Ultrasonography showed sensitivities ranging from 92.6 to 100%; however, it is highly operator-dependent. Finger palpation was shown to achieve suboptimal results and should be avoided. We concluded that radio-guided surgery is a preferable method. It showed high accuracy with minimal complications and operator dependence in detecting subcentimetre PNs when compared with other techniques such as ultrasonography, finger palpation, fluoroscopic, hook-wire, spiral-wire and microcoil localization.

Need for preoperative computed tomography-guided localization in video-assisted thoracoscopic surgery pulmonary resections of metastatic pulmonary nodules

BACKGROUND

Preoperative localization of pulmonary nodules is sometimes necessary when they are too small or distant from the surface of the visceral pleura to be detected during video-assisted thoracoscopic surgery. This study aims to present the criteria for localization and to evaluate the accuracy of the criteria.

METHODS

From April 2001 to March 2008, 178 patients with 224 nodules who underwent wedge resection of pulmonary metastatic nodules by video-assisted thoracoscopic surgery were reviewed retrospectively. Thirty-one patients (17.4%) including 35 nodules underwent thoracoscopic resection immediately after computed tomography-guided localization using hook wires. Criteria for preoperative localization were (1) maximum diameter of the nodule of 5 mm or less, (2) maximum diameter to minimum distance between the visceral pleura and inferior border of nodule of 0.5 or less, and (3) nodule with low-density image by computed tomography after chemotherapy. The accuracy of these inclusion criteria was statistically evaluated.

RESULTS

All 224 nodules were removed by wedge resection or additional segmentectomy. Nineteen nodules (54.3%) were detected in the thoracic cavity with preoperative localization. Sensitivity, specificity, positive predictive value, and negative predictive value were 11.1%, 99.5%, 66.7%, and 92.8%; 88.9%, 93.2%, 53.3%, and 99.0%; and 88.9%, 90.8%, 45.7%, and 98.9% in each preoperative finding of which a nodule met all (3 nodules), two or more (30 nodules), and one or more (35 nodules) of the three criteria, respectively.

CONCLUSIONS

This study suggests that preoperative localization should be considered before video-assisted thoracoscopic surgery operation if the pulmonary nodule meets two or more of our criteria.

Intraoperative ultrasonographic localization of pulmonary ground-glass opacities

OBJECTIVES

Ground-glass opacities are typically difficult to inspect and to palpate during video-assisted thoracic surgery. We therefore examined whether ultrasonographic assessments could localize ground-glass opacities and help to achieve adequate resection margins.

METHODS

An intraoperative ultrasonographic procedure was prospectively performed on 44 patients harboring ground-glass opacities of less than 20 mm in diameter to localize these lesions and to achieve adequate margins. We also examined whether there were any complications resulting from the intraoperative ultrasonogram, such as lung injury, heart injury, or arrhythmia. We excluded patients with both asthma and chronic obstructive pulmonary disease from this study inasmuch as the intraoperative ultrasonographic procedure is more difficult to interpret when residual air is present in the lung.

RESULTS

A total of 53 ground-glass opacities were successfully identified by intraoperative ultrasonography without any complications. Of the 20 mixed ground-glass opacities that we examined, 15 were found on palpation. However, only 4 (12.1%) of the 33 pure ground-glass opacities could be palpated. In all instances in which complete collapse of the lung was achieved (30/53 of these cases), high-quality echo images were obtained. Additionally, a strong correlation was found between the resection margins measured by ultrasonogram and the margins determined by histologic examination in the resected lung specimens (r(2) = 0.954, P < .001).

CONCLUSIONS

Intraoperative ultrasonography can both safely and effectively localize pulmonary ground-glass opacities in a completely deflated lung. This procedure is also useful for the evaluation of surgical margins in a resected lung. Hence, ultrasonography may assist surgeons to perform minimally invasive lung resections with clear surgical margins during the treatment of solitary lung ground-glass opacity.

Minimally invasive thoracoscopic ultrasound for localization of pulmonary nodules in children

PURPOSE

Children with cancer may develop lesions in the lung that may represent metastatic disease. Thoracotomy is considered the standard approach for resection of pulmonary nodules. Recently, thoracoscopic techniques have been applied in these situations. However, nodules that are deep in the lung parenchyma may not be visible. A technique has been developed whereby minimally invasive thoracoscopic ultrasound (MITUS) may be used to guide resection of deep pulmonary nodules.

METHODS

We conducted a retrospective review of children undergoing MITUS at our institution. Only patients with single isolated lesions were chosen to have this diagnostic procedure performed. Patients undergo single lung ventilation. Two 5-mm ports are inserted, one for the grasper and the other for the camera. One 12-mm port is inserted for the flexible 10-mm ultrasound probe and the endoscopic stapler. The patient has CO(2) insufflation to create a 5-mm Hg pneumothorax. Twenty mL/kg of normal saline is introduced into the chest cavity for acoustic coupling. The ultrasound probe is used to isolate the nodule(s), guide resection, and check margins. The specimen is removed and placed in a removable specimen bag to reduce the chance of port site recurrence. After the lung has been inspected, irrigation is removed, and a chest tube inserted.

RESULTS

Eight procedures were performed on 7 patients (5 males, 2 females) with a median age of 15.2 years (range, 4-18 years). Patients had primary diagnoses of osteosarcoma (n = 4), Wilms' (n = 2), and lymphoma (n = 1). The median size of the lesions that were being isolated was 0.6 cm (range, 0.3-2.9 cm). None of the nodules removed were visible on the surface of the lung. Of the 8 procedures, 7 led to the removal of a pulmonary nodule. Of the 7 nodules isolated, 5 were removed thoracoscopically, with two requiring minithoracotomy because of anatomical limitations. The histologic evaluation on these specimens included osteosarcoma (n = 4), abscesses (n = 2), fibrosis (n = 1), and lymph node (n = 1). The median hospitalization was 2.5 days (range, 2-39 days). One patient had a prolonged hospitalization because of air leak and sepsis.

CONCLUSION

Minimally invasive thoracoscopic ultrasound is a real time imaging tool that helps isolate small pulmonary lesions that may otherwise be difficult to see intraoperatively. We would advocate this technique for those patients having video-assisted thoracoscopy to assist clarifying whether focal lesions are malignant, thereby guiding therapy.

Video assisted thoracic surgery in children

Thoracoscopic surgery, i.e., video assisted thoracic surgery (VATS) has been in use in children for last 98 years. Its use initially was restricted to the diagnostic purposes. However, with the improvement in the optics, better understanding of the physiology with CO2 insufflation, better capabilities in achieving the single lung ventilation and newer vessel sealing devices have rapidly expanded the spectrum of the indication of VATS. At present many complex lung resections, excision of mediastinal tumors are performed by VATS in the experienced centre. The VATS has become the standard of care in empyema, lung biopsy, Mediastinal Lymphnode biopsy, repair of diaphragmatic hernia, etc. The article discusses the indications of VATS, techniques to achieve the selective ventilation and surgical steps in the different surgical conditions in children.

Intrathoracoscopic localization techniques

BACKGROUND

Several techniques for localizing pulmonary nodules have been described, but the advantages and disadvantages of each method remain unclear. We reviewed ultrasound, endofinger, finger palpation and wait and watch, radioguided, vital dye, fluoroscopic, agar marking, and needle wire methods for localizing pulmonary nodules.

METHODS

Original, peer-reviewed, and full-length articles in English were searched with PubMed and ISI Web of Sciences. Case reports and case series with less than 10 patients were excluded.

RESULTS

All localization techniques showed good reliability, but some carry a high rate of major or minor complications and drawbacks.

CONCLUSION

No ideal localization technique is available; thus, the choice still depends on surgeon's preference and local availability of both specialists and instruments.

Transthoracic Endosonography for the Intraoperative Localization of Lung Nodules

BACKGROUND

Transthoracic ultrasonography has been advocated for the localization of lung nodules during video-assisted thoracoscopic surgery (VATS) for nonperipheral nodules.

METHODS

Video-assisted thoracoscopic surgery for lung nodules was performed in 54 consecutive patients. Preoperative computed tomography (CT) diagnosed 65 lesions. Positron emission tomography (PET) identified 2 lesions not revealed by CT. All nodules were judged whether visible and/or palpable. Diameter and distance of the nodule from the anterior, lateral, and posterior chest wall were measured on CT scan and served in a discriminant analysis to predict which nodule would be neither visible nor palpable. The deflectable multifrequency (7.5 to 10 MHz) endosonography probe was used to identify the nonvisible and nonpalpable nodules.

RESULTS

Resected nodules were 69; 67 diagnosed preoperatively, and 2 intraoperatively by ultrasonography. At VATS exploration 16 of 65 (25%) of the CT diagnosed nodules were nonvisible and nonpalpable. The discriminant analysis failed to predict correctly whether nodules would be visible and/or palpable in 33% because of surrounding severe emphysema, proximity to a fissure, or to the hylum. The endosonography identified 15 out of 16 of the nonvisible and nonpalpable nodules, thus conversion to thoracotomy was necessary for one nodule. The combination of video, palpatory, and endosonographic inspections had 98% sensitivity and 100% specificity in localizing the nodules.

CONCLUSIONS

Intraoperative transthoracic ultrasonography is useful to guide VATS resection of lung nodules. It is a bedside tool, not requiring planning and coordination with the interventional radiology suite, thus you use it if you need it. It has no related morbidity, and may also have a role in revealing lesions occult at preoperative work-up.

An animal model for ultrasound lung imaging

In the past decade, a number of clinical investigators have used ultrasound (US) to image the lung during video-assisted thoracoscopic surgery (VATS). In contrast, animal studies have shown prohibitively high attenuation levels in the lung, incompatible with the ability to image the lung. We hypothesized that the use of anesthesia during VATS augments lung collapse upon exposure to atmospheric pressure; thus, making US lung imaging possible. To test this hypothesis, we compared the effect of two commonly used anesthetic protocols on our ability to image 200 microL of US gel injected in rabbit lungs using a pulse echo transducer at 13 MHz. The anesthetic protocol, using acepromazine, ketamine and isoflurane, allowed US lung imaging in rabbits. It is concluded that US at 13 MHz can detect 200 microL of US gel injected into the lung parenchyma in a rabbit model.