Uniportal Video-Assisted Thoracoscopic Segmentectomy for Early-Stage Non-Small Cell Lung Cancer: Overview, Indications, and Techniques

Twenty years have passed since uniportal video-assisted thoracoscopic surgery (VATS) was first reported. Several reports have already proven the minimal invasiveness of uniportal VATS. In addition, two large clinical trials recently demonstrated the benefits of segmentectomy for small peripheral early-stage non-small cell lung cancer. Uniportal VATS segmentectomy is considered the most beneficial minimally invasive surgery for patients with early-stage lung cancer. However, a high level of skill and experience are required to achieve this goal. Only a few reports have discussed specific techniques, particularly for complex segmentectomies. In this Special Issue, we reviewed previous reports on uniportal VATS segmentectomy regarding the indications, instrument selection, marking of the tumor location, methods of intersegmental plane identification, and lymph node dissection, including our own techniques with video content.

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.

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.

Ultrasound location of ground-glass opacity during thoracoscopic surgery

OBJECTIVES

Application of video-assisted thoracoscopy brought lung surgery into the minimally invasive era; the lack of tactile feedback using VATS, remains a disadvantage because surgeons are unable to locate lesions with a finger or device. This study aimed to investigate the effectiveness, the applicability and the utility of intraoperative ultrasound (IU), for the localization of small ground-glass opacity (GGO) lesions in the parenchyma, as a guide in finding their margins in a deflated lung.

MATERIALS AND METHODS

We included 15 consecutive patients undergoing diagnostic resection of GGOs via VATS in the Thoracic Surgery Unit of the University of 'Luigi Vanvitelli' of Naples from November 2019 to December 2021. They were under general anaesthesia, when the lung had been collapsed, the probe was placed in the region where the target lesion was thought to reside on the basis of low-dose computed tomography scanning. GGO could be identified their sizes, echo levels and posterior echo was recorded by IU when the lung was completely deflated.

RESULTS

We conducted a retrospective single-centre study. All GGOs were identified by IU. The mean size and depth were 14.1 ± 0.5 and 4.8 ± 0.3 mm, respectively. Six (40%) lesions had hyperechoic patterns, 9 (60%) had mixed echogenicity where the hyperechoic patterns were irregularly mixed with hypoechoic patterns. The final diagnoses included 2 (15%) atypical adenomatous hyperplasia; 2 (15%) adenocarcinomas in situ; 3 (23%) minimally invasive adenocarcinomas and 6 (46%) invasive adenocarcinomas.

CONCLUSIONS

The results of our study showed that IU could safely and effectively detect GGOs.

Missing lung nodule? Intra-operative contingency plan with O-arm imaging: a case report

Despite the availability of various modalities to locate small non-palpable pulmonary nodules during minimally invasive thoracoscopic surgery, precise lung nodule resection remains a challenge. Pre-operative localization techniques add additional time, expense, and complication rate. Intra-operative localization methods, such as ultrasound, may be a real-time solution, but challenges remain with visualizing deep parenchyma lesions and operator-dependent use. Many thoracoscopic wedge resections are performed using a combination of pre-operative imaging and intra-operative landmarks. Although usually cost and time-efficient, the problem occurs when a wedge resection is performed, and the nodule is not within the specimen. This case report describes the use of the O-arm Surgical Imaging System, a full-rotation imaging system that provides three-dimensional cone-beam imaging, in an 81-year-old male patient with a solid 8 mm left lower lobe lung nodule. After two unsuccessful wedge resections, we used the O-arm and finally resected the nodule with a negative surgical margin. The O-arm provided instant feedback regarding the nodule status, allowing a standard thoracoscopy room to function as a hybrid operating room without the need to reposition the patient. Rather than convert to a thoracotomy, proceed to a larger resection, or experience a missed nodule, the O-arm proved to be a helpful intra-operative tool to find a missing lung nodule.

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.

Simultaneous preoperative computed tomography-guided microcoil localizations of multiple pulmonary nodules

OBJECTIVES

To evaluate retrospectively the feasibility and safety of simultaneous multiple microcoil localizations of multiple pulmonary nodules prior to video-assisted thoracoscopic surgery (VATS).

METHODS

This retrospective cohort study enrolled 288 consecutive patients, who underwent computed tomography (CT)-guided microcoil localization and subsequent VATS at our academic hospital between July 2017 and June 2018. Of these patients, 36 with 79 pulmonary nodules undergoing simultaneous multiple microcoil localizations in the ipsilateral lung were designated the multiple localization group; the remaining 252 with 252 pulmonary nodules undergoing single microcoil localization were designated the single localization group. The main outcomes were the technical success and complication rates of the localization procedures. The Student t test and Mann-Whitney U test were used for continuous variables. The chi-squared test and logistic regression analysis were used to assess dichotomous variables.

RESULTS

The localization technical success rates of the multiple and single localization groups were 96.2% (76/79) and 98.0% (247/252), respectively (p = 0.326). The rate of any complication (pneumothorax or pulmonary hemorrhage) was significantly higher in the multiple localization than in the single localization group (55.6% vs 21.8%, respectively; p < 0.001). The incidence of pneumothorax was significantly higher in the multiple localization than in the single localization group (p < 0.001). The difference between the incidence of pulmonary hemorrhage in the 2 groups was not significant (p = 0.385).

CONCLUSIONS

Although preoperative CT-guided simultaneous microcoil localizations of multiple pulmonary nodules produced a significantly higher incidence of pneumothorax, the localizations were clinically feasible and safe.

KEY POINTS

• Simultaneous preoperative CT-guided microcoil localizations of multiple pulmonary nodules are clinically feasible and safe. • Simultaneous microcoil localizations of multiple pulmonary nodules produced a significantly higher incidence of pneumothorax.

A hybrid, image-based and biomechanics-based registration approach to markerless intraoperative nodule localization during video-assisted thoracoscopic surgery

The resection of small, low-dense or deep lung nodules during video-assisted thoracoscopic surgery (VATS) is surgically challenging. Nodule localization methods in clinical practice typically rely on the preoperative placement of markers, which may lead to clinical complications. We propose a markerless lung nodule localization framework for VATS based on a hybrid method combining intraoperative cone-beam CT (CBCT) imaging, free-form deformation image registration, and a poroelastic lung model with allowance for air evacuation. The difficult problem of estimating intraoperative lung deformations is decomposed into two more tractable sub-problems: (i) estimating the deformation due the change of patient pose from preoperative CT (supine) to intraoperative CBCT (lateral decubitus); and (ii) estimating the pneumothorax deformation, i.e. a collapse of the lung within the thoracic cage. We were able to demonstrate the feasibility of our localization framework with a retrospective validation study on 5 VATS clinical cases. Average initial errors in the range of 22 to 38 mm were reduced to the range of 4 to 14 mm, corresponding to an error correction in the range of 63 to 85%. To our knowledge, this is the first markerless lung deformation compensation method dedicated to VATS and validated on actual clinical data.

The application value of computed tomography in combination with intraoperative noninvasive percutaneous ultrasonic localisation of subpleural pulmonary nodules/ground-glass opacity in uniportal video-assisted thoracoscopy

Introduction

This study investigates the application value of preoperative noninvasive computed tomography (CT) localisation, combined with intraoperative percutaneous ultrasonic localisation, in the precise positioning and excision of subpleural pulmonary nodules/ground-glass opacity in uniportal video-assisted thoracoscopic surgery (U-VATS).

Aim

To derive the precise positioning and excision of subpleural pulmonary nodules by CT combined with intraoperative percutaneous ultrasonic localisation and to avoid the complications caused by preoperative CT-guided puncture localisation, reduce physiological and psychological stress such as anxiety, CT radiation dose, and treatment cost, and to improve the treatment satisfaction of patients.

Material and methods

A total of 54 patients with subpleural pulmonary nodules/ground-glass opacity (SPN/GGO), who were treated in our hospital from June 2017 to January 2020, were enrolled in this study. The patients were randomly divided into a treatment group (n = 23), and the nodules were scanned by high-resolution CT and marked at the shortest distance on the surface of the body prior to surgery. These pulmonary nodules were relocated by ultrasound at the original CT positioning points in the same body position following the administration of general anaesthesia. Then, the hookwire puncture location was performed under real-time guidance. For the control group (n = 31), the subpleural pulmonary nodules were located by CT-guided puncture and embedding a hookwire prior to surgery. Pulmonary wedge resection was performed by U-VATS in each group. The subpleural nodules were confirmed by the naked eye and rapid pathological diagnosis after surgery. The difference in positioning success rate, positioning time, the incidence of complications, and patient anxiety scores for subpleural pulmonary nodules were compared and analysed between the two groups.

Results

A total of 22 cases of subpleural nodules were successfully located in the treatment group at a success rate of 95.6% (22/23). The average positioning time for CT in combination with ultrasound was 22.0 ±5.9 min. In the control group, 31 cases of subpleural pulmonary nodules were satisfactorily located at a success rate of 100% (31/31). The average positioning time of CT was 24.2 ±5.4 min. The difference in positioning success rate and positioning time was not statistically significant (p = 0.24; p = 0.15) between the two groups. The incidence of complications and SAS anxiety scores in the treatment group were lower compared with the control group. The difference was statistically significant (p = 0.002; p < 0.001).

Conclusions

Preoperative CT combined with intraoperative percutaneous real-time noninvasive ultrasonic localisation can accurately locate subpleural pulmonary nodules, with a high degree of safety and good tolerance in patients who are suitable for U-VATS.

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.

Uniportal VATS approach to sub-lobar anatomic resections: literature review and personal experience

Surgical scientific literature contains relatively little information regarding the surgical outcomes of anatomic sublobar resections performed with the uniportal video-assisted thoracoscopic surgery (U-VATS) technique. This paper attempts to evaluate the role of U-VATS segmentectomies in the landscape of a minimally invasive approach to the treatment of early stage non small cell lung cancer (NSCLC).

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.

Multicenter, prospective, observational study of a novel technique for preoperative pulmonary nodule localization

OBJECTIVES

Minimally invasive surgery provides an ideal method for pathologic diagnosis and curative intent of small pulmonary nodules (SPNs); however, the main problem with thoracoscopic resection is the difficulty in locating the nodules. The goal of this study was to determine the safety and feasibility of a new localization technique tailored for SPNs.

METHODS

A computed tomography (CT)-guided technique, which has a tri-colored suture and claw with 4 fishhook-shaped hooks, was designed to localize SPN preoperatively. Then a multicenter, prospective study was conducted to evaluate the safety and feasibility of this device. The primary endpoints included safety (asymptomatic/symptomatic pneumothorax or parenchymal hemorrhage, and unanticipated adverse effects) and success rate (precise placement and device fracture, displacement, or dislodgement). The secondary endpoints included feasibility (duration of the localization procedure and device fracture or fault) and patient comfort (pain).

RESULTS

A total of 90 SPNs were localized from 80 patients. Overall, no symptomatic complications requiring medical intervention, with the exception of asymptomatic pneumothorax (n = 7 [7.8%]) and lung hemorrhages (n = 5 [5.6%]), were observed. The device was successfully placed without dislodgment or movement in 87 of 90 lesions (96.7%). The median nodule size was 0.70 cm (range, 0.30-1.0 cm). The median duration of the procedure was 15 minutes (range, 7-36 minutes). No patient complained of notable pain during or after the procedure.

CONCLUSIONS

This new device for SPNs is safe, and has a high success rate, feasibility and good tolerance.

Uniportal VATS Coil-Assisted Resections for GGOs

Backgrounds

Although uniportal video-assisted thoracic surgery (VATS) theoretically allows the direct palpation of any zone of the lung through a small incision, sometimes it can be difficult to localize pure ground-glass opacities anyway. The aim of this study is to evaluate the usefulness and safety of preoperative computed tomography (CT)-guided microcoil localization of GGO nodules in patients undergoing uniportal VATS lung resection.

Methods

The clinical data and CT images of 30 consecutive patients (30 pulmonary nodules) who underwent preoperative CT-guided coil localization and subsequent uniportal VATS resection, from January 2017 to October 2018, were reviewed.

Results

All the CT-localization procedures have been performed with success (30/30) and the mean procedure time was 35±15 minutes. The mean size of the nodules was 15,53±6,72 mm, and the mean distance of the nodules from the pleural surface was 19,08±12,08 mm. Eleven nodules (36,7%) were pure ground-glass opacities and 19 (63,3%) were mixed ground-glass with a solid component of 50% or more. In 5 cases, the localization procedure was complicated by asymptomatic pneumothoraxes and in 1 case the pneumothorax required chest tube insertion. In any case a conversion to thoracotomy was avoided because all nodules were identified and resected through uniportal VATS.

Conclusions

Preoperative CT-guided coil localization seems to be a feasible, safe, and accurate procedure. It makes uniportal VATS an easy approach even for resecting small, deep, and impalpable nodules.

Devices for image-guided lung interventions: State-of-the-art review

Lung cancer is the leading cause of cancer-related death. According to the American Cancer Society, there were an estimated 222,500 new cases of lung cancer and 155,870 deaths from lung cancer in the United States in 2017. Accurate localization in lung interventions is one of the keys to reducing the death rate from lung cancer. In this study, a total of 217 publications from 2006 to 2017 about designs of medical devices for localization in lung interventions were screened, shortlisted, and categorized by localization principle and reviewed for functionality. Each study was analyzed for engineering characteristics and clinical significance. Research regarding interventional imaging equipment, navigation systems, and surgical devices was reviewed, and both research prototypes and commercial products were discussed. Finally, the future directions and existing challenges were summarized, including real-time intra-procedure guidance, accuracy of localization, clinical application, clinical adoptability, and clinical regulatory issues.

Comparison between the application of microcoil and hookwire for localizing pulmonary nodules

OBJECTIVES

To compare the efficacy and safety of localization of small pulmonary nodules with microcoil and hookwire prior to surgical resection.

METHODS

A total of 112 patients who underwent preoperative computed tomography (CT)-guided localization of small pulmonary nodules were enrolled in this single-center retrospective non-randomized cohort study between June 2016 and June 2017. Seventy-nine patients who underwent percutaneous localization with microcoils formed the microcoil group; the remaining 33 patients underwent percutaneous localization with hookwires (hookwire group). The primary outcomes were the success and complication rates of the procedure. Student's t test was used for continuous variables, whereas chi-square analysis and logistic regression were used for dichotomous variables.

RESULTS

Video-assisted thoracoscopic surgery (VATS) was successfully performed in all cases, without conversion to thoracotomy. The localization success rate was 94.9% (75/79) in the microcoil group and 93.9% (31/33) in the hookwire group (p = 0.836). Hookwire group (p = 0.000) and nodule location of the lower lobe (p = 0.012) were associated with an increased incidence of pneumothorax. Hookwire group (p = 0.027) and decreased nodule diameter (p = 0.024) were associated with an increased incidence of moderate to severe chest pain, as well as an increased incidence of overall complications.

CONCLUSIONS

Although the deployment of the microcoil was more complex and required more time than hookwire placement, microcoil localization was associated with fewer complications.

KEY POINTS

• CT-guided percutaneous localization using a microcoil and that using a hookwire are equally effective for localizing small pulmonary nodules prior to resection with video-assisted thoracoscopic surgery. • Lung nodule localization using a microcoil was associated with fewer complications than localization using a hookwire.

Minimally Invasive Approaches to Pediatric Solid Tumors

Over the last decade, driven in part by the favorable adult experience and a crescendoing number of case series and retrospective reports in the pediatric surgical literature, minimally invasive surgical (MIS) approaches are increasingly used as adjunctive or definitive surgical treatments for an ever-expanding list of pediatric tumors. Although most current treatment protocols lack surgical guidelines regarding the use of MIS, this growing body of MIS literature provides a framework for the development of multicenter trial groups, prospective registries, and further centralization of subspecialist services. This article highlights the current available data on MIS approaches to a variety of pediatric malignancies.

Imaging techniques for minimally invasive thoracic surgery-Korea University Guro Hospital experiences

In this paper, we described our clinical experiences with respect to image-guided thoracic surgery, including procedures involving percutaneous injection of fluorescent dye, radiotracers, and hook wires, guided by preoperative computed tomography (CT); and transbronchial injection of fluorescent dye by using electromagnetic navigational bronchoscope technology. Our recent experience with the intravenous systemic injection of fluorescent dye for the intraoperative detection of pulmonary lesions and intersegmental planes are also described in this review.

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.

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.

Transthoracic needle biopsy of the lung

BACKGROUND

Image guided transthoracic needle aspiration (TTNA) is a valuable tool used for the diagnosis of countless thoracic diseases. Computed tomography (CT) is the most common imaging modality used for guidance followed by ultrasound (US) for lesions abutting the pleural surface. Novel approaches using virtual CT guidance have recently been introduced. The objective of this review is to examine the current literature for TTNA biopsy of the lung focusing on diagnostic accuracy and safety.

METHODS

MEDLINE was searched from inception to October 2015 for all case series examining image guided TTNA. Articles focusing on fluoroscopic guidance as well as influence of rapid on-site evaluation (ROSE) on yield were excluded. The diagnostic accuracy, defined as the number of true positives divided by the number of biopsies done, as well as the complication rate [pneumothorax (PTX), bleeding] was examined for CT guided TTNA, US guided TTNA as well as CT guided electromagnetic navigational-TTNA (E-TTNA). Of the 490 articles recovered 75 were included in our analysis.

RESULTS

The overall pooled diagnostic accuracy for CT guided TTNA using 48 articles that met the inclusion and exclusion criteria was 92.1% (9,567/10,383). A similar yield was obtained examining ten articles using US guided TTNA of 88.7% (446/503). E-TTNA, being a new modality, only had one pilot study citing a diagnostic accuracy of 83% (19/23). Pooled PTX and hemorrhage rates were 20.5% and 2.8% respectively for CT guided TTNA. The PTX rate was lower in US guided TTNA at a pooled rate of 4.4%. E-TTNA showed a similar rate of PTX at 20% with no incidence of bleeding in a single pilot study available.

CONCLUSIONS

Image guided TTNA is a safe and accurate modality for the biopsy of lung pathology. This study found similar yield and safety profiles with the three imaging modalities examined.

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.

Radioguided video-assisted resection of non-palpable solitary pulmonary nodule/ground glass opacity: how to do it

BACKGROUND

Detection of subcentimeter solitary pulmonary nodules (SPN) and ground glass opacities (GGO) is increased but their small size may make them difficult to be reached by computerized tomography (CT) guided fine needle agobiopsy or transbronchial biopsy. Surgical resection provides the gold standard for obtaining a specimen for histopathologic diagnosis, and video-assisted thoracic surgery (VATS) allows in many cases a minimally invasive technique of resections. The limit of VATS techniques is the need of nodule localization. Often-digital palpation is all needed to identify the appropriate area of resection, but sometimes it may be very difficult to identify and remove small, deep, non-palpable lesions. The criteria for nodule marking are unclear and variety of localization methods have been developed and they are effective but burdened by significant failure rate and complications. To increase the efficacy of thoracoscopic localization/ resection of small pulmonary nodules, we used the radioguided technique.

METHODS

Under CT guidance, the nodule was identified and a needle was inserted to reach lesional or perilesional tissue. A solution of ^99mtechnetium (^99mTc) macro-aggregates albumin diluted with iodized contrast medium was injected. After injection, CT was performed to confirm precise staining.

RESULTS

At VATS, a gamma detector probe allowed localization of nodules in all patients. Resection was performed, and suture margins were checked with the probe to search for residual hyperabsorption. All specimens underwent frozen section. Frozen section revealed diagnosis in all cases.

CONCLUSIONS

Radioguided surgery is a cost-effective strategy for evaluating suspicious SPN/GGO with a success rate close to 100%, extremely low morbidity, and zero mortality. Radioguided VATS may be useful for preoperative localization of deep, small lung nodules that cannot be digitally localized or for GGO opacities that can be difficult to palpate even with the open technique.