Superselective intra-arterial hepatic injection of indocyanine green (ICG) for fluorescence image-guided segmental positive staining: experimental proof of the concept

Opportunities and challenges of indocyanine green in gastrointestinal cancers for intraoperative and nano-medicine application

The morbidity and mortality of gastrointestinal tumours remain high worldwide. Surgical resection is currently the most critical radical therapeutic schedule, while postoperative complications and sentinel lymph node (SLN) identification are closely related to the outcome. Indocyanine green (ICG)-mediated fluorescence imaging is increasingly being used in gastrointestinal surgery. It has been embraced by various surgical disciplines as a potential method to improve lymph node detection and enhance surgical field visualization. ICG can passively concentrate in SLN because of enhanced permeation and retention effects. After excitation by near-infrared light devices, SLN can display higher intensity fluorescence, helping visualization for better lymph node dissection. In addition, visual assessment of intestinal blood flow through ICG may reduce the incidence of anastomotic leakage. Although it has good clinical application, ICG-imaging still faces some problems, such as a higher false-negative rate, poorly targeted biodistribution, and lower fluorescence contrast, due to the lack of active tumour targeting. Thus, different ICG-coupled nanoparticles with inherent characteristics or functional modification-enhanced SLN identification features for gastrointestinal cancers bring benefit through active tumour targeting, superior tumour-background ratio, and high resolution. Nano-ICG combined with potential substances, including enhanced imaging contrast and/or combination therapy (chemotherapy, targeted therapy, immunotherapy, etc.), have been packaged and accumulated in the tumour area through active targeting for multimodal imaging and treatment. In this review, we outline the intraoperative application and possible future nanodirections of ICG in gastrointestinal cancer. The prospects and challenges of nano-ICG diagnostic and therapeutic methods in clinical applications are also discussed.

Graphical Abstract

Transhepatic arterial approaches for ICG injection to guide laparoscopic anatomical hepatectomy: A case series study

BACKGROUND

Laparoscopic anatomical hepatectomy guided by near-infrared fluorescence imaging (NIR-FI) has been utilized extensively. However, it is difficult to resect "cone units" above the third branch of the Glissonean pedicle in the right posterior lobe using the laparoscopic positive or negative staining techniques. Therefore, we undertook a new laparoscopic segmentectomy based on the concept of "cone unit" assisted by interventional radiology combined with NIR-FI.

METHODS

Laparoscopic segmentectomy guided by NIR-FI via super-selective hepatic arteriography and trans-arterial injection of ICG was carried out on 13 patients with early-stage HCC between September 2020 and January 2022.11 of cases were successful, and relevant pathological characteristics and perioperative outcomes were retrospectively analyzed.

RESULTS

Two cases failed NIR-FI out of which one case involved over-staining to the non-target segment, and in the other case, which was to undergo laparoscopic segment V resection, only the ventral segment was stained while the imaging of the dorsal segment failed. In the intraoperative conditions, the tumor safe margin was 1.1 (0.7-1.55) cm, the interventional operation time was 50 (45.5-60.5) minutes, the operation time was 280 (242.5-307.5) minutes, the blood loss was 100 (50-200) ml, the postoperative hospital stay was 5 (4.5-5.5) days. No cases converted to laparotomy, and no serious postoperative complications developed.

CONCLUSIONS

NIR-FI through super-selective hepatic arteriography and trans-arterial injection of ICG can provide a clear and lasting navigation aid for laparoscopic segmentectomy, which may have positive implication for early-stage HCC with poor preoperative liver reserves.

Enhancing visualization and guidance in general surgery: a comprehensive and narrative review of the current cutting-edge technologies and future perspectives

BACKGROUND

In the last decade, there has been a great effort in developing new technologies to enhance surgical visualization and guidance. This comprehensive and narrative review aimed to provide a wide and extensive overview of the current state of the art on this topic and their near-future perspectives linked to the development of artificial intelligence (AI), by focusing on the most recent and relevant literature.

METHODS

A comprehensive and narrative review of the literature was performed by searching specific terms on PubMed/MEDLINE, Scopus, and Embase databases, assessing the current state of the art on this topic.

RESULTS

Fluorescence-guided surgery, contrast-enhanced ultrasound (CEUS), ultra-high frequency ultrasound (UHFUS), photoacoustic imaging (PAI), and augmented reality (AR) are boosting the field of image-guided techniques as the rapid development of AI in surgery is promising a more automated decision-making and surgical movements in the operating room.

CONCLUSION

Fluorescence-guided surgery, CEUS, UHFUS, PAI, and AR are becoming crucial to give surgeons a new level of information during the intervention, with the right timing and sequence, and represent the future of surgery. As many more controlled studies are needed to validate the employment of these technologies, the next generation of surgeons must become more familiar with the basics of AI to better incorporate new tools into the daily surgical practice of the future.

Fluorescence visualization for cancer DETECTION: EXPERIENCE and perspectives

The current review focuses on the latest advances in the improvement and application of fluorescence imaging technology. Near-infrared (NIR) fluorescence imaging is a promising new technique that uses non-specific fluorescent agents and targeted fluorescent tracers combined with a dedicated camera to better navigate and visualize tumors. Fluorescence-guided surgery (FGS) is used to perform various tasks, helping the surgeon to distinguish lymphatic vessels and nodes from surrounding tissues easily and quickly assess the perfusion of the planned resection area, including intraoperative visualization of metastases. The results of the insertion of fluorescence visualization as an auxiliary method to cancer detection and high-risk metastatic lesions in clinical practice have demonstrated enthusiastic results and huge potential. However, intraoperative fluorescence visualization must not be considered as a main diagnostic or treatment method but as an aid to the surgeon. Thus, fluorescence study does not dispense the diagnostic gold standards of benign or malignant tumors (conventional examination, biopsy, ultrasonography and computed tomography, etc.) and can be done usually during intraoperative treatment. Moreover, as fluorescence surgery and fluorescence diagnostic techniques continue to improve, it is likely that they will evolve towards targeted fluorescence imaging probes that will increasingly target a specific type of cancer cell. The most important point remains the search for highly selective messengers of fluorescent labels, which make it possible to identify tumor cells exclusively in the affected organs and indicate to surgeons the boundaries of their spread and metastasis.

Preliminary exploration of hepatic parenchymal near-infrared fluorescence imaging technique via retrograde biliary approach: a feasibility study (with video)

This paper explores the feasibility and principle of hepatic parenteral fluorescence imaging technology after retrograde injection of indocyanine green (ICG) through endoscopic nasobiliary drainage (ENBD). The data were collected from 53 patients with cholecystolithiasis and choledocholithiasis, from October 2022 to March 2023, diagnosed by fluorescence imaging technique retrograde biliary approach (FIT-RB). We divided the patients into two groups according to the features of liver parenchyma, the poor group (n = 34, including scattered or no imaging) and the good group (n = 19, regular uniform imaging). We compared and analyzed the perioperative results of the two groups and explored the influencing factors of the success of FIT-RB and the ICG concentration suitable for this imaging technique. The good imaging rate of the 53 enrolled cases was 35.8%. The bilirubin level before ENBD and laparoscopic cholecystectomy in the poor group was significantly higher than that in the good group (P < 0.001). The proportion of higher ICG concentrations (0.5 mg/mL) was significantly higher in the good group (P = 0.028). Our results demonstrated that the success rate of good imaging was 4.53 times higher than that of low-dose ICG (0.125 or 0.25 mg/L) cases at 0.5 mg/ml of ICG. The level of total bilirubin and direct bilirubin were negatively correlated with the imaging effect, and total bilirubin and direct bilirubin levels were important predictors of the efficacy of FIT-RB. FIT-RB is safe and feasible in patients with low site bilirubin levels. An ICG concentration of 0.5 mg/ml may be ideal for implementing this technique.

Trans-arterial positive ICG staining-guided laparoscopic liver watershed resection for hepatocellular carcinoma

Introduction

Anatomical liver resection is the optimal treatment for patients with resectable hepatocellular carcinoma (HCC). Laparoscopic Couinaud liver segment resection could be performed easily as liver segments could be stained by ultrasound-guided indocyanine green (ICG) injection into the corresponding segment portal vein. Several smaller liver anatomical units (liver watersheds) have been identified (such as S8v, S8d, S4a, and S4b). However, since portal veins of liver watersheds are too thin to be identified under ultrasound, the boundaries of these liver watersheds could not be stained intraoperatively, making laparoscopic resection of these liver watersheds demanding. Digital subtraction angiography (DSA) could identify arteries of liver watersheds with a diameter of less than 2 mm. Yet, its usage for liver watershed staining has not been explored so far.

Purpose

The aim of this study is to explore the possibility of positive liver watershed staining via trans-arterial ICG injection under DSA examination for navigating laparoscopic watershed-oriented hepatic resection.

Methods

We describe, in a step-by-step approach, the application of trans-arterial ICG injection to stain aimed liver watershed during laparoscopic anatomical hepatectomy. The efficiency and safety of the technique are illustrated and discussed in comparison with the laparoscopic anatomical liver resection via ultrasound-guided liver segment staining.

Results

Eight of 10 HCC patients received successful trans-arterial liver watershed staining. The success rate of the trans-artery staining approach was 80%, higher than that of the ultrasound-guided portal vein staining approach (60%). Longer surgical duration was found in patients who underwent the trans-artery staining approach (305.3 ± 23.2 min vs. 268.4 ± 34.7 min in patients who underwent the ultrasound-guided portal vein staining approach, p = 0.004). No significant difference was found in major morbidity, reoperation rate, hospital stay duration, and 30-day and 90-day mortality between the 2 groups.

Conclusions

Trans-arterial ICG staining is safe and feasible for staining the aimed liver watershed, navigating watershed-oriented hepatic resection under fluorescence laparoscopy for surgeons.

Super-Selective Intra-Arterial Indocyanine Green Administration for Near-Infrared Fluorescence-Based Positive Staining of Hepatic Segmentation: A Feasibility Study

BACKGROUND

Despite the increasing number of laparoscopic hepatic procedures for the resection of hepatocellular carcinoma (HCC), intraoperative tumor localization and demarcation remains challenging in comparison to open surgery. In this study, we evaluated the feasibility of positive liver segment staining through the super-selective intra-arterial indocyanine green (ICG) administration.

METHODS

Eight patients presenting with a single HCC underwent an interventional vascular procedure followed by laparoscopic surgery. A microcatheter was advanced into the hepatic artery branches perfusing the HCC followed by digital subtraction angiography and angiography computed tomography (angio-CT). Patients were then transferred to the operating room, and a laparoscopic hepatectomy was performed under ultrasound guidance. A 5 mL bolus of ICG with a concentration of .125 mg/mL was injected through the microcatheter, and a near-infrared laparoscope was used to detect the fluorescence signal to assess the correspondence between the fluorescence-based demarcation and the intraoperative ultrasound-based demarcation.

RESULTS

The duration for the angiography procedure was 32.7 +/- 5.3 min, and it took 242 +/- 118 min from the end of angiography procedure until the start of the surgical procedure. In all cases, the fluorescent liver segment was corresponding to the angio-CT findings. In 6/8 cases, fluorescence imaging was considered helpful in the identification of the resection line. In 3 patients, the resection line was changed according to the positively stained liver segment.

CONCLUSION

We successfully demonstrated the feasibility of the super-selective intra-arterial ICG administration for fluorescence-based positive staining of hepatic segmentation during laparoscopic surgery for HCC (NCT04266548).

Laparoscopic ultrasound-guided superselective portal vein injection combined with real-time indocyanine green fluorescence imaging and navigation for accurate resection of localized intrahepatic bile duct dilatation: a case report

Background

Primary intrahepatic bile duct dilatation can be very harmful to patients although it belongs to benign biliary disease. It can occur in any part of the liver, intraoperative laparoscopic ultrasound (LUS) guidance combine with real-time indocyanine green (ICG) fluorescence navigation are the means of choice for accurate surgical resection.

Case presentation

Herein we reported a 43-year-old female patient presented with repeated right upper abdominal pain and distension for 3 years and aggravated for half a year, without fever and jaundice. A diagnosis of localized bile duct dilatation with lithiasis in segment 4 (S4) was made on the basis of preoperative imaging. Correspondingly, we selected to perform a laparoscopic surgery with LUS guided real time ICG fluorescence imaging (ICG-FI) and navigation to make the operation more simply and accurately, as well as to retain normal tissues in a certain extent. Laparoscopic resection of S4b and partial S4a was successfully performed, without any complications.

Conclusion

Laparoscopic anatomical surgery for intrahepatic bile duct dilatation is a technically challenging operation. The combined use of preoperative three-dimensional computerized tomography (CT) planning, intraoperative LUS guided super-selection, ICG hepatic segment staining and real-time fluorescence navigation could help surgeons accurately complete the segmentectomy or subsegmentectomy with minimized trauma and maximized liver tissue preservation.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12893-021-01325-w.

Laparoscopic intraarterial catheterization with selective ICG fluorescence imaging in colorectal surgery

The quality of mesorectal resection is crucial for resection in rectal cancer, which should be performed by laparoscopy for better outcome. The use of indocyanine green (ICG) fluorescence is now routinely used in some centers to evaluate bowel perfusion. Previous studies have demonstrated in animal models that selective intra-arterial ICG staining can be used to define and visualize resection margins in rectal cancer. In this animal study, we investigate if laparoscopic intra-arterial catheterization is feasible and the staining of resection margins when performing total mesorectal excision with a laparoscopic medial to lateral approach is possible. In 4 pigs, laparoscopic catheterization of the inferior mesenteric artery (IMA) is performed using a seldinger technique. After a bolus injection of 10 ml ICG with a concentration of 0.25 mg/ml, a continuous intra-arterial perfusion was established at a rate of 2 ml/min. The quality of the staining was evaluated qualitatively. Laparoscopic catheterization was possible in all cases, and the average time for this was 30.25 ± 3.54 min. We observed a significant fluorescent signal in all areas of the IMA supplied, but not in other parts of the abdominal cavity or organs. In addition, the mesorectum showed a sharp border between stained and unstained tissue. Intraoperative isolated fluorescence augmentation of the rectum, including the mesorectum by laparoscopic catheterization, is feasible. Inferior mesenteric artery catheterization and ICG perfusion can provide a fluorescence-guided roadmap to identify the correct plane in total mesorectal excision, which should be investigated in further studies.

Evaluation of Near-infrared Fluorescence-conjugated Peptides for Visualization of Human Epidermal Receptor 2-overexpressed Gastric Cancer

Purpose

A near-infrared (NIR) fluorescence imaging is a promising tool for cancer-specific image guided surgery. Human epidermal receptor 2 (HER2) is one of the candidate markers for gastric cancer. In this study, we aimed to synthesize HER2-specific NIR fluorescence probes and evaluate their applicability in cancer-specific image-guided surgeries using an animal model.

Materials and Methods

An NIR dye emitting light at 800 nm (IRDye800CW; Li-COR) was conjugated to trastuzumab and an HER2-specific affibody using a click mechanism. HER2 affinity was assessed using surface plasmon resonance. Gastric cancer cell lines (NCI-N87 and SNU-601) were subcutaneously implanted into female BALB/c nu (6–8 weeks old) mice. After intravenous injection of the probes, biodistribution and fluorescence signal intensity were measured using Lumina II (Perkin Elmer) and a laparoscopic NIR camera (InTheSmart).

Results

Trastuzumab-IRDye800CW exhibited high affinity for HER2 (K_D=2.093(3) pM). Fluorescence signals in the liver and spleen were the highest at 24 hours post injection, while the signal in HER2-positive tumor cells increased until 72 hours, as assessed using the Lumina II system. The signal corresponding to the tumor was visually identified and clearly differentiated from the liver after 72 hours using a laparoscopic NIR camera. Affibody-IRDye800CW also exhibited high affinity for HER2 (K_D=4.71 nM); however, the signal was not identified in the tumor, probably owing to rapid renal clearance.

Conclusions

Trastuzumab-IRDye800CW may be used as a potential NIR probe that can be injected 2–3 days before surgery to obtain high HER2-specific signal and contrast. Affibody-based NIR probes may require modifications to enhance mobilization to the tumor site.

Indocyanine green staining for intraoperative perfusion assessment

Indocyanine green (ICG) is a fluorescent iodide-based dye which is used in hepatic surgery to evaluate the biliary tree, liver perfusion, and function. While liver perfusion assessment and delineation of anatomic regions has been performed using ultrasound, ischemic demarcation, or indigo carmine/methylene blue staining, ICG staining can overcome limitations associated with these techniques, such as rapid washout, lack of precision, non-demarcation in damaged livers, and lack of intraparenchymal fidelity. ICG can be used to fluoresce target segments/tumors (Positive staining) or counterstain normal liver tissue leaving areas of interest unstained (negative staining). Moreover, ICG enhancement patterns vary for different tumors, such as colorectal liver metastases vs. hepatocellular carcinoma, providing not only help with detection but also assessment of differentiation. In the field of oncology, benefits of ICG include detection of small radiographically occult tumors, distinction between cirrhotic nodules and cancer, identification of necrotic tumors in chemotherapy-damaged livers, and determining margins when intraoperative ultrasound is inadequate. While ICG has important and expanding indications in hepatic surgery, limitations include small depth of penetrance, need for special monitors/equipment, and potential for dye spillage. ICG is well tolerated, has a small learning curve, minimally invasive surgical integration, and options of both portal vein and peripheral vein injection and hence is a safe and versatile method of anatomic liver mapping, tumor visualization, and liver graft perfusion evaluation in oncologic surgery and liver transplantation. Advancements in technique and technology associated with ICG will aid in increasing the indications in hepato-biliary surgery.

Application of Indocyanine Green Fluorescence as an Adjuvant to Laparoscopic Ultrasound in Minimally Invasive Liver Resection

Background: Indocyanine green (ICG) fluorescence imaging has been extensively used in a variety of applications in visceral surgery. In minimally invasive liver resections, the detection of small superficial hepatic lesions using an intravenous injection of ICG before surgery represents a promising application. Methods: We analyzed 18 consecutive patients who underwent laparoscopic liver resection for superficial malignant tumors, namely 11 patients with hepatocellular carcinoma (HCC), 5 patients with colorectal liver metastases (CRLM), 1 patient with intrahepatic cholangiocarcinoma (ICC), and 1 patient with thyroid cancer metastasis, using ICG fluorescence as an adjuvant tool to intraoperative laparoscopic ultrasound (LUS). Results: An optimal ICG 15-minute clearance retention rate (R15 < 10%) and ICG plasma disappearance rate (<18%/minute) were present in 11 patients (61.1%) and in 14 patients (77.7%), respectively. Liver tumors were 29 in total, including 14 HCCs (48.3%), 13 CRLMs (44.8%), 1 ICC (3.4%), and 1 thyroid cancer metastasis (3.4%). Twenty-nine tumors (100%) were correctly visualized with ICG/fluorescence, as compared with 21 tumors identified with LUS (72.4%). After complete liver mobilization, ICG staining allowed to identify more superficial lesions (early HCC and small CRLM) in posterolateral segments (Segments 6 and 7) as compared with LUS (14 versus 10 lesions). In addition, in segments usually treated laparoscopically (e.g., left lateral segments), ICG was superior to LUS (10 versus 6 lesions) to identify superficial early HCC in patients with macronodular cirrhosis. Conclusions: ICG visual feedback might substitute the tactile feedback of the hand and might in some cases act as a "booster" of LUS for superficial hepatic lesions.

Demarcation Line Assessment in Anatomical Liver Resection: An Overview

Anatomical liver resection (ALR) is the preferred oncological approach for the treatment of primary liver malignancies, such as hepatocellular carcinoma and intrahepatic cholangiocarcinoma. The demarcation line (DL) is formed by means of selective vascular occlusion and is used by surgeons to guide ALR. Emerging intraoperative technologies are playing a major role to enhance the surgeon's vision and ensure a precise oncologic surgery. In this article, a brief overview of modalities to assess the DL during ALRs is presented, from the established conventional techniques to future perspectives.

Laparoscopic anatomical liver resection using indocyanine green fluorescence imaging

BACKGROUND

Anatomical liver resections guided by a demarcation line after portal staining or inflow clamping of the target area have been established as essential methods for curative treatment of hepatocellular carcinoma (HCC) and have subsequently been applied to other malignancies. However, laparoscopic anatomical liver resection (LALR) procedures are very difficult to reproduce, and the confirmation of demarcation of the hepatic segment on a monitor is also challenging. Recently, indocyanine green (ICG) fluorescence imaging has been used to identify hepatic tumors and segmental boundaries during hepatectomy. Herein, we describe LALR using ICG fluorescence imaging.

METHODS

Three patients underwent pure LALR using ICG fluorescence imaging at our institute. One patient underwent anatomical partial liver resection for HCC, another underwent segmentectomy 3 for metastatic liver cancer, and the third underwent right anterior sectionectomy for HCC. To visualize hepatic perfusion and the demarcation line by negative staining using an optical imaging system, 2.5 mg ICG was injected intravenously during surgery following clamping or closure of the proximal Glissonean pedicles.

RESULTS

For all three cases, ICG fluorescent imaging clearly delineated the demarcation lines and allowed identification of intersegmental planes to some extent because the tumor-bearing hepatic region became non-fluorescing parenchyma during parenchymal transection. This allowed surgeons to recognize the direction and guide the transection of the liver parenchyma when performing LALR.

CONCLUSION

LALR using ICG fluorescence imaging is a feasible procedure for resection of the tumor-bearing hepatic region and facilitates visualization of the demarcation line and identification of the boundaries of the hepatic sections.

Indocyanine green-based fluorescence imaging in visceral and hepatobiliary and pancreatic surgery: State of the art and future directions

In recent years, the use of fluorescence-guided surgery (FGS) to treat benign and malignant visceral, hepatobiliary and pancreatic neoplasms has significantly increased. FGS relies on the fluorescence signal emitted by injected substances (fluorophores) after being illuminated by ad hoc laser sources to help guide the surgical procedure and provide the surgeon with real-time visualization of the fluorescent structures of interest that would be otherwise invisible. This review surveys and discusses the most common and emerging clinical applications of indocyanine green (ICG)-based fluorescence in visceral, hepatobiliary and pancreatic surgery. The analysis, findings, and discussion presented here rely on the authors' significant experience with this technique in their medical institutions, an up-to-date review of the most relevant articles published on this topic between 2014 and 2018, and lengthy discussions with key opinion leaders in the field during recent conferences and congresses. For each application, the benefits and limitations of this technique, as well as applicable future directions, are described. The imaging of fluorescence emitted by ICG is a simple, fast, relatively inexpensive, and harmless tool with numerous different applications in surgery for both neoplasms and benign pathologies of the visceral and hepatobiliary systems. The ever-increasing availability of visual systems that can utilize this tool will transform some of these applications into the standard of care in the near future. Further studies are needed to evaluate the strengths and weaknesses of each application of ICG-based fluorescence imaging in abdominal surgery.

Enhanced Visualization: From Intraoperative Tissue Differentiation to Augmented Reality

Background

Optimal visualization of the operative field and methods that additionally provide supportive optical information form the basis for target-directed and successful surgery. This article strives to give an overview of current enhanced visualization techniques in visceral surgery and to highlight future developments.

Methods

The article was written as a comprehensive review on this topic and is based on a MEDLINE search and ongoing research from our own group and from other working groups.

Results

Various techniques for enhanced visualization are described comprising augmented reality, unspecific and targeted staining methods, and optical modalities such as narrow-band imaging. All facilitate our surgical performance; however, due to missing randomized controlled studies for most of the innovations reported on, the available evidence is low.

Conclusion

Many new visualization technologies are emerging with the aim to improve our perception of the surgical field leading to less invasive, target-oriented, and elegant treatment forms that are of significant benefit to our patients.

Indocyanine green fluorescence imaging techniques and interventional radiology during laparoscopic anatomical liver resection (with video)

BACKGROUND

To accomplish laparoscopic anatomical liver resection, intraoperative liver segmentation is necessary. Tattooing method or Glissonian approach will be used in a similar way to that in open liver resection. Moreover, in liver segment detection, the fluorescence of indocyanine green (ICG) means it has been recognized as a useful dye. In laparoscopy, however, there are technical difficulties in performing these conventional methods, so development of new techniques is necessary for liver segment identification. We report a pilot study using interventional radiology technique for laparoscopic intraoperative liver segmentation.

METHODS

Just prior to liver parenchymal resection, angiography was performed using a hybrid operation room. A catheter was inserted from the right femoral artery into the targeted arterial branch. After confirming the perfusion area by arteriography, embolic solution containing ICG was injected, and the branch was embolized. ICG fluorescence was observed by PINPOINT, a near-infrared imaging system.

RESULTS

Immediately after embolic solution injection, we were able to observe ICG fluorescence on the surface of the liver to be resected. This visual effect continued during liver parenchymal resection. We were able to confirm the intra-parenchymal boundary by observing ICG fluorescence on the cut surface of the resecting side and accomplished precise anatomical liver resection.

CONCLUSIONS

Our novel technique provides advances in laparoscopic anatomical liver resection performance. As two-dimensional laparoscopy lacks depth perception, additional visual information, such as ICG fluorescence imagery, is helpful as a navigation tool for precise laparoscopic anatomical liver resection.

Accuracy of a new intraoperative cone beam CT imaging technique (Artis zeego II) compared to postoperative CT scan for assessment of pedicle screws placement and breaches detection

PURPOSE

The goal of this study was to compare the accuracy of a novel intraoperative cone beam computed tomography (CBCT) imaging technique with that of conventional computed tomography (CT) scans for assessment of pedicle screw placement and breach detection.

METHODS

Three hundred and forty-eight pedicle screws were inserted in 58 patients between October 2013 and March 2016. All patients had an intraoperative CBCT scan and a conventional CT scan to verify the placement of the screws. The CBCT and CT images were reviewed by two surgeons to assess the accuracy of screw placement and detect pedicle breaches using two established classification systems. Agreement on screw placement between intraoperative CBCT and postoperative CT was assessed using Kappa and Gwet's coefficients. Using CT scanning as the gold standard, the sensitivity, specificity, positive predictive value, and negative predictive value were calculated to determine the ability of CBCT imaging to accurately evaluate screw placement.

RESULTS

The Kappa coefficient was 0.78 using the Gertzbein classification and 0.80 using the Heary classification, indicating a substantial agreement between the intraoperative CBCT and postoperative CT images. Gwet's coefficient was 0.94 for both classifications, indicating almost perfect agreement. The sensitivity, specificity, positive predictive value and negative predictive value of the CBCT images were 77, 98, 86, and 96%, respectively, for the Gertzbein classification and 79, 98, 88, and 96%, respectively, for the Heary classification.

CONCLUSIONS

Intraoperative CBCT provides accurate assessment of pedicle screw placement and enables intraoperative repositioning of misplaced screws. This technique may make postoperative CT imaging unnecessary.