Three-dimensional virtual neck exploration before parathyroidectomy

Parathyroidectomy for solitary parathyroid adenoma via trans-areola single site endoscopic approach: Results of a case-match study

BACKGROUND

This study aimed to establish the standardized procedure of trans-areola single site endoscopic parathyroidectomy (TASSEP), and to compare the performance of TASSEP with that of conventional open parathyroidectomy (COP).

METHODS

This study enrolled 40 patients with primary hyperparathyroidism (PHPT) who underwent TASSEP, and included 40 of 176 PHPT patients who underwent COP based on propensity score matching. The retrospective analysis was conducted based on prospectively collected data. Perioperative outcomes, including surgical profile, surgical burden and cosmetic results and follow-up were reported. The learning curve was described using a cumulative sum (CUSUM) analysis.

RESULTS

40 TASSEPs were completed successfully without conversions or severe complications. There was no statistically significant difference in operation time between TASSEP and COP groups (80.83 ± 11.95 vs. 76.95 ± 7.30 min, p = 0.084). Experience of 17 cases was necessitated to reach the learning curve of TASSEP. Postoperative pain score and traumatic index (C-reactive protein and erythrocyte sedimentation rate) in TASSEP were apparently lower than those in COP group (p < 0.05). During the proliferation and stabilization phases, TASSEP was associated with significantly better incision recovery and cosmetic scores. Postoperative serum calcium and PTH levels throughout the follow-up period indicated satisfactory surgical qualities in both groups.

CONCLUSION

Based on precise preoperative localization and intraoperative planning facilitated by three-dimensional (3D) virtual modeling, TASSEP can be feasibly performed on selected patients with satisfactory success rates and low complication rates, providing preferable cosmetic results and alleviating the surgical burden to a certain extent.

Efficacy of High-Resolution Preoperative 3D Reconstructions for Lesion Localization in Oncological Colorectal Surgery—First Pilot Study

When planning an operation, surgeons usually rely on traditional 2D imaging. Moreover, colon neoplastic lesions are not always easy to locate macroscopically, even during surgery. A 3D virtual model may allow surgeons to localize lesions with more precision and to better visualize the anatomy. In this study, we primary analyzed and discussed the clinical impact of using such 3D models in colorectal surgery. This is a monocentric prospective observational pilot study that includes 14 consecutive patients who presented colorectal lesions with indication for surgical therapy. A staging computed tomography (CT)/magnetic resonance imaging (MRI) scan and a colonoscopy were performed on each patient. The information gained from them was provided to obtain a 3D rendering. The 2D images were shown to the surgeon performing the operation, while the 3D reconstructions were shown to a second surgeon. Both of them had to locate the lesion and describe which procedure they would have performed; we then compared their answers with one another and with the intraoperative and histopathological findings. The lesion localizations based on the 3D models were accurate in 100% of cases, in contrast to conventional 2D CT scans, which could not detect the lesion in two patients (in these cases, lesion localization was based on colonoscopy). The 3D model reconstruction allowed an excellent concordance correlation between the estimated and the actual location of the lesion, allowing the surgeon to correctly plan the procedure with excellent results. Larger clinical studies are certainly required.

Original Preoperative Localization Technique of Parathyroid Adenomas by 3-Dimensional Virtual Neck Exploration

Objective. Preoperative imaging in primary hyperparathyroidism (PHPT) is essential for planning of parathyroidectomy-particularly for selection of a minimally invasive approach. The objective of this cohort study was to evaluate the diagnostic precision of 3D virtual neck exploration (3D-VNE), to evaluate its impact on choice of surgical approach, and to document the correlation with long-term outcomes. Methods. 235 consecutive patients with PHPT were studied (January 2014 to December 2018), with 6-month follow-up. 220 patients had a preoperative computed tomography (CT), 172 of these had a 3D-VNE based on the CT, and 226 patients had a Tc-99m sestamibi scan. Results. Sensitivity of exact, per gland, adenoma localization was 57.09% (95% CI: 50.85-63.10%) for nonspecialized radiologist interpretation of CT scan, 58.17% (95% CI: 51.99-64.10%) for Tc-99m sestamibi scan, and 90.21% (95% CI: 85.21-93.64%) for 3D-VNE, and thereby favoring 3D-VNE compared to CT scan alone (OR 34.5, 95% CI: 9.19-290.56%, P < 2.2 × 10^-16) and to Tc-99m sestamibi scan (OR 16.25, 95% CI: 6.05-61.42%, P = 3.1 × 10^-15). Specificity was 87.38% for CT scan, 86.36% for 3D-VNE, and 90% for Tc-99m sestamibi scan (P > .05). The cure rate was 100%. The long-term recurrence rate (RR) was 2.978%. The RR was 1.324% in the video-assisted parathyroidectomy group of 151 patients and 5.952% in the group of 84 patients with cervicotomy (P = .0459). Conclusion. CT-based 3D-VNE proved to be the most accurate localizing study in PHPT and aided in selecting patients for targeted minimally invasive parathyroidectomy, which was associated with the lower recurrence rate. 3D-VNE could be proposed as a first-line imaging study in patients with PHPT.

Precision image-guided colonic surgery: proof of concept for enhanced preoperative and intraoperative vascular imaging

BACKGROUND

Colorectal surgery has benefited from advances in precision medicine such as total mesorectal resection, and recently, mesocolon resection, fluorescent perfusion imaging, and fluorescent node mapping. However, these advances fail to address the variable quality of mesocolon dissection and the directed extent of vascular dissection (including high ligation) or pre-resection anastomotic perfusion mapping, thereby impacting anastomotic leaks. We propose a new paradigm of precision image-directed colorectal surgery involving 3D preoperative resection modeling and intraoperative fluoroscopic and fluorescence vascular imaging which better defines optimal dissection planes and vascular vs. anatomy-based resection lines according to our hypothesis.

METHODS

Six pigs had preoperative CT with vascular 3D reconstruction allowing for the preoperative planning of vascular-based dissection. Laparoscopic surgery was performed in a hybrid operating room (OR). Superselective arterial catheterization was performed in branches of the superior mesenteric artery (SMA) or the inferior mesenteric artery (IMA). Intraoperative boluses of 0.1 mg/kg or a continuous infusion of indocyanine green (ICG) (0.01 mg/mL) were administered to guide fluorescent-based sigmoid and ileocecal resections. Fluorescence was assessed using proprietary software at several regions of interest (ROI) in the right and left colon.

RESULTS

The approach was feasible and safe. Selective catheterization took an average of 43 min. Both bolus and continuous perfusion clearly marked pre-identified vessels (arteries/veins) and the target colon segment, facilitating precise resections based on the visible vascular anatomy. Quantitative software analysis indicated the optimal resection margin for each ROI.

CONCLUSION

Intra-arterial fluorescent mapping allows visualization of major vascular structures and segmental colonic perfusion. This may help to prevent any inadvertent injury to major vascular structures and to precisely determine perfusion-based resection planes and margins. This could enable tailoring of the amount of colon resected, ensure good anastomotic perfusion, and improve oncological outcomes.

Disappearing liver metastases: A systematic review of the current evidence

Advances in systemic chemotherapy have resulted in a significant increase in the reported response rates of colorectal liver metastases (CRLM) over time. Although radiologic response is usually prognostic of favorable outcomes, complete shrinkage of CRLM after chemotherapy, namely "disappearing liver metastases" (DLMs) poses significant therapeutic dilemmas. A systematic review of the literature was conducted to evaluate the existing evidence on the imaging and management of patients with DLMs using the PubMed (Medline), Embase and Cochrane library through December 21st, 2018. The following algorithm was used: "(disappearing OR vanishing OR missing OR (residual tiny)) AND ((liver OR hepatic) AND (metastasis OR metastases OR metastatic OR secondary))." From the 225 records retrieved, 15 studies were finally deemed eligible. A total of 479 patients with DLMs with a median age of 59.5 years (range, 30-83) were identified. Median number of DLM per patient ranged from 1 to 8.8. Median size of LMs prior to chemotherapy was 1.07 cm (range 0.3-3.5). The systemic treatment used to achieve DLMs included systemic chemotherapy alone (only 2 studies) or in combination with targeted agents (11 studies). The median number of chemotherapy cycles in the included studies was 7.8 (range 6-12). Identified factors predisposing to the development of DLM were small size (<2 cm), increased number of treatment cycles, oxaliplatin-based therapy, increased number of CRLM (≥3) and synchronous CRLM. Baseline and preoperative MRI with iv contrast showed the highest sensitivity for DLM detection. Fiducial placement facilitated pre- and intra-operative identification of DLM. Although resection of DLM decreased the local recurrence risk, there was no clearly demonstrated survival benefit after resecting all sites of disappearing lesions. Future randomized clinical trials are highly encouraged to provide strict, evidence-based recommendations for the treatment of patients with DLM.

Virtual and Augmented Reality in Oncologic Liver Surgery

Virtual reality (VR) and augmented reality (AR) in complex surgery are evolving technologies enabling improved preoperative planning and intraoperative navigation. The basis of these technologies is a computer-based generation of a patient-specific 3-dimensional model from Digital Imaging and Communications in Medicine (DICOM) data. This article provides a state-of-the- art overview on the clinical use of this technology with a specific focus on hepatic surgery. Although VR and AR are still in an evolving stage with only some clinical application today, these technologies have the potential to become a key factor in improving preoperative and intraoperative decision making.

A New Software Suite in Orthognathic Surgery : Patient Specific Modeling, Simulation and Navigation

Orthognathic surgery belongs to the scope of maxillofacial surgery. It treats dentofacial deformities consisting in discrepancy between the facial bones (upper and lower jaws). Such impairment affects chewing, talking, and breathing and can ultimately result in the loss of teeth. Orthognathic surgery restores facial harmony and dental occlusion through bone cutting, repositioning, and fixation. However, in routine practice, we face the limitations of conventional tools and the lack of intraoperative assistance. These limitations occur at every step of the surgical workflow: preoperative planning, simulation, and intraoperative navigation. The aim of this research was to provide novel tools to improve simulation and navigation. We first developed a semiautomated segmentation pipeline allowing accurate and time-efficient patient-specific 3D modeling from computed tomography scans mandatory to achieve surgical planning. This step allowed an improvement of processing time by a factor of 6 compared with interactive segmentation, with a 1.5-mm distance error. Next, we developed a software to simulate the postoperative outcome on facial soft tissues. Volume meshes were processed from segmented DICOM images, and the Bullet open source mechanical engine was used together with a mass-spring model to reach a postoperative simulation accuracy <1 mm. Our toolset was completed by the development of a real-time navigation system using minimally invasive electromagnetic sensors. This navigation system featured a novel user-friendly interface based on augmented virtuality that improved surgical accuracy and operative time especially for trainee surgeons, therefore demonstrating its educational benefits. The resulting software suite could enhance operative accuracy and surgeon education for improved patient care.

Virtual Reality Exploration and Planning for Precision Colorectal Surgery

BACKGROUND

Medical software can build a digital clone of the patient with 3-dimensional reconstruction of Digital Imaging and Communication in Medicine images. The virtual clone can be manipulated (rotations, zooms, etc), and the various organs can be selectively displayed or hidden to facilitate a virtual reality preoperative surgical exploration and planning.

OBJECTIVE

We present preliminary cases showing the potential interest of virtual reality in colorectal surgery for both cases of diverticular disease and colonic neoplasms.

DESIGN

This was a single-center feasibility study.

SETTINGS

The study was conducted at a tertiary care institution.

PATIENTS

Two patients underwent a laparoscopic left hemicolectomy for diverticular disease, and 1 patient underwent a laparoscopic right hemicolectomy for cancer. The 3-dimensional virtual models were obtained from preoperative CT scans. The virtual model was used to perform preoperative exploration and planning. Intraoperatively, one of the surgeons was manipulating the virtual reality model, using the touch screen of a tablet, which was interactively displayed to the surgical team.

MAIN OUTCOME MEASURES

The main outcome was evaluation of the precision of virtual reality in colorectal surgery planning and exploration.

RESULTS

In 1 patient undergoing laparoscopic left hemicolectomy, an abnormal origin of the left colic artery beginning as an extremely short common trunk from the inferior mesenteric artery was clearly seen in the virtual reality model. This finding was missed by the radiologist on CT scan. The precise identification of this vascular variant granted a safe and adequate surgery. In the remaining cases, the virtual reality model helped to precisely estimate the vascular anatomy, providing key landmarks for a safer dissection.

LIMITATIONS

A larger sample size would be necessary to definitively assess the efficacy of virtual reality in colorectal surgery.

CONCLUSIONS

Virtual reality can provide an enhanced understanding of crucial anatomical details, both preoperatively and intraoperatively, which could contribute to improve safety in colorectal surgery.

A New Era of Minimally Invasive Surgery: Progress and Development of Major Technical Innovations in General Surgery Over the Last Decade

Minimally invasive surgery (MIS) continues to play an important role in general surgery as an alternative to traditional open surgery as well as traditional laparoscopic techniques. Since the 1980s, technological advancement and innovation have seen surgical techniques in MIS rapidly grow as it is viewed as more desirable. MIS, which includes natural orifice transluminal endoscopic surgery (NOTES) and single-incision laparoscopic surgery (SILS), is less invasive and has better cosmetic results. The technological growth and adoption of NOTES and SILS by clinicians in the last decade has however not been uniform. We look at the differences in new developments and advancement in the different techniques in the last 10 years. We also aim to explain these differences as well as the implications in general surgery for the future.

Prospective Evaluation of Precision Multimodal Gallbladder Surgery Navigation: Virtual Reality, Near-infrared Fluorescence, and X-ray-based Intraoperative Cholangiography

OBJECTIVE

We aimed to prospectively evaluate NIR-C, VR-AR, and x-ray intraoperative cholangiography (IOC) during robotic cholecystectomy.

BACKGROUND

Near-infrared cholangiography (NIR-C) provides real-time, radiation-free biliary anatomy enhancement. Three-dimensional virtual reality (VR) biliary anatomy models can be obtained via software manipulation of magnetic resonance cholangiopancreatography, enabling preoperative VR exploration, and intraoperative augmented reality (AR) navigation.

METHODS

Fifty-eight patients were scheduled for cholecystectomy for gallbladder lithiasis. VR surgical planning was performed on virtual models. At anesthesia induction, indocyanine green was injected intravenously. AR navigation was obtained by overlaying the virtual model onto real-time images. Before and after Calot triangle dissection, NIR-C was obtained by turning the camera to NIR mode. Finally, an IOC was performed. The 3 modality performances were evaluated and image quality was assessed with a Likert-scale questionnaire.

RESULTS

The three-dimensional VR planning enabled the identification of 12 anatomical variants in 8 patients, of which only 7 were correctly reported by the radiologists (P = 0.037). A dangerous variant identified at VR induced a "fundus first" approach. The cystic-common bile duct junction was visualized before Calot triangle dissection at VR in 100% of cases, at NIR-C in 98.15%, and in 96.15% at IOC.Mean time to obtain relevant images was shorter with NIR-C versus AR (P = 0.008) and versus IOC (P = 0.00000003). Image quality scores were lower with NIR-C versus AR (P = 0.018) and versus IOC (P < 0.0001).

CONCLUSIONS

This high-tech protocol illustrates the multimodal imaging of biliary anatomy towards precision cholecystectomy. Those visualization techniques could complement to reduce the likelihood of biliary injuries (NCT01881399).

Use of natural user interfaces for image navigation during laparoscopic surgery: initial experience

BACKGROUND

Surgical environments require special aseptic conditions for direct interaction with the preoperative images. We aim to test the feasibility of using a set of gesture control sensors combined with voice control to interact in a sterile manner with preoperative information and an integrated operating room (OR) during laparoscopic surgery.

MATERIAL AND METHODS

Two hepatectomies and two partial nephrectomies were performed by three experienced surgeons in a porcine model. The Kinect, Leap Motion, and MYO armband in combination with voice control were used as natural user interfaces (NUIs). After surgery, surgeons completed a questionnaire about their experience.

RESULTS

Surgeons required <10 min training with each NUI. They stated that NUIs improved the access to preoperative patient information and kept them more focused on the surgical site. The Kinect system was reported as the most physically demanding NUI and the MYO armband in combination with voice commands as the most intuitive and accurate. The need to release one of the laparoscopic instruments in order to use the NUIs was identified as the main limitation.

CONCLUSIONS

The presented NUIs are feasible to directly interact in a more intuitive and sterile manner with the preoperative images and the integrated OR functionalities during laparoscopic surgery.

Robust augmented reality registration method for localization of solid organs' tumors using CT-derived virtual biomechanical model and fluorescent fiducials

BACKGROUND

Augmented reality (AR) is the fusion of computer-generated and real-time images. AR can be used in surgery as a navigation tool, by creating a patient-specific virtual model through 3D software manipulation of DICOM imaging (e.g., CT scan). The virtual model can be superimposed to real-time images enabling transparency visualization of internal anatomy and accurate localization of tumors. However, the 3D model is rigid and does not take into account inner structures' deformations. We present a concept of automated AR registration, while the organs undergo deformation during surgical manipulation, based on finite element modeling (FEM) coupled with optical imaging of fluorescent surface fiducials.

METHODS

Two 10 × 1 mm wires (pseudo-tumors) and six 10 × 0.9 mm fluorescent fiducials were placed in ex vivo porcine kidneys (n = 10). Biomechanical FEM-based models were generated from CT scan. Kidneys were deformed and the shape changes were identified by tracking the fiducials, using a near-infrared optical system. The changes were registered automatically with the virtual model, which was deformed accordingly. Accuracy of prediction of pseudo-tumors' location was evaluated with a CT scan in the deformed status (ground truth). In vivo: fluorescent fiducials were inserted under ultrasound guidance in the kidney of one pig, followed by a CT scan. The FEM-based virtual model was superimposed on laparoscopic images by automatic registration of the fiducials.

RESULTS

Biomechanical models were successfully generated and accurately superimposed on optical images. The mean measured distance between the estimated tumor by biomechanical propagation and the scanned tumor (ground truth) was 0.84 ± 0.42 mm. All fiducials were successfully placed in in vivo kidney and well visualized in near-infrared mode enabling accurate automatic registration of the virtual model on the laparoscopic images.

CONCLUSIONS

Our preliminary experiments showed the potential of a biomechanical model with fluorescent fiducials to propagate the deformation of solid organs' surface to their inner structures including tumors with good accuracy and automatized robust tracking.

Future of Minimally Invasive Colorectal Surgery

Minimally invasive surgery is slowly taking over as the preferred operative approach for colorectal diseases. However, many of the procedures remain technically difficult. This article will give an overview of the state of minimally invasive surgery and the many advances that have been made over the last two decades. Specifically, we discuss the introduction of the robotic platform and some of its benefits and limitations. We also describe some newer techniques related to robotics.

Augmented Reality Guidance for the Resection of Missing Colorectal Liver Metastases: An Initial Experience

BACKGROUND

Modern chemotherapy achieves the shrinking of colorectal cancer liver metastases (CRLM) to such extent that they may disappear from radiological imaging. Disappearing CRLM rarely represents a complete pathological remission and have an important risk of recurrence. Augmented reality (AR) consists in the fusion of real-time patient images with a computer-generated 3D virtual patient model created from pre-operative medical imaging. The aim of this prospective pilot study is to investigate the potential of AR navigation as a tool to help locate and surgically resect missing CRLM.

METHODS

A 3D virtual anatomical model was created from thoracoabdominal CT-scans using customary software (VR RENDER(®), IRCAD). The virtual model was superimposed to the operative field using an Exoscope (VITOM(®), Karl Storz, Tüttlingen, Germany). Virtual and real images were manually registered in real-time using a video mixer, based on external anatomical landmarks with an estimated accuracy of 5 mm. This modality was tested in three patients, with four missing CRLM that had sizes from 12 to 24 mm, undergoing laparotomy after receiving pre-operative oxaliplatin-based chemotherapy.

RESULTS

AR display and fine registration was performed within 6 min. AR helped detect all four missing CRLM, and guided their resection. In all cases the planned security margin of 1 cm was clear and resections were confirmed to be R0 by pathology. There was no postoperative major morbidity or mortality. No local recurrence occurred in the follow-up period of 6-22 months.

CONCLUSIONS

This initial experience suggests that AR may be a helpful navigation tool for the resection of missing CRLM.

Augmented Reality Guidance for the Resection of Missing Colorectal Liver Metastases: An Initial Experience

BACKGROUND

Modern chemotherapy achieves the shrinking of colorectal cancer liver metastases (CRLM) to such extent that they may disappear from radiological imaging. Disappearing CRLM rarely represents a complete pathological remission and have an important risk of recurrence. Augmented reality (AR) consists in the fusion of real-time patient images with a computer-generated 3D virtual patient model created from pre-operative medical imaging. The aim of this prospective pilot study is to investigate the potential of AR navigation as a tool to help locate and surgically resect missing CRLM.

METHODS

A 3D virtual anatomical model was created from thoracoabdominal CT-scans using customary software (VR RENDER(®), IRCAD). The virtual model was superimposed to the operative field using an Exoscope (VITOM(®), Karl Storz, Tüttlingen, Germany). Virtual and real images were manually registered in real-time using a video mixer, based on external anatomical landmarks with an estimated accuracy of 5 mm. This modality was tested in three patients, with four missing CRLM that had sizes from 12 to 24 mm, undergoing laparotomy after receiving pre-operative oxaliplatin-based chemotherapy.

RESULTS

AR display and fine registration was performed within 6 min. AR helped detect all four missing CRLM, and guided their resection. In all cases the planned security margin of 1 cm was clear and resections were confirmed to be R0 by pathology. There was no postoperative major morbidity or mortality. No local recurrence occurred in the follow-up period of 6-22 months.

CONCLUSIONS

This initial experience suggests that AR may be a helpful navigation tool for the resection of missing CRLM.

High intensity focused ultrasound (HIFU) applied to hepato-bilio-pancreatic and the digestive system-current state of the art and future perspectives

BACKGROUND

High intensity focused ultrasound (HIFU) is emerging as a valid minimally-invasive image-guided treatment of malignancies. We aimed to review to current state of the art of HIFU therapy applied to the digestive system and discuss some promising avenues of the technology.

METHODS

Pertinent studies were identified through PubMed and Embase search engines using the following keywords, combined in different ways: HIFU, esophagus, stomach, liver, pancreas, gallbladder, colon, rectum, and cancer. Experimental proof of the concept of endoluminal HIFU mucosa/submucosa ablation using a custom-made transducer has been obtained in vivo in the porcine model.

RESULTS

Forty-four studies reported on the clinical use of HIFU to treat liver lesions, while 19 series were found on HIFU treatment of pancreatic cancers and four studies included patients suffering from both liver and pancreatic cancers, reporting on a total of 1,682 and 823 cases for liver and pancreas, respectively. Only very limited comparative prospective studies have been reported.

CONCLUSIONS

Digestive system clinical applications of HIFU are limited to pancreatic and liver cancer. It is safe and well tolerated. The exact place in the hepatocellular carcinoma (HCC) management algorithm remains to be defined. HIFU seems to add clear survival advantages over trans arterial chemo embolization (TACE) alone and similar results when compared to radio frequency (RF). For pancreatic cancer, HIFU achieves consistent cancer-related pain relief. Further research is warranted to improve targeting accuracy and efficacy monitoring. Furthermore, additional work is required to transfer this technology on appealing treatments such as endoscopic HIFU-based therapies.

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

BACKGROUND

Intraoperative liver segmentation can be obtained by means of percutaneous intra-portal injection of a fluorophore and illumination with a near-infrared light source. However, the percutaneous approach is challenging in the minimally invasive setting. We aimed to evaluate the feasibility of fluorescence liver segmentation by superselective intra-hepatic arterial injection of indocyanine green (ICG).

MATERIALS AND METHODS

Eight pigs (mean weight: 26.01 ± 5.21 kg) were involved. Procedures were performed in a hybrid experimental operative suite equipped with the Artis Zeego^®, multiaxis robotic angiography system. A pneumoperitoneum was established and four laparoscopic ports were introduced. The celiac trunk was catheterized, and a microcatheter was advanced into different segmental hepatic artery branches. A near-infrared laparoscope (D-Light P, Karl Storz) was used to detect the fluorescent signal. To assess the correspondence between arterial-based fluorescence demarcation and liver volume, metallic markers were placed along the fluorescent border, followed by a 3D CT-scanning, after injecting intra-arterial radiological contrast (n = 3). To assess the correspondence between arterial and portal supplies, percutaneous intra-portal angiography and intra-arterial angiography were performed simultaneously (n = 1).

RESULTS

Bright fluorescence signal enhancing the demarcation of target segments was obtained from 0.1 mg/mL, in matter of seconds. Correspondence between the volume of hepatic segments and arterial territories was confirmed by CT angiography. Higher background fluorescence noise was found after positive staining by intra-portal ICG injection, due to parenchymal accumulation and porto-systemic shunting.

CONCLUSIONS

Intra-hepatic arterial ICG injection, rapidly highlights hepatic target segment borders, with a better signal-to-background ratio as compared to portal vein injection, in the experimental setting.

The quest for precision in transanal total mesorectal excision

Transanal total mesorectal excision (TME) is an emerging minimally invasive approach to rectal cancer, with encouraging preliminary results. However, the new surgical anatomy of the bottom-up approach complicates surgical understanding and increases the risks of inadvertent injuries to crucial anatomical structures, including nerves. Key elements to improve the safety and stimulate interest in such a complex technique might be robotics and image guidance, to enhance the level of precision. In this editorial, some of the technologies that could be used for precision TME are outlined, in light of the experience of our Institute for Image-Guided Surgery.

[Surgical treatment of secondary hyperparathyroidism: a systematic review of the literature]

Secondary hyperparathyroidism (HPT) has a high prevalence in renal patients. Secondary HPT results from disturbances in mineral homeostasis, particularly calcium, which stimulates the parathyroid glands, increasing the secretion of parathyroid hormone (PTH). Prolonged stimulation can lead to autonomy in parathyroid function. Initial treatment is clinical, but parathyroidectomy (PTx) may be required. PTx can be subtotal or total followed or not followed by parathyroid tissue autograft. We compared the indications and results of these strategies as shown in the literature through a systematic literature review on surgical treatment of secondary HPT presented in MedLine and LILACS from January 2008 to March 2014. The search terms were: hyperparathyroidism; secondary hyperparathyroidism; parathyroidectomy and parathyroid glands, restricted to research only in humans, articles available in electronic media, published in Portuguese, Spanish, English or French. We selected 49 articles. Subtotal and total PTx followed by parathyroid tissue autograft were the most used techniques, without consensus on the most effective surgical procedure, although there was a preference for the latter. The choice depends on surgeon's experience. There was consensus on the need to identify all parathyroid glands and cryopreservation of parathyroid tissue whenever possible to graft if hypoparathyroidism arise. Imaging studies may be useful, especially in recurrences. Alternative treatments of secondary HPT, both interventional and conservative, require further study.

Robotic surgery

BACKGROUND

Proficiency in minimally invasive surgery requires intensive and continuous training, as it is technically challenging for unnatural visual and haptic perceptions. Robotic and computer sciences are producing innovations to augment the surgeon's skills to achieve accuracy and high precision during complex surgery. This article reviews the current use of robotically assisted surgery, focusing on technology as well as main applications in digestive surgery, and future perspectives.

METHODS

The PubMed database was interrogated to retrieve evidence-based data on surgical applications. Internal and external consulting with key opinion leaders, renowned robotics laboratories and robotic platform manufacturers was used to produce state-of-the art business intelligence around robotically assisted surgery.

RESULTS

Selected digestive procedures (oesophagectomy, gastric bypass, pancreatic and liver resections, rectal resection for cancer) might benefit from robotic assistance, although the current level of evidence is insufficient to support widespread adoption. The surgical robotic market is growing, and a variety of projects have recently been launched at both academic and corporate levels to develop lightweight, miniaturized surgical robotic prototypes.

CONCLUSION

The magnified view, and improved ergonomics and dexterity offered by robotic platforms, might facilitate the uptake of minimally invasive procedures. Image guidance to complement robotically assisted procedures, through the concepts of augmented reality, could well represent a major revolution to increase safety and deal with difficulties associated with the new minimally invasive approaches.

Next step in minimally invasive surgery: hybrid image-guided surgery

Surgery, interventional radiology, and advanced endoscopy have all developed minimally invasive techniques to effectively treat a variety of diseases with positive impact on patients' postoperative outcomes. However, those techniques are challenging and require extensive training. Robotics and computer sciences can help facilitate minimally invasive approaches. Furthermore, surgery, advanced endoscopy, and interventional radiology could converge towards a new hybrid specialty, hybrid image-guided minimally invasive therapies, in which the three fundamental disciplines could complement one another to maximize the positive effects and reduce the iatrogenic footprint on patients. The present manuscript describes the fundamental steps of this new paradigm shift in surgical therapies that, in our opinion, will be the next revolutionary step in minimally invasive approaches.

Towards cybernetic surgery: robotic and augmented reality-assisted liver segmentectomy

BACKGROUND

Augmented reality (AR) in surgery consists in the fusion of synthetic computer-generated images (3D virtual model) obtained from medical imaging preoperative workup and real-time patient images in order to visualize unapparent anatomical details. The 3D model could be used for a preoperative planning of the procedure. The potential of AR navigation as a tool to improve safety of the surgical dissection is outlined for robotic hepatectomy.

MATERIALS AND METHODS

Three patients underwent a fully robotic and AR-assisted hepatic segmentectomy. The 3D virtual anatomical model was obtained using a thoracoabdominal CT scan with a customary software (VR-RENDER®, IRCAD). The model was then processed using a VR-RENDER® plug-in application, the Virtual Surgical Planning (VSP®, IRCAD), to delineate surgical resection planes including the elective ligature of vascular structures. Deformations associated with pneumoperitoneum were also simulated. The virtual model was superimposed to the operative field. A computer scientist manually registered virtual and real images using a video mixer (MX 70; Panasonic, Secaucus, NJ) in real time.

RESULTS

Two totally robotic AR segmentectomy V and one segmentectomy VI were performed. AR allowed for the precise and safe recognition of all major vascular structures during the procedure. Total time required to obtain AR was 8 min (range 6-10 min). Each registration (alignment of the vascular anatomy) required a few seconds. Hepatic pedicle clamping was never performed. At the end of the procedure, the remnant liver was correctly vascularized. Resection margins were negative in all cases. The postoperative period was uneventful without perioperative transfusion.

CONCLUSIONS

AR is a valuable navigation tool which may enhance the ability to achieve safe surgical resection during robotic hepatectomy.

Enhanced-reality video fluorescence: a real-time assessment of intestinal viability

OBJECTIVE

Our aim was to evaluate a fluorescence-based enhanced-reality system to assess intestinal viability in a laparoscopic mesenteric ischemia model.

MATERIALS AND METHODS

A small bowel loop was exposed, and 3 to 4 mesenteric vessels were clipped in 6 pigs. Indocyanine green (ICG) was administered intravenously 15 minutes later. The bowel was illuminated with an incoherent light source laparoscope (D-light-P, KarlStorz). The ICG fluorescence signal was analyzed with Ad Hoc imaging software (VR-RENDER), which provides a digital perfusion cartography that was superimposed to the intraoperative laparoscopic image [augmented reality (AR) synthesis]. Five regions of interest (ROIs) were marked under AR guidance (1, 2a-2b, 3a-3b corresponding to the ischemic, marginal, and vascularized zones, respectively). One hour later, capillary blood samples were obtained by puncturing the bowel serosa at the identified ROIs and lactates were measured using the EDGE analyzer. A surgical biopsy of each intestinal ROI was sent for mitochondrial respiratory rate assessment and for metabolites quantification.

RESULTS

Mean capillary lactate levels were 3.98 (SD = 1.91) versus 1.05 (SD = 0.46) versus 0.74 (SD = 0.34) mmol/L at ROI 1 versus 2a-2b (P = 0.0001) versus 3a-3b (P = 0.0001), respectively. Mean maximal mitochondrial respiratory rate was 104.4 (±21.58) pmolO2/second/mg at the ROI 1 versus 191.1 ± 14.48 (2b, P = 0.03) versus 180.4 ± 16.71 (3a, P = 0.02) versus 199.2 ± 25.21 (3b, P = 0.02). Alanine, choline, ethanolamine, glucose, lactate, myoinositol, phosphocholine, sylloinositol, and valine showed statistically significant different concentrations between ischemic and nonischemic segments.

CONCLUSIONS

Fluorescence-based AR may effectively detect the boundary between the ischemic and the vascularized zones in this experimental model.

Robotic duodenopancreatectomy assisted with augmented reality and real-time fluorescence guidance

BACKGROUND

The minimally invasive surgeon cannot use 'sense of touch' to orientate surgical resection, identifying important structures (vessels, tumors, etc.) by manual palpation. Robotic research has provided technology to facilitate laparoscopic surgery; however, robotics has yet to solve the lack of tactile feedback inherent to keyhole surgery. Misinterpretation of the vascular supply and tumor location may increase the risk of intraoperative bleeding and worsen dissection with positive resection margins.

METHODS

Augmented reality (AR) consists of the fusion of synthetic computer-generated images (three-dimensional virtual model) obtained from medical imaging preoperative work-up and real-time patient images with the aim of visualizing unapparent anatomical details.

RESULTS

In this article, we review the most common modalities used to achieve surgical navigation through AR, along with a report of a case of robotic duodenopancreatectomy using AR guidance complemented with the use of fluorescence guidance.

CONCLUSIONS

The presentation of this complex and high-technology case of robotic duodenopancreatectomy, and the overview of current technology that has made it possible to use AR in the operating room, highlights the needs for further evolution and the windows of opportunity to create a new paradigm in surgical practice.

Augmented reality-guided artery-first pancreatico-duodenectomy

BACKGROUND

Augmented Reality (AR) in surgery consists in the fusion of synthetic computer-generated images (3D virtual model) obtained from medical imaging preoperative work-up and real-time patient images with the aim to visualize unapparent anatomical details. The potential of AR navigation as a tool to improve safety of the surgical dissection is presented in a case of pancreatico-duodenectomy (PD).

METHODS

A 77-year-old male patient underwent an AR-assisted PD. The 3D virtual anatomical model was obtained from thoraco-abdominal CT scan using customary software (VR-RENDER®, IRCAD). The virtual model was superimposed to the operative field using an Exoscope (VITOM®, Karl Storz, Tüttlingen, Germany) as well as different visible landmarks (inferior vena cava, left renal vein, aorta, superior mesenteric vein, inferior margin of the pancreas). A computer scientist manually registered virtual and real images using a video mixer (MX 70; Panasonic, Secaucus, NJ) in real time. Dissection of the superior mesenteric artery and the hanging maneuver were performed under AR guidance along the hanging plane.

RESULTS

AR allowed for precise and safe recognition of all the important vascular structures. Operative time was 360 min. AR display and fine registration was performed within 6 min. The postoperative course was uneventful. The pathology was positive for ampullary adenocarcinoma; the final stage was pT1N0 (0/43 retrieved lymph nodes) with clear surgical margins.

CONCLUSIONS

AR is a valuable navigation tool that can enhance the ability to achieve a safe surgical resection during PD.

New technologies for single-site robotic surgery in hepato-biliary-pancreatic surgery

Laparoendoscopic single-site surgery (LESS) aims to reduce incision-related complications by using a single surgical access through which multiple instruments are inserted simultaneously. First descriptions of LESS procedures date back to the early 90 s, but the approach initially failed to gain popularity because of technical challenges that markedly impair the principles of laparoscopic ergonomics. In recent years LESS has been increasingly applied to hepatobiliary procedures including cholecystectomies and liver resections. However, the uptake of LESS in hepatobiliary is limited. The surgical robotic platform might play a fundamental role in facilitating the uptake of LESS by the surgical community since robotic science made it possible to develop adequate technology to deal with some of the LESS issues such as restoring surgical triangulation. In this paper the current state-of-the-art for robotic LESS applied to the hepatobiliary system and emerging technologies enabling safer LESS procedures have been reviewed and future perspectives commented on the light of our experience.