Stereotactic Navigation System for Laparoscopic Lateral Pelvic Lymph Node Dissection

Stereotactic Navigation-Assisted Laparoscopic Resection of Challenging Low Pelvic Tumors: A Case Series

(1) Introduction: The laparoscopic approach to low pelvic tumors is challenging and hindered by suboptimal tumor visualization and dissection, with possible oncological failure. Stereotactic navigation provides real-time image guidance that may optimize safety, accuracy, and precision when dissecting challenging low pelvic tumors. (2) Methods: Preoperative CT images were acquired with eight skin-fixed fiducials and loaded into a navigation system. A patient tracker was mounted on the bed side. Patient-to-image paired point registration was performed, and an instrument tracker was mounted on a laparoscopic instrument and calibrated for instrument tracking. Surgical operations were performed with real-time stereotactic navigation assistance. (3) Results: Three patients underwent stereotactic navigation surgery. Fiducial registration errors were good to optimal (±1.9, ±3.4, and ±3.4 mm). Lesions were easily identified and targeted with real-time navigation. Surgeries were uneventful. Histopathology examinations identified one retro-rectal schwannoma, one lateral pelvic recurrence from rectal adenocarcinoma, and one advanced anal canal carcinoma. No navigation-related complications, readmissions, or postoperative mortalities were observed. (4) Conclusions: The application of laparoscopic stereotactic navigation surgery to complex low pelvic tumors is feasible and could impact oncological surgical quality by enabling tumor targeting and ensuring resection margins. Further wider series are needed to confirm stereotactic navigation's impact on challenging low pelvic tumors.

Stereotactic navigation using registration based on intra-abdominal landmarks in robotic-assisted lateral pelvic lymph node dissection

BACKGROUND

We carried out robot-assisted lateral pelvic lymph node dissection (LPLND) for rectal cancer with a stereotactic navigation system. The purpose of this study was to evaluate the accuracy and feasibility of the system.

METHODS

We constructed a navigation system based on the Polaris Spectra optical tracking device (Northern Digital Inc., Canada) and the open-source software 3D Slicer (version 3.8.1; http://www.slicer.org ). We used the landmark-based registration method for patient-to-image registration. Body surface landmarks and intra-abdominal landmarks were used. We evaluated the time required for registration and target registration error (TRE; the distance between corresponding points after registration) for the root of the superior gluteal artery the root of the obturator or superior vesical artery, and the obturator foramen during minimally invasive LPLND for rectal cancer. Five patients who had LPLND for rectal cancer at the University of Tokyo Hospital between September 2020 and May 2021 were enrolled.

RESULTS

The mean time required for registration was 49 s with the body surface landmarks and 88 s with the intra-abdominal landmarks. The mean TRE improved markedly when the registration was performed using intra-abdominal landmarks. The mean TRE of the root of the superior gluteal artery, the root of the obturator or superior vesical artery, and the obturator foramen were 55.8 mm, 53.4 mm, and 55.2 mm with the body surface landmarks and 11.8 mm, 10.0 mm, and 12.6 mm with the intra-abdominal landmarks, respectively. There were no adverse events related to the registration process.

CONCLUSIONS

When stereotactic navigation systems are used for minimally invasive LPLND, the use of intra-abdominal landmarks for registration is feasible and may allow simpler and more accurate navigation than the use of body surface landmarks.

Laparoscopic surgery for median arcuate ligament syndrome using real-time stereotactic navigation

INTRODUCTION

In median arcuate ligament syndrome (MALS), a hyperplastic MAL causes compression and stenosis of the celiac artery (CA). The treatment involves releasing the external pressure on this artery by dissecting the ligament. However, it is difficult to identify the artery because of its deep anatomical location. Stereotactic navigation provides real-time information regarding the surgical instrument's location on computed tomography (CT) images. We utilized this system to overcome the difficulty of anatomical identification.

MATERIALS AND SURGICAL TECHNIQUE

We present a case of aneurysm rupture caused by MALS, which was treated with laparoscopic MAL dissection with real-time stereotactic navigation. Surgery was performed in a hybrid operating room with three-dimensional C-arm CT (Artis Zeego, Siemens) and an installed Curve navigation system (BrainLab). Preoperative CT images were aligned with intraoperative C-arm CT-like images and the surgical instrument position was projected onto preoperative CT images. After the left gastric artery isolation, the fibrous tissue surrounding the left gastric artery was dissected toward the CA while confirming the location of the CA and aortic wall using the navigation system. The CA's diameter was dilated from 1.8 to 2.6 mm with intraoperative angiography.

DISCUSSION

This is the first report of laparoscopic MAL dissection using real-time stereotactic navigation. Although navigation setting was time-intensive, this system helped us understand the anatomical structures and in safely and precisely dissecting the MAL.