Letter to the Editor: Endoscopic resection of intraventricular choroid plexus papillomas in infants

Tractography Navigated Endoscopic En-Bloc Excision of Pediatric Giant Choroid Plexus Tumor

Giant choroid plexus (CP) tumors in children pose a formidable surgical challenge due to extensive vascularity/blood loss, tumor size impeding early visualization of the pedicle, hydrocephalus/mass effect distorting cerebral localization, considerable prevalence of atypical tumors and carcinoma demanding excision without tumor spillage, and retraction-associated morbidity. However, total resection of CP papilloma has excellent potential for cure. This is probably the first report in the literature of diffusion tensor imaging navigation-guided tumor pedicle targeting, endoscopic devascularization and division of pedicle followed by en bloc delivery in optimally tackling most of these challenges in a 6-year-old girl presenting with a giant lateral ventricular CP tumor. Giant CP tumors pose a formidable challenge. Extensive vascularity can cause life-threatening blood loss in children.1 Large tumor size makes it impractical during microsurgery to achieve early visualization of pedicle.2 Hydrocephalus and mass effect can distort sulcal anatomy, with potentially devastating deficits.3 Still, prevalence of atypical tumors and carcinoma warrants excision without tumor spillage.4 In Video 1, we demonstrate our "10-D" steps of en-bloc excision, exploiting panoramic visualization of endoscope5: 1. Diagnosis, 2. Diffusion tensor imaging guided pedicle targeting, 3. Design position & exposure, 4. Durotomy, 5. Dissection of sulcus, 6. Delineation of pedicle, 7. Devascularization, 8. Division of pedicle, 9. Delivery of tumor, and 10. Dural & skin closure. The conventional superior parietal lobule approach to get the tumor en-bloc would have been from the posterosuperior direction, where the tumor is likely to conceal the pedicle. The trajectory to first get to the pedicle must be from an anterosuperior direction but will violate corticospinal fibers. Hence entry point was chosen in between, just posterior to the post-central sulcus. To accommodate the 'en-bloc' excision avoiding ventricular seedlings, a 5 cm mini-craniotomy was fashioned centered on the entry point planned in the navigation system. Ventricle was entered perpendicular to the sulcus through the roof of the atrium, with least cortical transgression and avoiding injury to laterally placed optic radiation and speech areas.6 A 30-degree, 4-mm endoscope was inserted anterolateral to the tumor and fixed. The wide-angled vision offered by endoscopes enhancing meticulous dissection is the likely cause of better neurological outcomes, as noted in other ventricular lesions.7 Pedicular attachment of the tumor is coagulated thoroughly and cut, ensuring initial sparing of venous drainage. The draining vein is then coagulated and divided. 'En-bloc' excision is also known in other vascular lesions to decrease the risk of bleeding.8 The angled optics & panoramic visualization helps to identify any possible tumor seedlings.9 This is probably the first report of endoscopic en-bloc excision of a giant choroid plexus tumor in literature.

Neuroendoscopy: intraventricular and skull base tumor resection in children

During the last 30 years, the neurosurgeons have witnessed a revolution in the practice of interventricular surgery. The advent of neuroendoscopy at the end of the 1980s has allowed a minimally invasive management of a very large series of pathologies in pediatric neurosurgery ranging from hydrocephalus to arachnoid cyst to intraventricular tumors. The progresses in the management of hydrocephalus, intracranial cyst, and the fluid filled collection nevertheless has been more rapid and radical due to the simpler equipment that is necessary to perform this kind of surgery. The intraventricular tumors instead have been addressed in a slower way, and for many years, the only endoscopic procedure that was allowed on interventricular tumors was a biopsy associated with the management of hydrocephalus. Only very small tumors have been considered operable for complete removal during many years due to the limitations of the neuroendoscopic equipment and to the small calibers of the working channel. More recently, the advent of new devices and new surgical techniques are offering new perspectives on the possibility of intraventricular tumor surgery in children. In this review, we describe the historical perspective of the learning curve of intraventricular tumor surgery under neuroendoscopic control and try to offer a view of the future perspective in the removal of larger intraventricular tumors, analyzing the main indications for intraventricular endoscopic tumor surgery. We offer as well an historical perspective of the evolution of skull base surgery and endonasal transsphenoidal approach for skull-based tumors in children. This kind of surgery that has acquired widespread acceptance for many pathologies in adult age has diffused more slowly in pediatric neurosurgery due to the anatomical limitation observed in these age range. Also in this field, the slow evolution of the technique and of the technology available to neurosurgeons has allowed a very significant expansion of indication for the minimally invasive removal of skull base tumors in children.

Resection of brain lesions with a neuroendoscopic ultrasonic aspirator - a systematic literature review

The development of minimally invasive neuroendoscopy has advanced in recent years. The introduction of the neuroendoscopic ultrasonic aspirator (NUA) increased the treatment spectrum of neuroendoscopy. This review aimed to present a systematic overview of the extent of resection, lesion characteristics, technical aspects, complications, and clinical outcomes related to using the NUA. Articles were identified by searching the PubMed/Medline, Embase, and Web of Science database through June 2022 with restriction to the last 20 years. We included case series, case reports, clinical trials, controlled clinical trials, meta-analyses, randomized controlled trials, reviews, and systematic reviews written in English. Studies reporting on endonasal approach or hematoma evacuation using the NUA were excluded. The references of the identified studies were reviewed as well. Nine full-text articles were included in the analysis, with a total of 40 patients who underwent surgery for a brain tumor using NUA. The most common underlying pathology treated by NUA was colloid cyst (17.5%), pilocytic astrocytoma (12.5%), subependymal giant cell astrocytoma (7.5%), subependymoma (7.5%), and craniopharyngioma (7.5%). Complete or near-total resection was achieved in 62.5%. The most frequently reported postoperative complication was secondary hydrocephalus (10%), meningitis/-encephalitis (7.5%), cognitive impairment (7.5%), and subdural hygroma (7.5%). In one case (2.5%), surgery-related death occurred due to a severe course of meningoencephalitis. According to the preliminary data, NUA seems to be a safe and efficient minimally invasive alternative to conventional microscopic resection of brain tumors. Further studies to investigate advantages and disadvantages of using the NUA are needed.

Endoscopic and Endoscopically-Assisted Resection of Intraventricular Lesions Using a Neuroendoscopic Ultrasonic Aspirator

The development of minimally invasive neuroendoscopy has advanced in recent years. The introduction of the neuroendoscopic ultrasonic aspirator (NUA) broadened the treatment spectrum of neuroendoscopy. We aim to describe our experience with the use of NUA for the resection of intraventricular lesions. Here, we present consecutive retrospective case series of adult and pediatric patients undergoing resection of an intraventricular lesion with a NUA (Endoscopic Neurosurgical Pen, Söring GmbH, Quickborn, Germany) between January 2019 and April 2020. Eight patients between the age of 0.5 and 73 years underwent surgery using NUA and were included in this study. In four patients, an endoscopic assisted (EA) resection of the lesion was undertaken, while in four patients, the lesion was removed using purely endoscopic (PE) resection. In all cases, gross/near total resection was achieved. The average blood loss was 142.5 ± 90.4 mL (range 50–300 mL). Transient morbidity was seen in four patients (50%), while permanent morbidity or mortality did not occur. The NUA seems to be a safe and valuable tool for the minimally invasive resection of intraventricular lesions in selected cases. The type, size, consistency, and vascularization of the lesion limit at times the purely endoscopic use of the NUA.