Ultrasound optic nerve sheath diameter evaluation in patients undergoing robot-assisted laparoscopic pelvic surgery

Optic Nerve Ultrasound Evaluation in Children: A Review

Managing patients with neurocritical illness requires monitoring and treating elevated intracranial pressure (ICP), especially in cases in children. In terms of precise and real-time measurements, invasive ICP measurements are presently the gold standard for the initial diagnosis and follow-up ICP assessments. As a rapid and non-invasive way to detect elevated ICP, point-of-care ultrasonography (POCUS) of optic nerve sheath diameter (ONSD) has been proposed. The utility of bedside POCUS of ONSD to detect elevated ICP with excellent diagnostic test accuracy in adults has already been demonstrated. Nonetheless, data on the relationship between POCUS of ONSD and ICP in children are scarce. Therefore, the purpose of this review is to point out the most recent findings from the pediatric published literature and briefly discuss what was assessed with ONSD ultrasound examination, and also to describe and discuss the diagnostic procedures available for optic nerve ultrasound appraisal. A search of the medical databases PubMed and Scopus was carried out. The terms such as "ocular ultrasonography", "ICP assessment", "children", "point-of-care ultrasound", and "POCUS" were searched. In conclusion, the use of the standardized A-scan technique coupled with the B-scan technique should be suggested to provide data that are as accurate, precise, repeatable, and objective as possible.

Optic Nerve Changes Detected with Ocular Ultrasonography during Different Surgical Procedures: A Narrative Review

Ultrasonographic appraisal of the optic nerve sheath diameter has become popular in recent years as a useful diagnostic tool to detect intracranial pressure variations. Intracranial hypertension is a life-threatening disease with possible poor clinical outcomes and can be caused by a variety of neurological and non-neurological conditions. Considering the latter, increases in intracranial pressure have also been described during several surgical procedures. Ocular ultrasonography might be utilized to identify intracranial pressure increases by evaluating optic nerve sheath diameter variations. The aim of this review is to provide a wide overview on the use of the optic nerve ultrasound evaluation to detect intracranial pressure changes during surgical procedures, also discussing the pitfalls of the B-scan technique, the most widely used for such a purpose. PubMed medical database, Web of Science and Scopus were used to carry out this review. The present review showed that ocular ultrasonography could be considered a valuable diagnostic tool in the surgical setting to indirectly assess intracranial pressure. However, the use of the B-scan ultrasound should always be coupled with the standardized A-scan technique for a more accurate, precise and trustworthy ultrasound assessment.

Robot-assisted tumorectomy for an unusual pelvic retroperitoneal leiomyoma: A case report

RATIONALE

Extrauterine leiomyoma occasionally occurs in rare locations with unusual growth patterns, especially pelvic retroperitoneal leiomyoma, which brings great challenges for surgeons to make a diagnosis. It is essential to distinguish benign from malignant retroperitoneal neoplasms according to the imaging manifestations. Laparotomy and laparoscopy are the common options for pelvic retroperitoneal neoplasms, while they may cause side effects during operation such as secondary damage. Appropriate surgical techniques should be adopted to ensure the complete excision of neoplasms meanwhile preserve the urination, defecation, and sexual function.

PATIENT CONCERNS

A 30-year-old woman was referred to our hospital because of dull pain in the perianal region for 1 month. Laboratory results including tumor markers were all within normal limits. The digital rectal examination revealed a huge and tough mass with smooth mucosa protruding into the rectal cavity from the rear area of rectum.

DIAGNOSIS

Imaging examinations were performed. Contrasted computed tomography (CT) of pelvis showed an enhanced retroperitoneal solid mass in the space between sacrum and rectum, and very close to the levator ani muscle. The mass was about 11.0*8.0 cm in size. Computerized tomography angiography (CTA) showed the distal branches of bilateral internal iliac artery went into the mass. Endoscopic ultrasonography (US) showed the mass compressed the rectum, as well as a clear boundary to the rectal wall. A histopathologic examination confirmed the mass was a pelvic retroperitoneal leiomyoma.

INTERVENTIONS

The patient underwent an operative resection with da Vinci Si surgical system after routine preoperative preparation. Anorectal motility was weekly monitored postoperation. No additional adjuvant therapy was performed.

OUTCOMES

The patient could walk after 1 day and defecate normally on the third day after operation. She was discharged on the seventh postoperative day. No adverse events including pelvic floor hernia or defecation dysfunction occurred in the follow-up period. At 4 weeks follow-up, the patient was pain-free and recovered well.

LESSONS

Although imaging examinations were crucial for retroperitoneal neoplasms, histopathological examination remains the "gold standard" for making a definite diagnosis. This case highlights the possibility of retroperitoneal leiomyoma occurring in a woman of reproductive age and the advantages of robotic surgical system in pelvic retroperitoneal surgeries.

Ultrasound Detection of Intracranial Hypertension in Brain Injuries

In recent years, the measurement of optic nerve sheath diameter with ultrasound to detect the presence of increased intracranial pressure has widely spread. It can be qualitatively and effectively used to identify intracranial hypertension. Intracranial pressure can rise due to acute injury, cerebral bleeding, hydrocephalus, brain tumors and other space-occupying abnormalities, and it is linked to a high death rate. The purpose of this review is to give a general overview of the most relevant scientific publications on ultrasonographic evaluation of the optic nerve in case of brain injuries published in the last 30 years, as well as to analyze the limits of the most extensively used B-scan approach. Fifty-two papers chosen from the PubMed medical database were analyzed in this review. Our findings revealed that ocular ultrasound is an useful diagnostic tool in the management of intracranial hypertension when it exceeds a certain value or after head trauma. As a result, an ultrasound of the optic nerve can be extremely helpful in guiding diagnosis and treatment. The blooming effect is one of the most critical restrictions to consider when using B-scan ultrasonography. Since amplitude-scan ultrasound, also known as A-scan, does not have this limit, these two diagnostic techniques should always be used together for a more full, accurate, and trustworthy ultrasound examination, ensuring more data objectivity.

Optic Nerve Drusen Evaluation: A Comparison between Ultrasound and OCT

This observational study compared optic coherence tomography (OCT) and B-scan in the detection of optic disc drusen. In total, 86 eyes of 50 patients with optic disc drusen (ODD) (36 bilateral) with a mean age of 34.68 ± 23.81 years, and 54 eyes of 27 patients with papilledema, with a mean age of 35.42 years ± 17.47, were examined. Patients with ODD, diagnosed with ultrasound, underwent spectral-domain OCT evaluation. With US, 28 ODD cases were classified as large (4 buried and 24 superficial), 58 were classified as point-like (6 buried, 49 superficial and 3 mixed). Then, all patients underwent OCT. OCT was able to detect the presence of ODD and/or peripapillary hyperreflective ovoid mass structure (PHOMS) in 69 eyes (p < 0.001). In particular, 7 eyes (8.14%) showed the presence of ODD alone, 25 eyes (29.07%) showed only PHOMS and 37 eyes (43.02%) showed ODD and PHOMS. In 17 eyes (19.77%) no ODD or PHOMS were detected. In the papilledema group, no ODD were observed with both US and OCT. OCT showed the presence of drusen or similar lesions in only 80.23% of the cases highlighted by the US scan, so it does not allow for certain ODD diagnoses, especially in the case of buried ODD.

Effect of Percutaneous Tracheostomy on Optic Nerve Sheath Diameter (TONS Trial)

How to cite this article: Di Paola I, Graziano M, Cornetta P. Effect of Percutaneous Tracheostomy on Optic Nerve Sheath Diameter (TONS Trial). Indian J Crit Care Med 2022;26(5):653.

Accuracy of Optic Nerve Sheath Diameter Measurements in Pocket-Sized Ultrasound Devices in a Simulation Model

Introduction

Transorbital sonographic measurement of optic nerve sheath diameter (ONSD) is an emerging non-invasive technique for the identification and monitoring of intracranial hypertension. In recent years, new pocket ultrasound devices have become available, and it is uncertain if they have the resolution to measure such small structures appropriately as compared to their predecessors. In this study, we measure the performance of three ultrasound units on a simulation model to establish their precision and accuracy.

Methods

ONSD was measured by three expert point-of-care sonographers using ultrasound machines three times on each of seven discrete ONS model sizes ranging from 3.5 to 7.9 mm. Two pocket ultrasounds (IVIZ, Sonosite, and Lumify, Philips) and one standard-sized portable ultrasound (M-Turbo, Sonosite) were used. Measurements were analyzed for mean error and variance and tested for significance using blocked covariance matrix regression analyses.

Results

The devices differed in their variances (Lumify: 0.19 mm², M-Turbo: 0.26 mm², IVIZ: 0.34 mm²) and their mean error (Lumify: -0.05 mm, M-Turbo: 0.10 mm, IVIZ: -0.10 mm). The difference in mean error between users is not significant (p = 0.45), but there is a significant difference in mean error between devices (p = 0.02).

Conclusions

Accurate ONSD measurement is possible utilizing pocket-sized ultrasound, and in some cases, may be more accurate than larger portable ultrasound units. While the differences in these devices were statistically significant, all three were highly accurate, with one pocket device (Lumify) outperforming the rest. Further study in human subjects should be conducted prior to using pocket ultrasound devices for in vivo diagnosis of intracranial hypertension.

Optic Nerve Ultrasound Evaluation in Idiopathic Intracranial Hypertension

Idiopathic intracranial hypertension (IIH) is a disease with a heterogeneity of possible causes, which needs to be quickly diagnosed. Ocular ultrasonography could be considered a useful tool to diagnose this condition in a fast and non-invasive way. In fact, Karl Ossoinig had already proposed this diagnostic tool in the 1970s for the evaluation of intracranial pressure changes under several pathological conditions, including idiopathic intracranial hypertension. The aim of this review is to analyze scientific articles published in the last 30 years concerning the use of ocular ultrasonography to assess optic nerve indices in patients with idiopathic intracranial hypertension. Specifically, 15 published articles found in PubMed database were included and analyzed in the present review. Our conclusion suggests that ocular ultrasonography is a reliable diagnostic technique to be utilized in all the cases of suspected raised intracranial pressure. To obtain the best possible accuracy and precision in the least invasive way, standardized A-scan seems to be the best choice.

Optic Nerve Ultrasound Evaluation in Animals and Normal Subjects

In recent years, ultrasonographic measurement of the optic nerve sheath diameter (ONSD) has been widely used to identify the presence of increased intracranial pressure (ICP). Intracranial hypertension is a life-threatening condition that can be caused by various neurological and non-neurological disorders, and it is associated to poor clinical results. Ultrasonography could be used to qualitatively and efficiently detect ICP increases, but to reach this purpose, clear cut-off values are mandatory. The aim of this review is to provide a wide overview of the most important scientific publications on optic nerve ultrasound normal values assessment published in the last 30 years. A total of 42 articles selected from PubMed medical database was included in this review. Our analysis showed that ocular ultrasonography is considered to be a valuable diagnostic tool, especially when intracranial hypertension is suspected, but unfortunately this research provided conflicting results that could be due to the different ultrasound protocols. This is mainly caused by the use of B scan alone, which presents several limitations. The use of B-scan coupled with the standardized A-scan approach could give more accurate, and reliable ultrasound evaluation, assuring higher data objectivity.