Volume 30, Issue 6 (9-2023)                   RJMS 2023, 30(6): 187-194 | Back to browse issues page

Research code: 15026
Ethics code: IR.IUMS.FMD.REC.1399.592
Clinical trials code: ---

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Neurosurgery Department, Medicine Faculty, Iran University of Medical Sciences, Tehran, Iran , smr.mohajery@gmail.com
Abstract:   (188 Views)
Background & Aims: Intraoperative ultrasound (IOUS) is a non-invasiveness, affordability, and the possibility of repeated use during surgery without significant time consumption. One of the attractions of this modality is the real-time imaging of the lesion. According to the nature of brain tumors, tissue movement can occur in each step of the surgery (including opening dura and start of resection). Thus, real-time intraoperative ultrasonography significantly helps the surgeon to identify the real-time location of the mass and close structures
Methods: Between 2019 and 2022, patients with brain tumors were evaluated. To select the samples, 33 patients with intra-axial brain tumors were initially selected. Then, the decisions of two neurosurgeons were collected regarding the possibility of gross total resection of tumors in these cases. As a result, 4 patients were excluded from the study, and 29 patients were included. In the next step, tumor resection was performed using IOUS. According to the pathology results, 10 patients with pathologies other than glioma were excluded, and 19 patients with glioma lesions were evaluated.
The patient was admitted with a brain tumor, and initial imaging was done. During surgery, the ultrasound probe with a sterile cover entered the surgical field before opening the dura. The exact location of the tumor was determined over the dura, and so the dura was opened. With the ultrasound guide, the location of the lesion was determined, and the resection of the lesion began. Then, ultrasound was performed intermittently to determine the tumor area, and surgery continued until the complete resection of the lesion. Within 72 hours after the surgery, an MRI was performed to evaluate the extent of resection.
In order to measure the tumor volume, MRI images with the same cut distance were evaluated. Therefore, the tumor area in all MRI imaging slices was added together and multiplied by the slice distance. Then, the amount of resection was calculated by comparing the volume of the tumor before and after surgery.
Results: 19 patients were selected to participate in the study. Three patients died after surgery and during hospitalization and were therefore not included in the follow-up, but only in the pre-surgical examinations.
The characteristics of the patients are listed in table 1. In this study, there were 7 women and 12 men, whose average age was 46.5 years (average 40 years for women and 50 years for men). Most of the patients were middle-aged adults. Regarding the alertness and functional status of the patients, the average GCS was 13, and the median GCS of the samples was 14. The minimum GCS was 9, corresponding to a 58-year-old man with recurrent glioblastoma. Also, the median KPS of the patients was 80, the minimum of which was 10 and related to the same patient with glioblastoma recurrence.
Regarding the location of the lesions, most of the lesions were observed in the frontal lobe and mostly on the left side. In 32% of patients (6 out of 19 patients), the tumor was located in the eloquent area, and the lesion had an ill margin in 17 out of 19 patients.
3 patients died after surgery and they were excluded from the analysis. In the remaining 16 patients, the average length of surgery was 3 hours, with a minimum of 1.5 hours and a maximum of 5 hours. The average intraoperative bleeding was 350 cc. Also, in examining the consciousness, the average GCS was 10.4 in one hour after surgery, 12.3 in 6 hours after surgery, and 12.8 in 24 hours after surgery. The average length of hospitalization in 16 patients with glioma who survived was 9.3 days, with a minimum hospitalization time of 3 days and a maximum of 38 days.
In 16 patients of this study, the size and amount of tumor resection were calculated according to the imaging done before and after the surgery. The mean size of the tumor in pre-surgical imaging was 30.44 cc. The smallest tumor was 3.5 cc in a 47-year-old woman with complaints of headache and convulsions, whose lesion was located in the right parietal, with glioblastoma pathology. There were no lesions left in imaging after surgery. Also, the largest tumor was 74 cc in a 52-year-old man with a complaint of anxiety. In imaging, a butterfly-type glioma was observed with frontal involvement on both sides (predominantly on the right side). In the post-surgery examination, only 56% of the tumor was resected, which happened due to the proximity of the lesion to the lateral ventricle and preventing the opening of the ventricle.
In the post-surgery imaging, the mean tumor size was 4 cc. In evaluating the extent of resection, an average of 90.5% of the tumor was resected. The largest residual tumor of 32 cc was related to the patient with a butterfly tumor, which was mentioned earlier.
Out of 16 patients examined, 11 patients were extubated in the operating room. The reason for non-extubation in 5 other patients was low GCS.
Based on the extent of resection, the amount of resection was divided into three categories: gross total resection (GTR) with a tumor removal rate of more than 95%, subtotal resection (STR) with a tumor removal rate between 80 and 95%, and partial resection (PR) with a tumor removal rate of less than 80%. According to this classification, there was only one patient with partial resection in the study.
In the comparison between the amount of resection and the complications after surgery, it was observed that resection of GTR is related to the amount of dysphagia experienced by the patient after surgery. It was also observed that the rate of extubation in women is significantly higher than in men. All 6 women in the study were extubated in the operating room, whereas only 5 out of 10 men were extubated during surgery. The study did not find any correlation between complications and the amount of tumor resection or bleeding, nor hospitalization of patients. However, more comprehensive studies are needed for a more detailed investigation.
Conclusion: Ultrasound during surgery can be used as a modality in brain tumor surgery because it has efficient results, and its use is easy and cheap. Although ultrasound cannot be considered as a substitute for other modalities during surgery to monitor the patient, its use can be beneficial for the patient.
Among the important advantages of using ultrasound during surgery that were observed in the patients of this study, we can mention the possibility of detecting the ventricles in the periphery of the tumor and preventing entry into the ventricle during surgery, which prevents the occurrence of significant complications such as ventriculitis. One of the reasons why complete resection was not performed in some patients was the long interval between preoperative imaging and surgery, which caused some tumor foci to be missed during surgery.
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Type of Study: Research | Subject: Neurosurgery

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