SURG-01. CYSTIC BRAIN METASTASES MANAGED WITH RESERVOIR PLACEMENT AND STEREOTACTIC RADIOSURGERY

BACKGROUND Stereotactic radiosurgery (SRS) has become a mainstay of treatment for patients with metastatic brain tumors. However, metastatic tumors with a large cystic component often exceed the size limit for safe and effective SRS. In such cases, surgical resection may not be the preferred first method of treatment, due to tumor location, patient co-morbidities, and patient preference. In such cases volume reduction by cyst aspiration followed by SRS may be a preferred option. OBJECTIVE To present the treatment of patients with cystic metastases using reservoir placement followed by SRS. METHODS Seven patients were treated with this method. We performed reservoir insertion for the aspiration of cystic component in each patient and followed that with outpatient SRS. RESULTS Mean overall volume reduction from this treatment method was 80% (range 46.5-94.9). Mean volume reduction from the cyst aspiration alone was 60.7% (range 3.5-90.9), and after SRS a further 71.6% (range 34.6-94.4), accounting for some cyst reaccumulation between the time of surgery and SRS. The interval between those two procedures were 24 days on average (range 11-58 days). Repeat reservoir aspiration was done a total of 10 times in 5 patients. CONCLUSION Cyst aspiration with reservoir placement followed by SRS is a good option for patients with large cystic brain metastases. The reservoir allows for repeat aspiration if needed. Catheter placement at the center of the cyst, and SRS within 2-3 weeks of surgery, can maximize the likelihood of a successful outcome.

19 10 Years of Tertiary Paediatric Centre Experience of Females Undergoing Surgery for Ovarian Torsions

Aim Review role and accuracy of imaging, and subsequent management, of patients with ovarian torsion managed at a tertiary paediatric centre. Method Retrospective review of notes for patients undergoing surgery for ovarian torsion over 10 years (2010-2019). Results 23 patients underwent surgery for ovarian torsion (one excluded due to lack of data). Median age 12 years[range 1-15]. 18/22 patients underwent imaging; 15/18 had USS, 12/15(80%) were diagnostic for ovarian torsion. 3/15 showed ovarian pathology prompting further imaging/surgery. 2/22 had initial MRI, 1 diagnostic for torsion. Time from symptom onset to surgery was assessed, data was incomplete for 4 patients. 10 patients were referred from ED/primary care; 5(50%) underwent theatre within 12 hours, 3(30%) 12-12hours and 2(20%) >24hours. 8 patients were referred from external hospitals; 2(25%) underwent theatre within 12 hours, 4(50%) 12-12hours and 2(25%) >24hours. Those having surgery>24 hours from symptom onset were awaiting imaging or had suspected other pathology. 4/22 underwent oophorectomy (open:laparoscopic=3:1) and 18/22 had detorsion +/- cyst aspiration/excision (open:laparoscopic:converted=2:15:1). Follow up imaging was performed in 13/18 patients who underwent detorsion and 2/5 who underwent oophorectomy. Of 3 patients undergoing oopherectomy who did not have follow up; 2 had benign cysts and 1 had a simple tubo-ovarian torsion. Conclusions We advocate early USS in females with presentation concerning for ovarian torsion, though a high index of suspicion is often required owing to non-specific symptoms. Imaging and transfer should be performed promptly to prevent delays in surgical management.

A clinicopathological study of ovarian endometriotic cysts

Endometriosis is an important gynecologic disorder with multifactorial causes, primarily affecting women during their reproductive years. Pathologically, it is the result of functional endometrium located outside the uterus which may vary from microscopic endometriotic implants to large cysts. Endometriotic cysts and infertility is a well-known association. Some patients are asymptomatic while others present with disabling pelvic pain, infertility, or adnexal masses. Cyst aspiration, fenestration and ablation of cyst wall are commonly performed surgical procedures. Excision of the cyst wall is an accepted surgical treatment owing to the low recurrence rates. A total of 35 patients who underwent ovarian cystectomy for endometriotic cysts between January 2019 and December 2020 were retrospectively identified. The clinical findings, gross and histopathological features were noted in each case. Microscopically, the presence or absence of ovarian tissue adjacent to the cyst wall was evaluated. If ovarian tissue was present, the morphologic characteristics were graded on a semi-quantitative scale of 0-4 as described by Muzii et al. The age group of patients ranged between 22-28yrs. Right side cysts accounted for the majority, however 6 cases had bilateral endometriotic cysts. Majority of patients presented with primary infertility (46.2%). The maximum weight recorded for these cysts was 35gm, size ranging between 4.5 to 18cm and median thickness of the cyst wall being 0.7cm. 68% of the cysts showed a lining epithelium, few showing atypia and oncocytic change. Fibrosis and hemosiderin laden macrophages were present in more than 70% of cases and endometrial glands and stroma in more than 50%. Inflammation when present was predominantly lymphocytic. On evaluation of the ovarian tissue, 42.8% of cases showed no follicles and the rest showing grades ranging from 1 to 4, with grade 1 accounting for majority. The present study further emphasizes endometriosis to be an important cause of primary infertility which needs to be recognized and treated appropriately. Recognition of these cysts on histopathological examination can be challenging at times when endometrial stroma is scant and in cases of tubo-ovarian masses where these lesions could mimic malignancy. The excision of endometriotic cyst wall may cause loss of functional ovarian tissue in patients with primary infertility and thus could effect the response to ovarian stimulation, ocyte recovery, implantation and fertilization rates in these patients.

RADI-01. Cystic brain metastases managed with reservoir placement and stereotactic radiosurgery

Background Stereotactic radiosurgery (SRS) has become a mainstay of treatment for patients with metastatic brain tumors. However, metastatic tumors with a large cystic component often exceed the size limit for safe and effective SRS. In such cases, surgical resection may not be the preferred first method of treatment, due to tumor location, patient co-morbidities, and patient preference. In such cases volume reduction by cyst aspiration followed by SRS may be a preferred option. Methods Seven patients were treated with this method. We performed reservoir insertion for the aspiration of cystic component in each patient and followed that with outpatient SRS. Results Mean overall volume reduction from this treatment method was 80% (range 46.5–94.9). Mean volume reduction from the cyst aspiration alone was 60.7% (range 3.5–90.9), and after SRS a further 71.6% (range 34.6–94.4), accounting for some cyst reaccumulation between the time of surgery and SRS. The interval between those two procedures were 24 days on average (range 11–58 days). Repeat reservoir aspiration was done a total of 10 times in 5 patients. Conclusion Cyst aspiration with reservoir placement followed by SRS is a good option for patients with large cystic brain metastases. The reservoir allows for repeat aspiration if needed. Catheter placement at the center of the cyst, and SRS within 2–3 weeks of surgery, can maximize the likelihood of a successful outcome.

Parathyroid cyst: A rare entity

Parathyroid cysts are an uncommon entity. They are classified as functioning and nonfunctioning cysts. Cyst aspiration with detection of parathyroid hormone is a useful tool to confirm the diagnosis. Here, we report four cases of parathyroid cysts. One patient had a functioning cyst. Ultrasonography of the neck revealed a cystic lesion behind the left lobe of the thyroid gland in two cases and a right cystic thyroid nodule in two cases. The cysts exerted a mass effect on the adjacent structures in two cases without clinical compressive symptoms. Fine-needle aspiration with detection of parathyroid hormone in the cyst fluid was performed in one case (nonfunctioning cyst): intracystic parathyroid hormone level was high. Recurrence was noted 1 month after the cyst aspiration. All patients underwent surgical treatment. Our series is characterized by two cases of nonfunctioning intrathyroidal parathyroid cysts which are very uncommon. They are mistaken for thyroid cysts. After surgery, no recurrence was noted. We aim to describe the epidemiological, clinical, and paraclinical features of this condition as well as its therapeutic modalities.

Percutaneous cyst aspiration with injection of two different bioresorbable bone cements in treatment of simple bone cyst

Introduction Simple bone cysts (SBCs) are common in children and adolescents. The risk of refracture and the probability of spontaneous healing in SBCs are mainly dependent on the activity of the cyst and can be quantified with the Cyst-Index. Avoiding pathological fractures is the primary goal. Our study presents a comparison of two different bioresorbable bone graft substitutes (BGSs) in the minimally-invasive treatment of SBC in the active stage by percutaneous cyst aspiration and injection. Methods Between 2006 and 2017, 38 patients (aged two to 37 years; mean age 12.4 (sd 5.6)) were treated with percutaneous cyst aspiration and refilled with bioresorbable BGSs in three hospitals. The cysts of 21 patients (11 humerus, five femur, four calcaneus, one fibula) were refilled with porous beta-tricalcium phosphate (PB-TP group) (ChronOS Inject) and of 17 patients (nine humerus, six femur, one calcaneus, one fibula) with hydroxyapatite/calcium sulphate (H/CS group) (CERAMENT|BONE VOID FILLER). There were 13 (62%) preceding fractures in the PB-TP group and eight (47%) in the H/CS group. The follow-up of all patients was at least two years. During follow-up, radiological healing (modified Neer classification), activity level, refracture rates, recurrence rates, resorption period and complications were analyzed. Results In all, 21 patients treated with PB-TP group experienced 27 operations (one refracture, three recurrences and one persistent cyst). A total of 17 patients treated with H/CS experienced 20 operations (one refracture and one recurrence). After six weeks, 95% in the PB-TP group returned to unrestricted activity with one refracture in the femur due to insufficient biomechanical stability and all returned to unrestricted activity in the H/CS group. Partial or complete radiological response was observed in 81% after 13 months (sd 3.4). Three recurrences (14%) occurred in the PB-TP group and one recurrence (6%) occurred in the H/CS group. The refracture rates were similar in both groups; one (5%) in the PB-TP group and one (6%) in the H/CS group. All H/CS treated cysts showed completed resorption after two years, whilst in PB-TP treated cysts no resorption occurred in five cases (25%) (p = 0.031). Two (10%) wound infections occurred in the PB-TP group and no infections occurred in the H/CS group. Conclusion Both PB-TP and H/CS can provide stability and prevent refracture in patients with single bone cysts at the upper extremity or the foot. For the proximal femur, additional stabilization is necessary, due to the weight-bearing and associated high refracture rate. The H/CS bone graft substitute has a better resorption rate than the PB-TP graft. Level of Evidence III

Anterior segment optical coherence tomography of intrastromal corneal cysts

We report a case of six-year-old boy who presented with a progressive intracorneal cyst in the left eye. Anterior segment optical coherence tomography (AS-OCT) was performed, and it showed the location of the cyst in the corneal stroma. Its dimension was measured to be 7.09 Å~ 2.12 mm. The cyst aspiration was successfully done. AS-OCT helped in the management and follow-up of the condition.