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Srinivasan, Siddharth

https://orcid.org/0000-0002-6882-9339

Mayo Clinic

University of Glasgow

Citations 2

Pineal parenchymal tumor of intermediate differentiation: Case series and literature review: Is it time for a consensus?
Srinivasan, Siddharth , Jampani, Ravi Teja, Chigurupati, Dhanwanth, Raju, Bharat , Subramanian, Susanth , Baxi, Udgam, Kanneganti, Yasaswi, Johnson, Sarah H. , Nayal, Bhavna, Vasudevan, Geetha , M, Deepak Nayak , Johnson, Sarah, Hegde, Ajay , Nair, Rajesh Parameshwaran , Ashraf, Mohammad, Menon, Girish

Surgical Neurology International | April 18, 2025 | Volume: 16 | Issue: No issue available | Pages: 138

10.25259/sni_1068_2024 Get It

Background Pineal parenchymal tumor of intermediate differentiation (PPTID) is a rare tumor. This study aims to evaluate patient outcomes and propose a treatment algorithm based on existing literature and our case series. Methods This prospective observational study includes seven patients diagnosed with PPTID through histopathology. We analyzed their clinical presentation, magnetic resonance imaging findings, surgical approaches, histopathological and immunohistochemical analysis, adjuvant treatments, and outcomes. We conducted univariate and multivariate statistical analyses. Results The mean patient age was 40 years, with a male predominance. All patients presented with hydrocephalus, four of which required cerebrospinal fluid diversion procedures. The average tumor size was 3.13cm, with 85.7% showing brain invasion. Surgical outcomes included one gross total resection, two near total resections, and four subtotal resections. The supracerebellar infratentorial (Krause) approach was used in 71.4% of cases. About 85.7% were diagnosed with grade 3 PPTID. Five patients received adjuvant radiotherapy. The analysis showed each additional mitosis unit decreased survival by 0.17 units, equating to roughly 2 months (P < 0.016). Follow-up ranged from 6 to 120 months, with a 5-year survival rate of 57.1%. Factors influencing survival included the extent of tumor resection, brain invasion, tumor grade, and adjuvant treatment, although it was not statistically significant due to the small sample size. Conclusion We propose a treatment algorithm for PPTID and highlight the importance of further research to understand its biological characteristics. Safe maximal resection appears beneficial for higher-grade PPTID, but the role of adjuvant treatment after complete resection of lower-grade tumors remains uncertain.
Intrapleural Migration of Ventriculoperitoneal Shunt due to Negative Intrathoracic Pressure
Srinivasan, Siddharth , Kanneganti, Yasaswi, Hegde, Ajay , Johnson, Sarah H. , Hegde, Ajay , Johnson, Sarah, Menon, Girish , Nair, Rajesh Parameshwaran

Asian Journal of Neurosurgery | June 7, 2024 | Volume: 19 | Issue: 03 | Pages: 408-411

10.1055/s-0044-1787675 Get It

Abstract Background Ventriculoperitoneal (VP) shunt is still a mainstay of treatment in centers for infants with aqueductal stenosis which is the most common cause of congenital obstructive hydrocephalus. Shunt migration remains a common complication. Delayed distal shunt tip migration into the thoracic cavity due to negative intrathoracic pressure is a rare occurrence. Case Presentation Authors report a 1-year-old infant presenting with drowsy sensorium, increasing head circumference, and bulging anterior fontanelle. Magnetic resonance imaging of the brain revealed significant obstructive hydrocephalus with periventricular seepage. A large expansile diverticulum of the suprapineal recess extending infratentorially compressing the dorsal midbrain and cerebellum inferiorly. The child underwent an emergency right-side VP shunt (medium pressure) in view of clinical symptoms of raised intracranial pressure. A right iliac fossa infraumbilical transverse incision was taken for placing the abdominal end. Visual confirmation of bowel was done after opening the peritoneum by two operating surgeons prior to inserting the distal catheter. Postoperative course was uneventful. The child presented 3 months later with acute dyspnea and diminished breath sounds on the right hemithorax. Neurologically, the child was active, feeding well, and anterior fontanelle was lax. A chest roentgenogram and computed tomogram (CT) of the thorax revealed complete shunt migration into the pleural space with significant pleural effusion on the right side. The distal shunt system on CT appeared to enter the pleural space below the 8th rib, probably indicating that there was subcostal tunneling of the shunt below the 8th rib space during the first surgery which was inconspicuous and subsequently over a span of 3 months due to sucking effect of negative intrathoracic pressure the shunt gradually migrated into the pleural cavity which led to the effusion. An emergency VP shunt revision was performed. The distal end below the chamber was retunneled subcutaneously into a new incision in the left paraumbilical region. Postoperative chest and abdomen roentgenograms showed resolving effusion and accurate shunt placement. The child required elective ventilation temporarily to tide over the underlying lung collapse and an intercostal tube drainage for the cerebrospinal fluid (CSF) hydrothorax for 2 days to aid in quicker weaning. The child was discharged on the 5th postoperative day. Discussion Intrapleural migration of VP shunts has been contemplated to be due to trauma during surgery, migration across foramen of Bochdalek or Morgagni, and negative intrathoracic pressure. Taub and Lavyne have classified thoracic complications of VP shunt as thoracic trauma during shunt tunneling, supradiaphragmatic migration of shunt or transdiaphragmatic migration of shunt, and pleural effusion complicated by CSF ascites. Transdiaphragmatic migration is commonly seen in pediatric population and supradiaphragmatic migration can be seen in any age group. We believe our case to be a type of supradiaphragmatic migration of the shunt which has occurred slowly over a span of time due to the negative intrathoracic pressure. The idea behind this clinical case image is to edify neurosurgeons, pediatricians, and intensivists to remain wary of such a complication.