Ventriculoperitoneal shunt abdominal complications
Protrusion of the catheter from the anus
Spontaneous knotting of the peritoneal catheter is a rare complication of the VP shunt 3).
Pyogenic liver abscess in Taiwan is most commonly due to Klebsiella pneumoniae infection in diabetic patients, and less frequently due to biliary tract infections. Liver abscess caused by ventriculoperitoneal (VP) shunt is very rare. We report a case of liver abscess caused by methicillin-resistant Staphylococcus aureus (MRSA), which developed as a complication of an infected VP shunt. A 53-year-old woman, who had shad a VP shunt implanted 3 months previously for hydrocephalus due to intracranial hemorrhage, presented with fever off and on, drowsiness and seizure attacks for 1 week. Computed tomography (CT) of the brain showed only mild right-sided hydrocephalus, and was negative for intracranial hemorrhage and intracranial mass. Analysis of cerebrospinal fluid showed significant pleocytosis and hypoglycorrhachia. CT scan of the abdomen disclosed a huge abscess in the right lobe of the liver. Cultures of both the cerebrospinal fluid and aspirated liver abscess isolated MRSA. The patient was treated with intraventricular and intravenous vancomycin, intravenous teicoplanin and oral rifampicin, followed by oral chloramphenicol and rifampicin. Percutaneous drainage of the liver abscess and externalization of the VP shunt were performed. The liver abscess had resolved almost completely on ultrasonography after 2 weeks of therapy. Liver abscess in patients with a VP shunt should be considered a possible abdominal complication of the VP shunt, and may be caused by unusual pathogens. Diagnosis requires CT scan and direct aspiration and culture of the liver abscess. Treatment requires management of both the liver abscess and the infected shunt 4).
The formation of a liver pseudocyst is a rare occurrence, and its mechanisms are still largely unknown.
Mallereau et al. reported the case of a 69-year-old woman with a ventriculoperitoneal shunt, inserted for the management of hydrocephalus after aneurysmal subarachnoid hemorrhage, presenting to the Accident and Emergency for acute cholecystitis. Besides confirming the diagnosis, an ultrasound investigation revealed the presence of a hepatic cyst. Conservative treatment with antibiotics and non-steroidal anti-inflammatory drugs was performed with favorable outcomes and resorption of the cyst. Interestingly the patient kept on presenting several similar episodes managed well by non-steroidal anti-inflammatory drugs alone, each of them associated with transient symptoms and signs of ventriculoperitoneal shunt malfunction. Computerized Tomography brain and lumbar puncture were normal, whereas the CT abdomen showed the ventriculoperitoneal shunt distal catheter passing through the hepatic cyst. Given the ventriculoperitoneal shunt malfunction, in the context of an infective/inflammatory process, a conversion of the ventriculoperitoneal shunt into a ventriculoatrial shunt was carried out with a successful clinical outcome.
Based on current literature they propose a clinical and radiological classification of such pseudocysts related to ventriculoperitoneal shunt. Clinical presentation, diagnostic findings, and management options are proposed for each type: purely infective, spurious (infective/inflammatory), and purely inflammatory. In the absence of system infection, a simple replacement of the distal catheter seems to be the best solution 5).
Optic nerve sheath diameter
In a study of Agrawal et al. optic nerve sheath diameter demonstrated a modest, statistically significant correlation with intracranial pressure, a predetermined level of diagnostic accuracy to justify routine clinical use as a screening test was not achieved. Measurement of optic disc elevation appears promising for the detection of elevated intracranial pressure, however, verification from larger studies is necessary 4).
Optic nerve sheath diameter ultrasonography
1) Hansen HC, Helmke K. Validation of the optic nerve sheath response to changing cerebrospinal fluid pressure: Ultrasound findings during intrathecal infusion tests. J Neurosurg. 1997;87:34–40.2) Helmke K, Hansen HC. Fundamentals of transorbital sonographic evaluation of optic nerve sheath expansion under intracranial hypertension. I. Experimental study. Pediatr Radiol. 1966;26:701–5.3) Liu M, Yang ZK, Yan YF, Shen X, Yao HB, Fei L, Wang ES. Optic nerve sheath measurements by computed tomography to predict intracranial pressure and guide surgery in patients with traumatic brain injury. World Neurosurg. 2019 Oct 17. pii: S1878-8750(19)32683-X. doi: 10.1016/j.wneu.2019.10.065. [Epub ahead of print] PubMed PMID: 31629929.4) Agrawal D, Raghavendran K, Zhao L, Rajajee V. A Prospective Study of Optic Nerve Ultrasound for the Detection of Elevated Intracranial Pressure in Severe Traumatic Brain Injury. Crit Care Med. 2020 Oct 13. doi: 10.1097/CCM.0000000000004689. Epub ahead of print. PMID: 33048902.