Metabolic acidosis: Acetazolamide will interfere with bicarbonate resorption in the kidneys, with a tendency to acidify the blood.
Dehydration: Acetazolamide is a mild diuretic and causes increased urination, with dehydration resulting unless fluid consumption is increased.
Calcium phosphate kidney stones: The renal tubular acidosis that results with chronic acetazolamide use can lead to the development of calcium phosphate calculi. This type of stone is uncommon. Its formation has been reported to be associated with long-term use of acetazolamide (61).
Infection:Most studies report a 5% or less rate of infection, with most infections occurring within several months of shunt placement. Treatment is usually antibiotics and a change in the shunt hardware once the infection is controlled.
Mechanical failures in hardware: Mechanical failures include occlusion, fracturing of material, migration of catheters or valves, and improper placement. Treatment is replacement of the failed portion of the system.
Overdrainage: Chronic overdrainage by a shunt can result in symptoms such as headache or orthostatic hypotension and secondary complications such as subdural collections, craniosynostosis, loculations of ventricles, and the slit ventricle syndrome.
Hemorrhage: Large series have reported a 1–2.5% incidence of hemorrhage. Although many hemorrhages do not interfere with the completion or success of the surgery, some can cause major disruption of postoperative management and failure in the attempted ETV (40, 41). There have been three cases reported where death resulted (41).
Injury to fornix and memory circuits: While rare, postoperative difficulties with memory have been reported with an incidence of less than 1% (40, 41).
Stretching of third nerve: Injury can occur to cranial nerves with resulting gaze paresis. While unusual (<1%), this injury does occur and typically is to the third nerve (41).
Injury to hypothalamus: Hormonal disruption has been reported to occur after an ETV (40, 41).
Inadequate management of hydrocephalus: Most series reporting on the success of ETVs for managing hydrocephalus cite a 60–75% success rate (11, 40, 42, 43). The majority of failures occur shortly after the surgery, with CSF leaks and signs of intracranial hypertension being the primary signs of failure.
Failure of ETV and death: There have now been reports of unrecognized obstruction of an ETV with death resulting from elevation in the ICP. Any patient with an ETV should be managed with this concern in mind (35, 36, 88).