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148 Clinical Pathways in Neuro-Ophthalmology, second edition
What Is the Surgical Management of PTC?
When medical therapy fails or when visual dysfunction deteriorates, surgical therapies
for PTC should be considered (Corbett, 1989). The indications for surgical therapy, as
suggested by Corbett and Thompson, are outlined in Table 7–11 (Corbett, 1989). The
two main procedures performed include lumboperitoneal shunt (LPS) and optic nerve
sheath fenestration (ONSF). Various authorities have vehemently advocated one or the
other procedure and both have their advantages and disadvantages, but there has been
no prospective study comparing the efficacy of the two procedures.
Lumboperitoneal shunt can relieve headache, diplopia, and papilledema, and can
reverse visual loss (Angiari, 1992; Burgett, 1997; Eggenberger, 1996; Johnston, 1988a,b;
Lundar, 1990; Rosenberg, 1993). This procedure may be performed if warranted in
pregnancy (Shapiro, 1995). Eggenberger et al retrospectively studied 27 patients with
PTC treated with at least one LPS to ascertain the efficacy of this treatment
(Eggenberger, 1996). The indications for LPS were intractable headache in 18 patients
(67%) and progressive optic neuropathy in 14 patients (52%). Visual function returned
to normal in both eyes of six patients, showed no change in either eye in four patients,
and improved in at least one eye in the remaining four. Four patients had unilateral and
one had bilateral sixth nerve palsies; all completely resolved postsurgery. The average
duration of follow-up for this population was 77 months (mean 47 months). A
functioning LPS was successful in alleviating symptoms in all of the patients studied
and no patient with a functioning shunt complained of shunt-related symptoms, such as
low-pressure headache or abdominal pain, within 2 months after the shunt was
performed.
The major complication of LPS is shunt failure requiring revision. The authors
concluded that placement of a LPS is a satisfactory treatment for the majority of
patients with PTC who require surgical therapy for the disorder even though some
patients ultimately require multiple shunt revisions.
Rosenberg et al reviewed the efficacy of cerebrospinal diversion procedures for PTC
in patients from six different institutions (Rosenberg, 1993). Thirty-seven patients
underwent a total of 73 LPS and 10 ventricular shunts. Only 14 patients remained
‘‘cured’’ after a single surgical procedure. The average time between shunt insertion and
shunt replacement was 9 months, although 64% of the shunts lasted less than 6 months.
Shunt failure (recurrent papilledema or increased CSF pressure on lumbar puncture)
(55%) and low-pressure headaches (21%) were the most common indications for
reoperation. Other reasons for shunt replacement included infection, abdominal pain,
radicular pain, operative complications, and CSF leak. The vision of most patients
improved (13) or stabilized (13) postoperatively. However, three patients who had
initially improved subsequently lost vision, six had a postoperative decrease in vision,
two patients improved in one eye but worsened postoperatively in the other, and four
lost vision despite apparently adequate shunt function. Shunt failure with relapse of
PTC occurred as late as 7 years after insertion. The authors concluded that CSF
diversion procedures have a significant failure rate as well as a high frequency of
side effects. Johnston et al reported 36 patients who during follow-up required a total
of 85 shunting procedures with an overall complication rate of 52% and a failure rate of
48% (Johnston, 1988a).
Burgett et al retrospectively analyzed clinical data from 30 patients who underwent
LPS for PTC and found LPS an effective means of acutely lowering intracranial pressure