The Xiao ProceduredWhat Have we Learned?

THE Xiao procedure, in which a skin central nervous
system/bladder reflex arc is created by lumbar to
sacral nerve rerouting, created an intense interest
in the urological and neurosurgical communities, as
well as raised the hopes of many patients who were
desperate to gain normal bladder and bowel function
without resorting to the traditional paradigm of
clean intermittent catheterization, antimuscarinic
agents and, at times, surgical reconstruction (such
as enterocystoplasty). In this issue of The Journal
Tuite et al (page 1735) report underwhelming results
from a prospective, randomized, double-blind
study examining this operation.1 They compared
patients who underwent cord detethering with and
without the Xiao procedure. Along with a host of
previous studies, this series makes it clear that the
initial enthusiasm for the Xiao concept as a method
to restore bladder and bowel function in patients
with spina bifida must be tempered.
The neurophysiological basis of this surgical
innovation had substantial scientific support.2 When
this technique was translated into the clinical arena,
the initial results of Xiao et al were nothing short of
spectaculardnearly 4 of 5 patients who underwent
the procedure gained near normal bladder and bowel
storage and emptying function within 12 to
18 months.3 On the heels of these promising results
many investigators, including urologists and neurosurgeons,
from various academic institutions around
the world went to learn this surgical technique from
Xiao himself in China. In many instances Xiao was
invited as a consultant. However, as many programs
attempted to replicate these results, it became clear
that objective improvements were marginal and patient
subjective improvement of bladder function did
not correlate with urodynamic findings. More
importantly the initial studies of Xiao et al demonstrating
success did not have an appropriate control
group, and, furthermore, they were neither randomized
nor blinded.
Designing and executing a randomized blinded
study involving a surgical procedure is a huge undertaking,
although as shown by Tuite et al,1 its
importance cannot be overemphasized, especially
when the desired outcome involves subjective
reporting of quality of life improvement. Tuite et al
report that not only was there no difference in terms
of gaining bladder emptying function between the 2
groups, but when asked to assess which patient was
in which group, ie experimental (with the Xiao procedure)
or control (without), neither the patients,
urologists nor study coordinators could predict. In
fact, the accuracy was about as good as a coin flip.
There were some differences between the 2 groups.
Total bladder capacity, suppression of uninhibited
bladder contractions and quality of life were better in
the group undergoing the Xiao procedure, which the
authors speculated could be due to sacral rhizotomy
rather than the proposed somatic-autonomic reflex
arc. Most importantly the outcome desired most by
patients, ie ability to empty the bladder without
clean intermittent catheterization, did not occur in
the group undergoing the Xiao procedure.
As scientists and clinicians, it is our duty to
continuously seek innovation and not simply settle
for the status quo. This pursuit requires outside the
box thinking that may require a departure from the
conventional wisdom. In this regard the Xiao procedure
is a wonderful example of bringing the bench
to the bedside and, thus, allowing the scientific
discoveries to push the boundaries of clinical innovation.
It is also an important reminder that our
excitement and enthusiasm must be tempered by
humility. Sometimes we stumble onto clinical findings
that seem to affirm our hypothesis but this can
quickly lead to unchecked confirmation of our biases.
As at many academic institutions, the motto for
the University of Michigan is “Artes, Scientia and
Veritas” (Art, Knowledge and Truth). The practice
of medicine is an art, and we are to constantly seek
to improve our knowledge by science. However, in
the end what we are ultimately after is the truth.
Confirmation of truth requires validation by many
in the community. In the case of the Xiao procedure
the truth is still out there.
John M. Park
Division of Pediatric Urology
C. S. Mott Children’s Hospital
University of Michigan Medical School and Health System
Ann Arbor, Michigan
0022-5347/16/1966-1608/0
THE JOURNAL OF UROLOGY®

2016 by AMERICAN UROLOGICAL ASSOCIATION EDUCATION AND RESEARCH, INC.
http://dx.doi.org/10.1016/j.juro.2016.09.069
Vol. 196, 1608-1609, December 2016
Printed in U.S.A.
1608 j www.jurology.com
REFERENCES
1. Tuite GF, Homsy Y, Polsky EG et al: Urological outcome of the Xiao procedure in children with myelomeningocele and lipomyelomeningocele undergoing spinal cord
detethering. J Urol 2016; 196: 1735.
2. Xiao CG, de Groat WC, Godec CJ et al: “Skin-CNS-bladder” reflex pathway for micturition after spinal cord injury and its underlying mechanisms. J Urol 1999; 162: 936.
3. Xiao CG, Du MX, Li B et al: An artificial somatic-autonomic reflex pathway procedure for bladder control in children with spina bifida. J Urol 2005; 173: 2112.