ANAL-SPHINCTER RECONSTRUCTION WITH THE GLUTEUS MAXIMUS MUSCLE - ANATOMIC AND PHYSIOLOGICAL CONSIDERATIONS CONCERNING CONVENTIONAL AND DYNAMIC GLUTEOPLASTY
Pj. Guelinckx et al., ANAL-SPHINCTER RECONSTRUCTION WITH THE GLUTEUS MAXIMUS MUSCLE - ANATOMIC AND PHYSIOLOGICAL CONSIDERATIONS CONCERNING CONVENTIONAL AND DYNAMIC GLUTEOPLASTY, Plastic and reconstructive surgery, 98(2), 1996, pp. 293-302
Myoplasties have acquired an important place in anal sphincter repair.
The use of the gluteus maximus muscle for sphincterplasty was reporte
d initially in 1902. However, in 1952, the gracilis sphincterplasty be
came more popular because of the accessibility of this muscle. Unfortu
nately, continence rates, especially after graciloplasty, remained unp
redictable because of inability to maintain muscle contraction despite
training programs. Training should induce a shift in muscle fiber typ
e distribution toward a more fatigue-resistant composition, with predo
minance of type I fibers. In order to obtain a more pronounced adaptat
ion in the contractile, histochemical, and metabolic properties of mus
cle fibers, postoperative intermittent long-term stimulation of the gr
aciloplasty was performed. As these results and the results of dynamic
cardiomyoplasty with an implantable myostimulator proved to be succes
sful, implantable pulse generators were used after graciloplasty. Subs
equently, continence rates after graciloplasties improved significantl
y. These data encouraged us to perform dynamic gluteoplasties for anal
sphincter repair. This paper presents the results in 7 patients treat
ed by conventional and 4 patients treated by dynamic gluteoplasty. Adv
antages and disadvantages of gluteoplasty were compared with those of
graciloplasty. The neurovascular pedicle of the gluteoplasty underwent
less traction after transposition compared with the graciloplasty bas
ed on cadaver studies. Gluteus muscle transfer far exceeded the amount
of muscle tissue of a normal anal sphincter despite muscle atrophy af
ter transposition. This guaranteed a contractile muscle cuff around th
e anal canal in contrast to the tendinous sling after graciloplasty. B
ecause of the excellent vascularization of the muscle, microperforatio
ns of the rectal mucosa caused by submucosal dissection were sealed, a
nd implantation of electrodes and a pulse generator in one surgical in
tervention was well tolerated. The myoplasty induced a double curvatio
n of the anal canal in contrast to the graciloplasty, which enhanced t
he natural anorectal angle. Patient evaluation revealed continence for
stool in 9 of the 11 patients; 7 of the 11 patients also were contine
nt for liquids, among them all of the patients who had undergone dynam
ic gluteoplasties. Mean basal pressure after dynamic gluteoplasty was
49 mmHg, which is lower than the reported mean basal pressure (62 mmHg
) during stimulation after dynamic graciloplasty. Squeeze pressure aft
er gluteoplasty, with or without stimulation, proved to be similar to
or higher than that obtained in dynamic graciloplasty. Comparing our r
esults of conventional gluteoplasty with the results of graciloplasty
prior to stimulation, higher pressures were obtained by the gluteoplas
ty, especially in squeeze pressures. In the last 5 patients intraopera
tive pressure measurements were used to restore the optimal resting le
ngth of the muscle after transposition. An intraluminal pressure of at
least 40 mmHg during rest and 80 to 120 mmHg during stimulation shoul
d be obtained to guarantee a future continent sphincter.