Добавил:
Sekretar
kiopkiopkiop18@yandex.ru
t.me/Prokururor I Вовсе не секретарь, но почту проверяю
Опубликованный материал нарушает ваши авторские права? Сообщите нам.
Вуз:
Предмет:
Файл:Ординатура / Хирургия / Библиотека им академика М.И. Перельмана / Книга_1784_Библиотеки_им_академика_М_И_Перельмана.pdf
228 Stern and Dalton
Figure 11 Occasionally stoma stenosis can be managed by interposition of full-
thickness skin (A). Severe cases require total reconstruction (B), although simple
advancement of the conduit may suffice.
Peristomal hernias, stoma prolapse, chronic intestinal fistulas, and
peristomal skin complications are dealt with elsewhere in this text and are
not discussed here.
When urine comes in contact with bowel mucosa, electrolyte and free-
water transfer can occur, resulting in metabolic abnormalities. The ileum
plays primarily an absorptive role; therefore patients with ileal conduits can
develop a hypernatremic, hypokalemic, hyperchloremic metabolic acidosis
[41]. This condition almost always occurs in the presence of renal insuffi-
ciency and can be treated with oral alkali. Occasionally a redundant conduit
secondary to either stomal stenosis or too long an ileal loop can result in a
Methods of Urinary Diversion 229
large amount of residual urine and hyperabsorption. These entities require
surgical correction.
Resection of large amounts of ileum can result in bile salt deficiencies
and steatorrhea or vitamin B
12
deficiency and megaloblastic anemia. These
conditions do not occur after a simple ileal conduit but may develop in
patients with previous small bowel resection or in whom large segments of
ileum are used in the construction of urinary reservoirs [42].
Filmer and Spencer [43] reviewed carcinogenesis in bowel segments
used for urinary diversion. Although adenocarcinoma occurring in an ileal
conduit is rare, several cases have been reported [44,45]. More commonly
described is adenocarcinoma in patients undergoing ileocystoplasty, sug-
gesting that long contact time between urine and bowel mucosa may play
a role in carcinogenesis.
SIGMOID COLON CONDUIT
Sigmoid colon conduit urinary diversion is used in those circumstances
when nonrefluxing ureteroenterostomies are desirable. When total pelvic
exenteration is required for locally advanced malignancies, a sigmoid colon
conduit obviates the need for an enteroenterostomy [46]. Mogg [47] popu-
larized the sigmoid colon conduit in the 1960s in an attempt to avoid the
complications of reflux.
Preoperative preparation is similar to that described for ileal conduits.
Again, the stoma site should be selected and marked preoperatively in the
left lower quadrant by the enterostomal therapist (ET), who must take body
habitus and scars into account.
The descending and sigmoid segments of the colon are mobilized
from the splenic flexure to the sacral promontory. A segment of sigmoid
colon approximately 20 cm long is selected and marked with stay sutures
(Fig. 12). The mesentery is carefully divided at right angles to the ends of
the conduit, with 4-0 silk sutures used for hemostasis. The distal mesenteric
division should include the superior hemorrhoidal artery to aid in mobility.
After removal of the attached fat and mesenteric attachments, the colon is
divided and the conduit is placed to the left. The colon is reapproximated
with either a hand-sewn or a stapling technique. The conduit is irrigated to
remove remaining intestinal contents, and the proximal end is closed in a
watertight manner with absorbable sutures.
Construction of nonrefluxing ureterocolostomies is performed accord-
ing to the method described by Leadbetter and Clarke [48]. The right ureter
is delivered under the sigmoid colon beneath the parietal peritoneum. Two
separate 5-cm incisions are made through the teniae, with care taken to
avoid injury to the mucosa (Fig. 13A). Submucosal instillation of saline
solution or saline with epinephrine (1:100,000) solution may facilitate dis-
230 Stern and Dalton
Figure 12 Sigmoid colon conduit. A, Segment of sigmoid colon approximately
20 cm long is selected and marked with stay sutures. B, Although adequate blood
supply should be ensured during creation of the sigmoid conduit, superior hemor-
rhoidal branch of inferior mesenteric artery may be divided to increase mobility of
distal segment.
section. Traction sutures of 4-0 silk are placed to aid in retraction, and the
mucosa is dissected from the muscular colon wall with fine scissors. The
end of each ureter is spatulated and a mucosa-to-mucosa anastomosis con-
structed with 5-0 chromic sutures (Fig. 13B). Stents are used at the sur-
geon’s discretion. The colonic wall is reapproximated with interrupted 4-0
silk sutures, with care taken to avoid obstruction of the ureter at the proxi-
mal tunnel (Fig. 13C). And additional stabilizing 4-0 chromic suture is
placed through the seromuscular layer of the ureter and the colon 2–3 cm
proximal to the tunnel. The nipple stoma is created as described for ileal
conduits with the exception of excising a slightly larger circle of skin and
subcutaneous tissue to accommodate the colonic segment.
TRANSVERSE COLON CONDUIT
The transverse colon conduit has been popularized by Schmidt [49]. It is
used primarily in situations where pelvic radiation has been given or mark-
Methods of Urinary Diversion 231
Figure 13 Antirefluxing ureterocolostomies. A 5 cm submucosal tunnel is cre-
ated for each ureter.
edly foreshortened ureters are present. The procedure essentially parallels
that of the sigmoid colon conduit, with the following exceptions.
The stoma can be placed in any of the four quadrants, allowing more
options if significant abdominal wall abnormalities are present. A 10- to
15-cm length of transverse colon is selected, and the greater omentum is
dissected from its superior surface. The blood supply is based on the middle
colic artery with extensive collateral circulation, making devascularization
of the segment unlikely (Fig. 14). The conduit is placed inferior to the
colon, and colocolostomy is performed according to the surgeon’s prefer-
ence. Colon conduits need not be placed in isoperistaltic fashion because
they empty by mass contraction. The end selected as the “nonstomal” end
should be closed in a watertight fashion. The ureters are delivered through
the posterior peritoneum with avoidance of angulation, and nonrefluxing
ureterocolostomies are constructed as described previously. Formation of
the nipple stoma is the same as discussed earlier.
232 Stern and Dalton
Figure 14 Transverse colon conduit.
ILEOCECAL CONDUIT
Gilchrist et al. [2] introduced the ileocecal segment as a urinary conduit in
an early attempt at continent diversion. Zinman and Libertino [50] used
this ileocecal segment to construct a nonrefluxing conduit. The stoma site
is again selected in the right lower quadrant. The conduit is based on the
ileocolic vessels, which can be visualized with transillumination of the mes-
entery (Fig. 15). After the right colon has been mobilized, the ileum is
divided approximately 10 cm proximal to the ileocecal valve and the colon
Figure 15 Ileocecal segment showing ileocolic vessels.
Methods of Urinary Diversion 233
is divided just proximal to the right colic artery. Bowel continuity is re-
stored according to the surgeon’s preference, with the conduit placed to the
right of the intact colon.
The antirefluxing ureterocolostomies depend on reinforcement of the
ileocecal valve as described by Zinman and Libertino (Fig. 16A)[50]. This
reinforcement is accomplished by intussusception of the ileum into the ce-
cum and by “wrapping” the redundant cecal wall around the ileum (Fig.
16B). Conjoined ureteroileostomies are then constructed, and the standard
stoma is made.
COMPLICATIONS AND LONG-TERM RESULTS
OF COLON CONDUITS
The immediate postoperative complications do not differ significantly from
those already discussed for the ileal conduit. The presence of non-refluxing
ureteral anastomosis has lead to stable renal function in 80–90% of patients
[48–50]. Nephrolithiasis tends to occur in those patients with failure of the
antireflux mechanism or those who develop acidosis from urine absorption.
Ureteroenteric anastomotic structure occurs with a frequency similar to that
of ileal conduits and is managed in the same fashion. The incidence of early
anastomotic obstruction may be higher because of the tunneling techniques,
Colonic mucosa is efficient at reabsorption of sodium and chloride,
although it does so less than the ileum. As with ileal conduits, the presence
Figure 16 Nonrefluxing ureteral anastomosis is dependent on reinforcement of
the ileocecal valve.
234 Stern and Dalton
of renal insufficiency or large amounts of residual urine may lead to hyper-
chloremic acidosis. A recent review of carcinogenesis in patients with intes-
tinal conduits documented six cases with colon conduits [51]. It is unclear
whether this carcinogenesis represents spontaneous colonic primary lesions
or lesions induced by urine-borne carcinogens.
CONTINENT RESERVOIRS WITH ABDOMINAL
WALL STOMAS
The past two decades have seen an explosion in interest in avoiding exter-
nal collecting devices. Several methods of continent urinary diversion have
been described, and modifications are reported frequently. The basic re-
quirements for a successful continent urinary diversion include (1) a large,
low-pressure reservoir, (2) absence of reflux, and (3) continence. The basic
methodologies are described below, although the reader is referred to the
References at the end of this chapter for detailed descriptions of all the
various modifications.
INDIANA POUCH
Gilchrist et al. [2] initially used the ileocecal segment in an attempt to
provide continent diversion. Their dependence on the unreinforced ileocecal
valve led to poor continence rates, and urologists did not embrace the pro-
cedure. At the University of Indiana, several modifications were introduced
in the 1980s: these developments led to what has become known as the Indi-
ana pouch [52,53]. The most important modifications include (1) plication
of the ileal segment and ileocecal valve to provide continence and (2) detu-
bularization of the bowel to avoid mass contraction and obtain greater res-
ervoir capacities.
Patient selection is important. The patient must be highly motivated
and cooperative in regard to postoperative care and lifelong intermittent
catheterization. Some surgeons believe that the need for postoperative radi-
ation therapy or chemotherapy obviates the use of continent diversion for
pelvic malignancies, although others use the procedure uniformly.
After mobilization of the terminal ileum and the ascending colon (in-
cluding the hepatic flexure), 25–30 cm of colon and 10 cm of terminal
ileum are measured and marked. The mesentery is examined to ensure ade-
quate blood supply, and the bowel is divided. An ileocolostomy is per-
formed according to the surgeon’s preference. The bowel is irrigated, and
the colon is opened along its antimesenteric border (Fig. 17A). The Indiana
group advises tapering the ileum and ileocecal valve before closure of the
Methods of Urinary Diversion 235
Figure 17 Indiana pouch. A, Extended ileocecal segment is isolated, and colon
is opened along its antimesenteric border. Nonrefluxing ureterocolostomies and
tapering of ileal limb are performed before closure of colonic segment. B, Colon
is closed in a Heineke-Mikulicz fashion. Flush stoma is constructed, and cecostomy
tube is placed for postoperative drainage.
reservoir. (Fig. 17B). A 12F catheter is placed, and the ileum is tapered
with the use of a GIA stapler. The ileocecal junction and valve are tapered
with 3-0 silk Lembert sutures. The 12F catheter is removed, and easy pas-
sage of a 16F catheter is ensured. Stented ureterocolostomies are con-
structed as described previously. To detubularize the reservoir and avoid
mass contractions, the colon is closed with two layers of 3-0 Vicryl suture
in a Heineke-Mikulicz fashion. A flush stoma is created in an appropriate
location, a cecostomy tube is inserted and delivered through the abdominal
wall, and the ureteral stents are brought out through a separate stab incision.
236 Stern and Dalton
Ease of catheterization is documented before closure. Drains are placed
dependently.
Mucous secretion poses a problem postoperatively and requires irriga-
tion via the cecostomy tube three or four times a day. After radiographs
have confirmed the absence of extravasation and obstruction, the patient is
discharged with instruction for home cecostomy tube irrigation. Intermittent
catheterization is taught 2 to 3 weeks after discharge and the cecostomy
tube removed.
In their most recent review [53], the Indiana group reported a 94%
continence rate with 4- to 6-hr catheterizations. Approximately 50% of pa-
tients require one nocturnal catheterization to remain dry. Approximately
2% of patients required reoperation for either reflux or ureterocolonic ob-
struction. Since use of the stapling technique was initiated, only 1 of 35
patients required revision of the efferent limb [54]. Hyperchloremic meta-
bolic acidosis occurs and occasionally requires oral alkali therapy.
MAINZ POUCH
Thuroff et al. [55] developed the Mainz pouch coincidentally with develop-
ment of the Indiana pouch. It differs in the use of a longer segment of ileum
(50 cm; Fig. 18) and a shorter segment of colon. Continence depends on the
construction of a nipple valve, as described for the Kock pouch. The reservoir
is constructed after detubularization of the colon and ileum along the antimes-
enteric border. A 10-cm segment of proximal ileum is used to construct the
nipple valve. Other aspects are similar to those described previously.
MITROFANOFF PRINCIPLE
Mitrofanoff [56] first reported the use of the appendix for the construction
of a continent stoma that could be catheterized. The appendix is mobilized
with preservation of its mesentery, and it may be tunneled into the bladder
or the cecal tinea, as in the construction of a nonrefluxing ureterocolostomy
(Fig. 19). The distal end of the appendix is opened, and a flush stoma is
created in a predetermined location. Most published series report conti-
nence rates usually higher than 90% using the Mitrofanoff principle [57].
Other structures used to construct a similar stoma include fallopian tubes,
ureters, umbilical vein, and ileum.
TUBE-WITHIN-A-TUBE CONTINENT STOMAS
Benchekroun [58] has also described a variation on the use of the ileocecal
segment to construct a continent reservoir. Of particular interest is his
Methods of Urinary Diversion 237
Figure 18 Mainz pouch. A shorter colonic segment and a longer ileal segment
as well as reliance on a nipple valve for continence differentiate the Mainz pouch
from the Indiana pouch.
method of constructing the continent stoma (Fig. 20). A separate 14-cm
segment of ileum is isolated and invaginated. The anterior surfaces are se-
cured with a continuous stitch of 3-0 Vicryl. When attached to the reser-
voir, the outer, mucosa-lined tube fills with urine, thereby compressing the
inner, serosa-lined catheterizable tube and providing continence. Of 160
patients, 142 were continent (27 of them required reoperation to achieve
continence) [59]. Koff et al. [60] used an imbricated ileal segment similar
to that used in the Indiana pouch. It is augmented by a second segment of
ileum approximately 10 cm long used to construct a urine-filled external
compression chamber (Fig. 21). The distal end of the ileal segment is spatu-
lated and wrapped around the imbricated ileal segment. A watertight attach-
ment is achieved with 3-0 Vicryl sutures. The proximal end is attached to
the reservoir, allowing the “cuff ” to fill with urine and compress the imbri-
cated segment, resulting in continence. Fourteen of 15 patients were conti-
nent, with 3 patients requiring reoperation for stoma problems.