Endometriosis is a common illness with an incidence of about 10% of all premenopausal women.
Deep infiltrative endometriosis is associated with high morbidity. The resection of deep
infiltrative endometriosis may be risky because of the nearby located anatomical structures
such as blood vessels, nerves, intestine and ureters, which are exposed for a lesion,
especially if involved in the endometriosis. The most common lesions in gynecological surgery
are those of the urinary tract. A retrospective study including 213 patients with DIE has
shown an affection of the lower urinary tract in DIE in up to 52.6% of cases. Most studies
list the bladder as the most common site of urinary tract DIE, with the ureter as the second
most common lesion site. In the cases of ureteric endometriosis, an ureterolysis is
indispensable as the complete resection of the endometriotic lesions is necessary to resolve
or prevent kidney congestion. In addition, the ureterolysis is mandatory in the course of
dissection of endometriotic nodules affecting the rectovaginal septum, the sacrouterine
ligaments or the rectum. Speaking from ureterolysis the investigators include the procedure
of freeing the ureter both from endometriotic nodules as a therapeutic procedure and from
physiological surrounding tissue and structures for full visualization. Since the
ureterolysis consists in a high-risk procedure for ureteral lesions, alternatives are
desirable. Ureteral injuries are among the most feared complications, as they can result in
serious consequences such as leakage of urine into the abdomen, congestion of the ureter or
kidney and loss of function of the kidney in question. In case of severe ureteral injury, it
must be reimplanted in the bladder or an anastomosis must be performed; if this is not
possible, a nephrostomy, i.e. direct drainage of urine from the kidney to the outside through
the skin, may be necessary. An early diagnosis and possibly already intraoperative therapy by
means of suture, insertion of double j catheter or other, is crucial for the prognosis of the
ureter and the kidney.
Until now, the preoperative ureteral stent placement has in many hospitals been the standard
method for ureteral identification and avoidance of injuries in patients with DIE and
imaging-proven involvement of the urinary tract. However, these stents often lead to pain,
dysuria and haematuria during the wearing period, which usually lasts several weeks. In
gynecologic surgery there is no evidence for the prophylactic ureteral stent placement in
order to avoid ureteral injuries.
The investigators investigate if ICG helps to visualize the ureter in laparoscopic operations
for deep infiltrating endometriosis and possibly could help prevent complete ureterolysis and
thus reducing the risk of lesions to the ureter.
ICG is a fluorescent dye that has been used since 1956 for various indications including
retinal angiography, determination of tissue viability, and cardiac and hepatic function
testing. It can be used intravenously to visualize vascularization with near-infrared
imaging. In the last decade, it has gained an important role in intraoperative visualization
of sentinel lymph nodes in tumor surgery and tissue perfusion. ICG has already been used and
described for the visualization of the ureters. However, these trials included small
populations of 10-30 patients. None of the studies mentioned has investigated the
visualization of the ureters in the case of endometriosis and with regard to possibly
reducing the necessity of ureteral dissection.
The investigators will perform a retrograde injection of ICG in the ureters during a
cystoscopy. ICG and thus the ureters are visualized in laparoscopy through near-infrared
light, which is included in our camera systems. The additional use of fluorescence imaging of
the ureters with ICG injected into the ureters during a laparoscopic resection of DIE is
supposed to improve the visualization of the ureters and therefore may prevent a complete
ureterolysis, considered as a high-risk procedure. It's a safe intervention, as ICG has been
shown to have an excellent security profile. Allergic reactions, which usually consist of
anaphylaxis, have been described extremely rarely. The intraureteral application of ICG has
been used clinically and been applied in studies. To date there have been no reports of
iatrogenic ureteral injury, perioperative complications or side-effects in patients
undergoing the procedure of intraureteral ICG administration. Therefore, the risk of the
ureteral administration of ICG is minimal. However, the investigators consider the benefit of
a better visualization of the ureters in laparoscopic operations for deep infiltrating
endometriosis as substantial.
The aim of the study is to prove the feasibility of ureteral visualization using
intraureteral ICG in 2D laparoscopy for women with deep infiltrating endometriosis by means
of near-infrared fluorescence imaging of the ureters.
In our secondary endpoints the investigators want to describe the duration time of ICG
injection, the duration until visualization of the ureters, the detection rate of fluorescing
ureters after ICG-injection, the duration until maximum fluorescence is achieved, the
duration until the ureters can no longer be displayed, the length of performed ureterolysis
in centimeters and the safety of intraureteral ICG injection.
