Retroperitoneal surgery-1 By Dr. Khattab Omar, MD Prof. & Head of Obstetrics and Gynaecology Department Faculty of Medicine, Al-Azhar University, Damietta

Introduction Retroperitoneal space of the true pelvis differs from retro-peritoneal areas elsewhere in the abdomen by the presence of the sub-peritoneal areolar (cellular) connective tissue.

We can recognize about 6 retroperitoneal spaces.

Cardinal lig

The subperitoneal area of the pelvis is partitioned into potential spaces by the various organs & their re-spective fascial coverings, and by the selective thick-enings of the endopelvic fascia into ligaments and septa.

Vesical fascia Cut edge of the peritoneum Vesicovaginal lig. & space

Indications for development of retroperitoneal surgical approaches 1- Malignancy & lymphadenectomy. 2- Endometriosis. 3- Chronic PID. 4- Tubo-ovarian abscess. 5- Large or interligamentous myoma 6- Complications in post-hysterect. reserved ovaries. 7- Hypogastric artery ligation. 8-Vaginally-inaccessible urinary fistula 9- Colpopexy. 10- Laparoscopic hysterectomy.

The paravesical space

It is limited laterally by the obturator internus and levator ani Ms, medially by the bladder pillars, inferiorly by the endopelvic fascia, superiorly by the lateral umbilical ligament, and posteriorly by the uterine artery.

This space can be developed by dissecting between the external iliac vessels and the anterior division of the internal iliac artery (precisely, the superior vesical artery) lateral to the bladder.

Steps

First, expose the external iliac vessels anteriorly near their entrance into the femoral canal by dividing the round ligament near the deep inguinal ring.

Note where the circumflex iliac vein crosses the external iliac artery Note where the circumflex iliac vein crosses the external iliac artery. The anterior division of the internal iliac artery lies just medial.

Cut round ligament going through the deep inguinal ring

Laparoscopically The space can be developed laparoscopically, but in different steps.

Developing the space lateral to the obliterated umbilical artery Developing the space lateral to the obliterated umbilical artery. Note direction of the pull exerted through the dissecting forceps (arrow)

Developing the space medial to the obliterated umbilical artery Developing the space medial to the obliterated umbilical artery. Note direction of the pull exerted through the dissecting forceps (arrow)

Surgical importance

On the lateral side of the para-vesical space lies the obturator fossa containing blood vessels, nerve and lymph nodes. Blunt dissection following the inward pelvic slope can be continued to the pelvic diaphragm.

GSI can be attributed to disruption of muscle and fascia of the proximal urethra  bladder neck hyper-mobility (midline defect). The pubo-cervical fascia acts as a suspending hammock for the bladder and urethra. The pravaginal fascia too plays an important role (paravaginal defect is the most common injury occurring >75%-80% of the time). Impaired support of the anterior vaginal wall is associated with stress incontinence and prolapse of the anterior vaginal wall.

All bladder neck surgeries carry a risk of postoperative detrusor instability and long-term voiding difficulties. All such techniques rely on creation of a "compensatory abnormality“. Ritchardson advised repair of the paravaginal defect that was so anatomic that it almost never resulted in either short- or long-term urinary retention, and the patients remained continent over the time.

Right paravaginal defect (the vagina's antero-lateral sulcus is avulsed away from the white line). The obturator foramen is 1.5-2cm above the white line. The defect is absent in the left side.

Entering the retroperitoneum

- A preoperative IVU is recommended. - In most cases, the round ligament may be divided and the peritoneum lateral to the infundibulopelvic ligament incised without difficulty. - With large masses or when the anatomy is severely distorted, a paracolic or lateral psoas approach is required.

The round ligament approach

Placing a retractor near to the round ligament provides upward traction on it. The ligament is then picked up & transfixed. The broad lig. should be incised sharply in its lateral portion overlying the psoas Ms. The peritoneum can then be incised cephalad lateral and parallel to the ovarian vessels. This is followed by sharp & blunt dissection. The initial dissection should be bounded by the posterior leaflet of the broad ligament & the ureter medially (the ureter attaches to the broad lig. peritoneum) and the iliac vessels and the pelvic side wall laterally.

The paracolic approach

It is useful when the pelvic anatomy is severely distorted and the round lig not easily identified, or if the pelvis is occupied with a mass.

The paracolic peritoneum is elevated and incised. The incision begins over the psoas muscle lateral to the ureter and ovarian vessels.

This is followed by combined sharp and blunt dissection to mobilize medially the coecum or sigmoid colon, or to visual-ize the ureters. Dissection is continued down into the pelvis using the ureter as the landmark (ureteric cath-eter ± inserted) around which both the ovarian and the iliac vessels may be identified.

Post Lt Rt Anter The incision begins over the psoas muscle lateral to the ureter and ovarian vessels.

The psoas muscle approach: The retroperitoneal space may also be entered over or lateral to the psoas muscle. Begin and stay medial to the iliac vessels.

Opening the pelvic sidewall triangles: The uterus is deviated to one side to de-lineate the triangle in the opposite wall. The base of the triangle is the round lig., the lateral border is the external iliac a., the medial border is the infundibulopelvic lig, and the apex is where the infundibul- opelvic ligament crosses the common iliac artery.

The peritoneum in the middle of the triangle is incised and the broad lig is opened by bluntly separating the extraperitoneal areolar tissue. Even tiny vessels should be coagulated. The incision is extended to the round ligament which is not divided at this time and then to the apex of the triangle lateral to the infundibulopelvic ligament.

The paravesical space is opened and the infundibulopelvic ligament is pulled medially.

Thanks prof morad k hasanein