Retroperitoneal anatomy By Dr. Khattab KAEO Prof. & Head of Obstetrics and Gynaecology Department Faculty of Medicine, Al-Azhar University, Damietta

The subperitoneal area of the true pelvis is parti- tioned into potential spaces by the various organs & their respective fascial coverings and by the selective thickenings of the endopelvic fascia into ligaments and septa. Introduction

The retroperitoneal spaces The paravesical space: This is developed by dissect ing between the external iliac vessels and the anter. division of the internal iliac artery (precisely, the superior vesical artery) lateral to the bladder. The uterine artery forms the posterior boundary of the space, while the levator ani muscles form its floor. First, expose the external iliac vessels 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. The anterior division of the internal iliac artery lies just medial. On the lateral side of the paravesical space lies the obturator fossa containing blood ves., nerve and lymph nodes. Blunt dissection following the inward pelvic slope can be continued to the pelvic diaphragm. The space is limited superiorly by the lateral umbilical ligament.

Cardinal ligament

Cut round ligament going through the deep inguinal ring

This is particularly useful in the following conditions (indications): 1- Malignancy. 2- Endometriosis. 3- Chronic PID. 4- Tubo-ovarian abscess. 5- Large or interligamentous liemyoma. 6- Redsidual ovaries. 7- Hypogastric artery ligation. Developing the retroperitoneal spaces

The pararectal space: It is bound laterally by the levator ani, medially by the rectal pillars, and posteriorly above the ischial spine by the anterolateral aspect of sacrum. Peripheral part of the cardinal ligament and the uterine artery divides the paravesical & the para- rectal spaces. To best develop the pararectal space, dissect between the first portion of the anterior division of the internal iliac artery laterally and the ureter medially. The uterosacral ligament and the ureter are located very near to each other between the rectovaginal and pararectal spaces. Remain close to the rectum to avoid the internal iliac vein and its side wall tributaries. To best develop the pararectal space, dissect between the first portion of the anterior division of the internal iliac artery laterally and the ureter medially. The uterosacral ligament and the ureter are located very near to each other between the rectovaginal and pararectal spaces. Remain close to the rectum to avoid the internal iliac vein and its side wall tributaries.

The vesicovaginal space: Incise the vesicouterine peritoneal fold transversely. Push the bladder down bluntly or by sharp dissection. Moist gauze packing usually controls any encountered slow venous bleeding. A common error is to dissect too close to the cervix and fail to get into the proper plane. Developing this space gives access to the vesicouterine ligament which contains the ureter as it passes to the bladder.

The rectovaginal space: Incise the peritoneum between the insertion of the two uterosacral ligaments (the rectal pillars contain the middle haemorrhoidal arteries). Bluntly dissect the vagina from the rectum by sweeping the palm along the posterior vaginal wall. For adherent areas, sharp dissection against the vagina is used. The vesicovaginal and rectovaginal spaces may be considerably altered. In such instances, developing the paravesical and the pararectal spaces first is very helpful.

The prevesical and presacral spaces: The prevesical space can be developed by gently dissecting the areolar tissue immediately posterior to the symphysis pubis. The presacral space can be developed by gently incising the over- lying parietal peritoneum. One may place the sigmoid colon to the left. Inside this space, encased in fat, is the sympathetic nerve plexus (the presacral nerve) in addition to the middle sacral artery and vein.

1988 FIGO SURGICAL staging: Stage I: Tumour limited to the uterus. Stage IA: Limited to the endometrium. Stage IA: Limited to the endometrium. Stage IB: Invaded  ½ the myometrium. Stage IB: Invaded  ½ the myometrium. Stage IC: Invaded > ½ the myometrium Stage IC: Invaded > ½ the myometrium Stage II: Extends to the cervix. Stage IIA: Endocervical glandular involvement Stage IIA: Endocervical glandular involvement Stage IIB: Cervical stromal involvement. Stage IIB: Cervical stromal involvement. Stage III: Spread to the pelvis. Stage IIIA: Invasion of uterine serosa &/or adnexa or +ve peri- toneal cytology. Stage IIIA: Invasion of uterine serosa &/or adnexa or +ve peri- toneal cytology. Stage IIIB: Vaginal metastasis. Stage IIIB: Vaginal metastasis. Stage IIIC: Pelvic or paraaortic LN metastasis. Stage IIIC: Pelvic or paraaortic LN metastasis. Stage IV: Advanced pelvic or distant metastasis Stage IVA: Bladder or bowel mucosa invasion. Stage IVA: Bladder or bowel mucosa invasion. Stage IVB: Distant and/or inguinal LN metastasis. Stage IVB: Distant and/or inguinal LN metastasis.

CIS is often sharply demarcated

Histologic types: 90% of endometrial adeno- carcinomas are of the endometrioid type. Degrees of differentiation: Poorly differentiated tumours are less responsive to adjuvant pro- gestogen therapy than well-differentiated tumours. Also, they deeply invade the myo- metrium early, while well-differentiated tumours tend to grow exophytically in the cavity. G1: ≤5% of a non-squamous or non-morular solid growth pattern. G2: 6%-50% of a non-squamous or non- morular solid growth pattern. G3: >50% of a non-squamous or non-morular solid growth pattern.

10% uncommon types: clear cell, papillary serous, mucinous carcin- oma and undifferentiated tumours. Clear cell adenocarcinoma is identi cal to that of the cervix, vagina & ovary. It is a high-risk tumour; early stages are comparable to G3 endometrioid adenocarcinoma. Papillary serous carcinoma tends to spread intra-abdominally, and is refractory to most standard therapy

Lymphatic spread: Lymphatic spread from the mid and lower portions is similar to that of the cervix. Fundal tumours spread through the broad and infudibulopelvic ligaments to the hypogastric, external iliac, common iliac & aortic nodes or through the round ligament to the superficial and deep lymph nodes. High risk endometrial adenocarcinoma: 1- >50% of the myometrial thickness is invaded (stage IC), involvement of the cervix (stage IIA, B) or adnexa (stage IIIA). 2- Poorly differentiated (grade 3). 3- Villoglandular type of endometrioid adeno- carcinoma if invaded the myometrium. 4- The uncommon types.

Presentation: Early growths are polyp- oidal; surface ulceration and necrosis  peri-/post-menopausal bleeding. Because this is ominous to both the patient & physician, delays in diagnosis are uncommon. Late cases may present with intermittent pus-like discharge. Postmenopausal bleeding or bloody- mucoid discharge indicates cancer in the genital tract in 50% of cases. Late cases may present with intermittent pus-like discharge. Postmenopausal bleeding or bloody- mucoid discharge indicates cancer in the genital tract in 50% of cases. The uterus feels symmet rically enlarged by the mass If affecting a senile uterus, clinical enlargement may not be produced. The uterus feels symmet rically enlarged by the mass If affecting a senile uterus, clinical enlargement may not be produced.

Work-up: History and examination: Most patients are in their 60s & 70s. Coexisting DM, hypertension & obesity. Endometrial biopsy for all wo men >40 with IUB It is also indicated if endometrial cells are noted on a Pap smear of a postmenopausal woman or if atypical glandular cells are noted on a smear of a premenopausal woman. Biopsy establishes the diagnosis with high sensitivity and specificity. Endometrial biopsy for all wo men >40 with IUB It is also indicated if endometrial cells are noted on a Pap smear of a postmenopausal woman or if atypical glandular cells are noted on a smear of a premenopausal woman. Biopsy establishes the diagnosis with high sensitivity and specificity. Ultrasonography could be re assuring if endometrial thickness is <3 cm in a menopausal woman. Ultrasonography could be re assuring if endometrial thickness is <3 cm in a menopausal woman.

Screening: Only worthwhile in highrisk popul: white, obese, on estrogen or tamoxifen, nulli para, with PCOS, granulosa cell tumour, per- sonal or family history of breast/ovarian/ colon cancer. Arrange 2-4 visits/year. Endo- metrial sampling is done using Vabra aspira- tor (postsounding) which is diagnostic in % of cases +ve results  additional endo cervical sampling, but endometrial curettage is unnecessary. If D & C is chosen: - At the end a polyp forceps is used to remove a polyp - If 1 swipe of the curet produces obvious endometrial carcinoma, further curettage is not necessary (may disseminate tumour cells). If there is hyperplasia, look for accompanying carcin- oma or ovarian tumour. The same work-up should be followed even if an obvious cause of postmenopausal bleeding such as cervical polyp or vaginitis is present.

Treatment Surgery: TAH BSO is the mainstay treatment. Chemotherapy: Progestational therapy may  respon- ses, but cures are unusual. MPA: For CIS: 400 mg in 4 w in divided doses, then 400 mg/month (5). For carcinoma: 400 mg/day for a week, then 400 mg 3 times/w for 2 w before surgery with the same course is given postoperatively if the tumour is ex- tended for >1/3 of the myometrium. For carcinoma: 400 mg/day for a week, then 400 mg 3 times/w for 2 w before surgery with the same course is given postoperatively if the tumour is ex- tended for >1/3 of the myometrium. Chemotherapy is attempted with distant metastasis. It includes cis-/ carbo-platin, doxorubicin & paclitaxil. Radiotherapy: Stage IIB necessitates preoperative external radiotherapy then TAH BSO. If the tumour is of low risk, no further treatment is required. PORTEC (Post Operative Radiation Therapy in Endometrial Carcinoma) : External radiotherapy lowers the rate of local recurr- ence to 4% (Vs 14% in the no-radiotherapy group). However, the complication rate is 25% among the irradiated patients Vs 6% in the no-radiotherapy group. For stage Ia G1,2 no postoperative radiotherapy is required. For stage Ib G1,2 postoperative brachytherapy is required. For stage Ic or G3 carcinomas, both are required.

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