Laparoscopic anatomy
Most complications following laparoscopic surgery could occur during the initial steps while introducing the needle or the midline and lateral trocars. Knowledge of the laparoscopic anatomy of the anterior and lateral pelvic walls is mandatory to reduce this risk. All 7 pictures included in this article were selected to a give good demonstration of landmarks important for the laparoscopist to remember.
The first photograph above shows the right inferior epigastric vessels which should be visualised before inserting the lateral trocars. They do not show on trans-illumination. They are seen raising peritoneal folds on the under surface of the anterior abdominal wall running anterior to the lateral part of the right round ligament as it enters into the right internal inguinal ring. The artery takes origin from the lower part of the external iliac artery and the vein joins the external iliac vein about 1.0 cm above the inguinal ligament. Both inferior epigastric vessels pass through the transversalis fascia across the transversus muscles up into the space between the rectus muscle and its posterior sheath.
The second photograph shows the uterus, both round ligaments and anteriorly the right and left obliterated umbilical arteries which raise peritoneal folds on the under surface of the anterior abdominal wall. They run from umbilicus downwards anterior to the lateral part of the round ligament into the broad ligament. Each fold could be followed down to reach the epsilateral uterine artery and could be used as a lead to that vessel in difficult cases.
The third photograph showed the uterus, round ligaments, fallopian tubes and both uterosacral ligaments posteriorly.
Knowledge of the lateral pelvic wall anatomy helps with proper dissection of such structures as the ureters, uterine vessels and lymph nodes. It also gives confidence leading to shorter operative time and patients’ safety. In essence the lateral pelvic wall is made of 3 layers:
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The superficial layer is made of the parietal peritoneum and the ureters attached to it .
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The second layer is made of the internal iliac vessels and their branches including the uterine vessels and the pelvic lymph nodes enclosed by mesenchyma.
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The third layer is made of the obturator internus muscle, obturator nerve, artery and vein plus the external iliac vessels.
Accordingly gradual dissection into the different layers would diminish injury risk and blood loss. It is always important to start working at a normal point and dissect into the abnormal area.
The ureters could be saved any damage as they could easily be mobilised together with the covering parietal peritoneum. A good example is to make incisions lateral and parallel to the uterosacral ligaments which would allow the ureters to move laterally away from the ligaments. This is important when these ligaments are to be cut or excised.
It is important to recognise the blood vessels flanking the ureter along its course from the pelvic brim into the ureteric tunnel. The uterine artery runs parallel and lateral to the ureter till it crosses anterior to it to reach the uterus 1.5-2.0 cm lateral to the cervix. This space could be a little wider on the left side. Other arteries that could be found lateral to the ureter include the internal iliac, obturator, inferior and superior vesical arteries as well as the obliterated umbilical artery which makes the terminal part of the anterior branch of the internal iliac artery. Immediately parallel and inferior-lateral to the ureter the vaginal artery would be seen. Other neighbouring vessels include the uterine veins and the middle rectal vessels. All these vessels could be injured during dissection of the lateral pelvic wall if they are not properly recognised and steps to protect them have not been taken. The inferior hypogastric nerve is especially at risk during dissection of the paracolic gutters.
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The neighbouring picture shows an incision parallel and lateral to the right uterosacral ligament. The ureter is seen through the peritoneum pulled away upwards with the parietal peritoneum. |
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This picture shows the right pelvic sidewall with the right ureter and right uterine artery lateral and parallel to it after excising the covering parietal peritoneum. This lady had extensive endometriosis on that side. |
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| Knowledge of the anatomy is most helpful when dealing with deep pelvic endometriosis The neighbouring picture shows the rectum stuck to the left uterosacral ligament and the back of the cervix with endometriosis |
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| Identification of left paracolic gutter allowed safe dissection of the rectum in this case. It is a good anatomical landmark as shown by fatty tissue in the deep recess between the rectum and the left uterosacral ligament. |
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Continued on Laparoscopic technique
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