The greater omentum is the most common site of metastasis from ovarian cancer and for this reason greater omentectomy has been recommended as an important aspect of surgical treatment of ovarian cancer.

Rationale of Omentectomy
Removal of omentum with gross metastasis is important as a therapeutic measure in cytoreductive surgery. There are various reports substantiating the survival benefits after omentectomy although none are randomized. The rationale of omentectomy relates to the following theoretical considerations:

1. The physiologic benefits of tumor mass excision: Omental cake can be very uncomfortable and contributes significantly to ascites. Its removal even as a palliative procedure significantly reduces ascites and improves the patient’s nutritional status.
2. Omental tumor excision is an important aspect of cytoreduction and increases the likelihood of response to chemotherapy. Skipper proposed ‘The fractional
   kill hypothesis’ which states that a given dose of drug will kill a constant fraction of cells as long as the growth fraction and phenotype are the same. So the
   lesser the tumor cell burden at the start of chemotherapy, fewer the number of cycles of treatment are needed. The chance of developing chemoresistant
   cell clones is also related to the initial tumor mass. However one has to bear in mind that suboptimal cytoreduction adversely affects outcome.
3. By reactivating the host immune mechanism: Large tumor masses due to excess tumor antigen expression, blocks the functioning of host immune system. Tumor cells produce immunologically suppressive substances and also induce suppressor lymphocytic activity.

Technique of Omentectomy
Omentum is freed from any adhesions to the parietal peritoneum or small bowel loops by sharp dissection. The infracolic omentum is lifted up to see its attachment to the transverse colon. (Fig. 1) The peritoneum is incised and the omentum is dissected off the serosa of transverse colon by sharp dissection through the correct plane by ligating or coagulating small vessels. If no macroscopic disease is seen in the omentum, infracolic omentectomy is completed by excising the omentum at the level of transverse colon.If there is gross disease in the omentum but not extending to stomach, total omentectomy is done sparing the gastro-epiploic vessels which are seen as an arcade 2 cm below the greater curvature. (Fig. 2, 3). In advanced cases at laparotomy a large friable, fixed slab of tissue is seen which is classically called ‘the omental cake’. (Fig. 4)

This may be adherent to the surrounding peritoneum, transverse colon, greater curvature of stomach and sometimes extends along the gastrosplenic ligament to splenic pedicle. Blunt dissection and traction on the tumor can result in bleeding. Using the electro surgical unit the tumor can be dissected off the peritoneum and
the anterior layer of peritoneum. The tumor is dissected off the greater curvature of stomach ligating the gastro epiploic vessels on either side. Now the omental cake is freed from the transverse colon by dissecting through the avascular plane. If the tumor is invading transverse colon it requires resection anastamosis of the colon (Fig. 5-9). When the tumor extends into the gastro splenic ligament and splenic hilum, splenectomy is usually necessary.