The standard tool used to dissect tumor on peritoneal surfaces from the normal tissues is a ball-tip electrosurgical handpiece. The ball-tipped instrument is placed at the interface of the tumor and normal tissues. The focal point for further dissection is placed on strong traction. The 3-mm ball-tip electrode is used on pure cut at high voltage for dissecting. High voltage coagulation is used to transect small (< 2 mm in diameter) vessels.
Using ball-tip electrosurgery on pure cut creates a large volume of plume because of the electroevaporation of tissue. To maintain visualization of the operative field and to preserve a smoke-free atmosphere in the operating theater, a smoke filtration unit is used. The vacuum tip is maintained 2 to 3 inches from the field of dissection whenever electrosurgery is used.
Specific surgical technique
In order to adequately perform cytoreductive surgery, the surgeon should use a specific preparation technique, called lasermode electrosurgery. Peritonectomies and visceral resections using the traditional scissor and knife dissection will unnecessarily disseminate a large number of tumor debris within the abdomen. Also, clean peritoneal surfaces devoid of cancer cells are less likely to occur with sharp dissection or opposed to electrosurgical dissection. Lasermode electrosurgery leaves a margin of heat necrosis that is devoid of viable malignant cells. Not only does electroevaporation of tumor and normal tissue at the margins of resection minimize the likelihood of persistent disease, but also it minimizes blood loss. In the absence of lasermode electrosurgery, profuse bleeding from stripped peritoneal surfaces may occur.
There are six different peritonectomy procedures that are used to resect cancer on visceral intra-abdominal surfaces or to strip cancer from parietal peritoneal surfaces. One or all six of these procedures may be required, depending on the distribution and volume of peritoneal disease.
- Abdominal exposure
The abdomen is opened from xiphoid to pubis and the xiphoid excised. Generous abdominal exposure is achieved through the use of a Thompson self-retaining retractor. First step of operation will be the resection of the central peritoneal compartment. Here it is necessary to cut out scars of previous laparotomies as well as the peritoneum beneath rectus abdominis mussels from xyphoid area to symphysis.
- Greater omentectomy and splenectomy
To free the mid-abdomen of a large volume of tumor, a complete greater omentectomy is performed. The greater omentum is elevated and then separated from the transverse colon using ball-tip electrosurgery. This dissection continues beneath the peritoneum that covers the transverse mesocolon so as to expose the pancreas. The gastroepiploic vessels on the greater curvature of the stomach are ligated and divided. In addition, the short gastric vessels are transsected. The mound of tumor that covers the spleen is identified. The peritoneum on the anterior surface of the pancreas may need to be elevated from the gland. Working from the anterior and posterior aspect, the splenic artery and vein at the tail of the pancreas are exposed. These vessels are ligated in continuity and proximally suture-ligated. This allows the greater curvature of the stomach to be reflected anteriorly from pylorus to gastroesophageal junction. Greater omentectomy is usually combined with splenectomy to achieve a complete cytoreduction. If the spleen is free of tumor, it is left in situ.
- Peritoneal stripping from beneath the left hemidiaphragm
To begin exposure of the left upper quadrant, the peritoneum beneath the epigastric fat pad that constitutes the edge of the abdominal incision is stripped off the posterior rectus sheath. Traction is to be achieved on the tumor specimen throughout the left upper quadrant. The left upper quadrant peritonectomy involves a stripping of all tissue from beneath the left hemidiaphragm to expose diaphragmatic muscle, left adrenal gland, and the cephalad half of the perirenal fat. To achieve a full exposure of the left upper quadrant, the splenic flexure of the colon is released from the left paracolic sulcus and moved medially by dividing tissue along Toldt's line. The dissection beneath the left hemidiaphragm is performed with ball-tip electrosurgery.
- Peritoneal stripping from beneath the right hemidiaphragm
The peritoneum and epigastric fat pad are stripped away from the right posterior rectus sheath to begin the peritonectomy in the right upper quadrant of the abdomen. Strong traction on the specimen is used to elevate the hemidiaphragm into the operative field. Ball-tip electrosurgery on pure cut is used to dissect at the interface of mesothelioma infiltrating the peritoneum and the muscle of the right hemidiaphragm.
- Dissection beneath the tumor through Glisson's capsule
The stripping of the tumor from the muscular surface of the diaphragm continues until the area the liver is encountered. Tmor formations on the superior surface of the liver will be electroevaporated . With blunt and ball-tip electrosurgical dissection, the tumor is lifted off the dome of the liver by moving through or beneath Glisson's capsule. Hemostasis is achieved as the dissection proceeds, using coagulation electrosurgery on the liver surface. Ball-tip electrosurgery is also used to extirpate the tumor from and around the falciform ligament, round ligament, and umbilical fissure of the liver.
- Removal of tumor from beneath the right hemidiaphragm, from the right subhepatic space, and from the surface of the liver
Tumor from beneath the right hemidiaphragm, from the right subhepatic space, and from the surface of the liver forms an envelope as it is removed en bloc. The dissection is simplified greatly if the tumor specimen can be maintained intact. The dissection continues laterally on the right to encounter the fat covering the right kidney. The right adrenal gland is visualized as the tumor is stripped from Morrison's pouch. Care is taken not to traumatize the vena cava or to disrupt caudate lobe veins that pass between the vena cava and segment 1 of the liver.
lesser omentectomy and cholecystectomy
The gallbladder is removed in a routine fashion from its fundus toward the cystic artery and cystic duct. These structures are ligated and divided. The plate of tissue that covers the structures that constitute the porta hepatis is usually infiltrated heavily by tumor. Using strong traction, the cancerous tissue that covers the structures is stripped from the base of the gallbladder bed toward the duodenum
stripping of the omental bursa
As one clears the left part of the caudate liver segment of tumor, the vena cava is visualized directly beneath. To strip the floor of the omental bursa, strong traction is maintained on the tumor. Ball-tip electrosurgery is used to divide the peritoneum joining the caudate lobe of the liver to the vena cava. Division of the phrenoesophageal ligament allows the crus of the right hemidiaphragm to be stripped of peritoneum.
- Pelvic peritonectomy
The peritoneum is stripped from the posterior surface of the lower abdominal incision, exposing the rectus muscle. The muscular surface of the bladder is seen as ball-tip electrosurgery strips tumor-bearing peritoneum and preperitoneal fat from this structure. The urachus must be divided and is placed on upward traction as the leading point for dissection of the visceral surface of the bladder. Round ligaments are divided as they enter the internal inguinal ring on both the right and left in the female patient.
The peritoneal incision around the pelvis is completed by dividing peritoneum along the pelvic brim. Right and left ureters are identified and preserved. In women, the right and left ovarian veins are ligated and divided at the level of the lower portion of the kidney. A linear stapler is used to divide the colon at the junction of sigmoid and descending colon. The vascular supply of the distal portion of the bowel is traced back to its origin on the aorta. The inferior mesenteric artery is ligated and divided. This allows one to pack all of the viscera, including the proximal descending colon in the upper abdomen.
Ball-tip electrosurgery is used to dissect beneath the mesorectum. An extraperitoneal suture ligation of the uterine arteries occurs just above the ureter and close to the base of the bladder. In women, the bladder is moved gently off the cervix, and the vagina is entered. The vaginal cuff anterior and posterior to the cervix is divided using ball-tip electrosurgery, and the perirectal fat inferior to the posterior vaginal wall is encountered. All the tumor that occupies the cul-de-sac should be removed intact with the specimen. The mid-portion of the rectal musculature is skeletonized and a roticulator stapler is used to staple the rectal stump closed.