In laparoscopy we routinely use five and ten mm ports. Of these the first two insert is called the primary or the camera port. The secondary ports vary in number depending on the type of surgery. An accessory secondary port may be required if the case is difficult in order to retract bowel or other viscera to enable visualization and proper identification of the anatomy.
For all practical purposes, the primary port hover around the umbilicus, as it marks the centre of the peritoneal cavity and all structures can be well focused and reached from this spot. Moreover, all the layers of the fascia converge at the umbilicus and the distance between the skin and the anterior peritoneum is leased here. But for anatomical reasons, e.g. in a patient with umbilical hernia the primary port can't be place around the umbilicus, and secondly if there are scars in the vicinity of the umbilicus due to previous surgeries, the primary port is placed at alternate points; the commonest being the palmers point. Other points which can be used for the introduction of the primary port are the right hypochondrium, suprapubic region and rarely the right iliac fossa. Now, all that we have discussed stands good when we are dealing with an intraperitoneal organ. And more or less a sort of standization is reached while deciding ports for surgery on an intraperitoneal organ.
Some organs can be approached both intraperitoneally as well as extra peritoneally, so do some surgeries. So, in these cases the ports are placed in the respective intraperitioneal or extraperitoneal spaces. Now standardization for placing these ports has not been achieved and placement of these ports mainly depends on individual preferences and there is not much choice as these spaces are limited, and are not huge like the peritoneal cavity.
Considering an organ, e.g. adrenal gland, which can be approached both intra-peritoneally and retroperitoneally, the decision is made based on the disease involving it. E.g. phaeochromocytoma – intraperitoneal, or if the gland is large or if it is suspected to be malignant, then also the intra peritoneal source is taken. In other cases, retroperitoneal route is preferred – reasons for which are given point wise.
Another example which I can thing of is the inguinal hernia, which can be approached both, by the intra and extraperitoneal routes. Of course the choice is made on factors like the type of hernia, previous surgery etc.
Advantages of retroperitoneal approach.
- Peritoneal cavity is not entered so there are not chances of formation of postoperative adhesions at a later date.
- There is no risk of contamination of the peritoneal cavity by the contests of the urinary tract.
- There is less risk of injury to the intraperitoneal organs.
- There is no need for retraction of intraabdominal visceras.
- There is no ileus in the postoperative period and hence faster convalescence as there is no need to mobilize the gut to expose the urinary tract.
- No need to change the position of the patient after creating pneumperitoneum like in nephrectomy.
- As most organs are retroperitoneal access to the site of lesion is direct.
- Less trocar punctures are needed as there is less requirements for retraction.
- It is safe even in patents with history of previous intraperitoneal surgeries.
- Less incidence of bowel herniation than with transperitoneal approach.
Disadvantages of retroperitoneal approach
- Less space is available to perform the surgery.
- There are few landmarks in the retroperitoneum. More experience and longer learning curve is needed for this approach.
- There are reports that suggest that there is greater absorption of CO² by this route and a higher incidence of pneumothorax or pneumomediastinum.
- This space is sometimes obliterated in patients with inflammatory pathologies like pyelonephritis.
- Large tumour mass does not all its free manipulation.
Advantages of transperitoneal approach.
- More space is available to perform the surgery.
- The anatomical landmarks are easy to identify and therefore shorter learning curve.
- Large tumour masses are easy to manipulate in the large peritoneal space.
Disadvantages of transperitoneal approach.
- Chances of formation of intraabdominal adhesions at a latter date.
- Contamination of the peritoneal cavity by ruinous contents.
- Risk of injury to intraperitoneal organs.
- Requires longer operative time.
- Risk increases in patients with previous history of intraperitoneal surgery.
- More chances of bowel herniation than with the retroperitoneal approach.
Ports for laparoscopic cholecystectomy.
Primary port - 10 mm
subumbilical / transumbilical.
Secondary ports – 5 mm subcostal in the anterior axillary line
5 mm subcostal in the mid clavicular line
10 mm epigastric region to the right of the falciform ligament.
Accessory port - 5 mm or 10 mm
3 to 4 cm above and to the left of the umbilicus.
Subumbilical
Secondary port - 7 mm / 10 mm
Right iliac fossa.
5mm left iliac fossa