In what locations are super obese patients slim and easy to operate?

Posted 12 years ago

Obese and super obese women in particular benefit froma laparoscopic approach if they need pelvic surgery. Open surgery carries a lot of risks, and in particular the risk of wound infection is very high (REF). Open TAH should be an operation of the past for normal weight but certainly for obese patients.

Unfortunately, the risk of conversion from laparoscopic to open increases with the body mass index. The higher the BMI the higher the risk of conversion. In our Australian LACE trial the rate of conversion was highest (~10%) in women above a BMI of 50 mg/m2. For those gynaecologists who audit themselves they would even know what their own conversion rate is.

When conversions are frequent, they always point to an area of difficulty or challenge. So what are those areas of concern in super obese patients? Entry into the abdomen, establishing of a pneumoperitoneum and placing the ports for surgery are definitely the first hurdles that gynaecologists need to master. Our post today is about “where shall we ideally place the ports in obese and super obese patients?” The other hurdle you have to take is the operation itself, the limited space that is available and the difficulties around anaesthetics. Partly, we discussed that previously.

Where and how you enter the abdomen depends in your default (primary) entry technique. Pretty much all of us have preferred entry techniques and pretty much any primary entry technique (Veress, Hasson, etc.) is doable in obese patients. However, I do hear sometimes that the “ports that I use are not long enough” or “do you use super long ports for obese patients?” I get worried when I hear these questions because most of the time we don’t need to ask ourselves those things. Long trocars are difficult to operate because they cause extensive friction and they tend to bend. Both of these issues will limit the free movement of your laparoscopic sticks. 

I normally use 4 ports of which three are short trocars (umbilicus [1], lower pelvis [2]), even in very obese women. In obese and super obese patients, only one trocar (right mid abdomen) should be long. In what areas are obese and super obese patients slim?

The first spot is at the lowest point, at the bottom of the umbilicus. In this area the skin is fused with the other layers of the abdominal wall and normally only a few millimetres thick. First, I insufflate CO2 gas with the Veress needle (Palmers point, suprapubic area, umbilicus) and then I use a syringe filled with local anaesthetic to map the area within the umbilicus for the shortest distance into the CO2 filled abdominal cavity. Unless there are adhesions underneath the umbilicus or bowel is herniated into the umbilicus, this technique works in the majority of operations. Your first port is set. Now you can even see.

The second and third ports can also be set in areas where obese patients are “thin”. There is a crease in the suprapubic area that also marks a slim area of the patient. The issue her is to reflect the fatty apron and make that area accessible. I need then only one additional port that is used by the surgical assistant on the right hand side at the level of the mid abdomen.

 So, why is it then, that port placement in obese and super obese women is considered so hard? There are some common mistakes made for fear to cause injury. Mistakes in obese and super obese women are often not very forgiving.

These common mistakes include …

• Failure to establish a pneumoperitoneum – you may require a long Veress needle to reach to peritoneum if you go through Palmers point. You may not be able to lift up the anterior abdominal wall needed to insert the Veress needle through the umbilicus. I prefer a suprapubic Veress needle entry in those challenging patients.
• Wrong umbilical incision – If you to make the umbilical incision not at the very bottom of the umbilicus but at the inferior wall of the umbilicus, the way down into the peritoneal cavity can become very long.  I normally evert the umbilicus and make a 5 mm incision at the very low point of it.
• Wrong suprapubic port placement – if you place the ports within the thick apron, you are almost unable to move your instruments and I have seen surgical instruments even bend. If your fulcrum is short, you can use short ports, the shear forces should be limited and you will be able to freely move your sticks.
• Diagonal port placement – If your ports don’t go exactly perpendicular to the abdominal wall, the length of the trocar needs to be extremely long (which you would like to avoid – see above).  Almost all ports have the tendency to retract and then you may have even CO2 gas insufflating into the subcutaneous fat layer, which makes that layer even wider and the whole operation may become undoable. I like the Applied Balloon ports that prevent the trocars from retracting and I also like the 100 mm or 150 mm J&J ports.

Once your ports are set in the right place, you are set to go. 

NB: The first O&G trainee who can name the anatomical landmarks numbered on the graph above will win a prize!