Spotlight on Technology…Fios® First Entry

| August 18, 2008 | 0 Comments

with Ramzi Alami, MD, and Vivek N. Prachand, MD

Dr. Alami is with Permanente Medical Group, Kaiser Permanente, San Francisco, California.
Dr. Prachand is with University of Chicago Medical Center, Chicago, Illinois.

What are some concerns with first entry for bariatric procedures?
Dr. Prachand: In laparoscopic surgery, some of the most potentially devastating and even life-threatening complications occur due to lack of visualization. During the operation itself, for example, injury to viscera can occur with instrument exchanges as they are brought into the field of view, particularly in inexperienced hands. Another major source of severe injuries in laparoscopy is during the initial abdominal entry and port insertion. Indeed, when one reviews reports of major vascular injuries, including aortic injury and iliac vein injury, these typically take place during the initial abdominal access.*

In many ways, obtaining laparoscopic access for bariatric procedures can be particularly challenging. In patients of normal weight, the standard open Hasson approach, which is probably the safest technique, can be done under direct visualization using a small incision, most commonly in the infraumbilical position—where there is a near absence of significant subcutaneous fat tissue and where the scar can be well hidden. Additionally, the open approach at other locations on the abdominal wall is usually straightforward due to the relative lack of subcutaneous adipose tissue. In bariatric patients, however, the abdominal wall tends to be much thicker, with significant subcutaneous fat deposits that need to be traversed before the fascia and peritoneal cavity are reached. Also, because the majority of bariatric operations take place in the upper abdomen, ports are typically placed in the supraumbilical abdomen. Indeed, the standard open infraumbilical approach is not an option for most bariatric patients, as the umbilicus itself is often located much lower on the abdominal wall relative to the abdominal viscera due to the enlarged, redundant pannus. Furthermore, in severely obese patients, a standard open dissection approach generally requires substantial extension of the incision and subcutaneous tissue dissection, which increases the risk of wound infection and potentially negating a major advantage of laparoscopy in these patients.

Dr. Alami: Bariatric surgery is no different than other laparoscopic procedures when it comes to concerns or risks of first entry—regarding potential injury to other organs and especially when there may be adhesions. What does differentiate bariatric patients from other patients is the thickness of the abdominal wall, which makes it much more difficult to use the open technique. Blind entry, on the other hand, has some protection in that the omentum is usually thick and protects some of the other organs, but there will still be incidences of injury with that technique.

What would be the ideal characteristics important for first entry?
Dr. Prachand: Safety is the first and foremost consideration. Second, access should be obtainable in a reasonably expeditious manner. Third, the skin incision and tissue trauma should be kept to a minimum. Fourth, the technique should be reproducible and reliable. Finally, the trauma to the fascia and the remaining fascial defect should be small enough to minimize the likelihood of port-site herniation.
Dr. Alami: Ideally, first entry should be safe in that there is minimal chance of injury to other organs, it can be achieved without the need for additional incisions or larger incisions, and it provides rapid insufflation of pneumoperitoneum.

What form of first entry were you trained to use in residency?
Dr. Prachand: We used a Veress technique: after creating a 12mm skin incision, we would lift the abdominal wall and insert a Veress needle. After insufflation of the abdominal cavity, a non-bladed trocar was inserted. Granted, this was nearly a decade ago and we did not have all of the currently available options. However, even then, I noted that the Veress technique was not always a straightforward process, and obtaining peritoneal cavity entry while elevating of the abdominal wall, which could be quite massive, was often challenging. Certainly, this remains a reasonable and acceptable technique, but today there are options that I think are safer and easier that obviate the need for blind needle or trocar
Dr. Alami: In my training, I used all forms of entry. Hasson technique was popular among many surgeons. We used the Veress needle in combination with blunt and bladed trocars (most dangerous in my experience), and used optical entry systems with and without Veress insufflation.

What is your preferred method of first entry now?
Dr. Prachand: I currently use an optical trocar with direct insertion and without prior establishment of pneumoperitoneum. I have found this approach to meet the characteristics that are important with regard to first port entry, which includes safety, efficiency, efficacy, and minimal required tissue trauma. The one significant drawback to this approach until now has been the inability to adequately insufflate the peritoneal cavity with the camera and inner cannula of the trocar in place under direct visualization. However, with the new technology provided by the Fios® port, which allows insufflation with minimal peritoneal penetration, this particular hurdle seems to have been overcome.

I think it is important to keep in mind that we are discussing bariatric patients with relatively thick abdominal walls. In contrast, direct optical trocar insertion without pneumoperitoneum is often challenging and difficult in very thin patients, as their anteroposterior diameter is much less and the risk of injury to bowel or retroperitoneal structures is probably higher if appropriate insertion technique is not used.

Dr. Alami: My preferred method currently is Fios®. An advantage of Fios® is that it allows entry under direct vision. For my gastric bypass patients, I go off midline with my first trocar, which allows me to see the different layers of the abdominal wall as I go through them. Typically, once I am at the posterior sheath, I slow down to make the entry more controlled, and this allows me to truly just get the tip of my trocar in. The pneumoperitoneum is then established within seconds as I can insufflate at a rate of at least eight liters per minute compared to 1 to 4 liters per minute with different Veress needles. This is a very safe technique in the morbidly obese as there is usually a nice preperitoneal fat layer that cushions the entry and tells me to slow down as I go through the peritoneum. Even when using this for midline entry (like my first port on a laparoscopic adjustable gastric band), the preperitoneal fat layer is protective and it remains very safe to do this. The subcutaneous tissues in morbidly obese patients are usually very soft and easily spread in response to this trocar, which also means that it leaves a small fascial defect that I do not usually have to close. Also, the chance of injuring vessels is minimized because I can see them as I go in. Using an open technique is very difficult in morbidly obese patients as the abdominal wall can be several inches thick, which would require a much larger incision and that will likely leak the gas.
In patients who have had significant previous surgery, I go in with Fios® at a “virgin” site like I would with any first entry system. The only time I prefer to use a Hasson is when I am fixing larger incisional hernias because those tend to have very extensive adhesions and there really is no safe answer there!

Please share your own benefit of using this first entry system.
Dr. Prachand: I think that the ability to insufflate under direct visualization has a significant advantage. With the previous generation of optical trocars, in essence once the peritoneum was penetrated, a relatively blind additional insertion of the trocar parallel to the abdominal wall was required so that the cannula and camera could be removed in order for the insufflation gas to reach the peritoneal cavity without obstruction. Under direct visualization, we can monitor to see the adequate creation of pneumoperitoneum while simultaneously monitoring intra-abdominal pressures, confirming the accurate positioning of the trocar.

What benefits would there be to teach this new method of entry to residents?
Dr. Prachand: This method meets the requirements important for first entry during laparoscopic bariatric procedures, and as such it is important that we teach our residents this technique as well as the others.

One point that I think bears additional emphasis, however, is that while we talk about this technology as being one that provides direct visualization during entry, there is in fact a substantial haptic component that must be observed and corroborated with the optical findings. There are different levels of resistance when passing through the subcutaneous fat tissue versus the anterior fascia versus the rectus muscle versus the posterior fascia versus the peritoneum; it is critical during the learning process that the learner pays close attention to, and correlates these forces with, the visual findings and proceeds with great caution or even withdraws the port if the haptic feedback is not meeting the expected visual findings. When the amount of tissue resistance is unusually high, it is often due to resistance at the level of the skin, and is relieved by extending the incision a millimeter or two.

*References for some of the information given by Dr. Prachand in answer to the first question are the following:
1. Schäfer M, Lauper M, Krähenbühl L. Trocar and Veress needle injuries during laparoscopy. Surg Endosc. 2001 Mar;15(3):275–80. Epub 2000 Dec 12.
2. Vilos GA, Ternamian A, Dempster J, Laberge PY, The Society of Obstetricians and Gynaecologists of Canada. Laparoscopic entry: A review of techniques, technologies, and complications. J Obstet Gynaecol Can. 2007;29(5):433–65.
3. Berch BR, Torquati A, Lutfi RE, Richards WO. Experience with the optical access trocar for safe and rapid entry in the performance of laparoscopic gastric bypass. Surg Endosc. 2006;20(8):1238-41. Epub 2006 Jul 24.
4. Ahmad G, Duffy JM, Phillips K, Watson A. Laparoscopic entry techniques. Cochrane Database Syst Rev. 200816;(2):CD006583.

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