Improvement of Patient Comfort & Safety During Laparoscopy

September 9, 2006
Hugo C. Verhoeven, MD
Hugo C. Verhoeven, MD

OBGYN.net Conference CoverageFrom the 9th Annual Congress of the International Society for Gynecologic Endoscopy, Queensland, Australia, May, 2000

Audio/Video Link  *requires RealPlayer - free download

Dr. Hugo Verhoeven:  “Good morning,  my name is Hugo Verhoeven, I am on the Editorial Board of OBGYN.net, and I’m reporting from the 9th Annual Congress of the International Society for Gynecologic Endoscopy at the Gold Coast in Queensland.  I have the great honor of talking this morning to Dr. Volker Jacobs who is working as a physician at the University of Kiel in Germany.  His main interest in the last few years has been the improvement of the safety and the comfort of the patients during laparoscopic procedures.  Good morning, my dear friend Volker. Our patients know that in the last few years there were a lot of improvements made in the field of laparoscopy techniques.  They know that everything is going quicker and easier but still the patients see the procedure as an unpleasant adventure, the discomfort is still very big.  Tell me what has happened in the last few years, what did you do to make it nicer for the patients, to reduce the discomfort, and especially to improve the safety of the procedure?”

Dr.Volker Jacobs:  “Parallel to the development of new laparoscopic procedures, we have taken a closer look at laparoscopic instruments and insufflation technique.  We evaluated instruments and developed models to further improve the performance as well as the patient’s safety.  Performance means establishing a pneumoperitoneum in a safer way, the pneumoperitoneum is needed to lift the abdominal wall upwards from the organs so the physician has a work space and a visual space to see and operate - it’s like a tent.  There is CO2 gas insufflated under low pressure into the abdomen, and the patient won’t feel that because she’s under general anesthesia.”

Dr. Hugo Verhoeven:  “But even if she’s under general anesthesia, after the procedure the patient will have shoulder pain and abdominal pain because of the pneumoperitoneum.  It is my understanding that the pneumoperitoneum is not something completely harmless during the surgery and it’s especially painful after the surgery.  So what are your thoughts about reducing the pain after the procedure and the risks during the performance?”

Dr.Volker Jacobs:  “Although carbon dioxide gas has been used for more than eighty years in laparoscopic procedures, it is well known that it can cause post-operative pain but carbon dioxide is eliminated and reabsorbed from the peritoneum within minutes, so pain lasting more than an hour or two would be related more to room air which can be pulled into the abdomen at the end of the procedure.  We have to make sure as a physician that at the end of the procedure the abdomen is not filled with normal room air because, as I just mentioned, carbon dioxide is eliminated within minutes from the abdomen.  Another very important aspect is laparoscopic hypothermia.  With increasing procedures and more sophisticated procedures lasting longer within the last few years, the amount of gas used has increased.  A high turnover of carbon dioxide gas is related to a decrease of intra-abdominal temperature, which after the procedure can lead to the fact that the patient is shaking, feeling discomfort, and waking up from the anesthesia not having a good feeling.  There are two ways to improve this, one is to warm the patient’s outside with external warming devices like warming pads or warming blankets, and the other aspect is that carbon dioxide gas has to be heated and hydrated so the patient won’t cool down.  Recent studies have shown this to be very effective, and I think this will soon be the standard in laparoscopic procedures.”

Dr. Hugo Verhoeven:  “Why isn’t this the standard now, and don’t we have alternatives to carbon dioxide?  Why are we using carbon dioxide and not other gases?”

Dr.Volker Jacobs:  “Other gases have been discussed and evaluated, one example is nitrous oxide which has been in use especially in the 1960’s but the disadvantage of nitrous oxide is that it’s combustible and because we are using electricity for cauterization in the abdomen, we can’t use a gas which is combustible.  Carbon dioxide has on the one hand no danger of being combustible; on the other hand, it’s completely eliminated through the lungs without reacting with the body.”

Dr. Hugo Verhoeven:  “We talked about carbon dioxide, the risks for pain after the procedure, and especially the risk of hypothermia.  You also worked quite a lot on safety of instruments – tell us something about that.”

Dr.Volker Jacobs:  “We established a model with which we could evaluate the performance of insufflation technique in the laboratory as well as intra-operatively.  From my point of view, it’s very important that the physician understands the technique completely because that’s the only way to solve problems, which can occur during an operation.  However, the insufflation technique has been proven to be very safe, it is pressure reliable, all instruments which are used are either disposable or are cleaned and re-sterilized after the procedure.  The instruments are tested not only by companies but also have to be given the approval by government institutions or have to get approval by law.  However, we found during our measurements that the performance can be increased so the procedures can be shortened.  The use of instruments which are better designed can be a benefit for the patient and shorten the procedure.” 

Dr. Hugo Verhoeven:  “Maybe you could give us some details about that - what could be improved exactly?”

Dr.VolkerJacobs:  “The big obstacle so far is the diameter in the insufflation system.  The smallest diameter in the insufflation system - and by insufflation system I mean the whole entire system from the insufflator through the insufflation hose to the patient’s abdomen – is determining the over all gas flow performance.  The larger the diameter is, the faster the peritoneum can be established or maintained in case of gas leakage. It is obvious that through a 10 mm trocar with a 10-mm optic inserted no gas with high flow rate can pass through.  Even without any instruments or optic inserted it is difficult to get more than 10 L/min at a nominal pressure of 12 mmHg through most disposable trocars.  Reusable trocars are in general more useful for high flow insufflation because they have a larger diameter at the insufflation supply at the trocar.  So it really makes no sense to me to buy an extreme flow insufflator with a gas flow rate of 20 or even 35 L/min instead of eliminating the resistance in the insufflation system first when you just want to increase the insufflation performance. Companies which I approached with this idea of improving the trocars and enlarging the diameter told me that nobody has complained so far about it, and physicians from my experience have not enough knowledge about basic physics to demand better products from the companies.  We as physicians have to develop new methods and to develop new models with which we can evaluate the insufflation technique we use and ask the companies how they can improve their products.” 

Dr. Hugo Verhoeven:  “The question for me is : if we are going to enlarge the diameter of the trocar, the hole in the body will be bigger, and the patient will of course ask the question : why is making the trocar bigger so important that the inflow of carbon dioxide is higher as it is now?”

Dr.VolkerJacobs:  “It is not a question of enlarging the diameter of the trocar, it’s a question of enlarging the diameter at the insufflation supply of the trocar which is attached to the trocar.  It doesn’t have anything to do with the patient but from the performance point of view, it’s very important to increase the diameter from, let’s say, 2 mm to 3 mm, because the flow rate is increased not linear but exponentially, proportional to the radius4.”

Dr. Hugo Verhoeven:  “That means you see possibilities of improvement. What are the prospects for the future?”

Dr.Volker Jacobs:  “The prospect for the future will be that we have to develop models with which the performance can be even better evaluated and improved.  We have to create design-optimized instruments - because insufflation components are not randomly combinable - to design an entire insufflation system, which is resistance and flow optimized from the insufflator to the patient.  And finally, the aim is to have better performance and cheaper equipment, which will increase the patient’s comfort as well as decrease insufflation and OR time.  Also, a very important aspect is the patient warming, as I mentioned earlier, external as well as gas heating and hydration devices will become standard in patient care sooner.”

Dr. Hugo Verhoeven:  “Thank you very much for this interview, and I hope the companies will be interested in your ideas and develop new devices to make a laparoscopy less unpleasant for the patient. Thank you very much.”