Minimally Invasive Surgery/Laparoscopic Surgery
 
Minimally Invasive Surgery (MIS) is not just about small incisions but a true revolution in the management of patients through surgical interventions.
 
The introduction of laparoscopic cholecystectomy in the late 1980s has become a new landmark in the history of surgery.  Since then, we have embarked in the quest for techniques and materials to carry out all forms of surgery through smaller and smaller incisions.  MIS is performed with long instruments and video cameras placed through small "port sites" in different parts of the body.  This can be accomplished by direct manipulation of the instruments and the camera by the surgeon or even remotely through robotic arms directed from a console within the operating room.
 
In 10 years MIS not only has changed techniques quite radically but also has made surgery much safer.  Safety has been accomplished by better exposure through perfected optics, better hemostasis through various techniques and a high degree of versatility in the possible tactics to be applied to handle the variants often encountered at surgery.
 
One early objection to MIS has been the potential of making surgery riskier by lengthening the operating time. Long before MIS the risk of surgery was significantly reduced by improved anesthesia techniques.  The safety of anesthesia reached a point where there was no longer a need to hurry through an operation. In fact, nowadays, the morbidity of an operation can potentially increase if hurrying results in increased blood loss. As independent variables, blood loss is a much stronger predictor of postoperative complications than operating time. 
 
Furthermore, blood loss usually extends the operating time and this defeats the purpose of hurrying in the first place.  As long as blood loss is kept to a minimum lengthening of an operation does not add risk to the patient. 
 
On the other hand the field magnification used in MIS has lowered the threshold for tolerance of bleeding.  As small a bleeding source may seem it is always controlled before it can interfere with proper visualization of the field. Consequently, blood loss has been significantly reduced for every MIS procedure in comparison to the open counterpart. 
 
Along with smaller incisions we have observed patients recover much faster and with much less pain.  In doing so, we also realized that other interventions we did around surgery were as invasive, and painful, as the incision itself.  Tubes places in the bladder (Foley catheters) and stomach (nasogastric or NGT) have been used routinely in most forms of surgery.  Nowadays, they are used very selectively, placed only after the patient is under anesthesia and often removed before the anesthesia is reversed. 
 
With the reduced blood loss there is less of a need for blood transfusion and blood work to monitor red cell counts.  Less incisional pain results in less need for narcotic analgesics which in turn allows for earlier mobilization of the patient and earlier return to full function of all body systems: respiratory, urinary, musculoskeletal and, in particular, gastrointestinal; thus eliminating the need for multiple tubes in the postoperative period, such as urinary catheters (Foley), nasogastric (NGT), drains (Jackson-Pratt and alike). 
 
In the pre-MIS era the anxiety of the surgeon waiting for the return of bowel function often led to obtaining imaging and laboratory studies which added more invasiveness and risk to the patient. The post-MIS area is also anxiety-producing for the nurses and surgeons caring for the patient: we have lost some "indicators" for monitoring possible, albeit unlikely, complications during recovery: hourly urinary output (measured through a urinary catheter), nasogastric output, and various measurements in blood.  We are also breaking some dogmas: patients go home before consuming a solid meal or having a bowel movement after bowel surgery.
 
MIS has lead to a reduction in the length of stay in the hospital and of the length of recovery at home. We are still informing patients that there is always the possibility of having to resort to the traditional open approach and that by doing so the hospital stay and recovery time can be extended. 
 
A very interesting observation we are now making is that when MIS is not feasible, or is not even tried at all, and the patient receives the same “minimalist” postoperative management the hospital stay and recovery time is similar to that of patients undergoing MIS. Therefore, incision and postoperative management can independently reduce length of stay and recovery time if applied under the minimalist concept. 
 
One dilemma for patients after MIS is the return to work. Those who work independently are happy to be back in a week or less. Some of those who are entitled to medical leave are disappointed when they realize that they cannot take as much time off as some workers who had surgery for the same disease through the conventional, open method.
 
The minimalism in incision, and invasiveness before and after surgery, should not be misinterpreted as a minimization of the risks of surgery.  Under elective circumstances, modern diagnostics allow us to detect, and correct, many disturbances of the functioning of vital organs prior to surgery, thus reducing risk. We can optimize heart function through medications and even interventions on the coronary arteries. 
 
In most cases, we can also ensure that lungs and kidneys are able to sustain the stress of surgery.   However, there is a limit to the sensitivity of these diagnostic modalities and to the efficacy of all these preoperative interventions, especially when we are performing surgery in patients who are reaching unprecedented ages for surgery. 
 
In addition, there are many factors that are still out of our control as surgeons: we can make a plan based on experience and all the studies on a particular patient and find during surgery that such plan is not executable. For instance there are many variants in the anatomy of blood vessels; an operation, which is ordinarily very safe in the typical configuration of blood vessels. 
 
Due to anatomic variations, unexpected or additional findings, or incidents that occur with surgery (unusual bleeding, spillage of infectious material), the scope of surgery may escalate beyond MIS.  While patients have always being informed about these possibilities it seems that in this MIS era it comes as a surprise when surgery has been extended due to intraoperative findings or occurrences.
 
Recent studies have given the green light for surgeons to apply MIS for cancer surgery in the abdomen and chest. Earlier studies had raised concerns about the completeness of cancer surgery through small incisions and the risk of implanting tumor cells in the incision through which the specimen is extracted.  Neither one of these concerns has proven valid; in fact preliminary data is showing better outcome in patients with cancer who undergo MIS versus traditional open approach. 
 
Scientists are now trying to explain this opposite and beneficial effect of MIS on cancer surgery. One possible explanation is that proportional to the invasiveness of the surgery there is a immunosuppressive response by the body, as if all the immune system is devoted to healing and establishing a barrier against infection losing its natural ability for cancer surveillance.
 
One problem we still struggle with when using MIS is the loss of tactile function.  This has heightened the need for gathering as much information as possible before surgery.  Imaging studies, such as CT scan and MRI, can give us precision in location and characteristics of the problem. Endoscopies with tattooing of the lesion are essential in the gastrointestinal tract. 
 
One solution already in the works is bringing to the operating room with imaging and endoscopic equipment to further minimize the invasiveness to the patient by doing this assessment in the same setting where surgery is to be done.  Another solution currently applied for bowel surgery is the ability to introduce a hand in the abdomen while maintaining the incision sealed from gas leakage.  In the case of bowel surgery this has come as solution to various problems: in addition to affording tactile function it allows extracting bulky specimens while protecting the incision from implantation of cancer cells.

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