Limitations of
minimal access surgery
To perform minimal access surgery with safety,
the surgeon must operate remote from the surgical field using an imaging system
which provides a two-dimensional representation of the operative site. The
endoscope offers a whole new anatomical landscape which the surgeon must learn
to navigate without the usual cues which make it easy to judge depth. The
instruments are longer and sometimes more complex to use than those common in
open surgery. The result of all this is that the beginner in minimal access
surgery is faced with significant problems of hand—eye co-ordination.
Stereoscopic imaging for laparoscopy is still in its infancy. Future
improvements in these systems will greatly enhance manipulative ability in
critical procedures such as knot tying and dissection of closely underlying
tissues. There are, however, some drawbacks, such as reduced display brightness
and interference with normal vision due to the need to wear specially designed
glasses. It is probable that brighter projection displays will be developed, at
Another problem occurs when there is
intraoperative arterial bleeding. Haemostasis may be very difficult to achieve
endoscopically because blood obscures the field of vision and there is a
significant reduction of the image quality owing to light absorption.
Some
of the procedures performed by this new approach are more technically demanding
and are slower to perform. Indeed, on occasion a minimally invasive operation is
so technically demanding that both patient and surgeon are better served by
conversion to an open procedure. Unfortunately, there seems to be a sense of
embarrassment or humiliation associated with conversion which is quite
unjustified. It is vital for surgeons and patients to appreciate that the
decision to close or convert to an open operation is not a complication but
instead usually implies sound surgical judgement.
Another
disadvantage of laparoscopic surgery is the loss of tactile feedback.
Laparoscopic ultrasonography might be a substitute for the need ‘to feel’ in
intraoperative decision making. Although ultrasonography has progressed
significantly
in the past several years, laparoscopic ultrasound remains in its infancy. The
rapid progress in advanced laparoscopic techniques, including biliary tract
exploration and surgery for malignancies, has provided a strong impetus for the
development of laparoscopic ultrasound. Although incompletely developed, this
technique already has advantages that far outweigh its disadvantages.
In
more advanced techniques the large piece of resected tissue, such as the lung or
colon, has to be extracted from the body cavity. Occasionally, the extirpated
tissue may be removed through a nearby natural orifice, such as the rectum or
the mouth. At other times a novel route may be employed. For instance, a benign
colonic specimen may be extracted through an incision in the vault of the
vagina. Although tissue ‘morcellators, mincers and liquidisers’ could be
used in some circumstances, this has the disadvantage of reducing the amount of
information available to the pathologist. Recent reports of tumour implantation
in the sites of port holes have raised important questions about the future of
the laparoscopic treatment of malignancy.
Hand-assisted
laparoscopic surgery is a newly developed technique. It involves the
intra-abdominal placement of a hand or forearm through a minilaparotomy incision
whilst pneumoperitoneum is maintained. In this way the surgeon s hand can be
used as in an open procedure. It can be used to
There
is a growing need for improvement in dissection techniques in laparoscopic
surgery and, specifically, for improving the safe use of electrosurgery and
lasers. Ultrasonic dissection and tissue removal has been utilised by a
growing number of specialities for several years. The adaptation of the
technology to laparoscopic surgery grew out of the search for alternative,
possibly safer, methods of dissection. The current units combine the functions
of three or four separate instruments, reducing the need for instrument
exchanges during a procedure. This flexibility, combined with the ability to
provide a clean, smoke-free field, improves safety while shortening operating
times.
Although
dramatic cost savings are possible with laparoscopic cholecystectomy, the
position is less clear cut with other procedures. There is another factor which
may complicate the computation of cost benefit. A significant rise in the
rate of cholecystectomy followed the introduction of the laparoscopic approach
as the threshold for referring patients for surgery lowered. The increase in the
number of procedures performed has led to an overall increase in the cost of
treating symptomatic gallstones.