A surgical complication can be defined as a development, which is generally to the detriment of the patient, arising either at the time of operation, or during postoperative period. Surgery is an art of working with the hands. Its name derives from the Latin word chirurgia, which in turn comes from the Greek cheiros (hand) and ergon (work).
The intimate relationship of the sinuses to the orbit and anterior cranial fossa have rendered sinus surgery a potent source of complications and thus in recent years medico-legal litigation. In 1929 Mosher regarded intranasal ethmoidectomy which he described as the “easiest way to kill a patient”. The use of multi angled endoscopes and imaging techniques of the sinuses might have reasonably been expected to diminish these problems, but instead has resulted in a number of serious complications all over the world. Sometimes the endoscopic technique is aggressively adapted by the surgeon without undue regard to the important structures around the sinuses and hence the development of disastrous complications. At the same time it is true to say that although serious complications have been reported in the literature i.e. orbital and intracranial, in experienced hands, these complications are extremely low, constituting less than one percent. Stankiewitz in 1989 reported 28 percent of complications in his first 100 patients, which ultimately dropped to nine percent following the learning curve in the subsequent 100 cases.
Albucasis, (Haeger K, 1988) a physician and a skilled surgeon of his time in middle ages (936 –1013 AD) stated “those who lack a good grasp of anatomy are prone to commit serious and even fatal mistakes.”
A thorough understanding of the surgical anatomy of the paranasal sinuses is of utmost importance and its variations properly understood by the endoscopic surgeon. Preoperative CT scanning should be regarded as mandatory prior to endo-scopic sinus surgery. Regarding instruments it is important that the surgeon understands that a straight 0 degree endoscope points to exactly the area in which one is looking. With angled endoscopes such as 30° and 70°, one is not looking where one is pointing, and as a result, distortion of the operative field occurs leading to excessive tissue trauma, bleeding and higher risk of complications.
In the early stages of the learning curve, it is imperative that the surgeon should keep checking from outside the nose to see where the endoscope is entering into the nose. This can only be done with a 0° endoscope. The angled endoscopes such as 30° and 70° are more useful for looking around the corners and crevices of the nose and paranasal sinuses, e.g. working in the maxillary sinus, frontal recess etc. In vast majority of the patients a 0° endoscope is strongly recommended for routine surgery, as it does not cause any distortion or foreshortening of the operating view. This results in a better orientation of the anatomical structures compared to angled endoscopes.
It takes a few years of experience in endoscopic sinus surgery to handle successfully 30° and 70° endoscopes with ease. It is also important for the endoscopic surgeon to realise that the deeper the penetration and the operative procedure, the greater the importance of the 0° endoscope. In these circumstances, the surgeon must know precisely where he is and where the instruments are pointing. The surgical orientation becomes more difficult in the posterior ethmoids than in the sphenoid sinuses due to the anatomical location of the posterior ethmoid cells. The 0° endoscope also avoids trauma, which unfortunately occurs with angled endoscopes due to distortion of the operative field. Trauma during operative procedure causes bleeding which makes surgery potentially dangerous as anatomical landmarks become unclear. Ideally one should have 0 and 30 degree endoscopes in the outpatient for diagnosis. A 0° endoscope may not be adequate for diagnosis for the diseases in the lateral wall of the nose, yet the 0° endoscope is the instrument of choice for the majority of the patients during surgery. In authors' experience 2.7 mm 30 degree endoscope is most ideal for diagnosis as it can be negotiated through narrow areas of the nose 4especially in the presence of septal spurs, deflections and in children with ease. A flexible endoscope have been used for diagnostic purpose, however its relatively smaller diameter and the optical distortion should be taken into consideration prior to interpretation of the findings
A potential endoscopic surgeon should practice endoscopic sinus surgery dissection preferably on fresh cadavers. Preserved cadavers in anatomy department are not the ideal situation as usually it contains considerable amount of debris. The tissues in the preserved cadavers peel off easily unlike normal mucous membrane. At the same time quite often the position of the cadaver is hyperextended making surgical orientation more difficult. In some cadavers there remains a strong and highly irritating smell of either formalin or any other preservative making dissection very unpleasant.
Carefully selected patients with minimal disease should be operated in the initial stages preferably under local anaesthesia. The patient himself warns the surgeon if the surgeon is near the orbit and/or skull base inspite of thorough local anaesthesia and adequate sedation. After some experience the surgeon should undertake surgery under general anaesthesia. The surgeon should only tackle revision surgery and advanced procedures, such as muco-celes, tumors and frontal sinus surgery after considerable experience with endoscopic techniques.
Begin with simple procedures such as uncinec-tomy, ethmoidectomy and middle meatal antro-stomy in the early stages, then gradually going through the ground lamella into the posterior ethmoids, opening the anterior wall of the sphenoid and finally tackling the frontal recess pathology.
Prevention of complications in endoscopic sinus surgery begins when the patient is first seen in the outpatient's clinic rather than in an operating theatre. The following scheme should help the surgeon to avoid complications:
- Basic understanding of the pathophysiology of chronic inflammatory diseases of the sinuses.
- Proper diagnosis by means of detailed history taking, an orderly and attentive nasal endoscopy and CT scanning of the sinuses. The interpretation of the CT scan and diagnostic endoscopic evaluation should be done in conjunction with the patient's history.
- A thorough knowledge of surgical anatomy of the paranasal sinuses especially in relation to the orbital and intra cranial structures.
- Feeling comfortable with handling the instruments first in the outpatients department for diagnosis.
- A thorough preoperative preparation of the nose.
- Assess systemic medical conditions that may affect nose and sinuses.
Prevention of complications begins with adequate history and careful and complete nasal and sinus examination. A complete physical examination is essential to make sure the patient is in good health generally. This should be done regardless of age. Patients are again examined the day before surgery to rule out any upper respiratory tract infection. If there is any question whatsoever about feasibility of the sinus surgery, the operation should be postponed. The surgical procedure is performed as carefully and as skillfully as is possible within the capabilities of the surgeon. Under these conditions, the possibility of a serious complication is markedly reduced. However, under most ideal conditions, complications do occur and one must be prepared to handle them promptly and completely.
PREOPERATIVE PREPARATION
Certain preoperative preparations are mandatory so as to prevent operative and postoperative complications.
General Precautions
If the patient has or just recovering from acute upper respiratory tract infection, the operation should not be carried as it will only result in excessive bleeding due to mucous membrane congestion, oedema and vasodilatation. Patients suffering from hypertension should be well under control before embarking upon surgery. Patients suffering from bleeding diathesis should be 5properly investigated and only after joint consultation with the expert haematologist, procedure should be considered. Similarly patients on aspirin, warfarin etc. should have appropriate investigations before considering surgery.
Preoperative Steroids
Patients suffering from gross polyposis would benefit from a short course of systemic steroids in an attempt to reduce the size of the polyps and allowing surgical landmarks to be identified easily. Steroids may also help patients suffering from chest symptoms as a result of naso bronchial syndromes.
CT Scans
CT scan of the patients should be available at all times in the theatre during surgery. This is not only to plan an individual procedure but also to refer the scan during the operation to appreciate the pneumatisation of the various air cells and identify the level of the skull base to the nasal cavity.
LOCAL ANAESTHESIA FOR FESS
Endoscopic sinus surgery under local anaesthesia offers a great deal of advantage over general anaesthesia. This is mainly due to the fact that inspite of sedation and thorough preparation of the nasal cavity, if the surgeon approaches skull base and or orbit, the patient inevitably will feel the pain which would warn the surgeon. The surgeon should be familiar with the nerve supply of the nose to anaesthetize the nose and inject at the appropriate sites to “ block” the sensory nerves.
It is important to remember that the local anaesthesia will not control the pain of cautery.
Aspiration before injection of local anaesthetic should be performed to avoid direct entry into the vessel. Blindness has been reported by accidentally injecting into the vessel, causing retrograde flow through ophthalmic artery, leading to vasospasm and ischaemia of the optic nerve and retina. The surgeon should be well aware of the toxicity and over dosage of the various anaesthetic agents. Preoperative consultation with the anaesthetist is advisable.