Complications in Transoral Laser Microsurgery of Malignant Tumors of the Larynx and Hypopharynx
Complications may arise during and after surgery and can be divided into minor and major complications:
Minor complications are those that can be treated medically without sequelae for the patients or that can be dealt with using a “wait-and-see” policy.
Major complications are those needing a blood transfusion, or either a revision surgery, or treatment in an intensive care unit or both.
In this chapter, potential complications and their rates will be analyzed; prognostic factors and tips and tricks to prevent and to manage complications will be addressed.
Complications may reduce the quality of life because of the need for a temporary or even permanent tracheostomy or gastrostomy.
Risk Factors and Incidence
Transoral laser microsurgery has become the standard procedure for the resection of malignant tumors of the larynx and hypopharynx. Recent reports show good results also for advanced tumors.1,2 Although in experienced hands the laser approach seems to be a safe procedure,3–6 this is mainly because most studies deal with small glottic tumors. Large tumors and those located in the hypopharynx or the supraglottic region are usually well vascularized presenting a potentially high risk of postoperative bleeding. Also, the extension of the resection may jeopardize deglutition from microaspirations to aspiration pneumonia.
The following factors are significantly related to the complication rate
Our experience on over 900 consecutively treated patients with primary curative intention by means of transoral laser resection, could rule out the following potential factors: gender, arterial hypertension, diabetes mellitus, and tumor exposure, which therefore have no significant influence on the incidence of postoperative complications.
Table 19.1 reflects the incidence of severe complications for microsurgical transoral laser resections.
Most intraoperative complications refer to anesthesic problems related to the use of the CO2 laser and include accidental burning, ignition of the upper airways, ocular lesions, mucosal edema, and obstruction of the airway. Most of them were already described during the initial period of laser use, between the 1970s and 1990s,8–11 which led to protocols of general recommendations to avoid them.12,13
Nowadays, little or no anesthesiologic complications are to be expected if the recommendations in the use of the carbonic laser are strictly followed. Hence, Steiner and Ambrosch14 report a 0% rate of anesthesiologic complications in a large series of 704 patients with malignant tumors of the larynx and hypopharynx. We observed the ignition of steristrips, used to fix both tubes employed during jet ventilation, which was resolved without any major complication.15
Following the literature, the rate of postoperative complications after transoral laser surgery is lower than after conventional external partial surgery.16–20 Nevertheless, the fact that after larger transoral resections patients are kept without a tracheostomy, leaves them in a potentially risky situation if a complication arises. Therefore, some authors recommend keeping patients intubated overnight who have undergone an extensive resection particularly of the supraglottic region18,21 or in patients of advanced aged. Others advocate temporary (preventive) tracheostomy after large resections.
This is probably the most feared complication after transoral resections, with a calculated mortality rate of 0 to 0.3%.14,19,22 The reported incidence is ~ 5% by Hinni et al,1 6% by Rudert et al.23 and 7% by Ambrosch and Steiner.24 In a recent review on 1,528 cases, Ellies and Steiner25 had 72 patients (4.7%) with postoperative bleeding. In seven of these the external carotid artery needed to be ligated. In our series of 905 patients, 33 patients (3.6%) had postoperative bleeding as a major complication, two of them died as a consequence, one at postoperative day 7 (in hospital), the other at postoperative day 10 (at home).
Glottic tumors rarely bleed, even after larger resections, whereas the risk increases considerably in supraglottic and hypopharyngeal tumors, even when the local extension is small.18,26,27 In our experience postoperative bleeding tends to occur during the first 48 hours after surgery or is delayed until around 7 to 10 days later. To reduce the risk of early bleeding some authors advocate leaving patients intubated for 24 to 48 hours after extended resections.18,21 Delayed hemorrhages may be associated with severe sequelae or even death.1,7,19,22
When a simultaneous neck dissection is planned in extended tumor resections, the ligation of laryngeal or hypopharyngeal vessels can be performed in the neck.
For the resection of larynx tumors there are two areas with a higher tendency to bleed: the posterior and lateral, just in front of the arytenoid; and the superior and lateral to the thyroid cartilage. In supraglottic tumors, the laryngopharyngeal plicae contain the major vessels and in tumors of the hypopharynx, the lateral wall is at risk.
Management of postoperative hemorrhage depends on the amount of bleeding and its potential tendency to be self-limiting, but it sometimes includes the need for general anesthesia to cope with the vessel. Most bleeding can be resolved by identifying the vessel and applying electrocautery or clipping (vascular) forceps.14,18,23,24,28 However, it may become difficult to identify an intermittently oozing vessel in the middle of a large operated surface with extensive fibrin exudation. Exceptionally, ligation of the external carotid artery may be indicated14 or a supraselective embolization of the involved vessel.7 The latter was needed in just one of our patients.
The best treatment for postoperative bleeding is its prevention. Larger vessels should be dissected or identified during surgery and double-clipped (Figs. 19.1, 19.2, 19.3, 19.4). Coagulation alone may not be sufficient.