Keywords
suspension laryngoscopy - endolaryngeal surgery - suspension microlaryngoscopy - laryngoscopy
complications
Introduction
Suspension laryngoscopy (SL) is a commonly performed procedure among otolaryngologists.
It allows for bimanual surgery of the endolarynx, and the surgeon may address a variety
of benign and malignant lesions utilizing this technique. Despite its common use in
laryngeal surgery, there is no clear agreement regarding the true complication rate
of this procedure and what is defined as a complication or expected side effect. Complications
of SL can be categorized as either major or minor.[1] Major complications of SL are fortunately uncommon, and include airway compromise,
esophageal perforation, and cardiac arrhythmia.[1]
[2]
[3]
[4] Minor complications are much more common after SL, and prior studies have primarily
classified these as dental injuries, nerve dysfunction, and mucosal trauma.[5]
[6]
[7]
[8]
Regarding nerve dysfunction, one study demonstrated that alterations in tongue sensation
were common after SL, which were considered as likely being due to lingual nerve injury.[8] Likewise, transient gustatory changes have been reported after laryngeal surgery,[9]
[10] as well as hypoglossal nerve injuries.[11] Rosen et al[7] also found alterations in taste or tongue sensation to be a common complication
after SL, having been the most common postoperative complication in their series,
occurring at an incidence of 37.5%. The mechanism of injury is likely forceful compression
or stretching of the nerve, and sensory deficits are usually transient, with complete
recovery expected within several weeks to months postoperatively.[12] Nonetheless, one study showed that those patients whose operations lasted > 1 hour
were almost 4 times more likely to develop postoperative tongue-related complaints
than those whose operations that lasted < 30 minutes.[8] Thus, operative time in SL appears to effect patient outcomes. Indeed, another study
demonstrated similar findings in that all of the procedures in their series lasting > 60
minutes revealed at least 1 extra-laryngeal complication.[13]
Injuries to the oral mucosa and to the dentition have also been observed frequently
after SL. Indeed, 1 study observed a 51% incidence of oral cavity lesions and a 6.5%
incidence of dental injury in their prospective analysis of 339 consecutive SL cases.[14] In contrast, Rosen et al[7] reported no observed dental injuries or mucosal lacerations in their series of 56
SL procedures, and Dos Anjos Corvo et al[13] experienced only 1 case of dental injury in their series of 37 procedures, but reported
a total of 48 oral cavity injuries among the 36 patients studied. Protection of the
teeth, of the lips, and of the oral mucosa is often provided by using a standard dental
guard, although this is not mentioned in many reports of SL.
Despite the variability in the incidence and in the type of postoperative complications,
several studies have shown that adverse effects occur regularly with SL, although,
fortunately, they are often short-lived and of minimal consequence. The present study
was designed to evaluate the postoperative complications of SL, and provides the experience
of a single surgeon. The present report differs from other series that have been presented
in that a consistent technique for the protection of the dentition and of the oral
mucosa, as well as a limited suspension time, were employed in all cases. We hypothesize
that a standardized technique with particular attention to the protection of the dentition
and of the oral mucosa, as well as a conscious effort to limit suspension time may
decrease the overall incidence of oral cavity and pharyngeal complications of SL.
Methods
The present study was determined to be exempt from review and approved by the Lake
Erie College of Osteopathic Medicine (LECOM) Institutional Review Board. All of the
SL procedures performed by the senior author (Fornelli R. A.) from November 2008 through
September 2014 were retrospectively reviewed. Data collected included patient age,
gender, smoking status, presence of dentition, procedure performed, type of scope
and suspension system utilized, and presence of postoperative complications or complaints
and information regarding their resolution. To represent a complete case series of
SL events, no cases in the time frame reviewed were excluded. Data was codified and
entered into an Excel (Microsoft Corp., Redmond, WA, USA) database spreadsheet. Statistical
analysis was performed on the collected data. The chi-squared test was used to determine
statistical significance for incidences using a significance level of p < 0.05.
All of the patients underwent rigid direct laryngoscopy under general anesthesia.
Various laryngoscopes were used and suspension was employed most commonly with the
Lewy suspension system (Pilling Corp., Fort Washington, PA, USA). Other methods for
suspension utilized in the series were the Zeitels Universal Modular Glottiscope (UMG)
System (Endocraft LLC, Providence, RI, USA), or with a manual technique. In one case,
the Weerda distending operating laryngoscope (Jull Surg, New Delhi, India) was suspended
using a fulcrum. If maxillary dentition was present, a standard silicone dental guard
was placed over the teeth and two dampened gauze sponges were used to reinforce the
dental guard and provide additional protection to the upper lip and to the gingival
mucosa. In edentulous patients, four dampened gauze sponges were placed over the upper
alveolar mucosa and the lip for protection. In addition, the suspension time was limited
to 30 consecutive minutes in every case. During cases in which > 30 minutes of suspension
time was necessary, the patients were relieved of suspension for ∼ 3 minutes prior
to resuspending the laryngoscope.
It should be noted that at the 1-week postoperative visit, the surgeon meticulously
inquired about complications based on previously published known complications.[1]
[2]
[7]
[9] This was then documented in each medical record, which allowed for an accurate chart
review. The patients were followed 1 week postoperatively and then 3 months postoperatively.
Any patient with a complication noted either during the procedure or at the first
postoperative visit was then followed monthly until the resolution of the complication.
Results
A total of 213 consecutive SL cases were reviewed in the present study, involving
174 patients (94 male, 80 female). A total of 23 patients underwent 2 different SL
events, and 4 patients were involved with ≥ 3 SL events. The average patient age was
58.5 years old, and ages ranged from 24 to 89 years old. There were no repositioning
procedures, and none of the patients required a total suspension time > 60 minutes.
A variety of procedures were performed for both benign and malignant lesions, including
phonomicrosurgery with microflap excision, vocal fold augmentation, vocal fold steroid
injection, laryngeal microdebrider techniques, endolaryngeal biopsies, carbon dioxide
laser mucosal ablation and cordectomy, as well as cases combined with esophagoscopy
and rigid tracheobronchoscopy. There was no association between the type of procedure
and of the complications. The records of the patients were reviewed from postoperative
office visits ∼ 1 week after the surgery, and all of the complaints were recorded.
The most common postoperative complaint after SL was “sore throat”, occurring in 29%
of the cases, followed by “hoarseness”, which occurred in 23% of the cases. Other
less frequent symptoms included “cough,” “frequent throat clearing,” “intermittent
ear pain,” and globus sensation. A total of 47% percent of the cases reported no complaints
after the surgery.
[Table 1] shows the characteristics of the patients who experienced complications in the present
study. A total of 4 patients in the series experienced complications related to altered
sensation in the tongue postoperatively (2 paresthesia, 2 pain), for an overall incidence
of 1.9%. Each of the patients experiencing tongue paresthesias had resolution of their
symptoms at follow-up visits 3 months later, while both patients reporting tongue
pain were lost to further follow-up. There were no cases involving change in taste,
in tongue mobility, or tongue laceration.
Table 1
Characteristics among patients who experienced complications
|
Complication
|
Gender
|
Smoking status
|
Dentition
|
Suspension system
|
Scope type
|
|
Left tongue numbness
|
Male
|
Former smoker
|
Dentulous
|
Lewy
|
Ossoff-Pilling
|
|
Tongue pain
|
Female
|
Nonsmoker
|
Dentulous
|
Lewy
|
Ossoff-Pilling
|
|
Ulceration of upper and lower alveolar ridges
|
Male
|
Former smoker
|
Edentulous
|
Lewy
|
Ossoff-Pilling
|
|
Left nasal tip burn
|
Male
|
Nonsmoker
|
Dentulous
|
Zeitels UMG
|
Zeitels #4
|
|
Burning sensation in the tongue
|
Female
|
Smoker
|
Edentulous
|
Lewy
|
Ossoff-Pilling
|
|
Loose right mandibular tooth
|
Female
|
Former smoker
|
Dentulous
|
Zeitels UMG
|
Zeitels #4
|
|
Tongue pain
|
Female
|
Nonsmoker
|
Dentulous
|
Lewy
|
Ossoff-Pilling
|
|
Right upper lip tenderness
|
Female
|
Smoker
|
Edentulous
|
Lewy
|
Dedo
|
Abbreviation: UMG, universal modular glottiscope.
Two patients in the series experienced oral mucosal alterations after the SL (1 upper
and lower alveolar ridge ulceration, 1 upper lip paresthesia). The mucosa ulcerations
were healed at a follow-up visit 5 months later, while the patient with lip paresthesias
did not have further follow-up. There was one dental injury in the series, in which
a patient reported a loose mandibular tooth postoperatively. In addition, one patient
experienced a nasal tip burn from the light carrier during the SL. Altogether, these
8 complications represent a postoperative complication rate of 3.8% in the present
series.
[Table 2] shows the incidence of all postoperative complications according to clinical factors
of gender, smoking status, dentition, suspension system, and scope type. The incidence
of experiencing a postoperative complication was greater when using the Zeitels UMG
system (12.5%) compared with using the Lewy system (3.3%), though this was not significant
(p = 0.4). Likewise, gender (p = 0.19), smoking status (p = 0.55), dentition (p = 0.6) and scope type (p = 0.2) were not associated with a significant increase in postoperative complications
after the SL.
Table 2
Incidence of postoperative complications after suspension laryngoscopy
|
Total number of cases
|
Patients with complications
|
|
p-value*
|
|
|
(n)
|
(%)
|
|
|
Gender
|
|
|
|
0.19
|
|
Male
|
127
|
3
|
2.4
|
|
|
Female
|
86
|
5
|
5.8
|
|
|
Smoking status
|
|
|
|
0.79
|
|
Nonsmoker
|
59
|
3
|
5.1
|
|
|
Smoking history
|
152
|
5
|
3.3
|
|
|
No Record
|
2
|
0
|
0
|
|
|
Dentition
|
|
|
|
0.88
|
|
Edentulous
|
64
|
3
|
4.7
|
|
|
Dentate
|
148
|
5
|
3.4
|
|
|
No record
|
1
|
0
|
0
|
|
|
Suspension system
|
|
|
|
0.4
|
|
Lewy
|
182
|
6
|
3.3
|
|
|
Zeitels UMG
|
16
|
2
|
12.5
|
|
|
Weerda
|
1
|
0
|
0
|
|
|
No record
|
8
|
0
|
0
|
|
|
None
|
6
|
0
|
0
|
|
|
Scope type
|
|
|
|
0.53
|
|
Ossoff-Pilling
|
150
|
5
|
3.3
|
|
|
Dedo-Pilling
|
30
|
1
|
3.3
|
|
|
Zeitels UMG
|
16
|
2
|
12.5
|
|
|
Holinger
|
8
|
0
|
0
|
|
|
Weerda
|
1
|
0
|
0
|
|
|
No record
|
8
|
0
|
0
|
|
Abbreviation: UMG, universal modular glottiscope.
*Chi-squared test.
As shown in [Table 3], when directly comparing the Lewy and Zeitels UMG suspension systems regarding the
risk of developing a tongue-specific complication, the risk present by the Lewy system
was greater (2.2% versus 0%). However, this finding did not meet the criterion for
statistical significance (p = 0.55).
Table 3
Incidence of tongue complications among Lewy and Zeitels universal modular glottiscope
suspension systems
|
Total number of cases
|
Patients with tongue complications (n)
|
(%)
|
p-value*
|
|
Suspension system
|
|
|
|
0.55
|
|
Lewy
|
182
|
4
|
2.2
|
|
|
Zeitels UMG
|
16
|
0
|
0
|
|
Abbreviation: UMG, universal modular glottiscope.
*Chi-squared test.
Discussion
The complications in the present series included all of the patient complaints that
were unrelated to the surgical biopsy or resection. Therefore, complaints of sore
throat and/or of hoarseness, which were found in 43% of the postoperative patients,
were either unchanged from the preoperative setting or expectant given the nature
of their surgery and orotracheal intubation. The overall complication rate after SL
in the present series was of 3.8%, which is lower than any reported in the literature,
to our knowledge. Like other reports, our complications were classified primarily
into dental, mucosal, or nerve injuries.[7]
[13]
[14]
[15] The incidence of complications was greater among female patients (5.8%) versus males
(2.4%), although this was not significant (p = 0.19). In addition, the incidences of other factors associated with complications
were compared, such as smoking status (5.1% among nonsmokers, 3.3% in patients with
smoking history), dentition (4.7% among edentulous patients, 3.4% in dentate patients),
suspension system (3.3% Lewy, 12.5% Zeitels), and scope type (3.3% Ossoff-Pilling,
3.3% Dedo-Pilling, 12.5% Zeitels UMG), and none of them were shown to be significant.
Two primary factors can have contributed to the overall decrease in the incidence
of complications in the present study compared with other series. First, unlike other
reports, the consecutive suspension time in the present series was limited to 30 minutes
in all of the operative cases. Decreasing the time of suspension is thought to thereby
limit both stretching and compression of the lingual nerve, which are physiologic
factors considered responsible for tongue symptoms after SL.[12] In particular, ischemia has been shown to be a primary characteristic involved in
nerve stretch injuries.[12] Limiting the suspension time can, therefore, limit the time of ischemia to the lingual
nerve and to the soft tissues of the tongue. The importance of limiting the suspension
time was highlighted by Tessema et al,[8] who concluded that the risk of developing tongue-related symptoms was 3 times higher
for surgeries lasting between 30 and 60 minutes, and 5 times higher for those lasting > 1
hour compared with procedures lasting < 30 minutes. One study also found that the
duration of the SL rather than the pressure applied to the laryngopharynx and to the
tongue base was correlated with greater postoperative throat pain.[16] Given the increased sophistication of endolaryngeal procedures performed today,
these surgeries are now requiring greater precision and longer operative times.[8] Our results demonstrate that a low incidence of tongue-specific complications (1.9%)
can be achieved by limiting the consecutive suspension time in SL cases. Of note,
the present series includes both SL cases lasting < 30 minutes as well as longer cases
in which the patients were temporarily relieved of suspension after 30 consecutive
minutes. Despite a low incidence of overall tongue complaints in the present series,
future prospective research comparing complications of shorter operative cases with
those in which suspension is interrupted would further elucidate the effectiveness
of temporary interruption of suspension in SL procedures.
A second factor related to our study population that has likely contributed to a relatively
low complication rate is using an adequate and consistent method for protecting the
dentition, the lips, and the oral mucosal surfaces. All of the patients with maxillary
dentition had their upper teeth protected with a standard silicone dental guard with
two overlying damp sponges to add further protection to the upper lip and to the gingiva,
as well as to reinforce the protection of the upper teeth. The upper alveolar ridge
mucosa and lips of edentulous patients were protected with four damp gauze sponges
in all of the cases. Only two patients in the present series reported complications
related to oral mucosal alterations, and one patient experienced a loose tooth postoperatively.
Of note, the dental injury in our series was of a mandibular tooth, and thus it was
not protected. In contrast to our results, 51% of the patients in the series by Klussmann
et al[14] experienced an oral cavity lesion after SL. The authors report using a “standard
dental guard made from silicone” for all of the patients.[14] Lip injuries were observed in 27% of all patients, and mucosal lesions of the maxilla
were observed in 61% of all oral cavity lesions.[14] Moreover, dental injuries were observed in 6.5% of all of the patients in their
series, with loosening of the teeth being the most frequently observed finding.[14] In our experience, a standard dental guard does not provide adequate protection
of the upper lip, and often fits poorly on the teeth of the patients, and even worse
along edentulous alveolar ridges. Indeed, other authors have found standard dental
guards to be poor-fitting as well, and have recommended the use of molded mouth guards
instead.[17] Therefore, the present series demonstrates that a standard technique with greater
protection of the teeth and of the oral cavity mucosa can limit dental and oral mucosal
complications.
Since the data collection and review was done via a review of the charts of a single
surgeon with significant laryngeal surgery experience, our retrospective case series
has expected inherent limitations. Several discrepancies between our report and those
mentioned above may be influenced in part by our differences in methods of data collection.
Whereas Klussmann et al[14] re-examined patients within 24 hours after the surgery, our patients were examined
at postoperative office visits approximately 1 week postsurgery. Therefore, it is
possible that minor mucosal lesions could have either healed or been overlooked if
patients were not significantly bothered by them. While selection bias is inherent
to retrospective reviews, all of the postoperative issues were actively sought in
our series, and all of the problems unrelated to biopsy or resection were considered
complications of SL.
Lastly, one patient in the present series experienced a burn to his nose from the
laryngoscope light carrier while undergoing SL. Although this is a rare occurrence,
the intense heat generated from the light carrier can inadvertently injure structures
it enters in contact with if it is loosened from the laryngoscope. An additional protective
measure that we have adopted since this occurrence is to wrap a moist sponge around
the light carrier when using the Zeitels UMG system and to cover the face of the patient
with a towel to protect against inadvertent instrumentation or burns to the face.
Future prospective studies using a larger cohort with specific suspension times and
protection techniques are needed to elucidate the precise maneuvers and parameters
that reduce complications in SL.
Conclusion
Only 3.8% (8/213) of the cases in the present series experienced complications, which
is significantly less than the rates observed in other reports. Consistent protection
of the dentition and of the oral mucosa, and limiting suspension times to periods
of 30 minutes regardless of the necessary operative time are factors unique to our
series and may bear significance in reducing complications in endolaryngeal surgery.
Future prospective studies using consistent and conscientious techniques, such as
the ones we have described, may provide more insight into more accurate complication
rates and, ultimately, safer SL procedures.
