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Dysphonia and Dysphagia Following the Anterior Approach to the Cervical Spine
Catherine P. Winslow, MD;
Timothy J. Winslow, MBA;
Mark K. Wax, MD
Arch Otolaryngol Head Neck Surg. 2001;127:51-55.
ABSTRACT
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Background Speech and swallowing dysfunctions are common following the anterior
approach to the cervical spine. Despite functional morbidity and legal implications,
the incidence and etiologic factors of these complications have not been adequately
elucidated.
Objective To better define speech and swallowing dysfunction both in the quantitative
and qualitative sense.
Methods A questionnaire was mailed to 497 patients who had undergone anterior
cervical fusion or anterior cervical discectomy at a university hospital (study
group). One hundred fifty questionnaires were sent to a control group.
Results The study group response rate was 46%; the control group response was
51%. The incidence of hoarseness in the study group was 51%; the incidence
in the control group was 19%. The difference was statistically significant
(P<.01). Dysphagia was present in 60% of study
group patients vs 23% of control group patients (P<.01).
Qualitative questions revealed that constant hoarseness, pain with talking,
difficulty eating solid foods, and odynophagia were significantly more common
following the anterior approach to the cervical spine.
Conclusions Our findings show a much higher incidence than previously reported of
both voice and swallowing impairment following the anterior approach to the
cervical spine. Hoarseness and dysphagia may adversely affect recovery and
the patient's sense of well-being. Preoperative counseling and postoperative
evaluation are essential.
INTRODUCTION
THE ANTERIOR approach has become popularized among neurosurgeons and
orthopedic surgeons for operative exposure of the cervical spine. However,
abnormalities in voice and swallow are commonly noted following this technique.
While these problems hold important functional and legal implications, little
attention has been generated and minimal research has been conducted to solve
these issues. The incidence is uncertain, and the etiology is speculation.
This study was designed with the intent of better defining this complication,
both in the quantitative and qualitative sense.
PATIENTS AND METHODS
A questionnaire study was performed at a university hospital. All patients
who had undergone anterior cervical fusion (ACF) or anterior cervical discectomy
(ACD) within a 10-year period were identified by surgical coding. A control
group of patients who had undergone general anesthesia for an unrelated orthopedic
procedure (lumbar laminectomy) was identified. Questionnaires regarding speech
and swallowing function were mailed to both populations. Questions also addressed
additional complications and satisfaction with the procedure. For purposes
of brevity, the questionnaire is not included in this article. A 3-page confidential
questionnaire was mailed to patients, with patients having the option of citing
their names. Demographic data were elicited. Patients were asked if they had
any difficulties preoperatively with swallowing or hoarseness and whether
there was any history of neck surgery. If patients answered yes to prior neck
surgery, they were asked to describe it. They were asked whether they had
previously been diagnosed as having acid reflux or stomach acid problems.
If the answer was yes, they were asked if they took medication and whether
it was prescription medication. Patients were asked which side of the neck
their scar was on, whether a bone graft was used, and the levels of surgery
in the cervical spine, if known. Rating scales (0-10) were provided for patients
to evaluate the perceived impact of hoarseness and swallowing after surgery
for those who were symptomatic, and all patients were asked to rate satisfaction
with surgery. Queries regarding specific components of hoarseness and dysphagia
in symptomatic patients were made in an attempt to further delineate the complaints
(Table 1). Patients who were symptomatic
were asked how quickly after surgery the problems began and how long they
lasted. Details regarding surgical procedures were not obtained. A preliminary
chart review revealed vastly different dictated details that were not consistent
enough to analyze.
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Table 1. Specific Questions Asked of Patients Who Answered Affirmatively
That They Had Difficulties With Speech or Swallowing Since Surgery
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Results of all questionnaires were recorded in a relational database
and analyzed using a statistical program and spreadsheet. Statistical analysis
was conducted using a 2-tailed, large-sample test for the population proportion
and population mean. A standardized form test statistic, the z value, was calculated in determining P values.
Confidence intervals were established at 95% or .05  for population
proportions and 99% or .01 for population mean calculations.
RESULTS
There were 497 patients entered into the study group. One hundred twelve
questionnaires (22.5%) from the study group were eliminated on return because
of an incorrect address in the hospital database. Of the remaining questionnaires,
176 were completed (46% response rate). There were 82 men and 94 women in
the group. Average patient age was 53.2 years. A right-sided approach was
used in 135 patients, left-sided in 14, and frontal in 12; 15 patients did
not respond. A bone graft was used in 73 patients. The mean time since surgery
was 3.3 years. Hoarseness was present in 89 patients (51%) following ACF or
ACD. Dysphagia was present in 105 patients (60%) (Figure 1). Twenty-one patients had previous ACF or ACD. Reflux was
noted in 27% of patients. Eighteen percent noted difficulties breathing postoperatively.
Four patients (2%) had been evaluated by an otolaryngologist, and 2 had surgery
related to airway problems.
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Incidence of hoarseness and dysphagia in all patients.
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One hundred fifty questionnaires were sent to patients who had lumbar
laminectomy performed within the previous 5 years. Seventy-seven questionnaires
from this control group were returned (51% response rate). Patients were asked
whether they had previously undergone ACF or ACD; those who answered yes were
excluded from analysis. A total of 62 questionnaires from the control group
were evaluated. There were 28 men and 34 women. Average patient age was 61.2
years. The mean time since surgery was 1.7 years. Hoarseness was present in
12 patients (19%). Dysphagia was noted in 14 patients (23%). Reflux was present
in 35% of patients. Fourteen percent of patients noted postoperative difficulties
with breathing. Two patients (3%) had been seen by an otolaryngologist, and
none had surgery for their problems.
Patients were queried regarding specific symptoms (Table 2). Study group patients with postoperative hoarseness were
more likely to complain of constant hoarseness and pain with talking (P<.001). Control group patients were more likely to
cite symptoms of voice breathiness and cracking, muffled voice, and worsening
at night (P<.01). Patients with dysphagia in the
study group were more likely to note difficulty with solid foods, odynophagia,
and pneumonia since surgery (P<.01). Patients
in the control group were more apt to note difficulty with liquids or saliva
and coughing as present. There were more patients in the control group evaluated
by a physician for their problems than in the study group (P<.03). Surprisingly, previous ACF or ACD in the study group did
not correlate to an increase in postoperative complaints.
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Table 2. Qualitative Symptoms of Hoarseness and Dysphagia (of All Patients)*
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Patients who noted difficulty breathing following surgery were evaluated
as a subset. Patients in the study group had a high incidence of hoarseness
and dysphagia (72% and 78%, respectively). Reflux was present in 38% of these
patients. In the control group, the incidence of hoarseness and dysphagia
was also high (44% and 78%, respectively). Reflux was present in 67% of these
control group patients.
Patients who noted symptoms of reflux were then evaluated as a separate
group to determine if this complaint had an effect on symptom prevalence.
Patients with reflux in both the study and control groups were more likely
to note difficulties breathing postoperatively (25% and 27% vs 18% and 6%
in the general study and control group, respectively). Patients with gastroesophageal
reflux disease (GERD) who had postoperative dysphagia or dysphonia were statistically
more likely to be in the study group (P<.01).
Patients in both the control and study groups who noted difficulties
in voice and swallowing before surgery were assessed independently (Table 3). In the study group, 16 (94%)
of 17 patients noted both hoarseness and dysphagia in the postoperative course.
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Table 3. Patients With Preoperative Difficulties With Voice and Swallowing
(of All Patients)*
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Additional complications occurred in 45 patients following ACF or ACD.
The most common complications were no improvement or pain following surgery
(n = 24) and need for further surgery (n = 5). There was 1 each of the following:
esophageal perforation, scar revision, tracheal stenosis, difficult intubation,
and hip fracture from bone graft.
A rating scale was provided to patients to assess the impact of voice
and swallow changes on recovery. A score of 0 represented no impact on recovery
by hoarseness or swallowing changes, and 10 represented "extremely disruptive."
A score of 5 was considered "troublesome." The mean for impact of hoarseness
in the study group was 4.3; in the control group, it was 2.2. The mean for
impact of dysphagia on recovery in the study group was 4.4, and in the control
group, it was 2.9. Using a 95% confidence interval, this difference is significant
to .05 .
A separate scale was provided to determine the patient's overall satisfaction
with the surgery. This was also based on a scale of 0 to 10, with 0 representing
"not satisfied at all" and 10 indicating the patient was "completely satisfied."
The mean was calculated. The mean of the entire study group was 7.5, and the
control group mean was 7.3. The subgroup of hoarse patients listed a mean
of 7.2 for the study group and 6.3 for the control group. Patients with dysphagia
in the study group listed a mean of 7.2, and in the control group, a mean
of 7.1. Finally, patients who cited "other complications" in the study group
had a mean score of 5.9, and in the control group, this subset noted a mean
of 6.3. There was no statistically significant difference in satisfaction
with surgery between the study and control groups.
The duration of symptoms was evaluated (Table 4). Patients were instructed on the questionnaire to circle
the most appropriate option, including persistent symptoms of less than 24
hours, 1 to 3 days, 3 to 7 days, 1 to 2 weeks, 2 to 4 weeks, less than 6 months,
and less than 1 year. The study group was more likely to have symptoms of
both hoarseness and dysphagia for more than 1 month. This difference was statistically
significant (P = .002 and P=.048,
respectively).
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Table 4. Duration of Symptoms*
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The side of approach to the cervical spine was ascertained in the study
group, and the side of approach was evaluated with respect to symptoms. A
right-sided approach was favored by surgeons and was used in 135 patients.
Fifty percent of patients with this approach were hoarse, and 64% had dysphagia.
The left-sided approach was less common, with only 14 patients noting this
exposure. Seventy-one percent of these patients were hoarse, and 57 had postoperative
swallowing problems. Twelve patients noted a scar in the front of the neck.
With the frontal approach (scar in midline), 50% complained of both hoarseness
and dysphagia. This category was evaluated separately, because it could not
be determined which side was actually dissected. Fifteen patients did not
provide an answer to this question.
COMMENT
The anterior approach to the cervical spine affords excellent exposure
to the orthopedic and neurosurgeons who perform ACF and ACD. Controversy exists
as to the frequency of complications and whether a right- or left-sided approach
is anatomically more sound.
The incidence of hoarseness following this procedure is noted in the
literature to occur in 0.06% to 21% of patients (mean, 3.6%).1, 2
Injury to the recurrent laryngeal nerve, either from stretching or sectioning,
is a well-known but rare source of hoarseness. Laryngeal injury from endotracheal
intubation is also rare, with a 5% to 33% incidence.3, 4
However, this may become more prevalent when significant retraction and consequent
pressure occur during surgery. Infection is also rare but must remain in the
differential diagnosis. Edema and fibrosis of the larynx is hypothesized to
be a more common source of hoarseness and dysphonia following this procedure.
This may occur as a result of retraction devices designed to provide adequate
surgical exposure by displacing the larynx laterally. Our study showed a subjective
incidence of 51%, much greater than that described in previous reports. Even
more impressive is that the symptoms persisted for longer than 6 months in
38% of symptomatic patients. It appears that patients rarely are referred
to otolaryngologists or speech pathologists for further evaluation.
It is questionable whether there is any difference in laryngeal injury
with a right- or left-sided approach. One study5
has shown an increased strain placed on the right recurrent laryngeal nerve
with retraction, as opposed to the left. The right-sided approach is favored
by surgeons and avoids the thoracic duct. Our study shows an increased incidence
of hoarseness with a left-sided surgical approach (71% via left-sided approach
vs 50% with a right-sided approach). This question deserves further attention.
The incidence of dysphagia as a result of ACF or ACD is also widely
disputed. Some authors cite some degree of dysphagia in all patients postoperatively,6 and other authors do not consider it a surgical complication.
Some authors7, 8 noted an incidence
varying from 2% to 45%. The etiology, again, is uncertain. Hematoma, edema,
infection, denervation, and bone graft dislodgement are all possible causative
factors.9 A 1995 study8
attempted to elucidate the source of dysfunction. Questionnaires were mailed
to 100 patients 12 to 22 months postoperatively; 73 responded. The postoperative
incidence of dysphagia was 45%, with 12% of patients having persistent problems
for more than 6 months. Five patients were evaluated with barium swallows
and manometry. The barium esophagrams were all normal, and manometry revealed
elevated pharyngeal pressures. Another study10
evaluated 13 patients with dysphagia following ACF or ACD. Prevertebral edema,
diminished pharyngeal wall function, impaired opening of the upper esophageal
sphincter, ineffective epiglottic deflection, and postswallow residue in the
vallecula, pyriform sinuses, and posterior pharyngeal wall were seen. Neurogenic
causes related to the pharyngeal plexus and superior laryngeal nerves and
edema were thought to be responsible.
Our dysphagia incidence of 60% is higher than most reports. Thirty-two
percent of patients had symptoms for more than 6 months. It was somewhat surprising
that some specific complaints of speech and swallow dysfunction were actually
more prevalent in the control group than the study group. The fact that pain
with both talking and swallowing was significantly more common in the study
group is notable. Also, the constant hoarseness that is noted by study patients
may represent true laryngeal injury, as opposed to the more intermittent problems
noted by the control group. Although rare, only study group patients noted
postoperative pneumonia. It is not known if this was related to aspiration.
Patients who experienced difficulties breathing in the postoperative period
were more likely to have hoarseness and dysphagia in both the study and control
groups. It is possible that, again, this group represents true laryngeal injuries.
Several subgroups were evaluated separately to determine if there were
any common themes in the symptomatic patients. It was thought that a diagnosis
of reflux would predispose patients to postoperative problems. Although there
was a significant difference in dysphonia and dysphagia between patients with
GERD in the study and control groups, this was reflective of the study findings
in general. The incidence of GERD among all study group patients vs those
with postoperative hoarseness and dysphagia remained constant, although high.
It is not known if reflux in edematous tissue would delay the healing process.
Further evaluation is warranted.
Patients who had preoperative difficulties with swallow and voice were
also evaluated as a subgroup. This subset of patients was small for both the
study and control groups. However, there was an alarmingly high incidence
of postoperative problems with both voice and swallowing in the study group,
which was not reflected in the control group. At 94% incidence of postoperative
problems, this subset showed the most promise in identifying patients who
may be predisposed to postoperative problems. At the very least, this is a
viable screening question in the preoperative evaluation, and patients who
answer yes may benefit from referral to a speech pathologist and otolaryngologist
for further workup and counseling.
It is notable that, despite the impairment in the recovery process symptomatic
patients perceived, these patients were apparently not dissatisfied with the
procedure. Although the voice and swallow dysfunctions are noticed by the
patients and considered to be detrimental, those affected are apparently able
to separate these complications from surgical improvement from the ACF or
ACD.
This study has several limitations. First, it is a questionnaire study
and is both retrospective and subjective. Second, it was conducted with patients
who received their procedures at only one institution. It may be reflective
solely of an academic institution. Finally, no objective data were obtained
to verify the subjective findings or attempt to determine an etiology. This
is the topic of ongoing research. It is, however, the largest study on this
topic. Some debate exists in the literature regarding the functional impact,
as well as existence, of these problems. Determining the presence and impact
of dysphonia and dysphagia following the anterior approach to the cervical
spine before instituting a more extensive, invasive study was imperative.
Since no recent studies could be found that accurately describe the incidence
of postoperative dysphagia and dysphonia following endotracheal intubation,
a control group was believed to be vital to interpreting data. The control
group consisted of patients undergoing a nonrelated procedure, also performed
by the same orthopedists and neurosurgeons. Patients with previous ACF were
excluded from the control group in an attempt to avoid crossover. Positioning
in a lumbar laminectomy does involve turning the patient over into a prone
position, and this, if anything, may overestimate the amount of laryngeal
complaints in patients undergoing endotracheal intubation.
CONCLUSIONS
The study is limited in being a retrospective questionnaire study, dependent
on accurate patient recall. It is representative of a university hospital
and may not reflect private institutions. A large cohort and control group
were used to improve data analysis; however, a prospective study is still
optimal and needed. Unfortunately, the etiology of these problems cannot be
determined on the basis of this study.
Our study shows a much higher incidence of dysphagia and dysphonia following
the anterior approach to the cervical spine than previously reported. Postoperative
hoarseness was noted in 51% of patients following ACF or ACD. A postoperative
incidence of dysphagia of 60% was present. Patients with preoperative hoarseness
and dysphagia had a very high incidence (94%) of both voice and swallow difficulties
in the postoperative course. Patients with difficulty breathing postoperatively
noted a much higher incidence of hoarseness and dysphagia than the control
group. Patients with GERD in our study were more likely to note difficulties
breathing in the postoperative period, and those in the study group were significantly
more likely to have postoperative voice and swallow problems. Symptoms persisted
for more than 6 months in 38% of those patients with hoarseness and 32% of
patients with dysphagia. Hoarseness and dysphagia may adversely affect recovery
and the patient's sense of well-being. A history of dysphonia or dysphagia
should be elicited preoperatively. These patients may be at a much higher
risk of postoperative problems and should be counseled accordingly.
AUTHOR INFORMATION
Accepted for publication July 13, 2000.
Presented at the Academy of Otolaryngology–Head and Neck Surgery
annual meeting, San Antonio, Tex, September 14, 1998.
From the Department of Otolaryngology–Head and Neck Surgery,
Oregon Health Sciences University, Portland. Dr Winslow is now with the Department
of Otolaryngology, Walter Reed Army Medical Center, Washington, DC.
Corresponding author: Catherine P. Winslow, MD, Department of Otolaryngology,
Walter Reed Army Medical Center, Bldg 2, Room 6B, Sixth Floor, 6825 Georgia
Ave, Washington, DC 20307 (e-mail: cwinslow{at}pol.net).
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