Keywords
debridement - infection - lavage - neck - surgical wound - deep neck infection
Introduction
The most common etiologies of deep neck infections (DNIs) are odontogenic infections,
usually polymicrobial in nature, due to poor oral hygiene, followed by contiguous
extension of tonsillar/pharyngeal infections.[1]
The mechanism by which these infections spread is through lymphatic extension, hematogenous
dissemination, or direct extension.[2] These infections may ascend or descend through the deep neck fascia planes, increasing
morbidity and mortality.[3] Airway compromise, descending mediastinitis, and necrotizing fasciitis are among
the severe complications.[4]
Appropriate patient care requires knowledge of the location and extent of the infection.
Therefore, characterization with detailed imaging studies is crucial. Contrast-enhanced
computed tomography (CT) scans are the gold standard for diagnosis. Regarding management,
aggressive monitoring and control of the airway is the priority, followed by appropriate
antibiotic coverage. If surgical intervention is warranted, intraoral and/or extraoral
incision and drainage should be performed. The incision provides the means for drainage
and for cleansing of the pocket collection. Currently, there are various cleaning
solutions available and different mechanical methods to deliver the wound irrigation
solutions.
To date, no study has shown the superiority of any of the cleansing solutions used
in the head and neck. The most common solutions currently in use are normal saline
solution, and solutions containing iodine and antibiotics.[5] However, there is no available data to determine if there is any significant difference
between the intraoperative mechanical delivery method used to clean after incision
and drainage.
The irrigation pressure in pounds per square inch (psi) that is applied over the tissue
depends on the mechanical method used. Some studies suggest that methods that exert
an irrigation pressure lower than 4 psi are not sufficient for adequate cleaning.
One example of a low-pressure system is the bulb syringe, which exerts pressure ranging
from of 0 psi to 1 psi. Moreover, multiple studies recommend the use of an irrigation
method that generates pressure between 4 psi and 15 psi for adequate cleansing. Nonetheless,
this recommendation is based on data that has been exported from studies that compare
different mechanical methods for wound irrigation outside the head and neck.[6]
Based on these studies, multiple devices that exert different amounts of pressure
have been developed for wound irrigation, such as the Irrisept (Irrimax Corporation,
Lawrenceville, GA, United States), a manual device that exerts pressure ranging from
7 psi to 8 psi.[7]
Irrisept contains 0.05% of chlorhexidine gluconate in sterile water. Chlorhexidine
gluconate is known as an antiseptic agent with broad antimicrobial action against
Gram-positive and Gram-negative organisms, anaerobes, aerobes, and yeasts. Nonetheless,
the low concentration of chlorhexidine gluconate in Irrisept acts solely as a preservative
for the product.[8]
[9]
[10]
To our knowledge, there is a lack of data on the use of different mechanical methods
for the intraoperative lavage of DNIs.[11] It is well established that the use of a device that exerts between 4 psi and 15
psi has an additional benefit for wound irrigation when compared with conventional
methods.[6] However, the use of these devices in the head and neck region has not been documented.
The main objective of the present study was to compare two different mechanical methods
for intraoperative neck wound lavage. The goal was to create one cohort composed of
patients treated with a low-pressure system (bulb syringe) and compare it to a second
cohort, composed of patients in whom the lavage was performed with Irrisept, a system
capable to generate higher pressure.
Methods
The present study was reviewed and approved by the Institutional Review Board (approval
number B1660118).
We performed a retrospective cross-sectional analysis of patients with a diagnosis
of DNI managed at our institution from June 2016 to December 2017. We chose to start
the analysis in 2016 because this is when the Irrisept irrigation system was introduced
for DNIs at our institution. Using the Electronic Medical Record (EMR) database, data
on the patient population was obtained with the use of applicable International Classification
of Diseases (ICD) 9th and 10th edition codes for head and neck infections.
The inclusion criteria were patients diagnosed with deep neck space infection by physical
examination and/or CT scan, and those whose surgical intervention was solely performed
by the Otolaryngology–Head and Neck Service of our institution from 2016 to 2017.
The exclusion criteria were diagnosis of peritonsillar abscess, surgical intervention
at other institutions, and treatment discontinuation against medical advice.
A total of 42 medical records were reviewed. For each patient, the following data
was collected: demographics, comorbidities, smoking history, history of ethanol or
drug use, symptomatology in history of present illness, previous formation of neck
abscess, current location of the DNI, CT findings pertinent to the location of the
DNI, history of antibiotic use, type of surgery performed (transcervical approach,
transoral approach or both), irrigation method used during surgery (low- or high-pressure
device), airway management, drain placement, amount of steroids required after surgery,
the need for reintervention in the operating room, length of hospital stay, and postoperative
complications.
The study personnel extracted the pertinent data from each record using a collection
instrument. The database was developed using Microsoft Excel (Microsoft Corp., Redmond,
WA, United States) spreadsheets and stored in computer network files of the Division
of Otolaryngology–Head and Neck Surgery in a secure location. A master database was
then established, and a non-identifiable ID number was assigned to each patient. This
was all performed in accordance with regulations of the Health Insurance Portability
and Accountability Act (HIPAA).
Two study cohorts were created according to the mechanical irrigation method used
during surgery: the first was composed of patients treated with an intraoperative
low-pressure (0 psi to 1 psi) irrigation method (bulb syringe), and the second, of
patients treated with a high-pressure system (Irrisept).
For the statistical analysis, a univariate analysis was performed using the sample
size (n) and the relative frequencies (%). The data analyzed included the therapeutic
outcome and surgical treatment. Pearson Chi-squared tests were used, with values of
p < 0.05 considered statistically significant.
Results
Within the study period, 42 patients underwent surgery due to DNI. Most of the patients
were male (76%) and older than 18 years of age (83%). The most common comorbidities
were hypertension, immunocompromised state, and diabetes mellitus. Most of the sample
had never smoked (64%), and the most common symptoms presented by them were dysphagia,
neck pain, and odynophagia ([Table 1]).
Table 1
Demographics of the study participants
|
Patient demographics
|
n (%)*
|
|
Gender
|
|
Male
|
32 (76%)
|
|
Female
|
10 (24%)
|
|
Age
|
|
> 18 years old
|
35 (83%)
|
|
< 18 years old
|
7 (17%)
|
|
Comorbidities
|
|
Hypertension
|
12 (29%)
|
|
Immunocompromised (cancer, obesity, daily steroid use, end-stage renal disease, hepatitis
C virus)
|
8 (19%)
|
|
Diabetes mellitus
|
6 (14%)
|
|
Intravenous drug abuser
|
2 (4%)
|
|
Smoking status
|
|
Never smoked
|
27 (64%)
|
|
Smoker
Unknown
|
8 (19%)
7 (17%)
|
|
Presenting symptoms
|
|
Dysphagia
|
29 (69%)
|
|
Neck pain
|
25 (60%)
|
|
Odynophagia
|
22 (52%)
|
|
Sore throat
|
15 (36%)
|
|
Change in voice (hoarseness, muffled voice)
|
10 (24%)
|
|
Trismus
|
10 (24%)
|
|
Neck swelling
|
7 (17%)
|
|
Shortness of Breath
|
6 (14%)
|
Note: *Total n = 42.
In most of the cases (n = 10), multiple neck spaces were affected. The parapharyngeal space was most commonly
affected (n = 10), followed by the retropharyngeal space (n = 8). Abscess formation was observed at the anterior compartment of the neck in 3
patients, and at the masticator space in another 3 patients; 6 subjects had necrotizing
fasciitis; 1 had an abscess at level 5 (left side); and 1 had a submental abscess.
The patients were hospitalized for a mean of 15 days (range: 3 to 103 days). All patients
underwent incision, drainage, and cleansing of their DNI in the operating room. All
patients received intravenous antibiotics on admission.
The Pearson Chi-squared test was performed to examine whether the initial surgery
and treatments were independent ([Table 2]). Three surgical approaches were used in the initial surgery: transcervical, transoral,
and the combined approach. For wound irrigation, two methods were compared: the bulb
syringe, which is classified as a device with low-output pressure, the Irrisept, a
high-output pressure system.
Table 2
Comparison of initial surgical approach and irrigation system
|
Initial surgery
|
Irrigation with highpressure (psi) device: n (%)
|
Irrigation with low-pressure (psi) device: n (%)
|
p-value
|
|
Transcervical
|
23 (96%)
|
12 (67%)
|
0.034
|
|
Both approaches
|
1 (4%)
|
3 (17%)
|
|
Transoral
|
0 (0%)
|
3 (17%)
|
The comparison between the surgical approach and irrigation method used ([Table 2]) revealed that the results of the Chi-squared test of independence were statistically
significant (p = 0.034), suggesting that the initial surgery and treatment (irrigation method) are
related to one another. This means that for both irrigation systems (high- and low-pressure),
the approach most commonly performed in the initial surgery was the transcervical
(96.0% and 67.0% respectively), followed by the combined (4.0% and 17.0% respectively)
and transoral approaches (0% and 17.0% respectively).
The association regarding the requirement for intraoperative tracheostomy and previous
use of antibiotics with the irrigation system used is shown in [Tables 3] and [4] respectively. No statistically significant difference between the high- and low-pressure
groups was found (p = 0.35 and 0.21, respectively). Furthermore, [Table 5] presents the associations involving the postoperative requirement of a high dose
of steroids, the need for reintervention, and the hospital length of stay (LOS) with
the treatments. We found no statistically significant difference between the high-
and low-pressure groups in terms of the need for steroids (p = 0.22), for reintervention (p = 1.00), and the hospital LOS (p = 0.78). The same ratio of intra-operative drain placement was found between both
treatment groups.
Table 3
Comparison of incidence of tracheostomy placement and irrigation system
|
Tracheostomy
|
Irrigation with high-pressure (psi) device: n (%)
|
Irrigation with low-pressure (psi) device: n (%)
|
p-value
|
|
Yes
|
14 (58%)
|
7 (39%)
|
0.35
|
|
No
|
10 (42%)
|
11 (61%)
|
Table 4
Comparison of previous use of antibiotics and irrigation system
|
Previous use of antibiotics
|
Irrigation with high-pressure (psi) device: n (%)
|
Irrigation with low-pressure (psi) device: n (%)
|
p-value
|
|
Yes
|
8 (33%)
|
10 (56%)
|
0.21
|
|
No
|
16 (67%)
|
8 (44%)
|
Table 5
Association between postoperative high dose of steroids, surgical reintervention,
hospital length of stay, and irrigation system
|
Postoperative high dose of steroids
|
Irrigation with high-pressure (psi) device
|
Irrigation with low-pressure (psi) device
|
p-value
|
|
Yes
|
11 (46%)
|
12 (67%)
|
0.22
|
|
No
|
13 (54%)
|
6 (33%)
|
|
Need for reoperation
|
|
Yes
|
5 (21%)
|
3 (17%)
|
1.00
|
|
No
|
19 (79%)
|
15 (83%)
|
|
Length of stay
|
|
0–7 days
|
9 (38%)
|
9 (50%)
|
0.78
|
|
8–14 days
|
7 (29%)
|
4 (22%)
|
|
> 14 days
|
8 (33%)
|
5 (28%)
|
The postoperative complications (endpoints) reported were laryngeal edema (n = 3), pneumonia (n = 4), septic shock (n = 1), empyema (n = 2), scar hypertrophy (n = 3), mediastinitis (n = 1), and pneumomediastinum (n = 1). They were compared between the two treatment groups, and no statistically significant
difference was found ([Table 6]).
Table 6
Association between complications and irrigation system
|
Complications
|
Irrigation with high-pressure (psi) device: n (%)
|
Irrigation with low-pressure (psi) device: n (%)
|
p-value
|
|
Yes
|
9 (38.0%)
|
9 (50.0%)
|
0.42
|
|
No
|
15 (62.0%)
|
9 (50.0%)
|
Discussion
As seen in the present study, peritonsillar, parapharyngeal, and retropharyngeal collections
are the most common sites of infection.[12] Patients with peritonsillar abscesses were excluded from our analysis because most
of them do not require intervention in the operating room. From our data, the parapharyngeal
was the deep neck space most commonly affected, followed by the retropharyngeal space.
The anatomic limitations and the direction for the spread of these DNIs are demarcated
by multiple layers of cervical fascia that form at least 11 deep neck spaces.[13] The morbidity and mortality associated with DNI and abscess are decreasing due to
improvements in airway management, availability of CT imaging, and earlier presentation
and diagnosis.[2]
Some of the risk factors for the development of deep neck abscess are poor oral hygiene
leading to odontogenic infection and immunocompromised state, such as that caused
by diabetes mellitus. It has been reported[8] that other risk factors for the development of DNI include tonsillitis and smoking.
Nonetheless, most of our sample had never smoked.
Incision and drainage are the mainstays of the surgical therapy.[11] However, reinfection is a potential complication, and proper wound cleaning, debridement,
and postoperative care should be provided. There are multiple irrigation methods available
for proper wound cleansing after incision and drainage. Some of the standard irrigation
methods currently used for head and neck infections are normal saline solution and
solutions containing iodine and antibiotics.
To enhance wound cleansing, multiple methods to deliver the irrigation solution have
been described in the literature. However, to date, there is no consensus to define
what is a high- and a low-pressure device. Nonetheless, the current literature favors
irrigation pressure between 5 psi and 15 psi. Lower pressure is associated with inadequate
removal of debris, and higher pressure, with tissue trauma.[6]
[14]
[15] Yet, to the extent of our knowledge, there are no studies on the effect of the mechanical
methods of the irrigation systems in the head and neck region.
In the present study, we compared the irrigation method with a bulb syringe, which
exerts an output pressure of 0 psi to 1 psi to the Irrisept system, which exerts 7
psi 8 psi of pressure over the tissue.
After a retrospective review, we found no statistical differences regarding the irrigation
methods and the need for tracheostomy, for a postoperative high dose of steroids,
or the use of antibiotics prior to incision and drainage. With these results, we can
extrapolate that there is no difference in the complexity of the DNI between the groups.
Additionally, we found no statistically significant difference involving the hospital
LOS and the need for surgical reintervention between the two cohorts.
Moreover, DNIs are characterized by their rapid evolution and spread. Consequently,
patients can suffer from severe complications, such as acute edema of the larynx with
respiratory obstruction, mediastinitis, necrotizing fasciitis, empyema, pericarditis,
and jugular vein thrombosis.[1]
[2] Based on this data, we collected information on the development of these complications
in the postoperative period. Nonetheless, when comparing irrigation methods and the
incidence of these complications, the rates appear to be similar for both groups ([Table 6]). A possible explanation is that both irrigation methods have the same efficacy.
Published data suggests that there is no difference in the cleansing efficacy between
low- and high-pressure irrigation systems. Moreover, some studies[16]
[17] report that pulsatile lavage irrigation and high-pressure systems can impair the
wound healing process. However, in the present study, the Irrisept system was a safe
and viable alternative for irrigation of DNIs after incision and drainage because
no harmful or adverse events were reported after its use.
Nonetheless, the present study contains several major limitations. One of the notable
limitations is its retrospective nature and small sample size. In addition, there
was a difference in the baseline characteristics of both groups. Six of the included
patients had necrotizing fasciitis, which is known to be a distinct disease entity,
characterized by a more aggressive course. Moreover, pediatric and adult DNIs are
somewhat distinct entities. Pediatric patients tend to experience a more favorable
natural course of the disease when compared with adult patients.
Additionally, the choice of intraoperative irrigation method represents a bias because
we opted to use the high-pressure delivery system when the patient had a more serious
infection such as in the cases of necrotizing fasciitis. Also, more than 50% of the
pediatric patients were part of the low-pressure group. These differences in baseline
characteristics between the cohorts could have affected the outcomes of the present
study.
Therefore, it is reasonable to conclude that we did not find significant statistical
differences between the treatment groups because the high-pressure group had a higher
patient load with a more aggressive infectious process, and the low-pressure group
had a higher load of patients with favorable outcomes (pediatric population). This
distinction could explain why we did not observe better outcomes in the high-pressure
group.
Moreover, data on the use of irrigation outside of the operating room through drains
and the drain removal timeline were missing, which has also added a source of bias
to the present study.
Due to the aforementioned bias, the strength of the conclusions we can draw is limited,
and the external validity of the study is not high. Nonetheless, the present study
is very valuable because it opens the possibility of conducting of future studies
at our institution and/or at other academic centers.
Conclusion
The present study is valuable because it is the first to evaluate the difference between
surgical wound irrigation systems in the head and neck. At this point, we suggest
that the rates of reoperation, postoperative outcomes, and complications were similar
regardless of the irrigation pressure used. This finding indicates that the low-pressure
system is an acceptable, low-cost alternative for the irrigation of DNIs. Nonetheless,
a more robust study, such as a prospective randomized control trial, is necessary
to assess if there is a difference between the irrigation method used in the head
and neck for surgical wound cleansing.
