Sinonasal anatomical findings associated with revision functional endoscopic sinus surgery in chronic rhinosinusitis

Abstract

Background

Functional endoscopic sinus surgery (FESS) is a crucial additional procedure employed in the management of chronic rhinosinusitis (CRS). It has mostly overtaken the external methods for managing CRS that do not respond to medicinal treatment. Over the years, several instruments have been created to eliminate anatomical obstructions and restore proper function in the sinus drainage pathways. The purpose of this work was to reflect on various anatomical findings after primary functional endoscopic sinus surgery and their relationship with sinus surgery revision.

Methods

This is a prospective cohort study conducted on 40 participants with CRS. The Sino-Nasal Outcome Test version 22 (SNOT-22) was utilized as a measure of results and was filled out by participants both prior to and following their operation (at the 6-month and 12-month intervals).

Results

There were multiple anatomical findings encountered in CRS persistence and subsequent need for revision FESS; the most common was incomplete ethmoidectomy (both anterior and posterior) 62.5% (N = 25), and the least common was misplaced antrostomy and partial or full resection of the middle turbinate 7.5% (N = 3). Preoperative total SNOT-22 scoring ranged from 42 to 86 with mean 58.83 ± 12.08, while 6-month postoperative scoring ranged from 10 to 32 with mean 21.48 ± 5.12, and 12-month postoperative scoring ranged from 15 to 37 with mean 28.83 ± 5.52. There was significant improvement (P = 0.001). The ages of patients range between 18 and 62 years.

Conclusions

Several common anatomical findings are often found during revision surgeries by analysis of CT scans and endoscopic examination of participants who underwent revision FESS for recurrent or persistent CRS, and this often shows persisting anatomical features or incompletely excised cells that correspond to persistent symptoms and signs of CRS, and the most common was incomplete ethmoidectomy. Also, there was significant improvement regarding outcome measure SNOT-22, 6-month and 12-month period postoperative as contrasted with preoperative scoring.

Background

Messerklinger introduced functional endoscopic sinus surgery (FESS) in the 1970s, using the Hopkins rod telescope, aiming to protect the nasal mucosa [1, 2]. The long-term outcome rates of FESS are exceptionally high, with more than 90% of patients experiencing significant improvements in their symptoms. Failure is indeed a possibility, with documented rates ranging from 2 to 24% following the initial surgical procedure. Possible causes of failure can include an inaccurate diagnosis, substandard technique for surgery, insufficient surgery, postoperative scars, inappropriate postoperative medical treatment, or the return of the condition [3,4,5,6].

After confirming that the participant is eligible for revision surgeries, the subsequent task is to perform a procedure that is both safe and thorough, despite the added complexity and higher risk of problems due to anatomical changes resulting from earlier surgeries. During revision sinus surgery (RSS), important anatomical features may be changed or absent, which might raise the likelihood of problems such as ocular damage, leakage of cerebrospinal fluid (CSF), and excessive blood loss. The middle turbinate, that is a frequently utilized point of reference, may have been surgically excised or modified. Previous surgeries may result in the absence of barriers that include the skull base and the lamina papyracea. Hence, it is crucial to identify and establish consistent reference points, and to conduct the analysis in a systematic progression from familiar to unfamiliar areas [6].

CT imaging aids in verifying anatomical landmarks. While it should not be used as a substitute for the surgeon’s awareness of the anatomy of the sinus, it can assist the surgeon in RSS when the usual anatomical landmarks might be absent. Additionally, it enhances the confidence of the surgeons when they deal with diseases that are adjacent to the orbit, base of the skull, carotid artery, or optic nerve. This method allows for more precise and assured access to high-risk locations including the base of the skull and frontal recess, resulting in the most comprehensive surgical outcomes [7].

The purpose of this work was to reflect on various anatomical findings after primary functional endoscopic sinus surgery and their relationship with sinus surgery revision.

Methods

This prospective cohort study includes 40 patients as measured utilizing Epi-Info software statistical package formed by WHO and Center for Disease Control and Prevention, Atlanta, Georgia, USA, version 2002, and the power of the study was 95%. Patients with persistent manifestations together with CT and endoscopic evidence of CRS despite previous endoscopic sinus surgery (ESS) and continued maximal medical therapy, at least for 1 year, are included. Patients had diagnostic criteria of CRS according to EPOS 2020 [8]. The condition requires the existence of at least two symptoms, this must be one of the following: nasal discharge (either posterior or anterior nasal drip), blockage, obstruction, or congestion. Pain or pressure in the face may accompany these manifestations, and may or may not include a diminished or absent sense of smell, for ≥ 12 weeks, in the absence of symptom resolution and with radiological signs of CRS. The ages of patients range between 18 and 62 years. Cases were allocated from February 2021 to November 2023 from the outpatient clinic of Otorhinolaryngology Department of Tanta University Hospital, approval code (34,355/12/20).

The criteria for exclusion were patients with sinonasal tumors, invasive fungal sinusitis, cystic fibrosis, non-rhinologic causes of facial pain and headache, who did not have any radiological evidence of thickening in the mucosa of nasal sinuses after therapy, and those who had undergone surgery for conditions such as mucoceles, trauma, Kartagener’s syndrome, or other primary mucociliary abnormalities. The study was undertaken after an ethical approval was granted by the Tanta University Hospital Ethics Committees. A well-informed consent had been received from each participant prior to enrolment in the work.

The data was obtained prospectively at the Department of Otolaryngology–Head & Neck Surgery, Tanta University, and incorporated demographic information in addition to pre- and postoperative computed tomography scanning of the nose and paranasal sinuses coronal, sagittal, and axial views, endonasal endoscopic examination, and a validated rhinosinusitis-specific quality of life instrument: the Sino-Nasal Outcome Test version 22 (SNOT-22) scoring.

Intervention

Participants were allocated to one group of 40 individuals using sequence generation and allocation methods. Each participant underwent a standard examination of the ear, nose, and throat (ENT), as well as a preoperative assessment using endoscopy and radiological imaging, specifically CT scans of the paranasal sinuses and nose in coronal, axial, and sagittal views. These scans were particularly crucial for fully understanding the paranasal sinus anatomy in order to plan the surgery effectively. Prior to the revision surgery, a methodical evaluation of the patient was conducted in order to determine the underlying factors contributing to the ongoing illness.

It is necessary to regulate the host and surrounding variables that contribute to the condition. The effects of the environment encompass smoking cigarettes, chemical irritants, air pollution, allergenic particles in the air, and mold. These agents restrict the normal movement of mucus and cause continuous irritation of the mucous membranes. It was crucial to identify, eliminate, or control these elements. Whenever feasible, the first CT scan was contrasted with the postoperative scan in order to recognize any novel or remaining ailment from the primary surgery, in addition to postoperative alterations like new bone formation or scar tissue. Multiple nasal endoscopies and radiographic examinations were performed to uncover potential anatomical and iatrogenic factors, while medicinal treatment is being optimized.

The procedures were performed using general anesthesia and an endoscopic endonasal technique. Subjects were provided with a comprehensive explanation of surgical techniques, as well as a comprehensive review of the related hazards and advantages (Figs. 1, 2, 3, 4, 5, and 6).

Fig. 1

Computed tomography paranasal sinuses coronal view showing Rt partial inferior turbinectomy, bilateral maxillary and ethmoid sinusitis and Lt synechia between middle turbinate and lateral nasal wall and nasal septum (asterisk)

Fig. 2

Endoscopic view (0° rigid endoscope) showing synechia (adhesions) between middle turbinate and lateral nasal wall and nasal septum

Fig. 3

Computed tomography paranasal sinuses coronal view showing bilateral recurrent polyps filling the nasal cavity

Fig. 4

Computed tomography paranasal sinuses axial view showing residual ethmoid cells, recurrent polyps (ethmoidal), Rt wide compared to incomplete Lt sphenoidotomy (arrow) and posterior septal perforation

Fig. 5

Intraoperative endoscopic view (0° rigid endoscope) showing polyps in Rt middle meatus

Fig. 6

Computed tomography paranasal sinuses coronal view showing Lt bulky hypertrophied MT (asterisk), bilateral residual ethmoid cells, Rt partial inferior turbinectomy and Rt septal deviation

Statistical analysis

Participants were instructed to evaluate their symptoms using a verified rhinosinusitis-specific quality of life instrument: Prior to and following operations (at 6 and 12 months), participants performed the Sino-Nasal Outcome Test version 22 (SNOT-22).

Results

A total of 40 participants undergone revision FESS due to persistent CRS because of persistent, residual, and/or retained anatomical variants were assessed with CT and endonasal endoscopic examination, whose ages were ranging from 18 to 62 years (mean of age with/without standard deviation = 36.58 ± 12.56). The study population comprised 29 males (72.5%) and 11 females (27.5%) (Table 1).

Table 1 Number of patients in relation to gender

As regards the number and percentage of smokers, there were 26 nonsmokers (65%) and 14 smokers (35%). Regarding the distribution of side of CRS revision endoscopic sinus surgery (RESS) (right, left or bilateral), there were 2 right, 4 left, and 34 bilateral ones (Fig. 7).

Fig. 7

A Percentage of smokers and B the distribution of side of chronic rhinosinusitis

As regards the number and percentage of each anatomical finding according to preoperative radiologic assessment and endoscopic examination (preoperative and intraoperative), they were as follows from the most to the least common: incomplete ethmoidectomy (both anterior and posterior) 62.5% (N = 25), incomplete sphenoidotomy 42.5% (N = 17), recurrent polyps 35% (N = 14), frontal sinus ostium stenosis 35% (N = 14); adhesions (synechiae) 22.5% (N = 9), middle meatal stenosis 22.5% (N = 9), lateralization of the middle turbinate 20% (N = 8), residual uncinate process 17.5% (N = 7), associated nasal septal deviation 15% (N = 6), osteitic bone 15% (N = 6), residual concha bullosa 12.5% (N = 5), an oversized antrostomy 10% (N = 4), maxillary sinus recirculation 10% (N = 4), associated inferior turbinate hypertrophy 10% (N = 4), misplaced antrostomy 7.5% (N = 3), partial or full resection of the middle turbinate 7.5% (N = 3) (Fig. 8).

Fig. 8

Percentage of anatomical findings

Regarding the comparison of mean total preoperative, 6-month and 12-month postoperative symptoms scoring according to SNOT-22 score, preoperative total SNOT-22 scoring ranged from 42 to 86 with mean 58.83 ± 12.08, while 6-month postoperative scoring ranged from 10 to 32 with mean 21.48 ± 5.12, and 12-month postoperative scoring ranged from 15 to 37 with mean 28.83 ± 5.52. There was significant improvement (P = 0.001) (Table 2).

Table 2 Number and percentage of anatomical findings

SNOT-22 was significantly different at all different times. SNOT-22 was significantly lower after 6 months and 12 months compared to preoperative (P value = 0.001), while insignificantly different between after 6 months and 12 months (Table 3).

Table 3 SNOT-22 for studied groups

Discussion

Despite its status as a common method for addressing chronic sinusitis, the main FESS has a failure rate ranging from 2 to 24% [5]. Revision endoscopic sinus surgery (RESS) has shown effectiveness for individuals who have previously had unsuccessful primary FESS [9]. Typically, RESS is required following 10 to 18% of initial surgeries [10].

The choice to do another procedure on an individual with disease in the sinuses is mostly based on the existence of a symptomatic blockage in the drainage of sinuses or the existence of a substantial degree of the sinus illness. Due to the characteristics of ESS and the proximity of multiple vital structures, it is essential to practice caution in order to prevent significant intraoperative difficulties resulting from harm to neighboring structures [11,12,13]. Therefore, it is crucial to conduct imaging of the sinuses prior to operation and thoroughly comprehend the patient’s anatomy.

Multiple factors have been cited as the causes of the primary FESS’s failure. Kennedy  [14] found that individuals who had bilateral ethmoid diseases and other illnesses in two or more dependent sinuses on each side, in addition to those who had widespread polyps, experienced significantly poorer outcomes following FESS compared to those with less severe sinus illness.

The indications for RSS may be broadly classified into four primary groups: incomplete prior surgery, complications caused by prior surgery, recurring or persistent sinus illness, and histological confirmation of neoplasia.

The first situation arises when a previous surgical procedure has not been fully completed. This occurs when there is recurrent acute sinusitis or refractory CRS with persistent ethmoid cells or an inadequately corrected deviated nasal septum that obstructs access or drainage. Cells that have not been fully removed can be recognized by their characteristic position and appearance.

Frequently, the anterior ethmoid cells and agger nasi have been preserved after surgery, whereas the posterior ethmoids are cleared in a straight line towards the skull base. Unopened infraorbital ethmoid (Haller) cells have the ability to block the passage of the maxillary sinus. The “missed ostium sequence” refers to a situation where the most anterior part of the uncinate process is not completely removed, resulting in the obstruction of the natural maxillary sinus ostium’s position. This was described by Parsons et al. [10]. This hinders the connection between the middle meatal antrostomy and the natural ostium, leading to a phenomenon of recirculation. In this case, the movement of cilia in the respiratory tract leads to the mucus returning to the sinus, resulting in a functional blockage of the maxillary sinus and ongoing sinus illness.

The most frequent anatomical variations denoted above in this study according to preoperative radiologic assessment and endoscopic examination (preoperative and intraoperative) were as follows from the most to the least common: incomplete ethmoidectomy (both anterior and posterior) 62.5%, incomplete sphenoidotomy 42.5%, recurrent polyps 35%, frontal sinus ostium stenosis 35%, adhesions (synechiae) 22.5%, middle meatal stenosis 22.5%, lateralization of the middle turbinate 20%, residual uncinate process 17.5%, associated nasal septal deviation 15%, osteitic bone 15%, residual concha bullosa 12.5%, an oversized antrostomy 10%, maxillary sinus recirculation 10%, associated inferior turbinate hypertrophy 10%, misplaced antrostomy 7.5%, partial or full resection of the middle turbinate 7.5%.

As compared with other studies, multiple studies have examined the factors behind the persistence or recurrence of disease after surgery, and have provided data on the prevalence of different anatomical findings.

In their study, Lazar et al. [15] examined 63 individuals who had undergone RSS. They discovered that 43% of these individuals had notable adhesions, primarily located between the lateral nasal wall and the middle turbinate. These adhesions resulted in ostiomeatal complex obstruction. Twenty-two percent experienced the reappearance of the frontal or ethmoid recess polyps. In a work performed by Chu et al. [16], it was discovered that out of 153 instances of revision, the anterior ethmoid sinus observed the most impact from ongoing mucosal illness. The most often observed result related to mucosal illness was the existence of postoperative scarring in the middle meatus following a partial middle turbinectomy. According to Chambers [17], the primary reason for failure was the presence of remnant ethmoid air cells, along with scarring in the middle meatus region. In their study, Moses et al. [5] discovered that the most common observations during RSS were adhesions, stenosis of the maxillary ostium, recurring polyposis, residual concha bullosa, and insufficient excision of agger nasi cells.

Ramadan [18] investigated 52 revision instances and found that the most frequent reason for failure was the presence of adhesions in the ethmoid area and remaining air cells, accounting for 30.7% of instances. This was followed by stenosis of the ostium of the maxillary sinus (27%), stenosis of the frontal sinus ostium (25%), and recirculation of the maxillary sinus (15%).

Parsons et al. [10] identified “missed ostium sequence” as the key reason for the failure of primary FESS. The failure to detect the maxillary ostium was due to an inadequate excision of the uncinate process, which led to the recirculation of the maxillary sinus.

In their study, Musy and Kountakis [19] discovered that the primary reason for surgical failure was the lateralization of the middle turbinate, which was observed in 78% of cases. Subsequent procedures included an incomplete removal of the anterior part of the ethmoid bone (64%), scarring in the frontal recess (50%), an incomplete removal of the posterior part of the ethmoid bone (41%), and stenosis of the middle meatal antrostomy (39%). Agger nasi cells were preserved in 49% of the individuals, whereas a retained uncinate process was determined in 37% of participants. Recurrent polyposis was observed in 37% of patients.

Khalil et al. [20] analyzed the radiological results of 63 individuals who had RSS. Residual anterior and posterior ethmoid cells were discovered in 97% and 92% of recipients, correspondingly (96% and 92% of sides, correspondingly). Residual frontal cells had been observed in 97% of the individuals (96% of sides). Residual uncinate processes were observed in 60.3% of the participants (57.1% of sides). A lateralized middle turbinate was discovered in 17.5% of participants (11.1% of sides), while septal deviation was observed in 15.9% of participants. Residual Haller cells were seen in 25.4% of participants (23% of sides), while an obstructed sphenoid ostium was observed in 68.3% of participants (65.9% of sides).

Chiu and Vaughan [21] found that out of their group of 67 patients who needed to have their frontal sinuses operated on again, 79.1% had remaining agger nasi cell or ethmoid bulla remnants, 38.8% had the uncinate process still present, 35.8% had a remaining lateralized middle turbinate, 29.9% experienced recurrent polyposis, 11.9% had unopened frontal recess cells, and 4.5% had new bone growth in the frontal recess.

Otto and DelGaudio [22] investigated the remaining anatomical characteristics of 289 frontal sinuses in a group of 127 individuals who required revision FESS. In 67% of the revised frontal recesses, the predominant observations were inflammatory mucosal illness, which included the presence of polyps and inflammatory edema causing obstruction in the frontal recess and/or frontal sinus. In addition, they often encountered obstructed frontal recesses due to the presence of retained cells or septations. Approximately 74% of the revised frontal sinuses have been determined to be blocked by remaining ethmoid cells. Among them, 13% consisted of agger nasi cells, while 53% were comprised of additional anterior ethmoid cells, which include the suprabullar cells, ethmoid bulla, supraorbital ethmoid cells, or frontal bullar cells. Frontal sinuses showed residual frontal cells in 8% of cases.

The study included 26 individuals who did not smoke, accounting for 65% of the participants, and 14 individuals who were smokers, accounting for 35% of the participants. Smoking is a risk factor that can be changed, as explained by Wu [23]. In a study analyzing participants with CRSwNP over 25 years, those individuals underwent revision ESS performed by a single surgeon. The stated average time till revision was 4.8 years, which was nearly halved to 2.82 years in patients who smoked.

In a prospective study, Görgülü et al. [24] determined that implementing smoking restrictions and minimizing exposure to cigarette smoke can serve as a crucial strategy in preventing and reducing the recurrence of nasal polyposis among individuals with this condition. In the same study, Görgülü O. statistically analyzed the effect of allergy on polyp recurrence after endoscopic surgery, but no direct correlation was identified between allergies and nasal polyposis.

In this study, there was a slight positive correlation between smoking and severity of symptoms that were determined by the validated quality of life (QOL) scoring system (SNOT-22), and the percentage of recurrence of sinonasal polyposis at 12 months postoperative.

The mean age was 36.58 ± 12.56. The study included participants ranging in age from 18 to approximately 62 years old. We noticed in our study that age did not affect the outcome. No significant variation existed as regards age.

In this work, 29 patients were males (72.5%), and 11 patients were females. There was no significant relation between the success rate and the sex of the patients, and no significant variation existed in outcome as regards sex.

This study depended on the Sino-Nasal Outcome Test version 22 (SNOT-22), an outcome measure completed by participants prior to and following surgeries (between 6 and 12 months).

According to Soler et al. [25] study in 2018, about 300,000 ESS surgeries are performed annually in the USA, primarily to enhance the participants’ QOL. The rate of ESS varies geographically and in outcomes across medical centers. Recently, the SNOT‐22 has been considered the highest‐quality sinus‐specific QOL instrument available.

According to DeConde et al. [26] study in 2014, 110 patients with CRS underwent ESS. SNOT-22 scoring was done preoperatively and 6, 12, and 18 months postoperatively. Substantial enhancements in SNOT-22 scores existed among preoperative and 6 months postoperative across both SNOT-22 total and subdomain scores (P < 0.001). No statistically significant variation existed among the 6-month, 12-month, and 18-month postoperative total SNOT-22 score or its subdomains (P ≥ 0.125).

According to a multi-institutional cohort work published by Soler and Smith [27] study in 2010, 127 patients with CRS underwent ESS. Success occurs in 85 to 95% of patients. Assessments of QOL after 6 months correspond to those following 20 months.

In another multi-institutional prospective cohort study published by Smith et al. [28] in 2010, 302 patients with CRS underwent ESS and were followed up for 18 months postoperatively. The total enhancement of QOL amounts to 70–80%.

In this study, preoperative total SNOT-22 scoring ranged from 42 to 86, with a mean of 58.83 ± 12.08. Six months postoperative scoring ranged from 10 to 32, with a mean of 21.48 ± 5.12, and 12-month postoperative scoring ranged from 15 to 37, with a mean of 28.83 ± 5.52. There was a significant improvement (P = 0.001).

Conclusions

This work utilized CT scans and endoscopic examination to analyze the anatomic findings encountered during revision surgery for individuals with persistent or recurrent CRS. The results frequently showed the presence of persistent anatomical structures or incompletely resected cells, which were correlated with ongoing symptoms and signs of CRS. Also, in this study, we depended on SNOT-22 as an outcome measure 6 and 12 months postoperative and compared it with preoperative scoring and there was a significant improvement. Finally, performing a thorough dissection of the cell group, along with the utilization of angled endoscope and identification of potential predisposing features, can help minimize the need for additional surgeries.