Preservation Palatopharyngoplasty for Obstructive Sleep Apnea: Predictors and Clinical Outcomes

Abstract

Objective

To evaluate clinical outcomes of Preservation Palatopharyngoplasty (PPPP), in a broader cohort, and identify predictors significantly associated with improved surgical outcomes in patients with moderate to severe obstructive sleep apnea (OSA).

Study Design

A retrospective cohort study.

Settings

A tertiary care center.

Methods

The study was conducted on adult patients with moderate to severe OSA who underwent PPPP. Objective sleep parameters and subjective symptom scores including the Epworth Sleepiness Scale (ESS), Standardized List Evaluating Apnea (SLEAP), and Nasal Obstruction Symptom Evaluation (NOSE) scale were compared pre‐ and postoperatively. Linear regression was performed to identify predictors of AHI reduction.

Results

A total of 53 patients (mean age 49.8 ± 12.7 years, mean BMI 35.6 ± 7.8) were included. Surgical success and cure were achieved in 88.9% and 37% of patients, respectively. Significant postoperative improvements were observed in AHI, RDI, and ODI (all P < .001), as well as in ESS, SLEAP, and NOSE scores (all P < .05). Linear regression identified higher baseline BMI, higher preoperative AHI, larger palatine tonsils, lower NOSE scores, and lateral pharyngeal wall collapse on Müller's maneuver emerged as significant predictors of AHI reduction.

Conclusion

The PPPP is a is a tissue‐preserving, safe, and effective palatal surgical technique that significantly improves both objective and subjective outcomes in patients with moderate to severe OSA. Its effectiveness extends across a wide range of BMI and baseline disease severity.

Obstructive sleep apnea (OSA) is a common disorder characterized by recurrent upper airway collapse during sleep, resulting in intermittent hypoxia, sleep fragmentation, and significant endocrinological, cardiovascular, and neurocognitive consequences. ¹ Understanding the phenotypic variations in this disease is key to achieving successful management. Continuous positive airway pressure (CPAP) remains the first‐line therapy due to its non‐invasiveness, efficacy in reducing the apnea‐hypopnea index (AHI), and improvements in quality of life. ² However, poor long‐term adherence to CPAP is frequently reported, leading to consider alternative treatments such as oral appliances, positional therapy, weight loss interventions, and surgical procedures. ³ , ⁴ Recent evidence suggests that, in appropriately selected patients, surgical management may be associated with lower long‐term healthcare utilization and costs compared to nonsurgical treatment. ⁵

Palate surgeries are among the most commonly performed surgical procedures for the treatment of OSA in adults. ⁶ These procedures address the redundancy and collapsibility of the soft palate and pharyngeal wall, with the goal of expanding the retropalatal and oropharyngeal airway space and reinforcing the soft tissue to reduce airway collapse. After describing the technique and its outcomes in patients with high Mallampati scores, ⁷ this study aims to describe clinical outcomes of Preservation Palatopharyngoplasty (PPPP), and investigate factors associated with surgical success.

Methods

Study Settings

Institutional Review Board approval was obtained from the Medical University of South Carolina Office of Research Integrity (Protocol #00129710; IRB #129710) prior to the initiation of the study. This is a retrospective cohort study conducted at the sleep and facial skeletal surgery division of the Medical University of South Carolina, a tertiary care center. The PPPP was offered to patients based on our algorithm as part of Phase I treatment for OSA. ⁸ Candidates were selected based on findings of awake and/or drug‐induced sedation endoscopy (DISE) featuring redundant soft palate, enlarged tonsils, or decreased diameter of the oropharyngeal airway. All PPPP surgeries were performed from August 2023 through January 2025. We included adult patients (aged ≥18 years) who underwent PPPP for clinically significant OSA, defined as an AHI greater than 15 events per hour. Other inclusions were failure to meet HGNS candidacy, lack of skeletal deficiency, grade 3+ tonsils, or larger. All procedures were performed by a single senior surgeon (MAW). Exclusion criteria included patients under 18 years of age, those without a confirmed diagnosis of OSA, those with mild disease (AHI <15 events/h), those who underwent PPPP solely as part of the initial plan for Phase II treatment, or those who had previously undergone hypoglossal nerve stimulation, tongue‑base reduction, or maxillomandibular advancement.

Outcomes Measurement

The primary outcome was the change in objective sleep study parameters, comparing preoperative and 6‐month postoperative data. Secondary outcomes included subjective improvement assessed using 3 validated questionnaires: the Epworth Sleepiness Scale (ESS) and the Standardized List Evaluating Apnea (SLEAP)—a quality‑of‑life instrument specific to patients with OSA, and Nasal Obstruction Symptom Evaluation (NOSE) Scale—administered at 3 months and at 6 months or longer postoperatively. ⁹ , ¹⁰ , ¹¹ Additionally, To identify potential predictors of treatment response, AHI reduction was analyzed in relation to age, sleep study parameters (including baseline AHI 3% and 4%), body mass index (BMI), palatine and lingual tonsil grades (based on the Brodsky and Friedman classifications), and findings from the Müller maneuver. ¹² , ¹³ , ¹⁴ Surgical success was determined using Sher's criteria (Sher₂₀), defined as achieving a postoperative AHI of fewer than 20 events per hour and/or a reduction in AHI of at least 50%. Modified Sher's criteria (Sher₁₅) were defined as achieving a postoperative AHI of fewer than 15 events per hour and/or a reduction in AHI of at least 50%. Surgical cure was defined as a postoperative AHI of less than 5 events per hour. ¹⁵ , ¹⁶ , ¹⁷

Surgical Technique and Postoperative Care

The surgical technique has been described in our previous publication and is illustrated in Figure 1. ⁷ Postoperatively, patients are admitted for 24‐hour observation. Oral intake typically consists of a soft diet or as tolerated. Pain is managed with scheduled acetaminophen, while oxycodone is prescribed as needed for breakthrough pain, given the increased risk of chronic opioid use. ¹⁸ Prophylactic antibiotics are also prescribed, as their use has been associated with a reduced risk of postoperative complications. ¹⁹

Figure 1.

Intraoperative illustration of PPPP steps and anatomical landmarks: (A) preoperative appearance; (B) surgical field after tonsillectomy; (C) suture placement through key structures; (D) final appearance post‐procedure. PPPP, Preservation Palatopharyngoplasty.

Statistical Analysis

All statistical analyses were conducted using SPSS version 30.0 (IBM Corp.). Descriptive statistics were used to summarize patient demographics, baseline characteristics, and outcomes. Categorical variables were expressed as counts and percentages. Continuous variables were reported as means with standard deviations or medians with interquartile ranges, depending on data distribution. All continuous variables were tested for normality with the Kolmogorov‐Smirnov test. Paired comparisons between preoperative and postoperative sleep study parameters and questionnaire scores were performed using the Wilcoxon signed‐rank test. A multiple linear regression model was performed to identify predictors associated with greater reductions in AHI. A P < .05 was considered statistically significant for all statistical tests.

Results

A total of 53 patients (mean age 49.8 ± 12.7, range 20‐69; mean BMI 35.6 ± 7.8) were included in the analysis. The cohort comprised 59.3% males and 40.7% female participants. Surgical success was achieved in 88.9% of patients using Sher₂₀ criteria and in 83.3% using Sher₁₅ criteria, while 37% of patients attained surgical cure (Table 1).

Table 1.

Patient Demographics, Clinical Characteristics, and Surgical Outcomes (N = 53)

Variable		Value
Age (years)	Mean ± SD	49.8 ± 12.7
Sex, n (%)	Male	32 (59.3%)
	Female	22 (40.7%)
BMI	Mean ± SD	35.6 ± 7.8
Tonsils grade	0	2 (3.8%)
	1	7 (13.2%)
	2	16 (30.2%)
	3	18 (33.9%)
	4	10 (18.9%)
Achieved surgical success (Sher20)	Yes	48 (88.9%)
	No	6 (11.1%)
Achieved surgical success (Sher15)	Yes	45 (83.3%)
	No	9 (16.7%)
Achieved surgical curea	Yes	20 (37%)
	No	34 (63%)

Abbreviation: BMI, body mass index.

^a Based on Sher's criteria.

Objective Outcomes

Postoperative sleep study parameters demonstrated significant improvements (Table 2). Mean AHI (3% desaturation threshold) decreased from 50.1 ± 34.5 to 22.6 ± 12.7 (P < .001), and mean AHI (4% threshold) decreased from 42.0 ± 29.0 to 16.3 ± 15.4 (P < .001). Similarly, RDI and ODI showed significant reductions (both P < .001). Time and percentage spent with oxygen saturation below 90% also improved significantly (P = .003 and P < .001). However, nadir oxygen saturation and REM sleep percentage did not show statistically significant changes.

Table 2.

Comparison Between the Preoperative and Postoperative Changes After PPPP

Parameter	Preoperative (Mean ± SD)	Postoperative (Mean ± SD)	P‐value
Sleep study
AHI 3%	50.1 ± 34.5	22.62 ± 12.70	<.001
AHI 4%	42 ± 29.04	16.32 ± 15.44	<.001
RDI	52.6 ± 33.2	27.92 ± 13.50	<.001
ODI	43.4 ± 36.26	22.4 ± 15.9	<.001
Nadir (%)	78.6 ± 8.45	81.4 ± 8.16	.072
Time under 90% (minutes)	38.01 ± 48.10	17.23 ± 29.53	.003
Time under 90% (%)	10.78 ± 15.7	3.34 ± 6.8	<.001
REM %	16.5 ± 9.10	20.20 ± 8.40	.081
Subjective outcome
ESS (3 months)	9.83 ± 6.33	7.76 ± 6.32	.037
ESS (≥6 months)	9.83 ± 6.33	7.25 ± 5.5	.038
SLEAP (3 months)	40.88 ± 18.40	27.69 ± 17.19	<.001
SLEAP (≥6 months)	40.88 ± 18.40	28.29 ± 19.63	.002
NOSE (3 months)	45.15 ± 26.61	30.47 ± 25.25	.004
NOSE (≥6 months)	45.15 ± 26.61	23.75 ± 19.66	<.001

Subjective Outcomes

Follow‐up at 3 months and at 6 months or longer demonstrated significant improvements in patient‐reported outcomes. ESS scores decreased from 9.8 ± 6.3 preoperatively to 7.3 ± 5.5 at longer follow‐up (P = .038), reflecting a shift from higher‐normal/mild excessive daytime sleepiness into the lower‐normal range (Figure 2). SLEAP scores improved from 40.9 ± 18.4 to 28.3 ± 19.6 (P = .002), indicating a clinically meaningful improvement in sleep‐related quality of life. Similarly, NOSE scores decreased from 45.2 ± 26.6 to 23.8 ± 19.7 (P < .001), consistent with a substantial reduction in nasal obstruction symptoms. No cases of postoperative secondary bleeding, velopharyngeal insufficiency (VPI), pharyngeal stenosis, or hospital readmission were reported.

Figure 2.

Before‐and‐after plot illustrating individual changes in objective and subjective measures among OSA patients who underwent PPPP.

Predictors of Outcome

Linear regression analysis identified several significant predictors of postoperative AHI reduction (Table 3). Higher baseline BMI (P = .005), higher preoperative AHI at both 3% and 4% desaturation (P < .001), and larger palatine tonsil grade (P <  .001) were associated with greater improvements, suggesting that patients with more severe disease and larger tonsillar hypertrophy may derive the most benefit. Lower baseline NOSE scores (P = .034) predicted greater AHI reduction, possibly reflecting the influence of nasal airflow resistance on surgical outcomes. In addition, lateral pharyngeal wall collapse observed on Müller's maneuver (P = .017) was significantly associated with postoperative improvement, indicating that patients with this collapse pattern are particularly responsive to PPPP. Age, gender, lingual tonsil grade, and other Müller's maneuver findings were not significantly associated with AHI reduction.

Table 3.

Predictors of AHI Reduction Using Linear Regression

Variable	B (Linear regression)	P‐value
Age	−0.492	.144
BMI	1.491	.005
Sex	−13.83	.106
Pre‐op AHI 3%	0.807	<.001
Pre‐op AHI 4%	0.099	<.001
Palatine tonsil grade	15.052	<.001
Lingual tonsil grade	−0.170	.973
NOSE score (baseline)	−0.344	.034
Müller's maneuver
Soft palate collapse	−1.835	.722
Lateral pharyngeal wall collapse	11.917	.017
Base of tongue collapse	−2.979	.467

Discussion

In our preservation technique, careful attention is given to preserving the integrity of the oropharyngeal musculature particularly the palatopharyngeus. The approach is based on anchoring redundant muscles and/or mucosa to stable anatomical landmarks, such as the pterygomandibular raphe, the superior constrictor, or the pterygoid hamulus. This preservation‐based approach is designed to maintain the functional and structural integrity of the soft palate and lateral pharyngeal wall, while taking advantage of anatomical attachments to maximize airway expansion vectors. By minimizing tissue violation, the technique aims to reduce postoperative morbidity and preserve natural palatal mechanics—reflected in the absence of VPI symptoms.

Fujita et al first described UPPP as a surgical procedure involving the resection of redundant tissue from the soft palate, uvula, and posterior pharyngeal wall to enlarge the oropharyngeal airway space. ²⁰ While initially promising, the outcomes of traditional UPPP were highly variable and influenced by multiple factors, including anatomical differences, surgical technique, and patient selection. ²¹ , ²² , ²³ Moreover, the procedure was associated with a notable incidence of postoperative complications, such as VPI, foreign body sensation, voice changes, dysphagia, altered taste, and oropharyngeal dryness. ²² , ²³

In response to these limitations, several modifications to the traditional UPPP technique have been developed. Lateral pharyngoplasty was introduced to address lateral wall collapse, and later expansion sphincter pharyngoplasty was desribed, as a more functionally oriented approach that preserves palatal musculature and reorients pharyngeal muscle tension vectors. ²⁴ , ²⁵ This technique has demonstrated superior outcomes compared to traditional UPPP. A pooled analysis showed an overall surgical success rate of 86.3%, with the AHI decreasing from a mean of 40.0 ± 12.6 to 8.3 ± 5.2. ²⁶ Another modification of the technique was introduced by Vicini et al, who changed the anchoring point of the palatopharyngeal flap from the arching fibers of the palatoglossus muscle, as used in expansion sphincter pharyngoplasty to the pterygomandibular raphe. Their technique also involved the use of barbed sutures for tissue approximation. ²⁷ In their series, the AHI decreased significantly from 33.4 ± 19.5 to 13.5 ± 10.3, with a reported surgical success rate of 73%. ²⁸

In our study, we observed significant reductions across all objective respiratory parameters and achieved high surgical success rates of 88.9% based on Sher₂₀ criteria and 83.3% based on Sher₁₅ criteria. These outcomes were comparable to those reported with other palatal procedures, despite that our results were achieved in a cohort with a markedly higher baseline AHI and a significantly elevated BMI. ²⁶ , ²⁹ Furthermore, PPPP has previously been shown to yield favorable outcomes in another challenging subgroup—patients with high Modified Mallampati scores. ⁷

Notably, the magnitude of postoperative AHI reduction correlated positively with baseline AHI, a trend likely explained by the greater margin for improvement among patients with more severe disease. A similar positive correlation was observed with BMI, likely due to the association between higher BMI and elevated baseline AHI. Importantly, however, elevated BMI did not appear to limit the extent of postoperative improvement. Nevertheless, weight‑reduction therapy should still be considered alongside surgical treatment when appropriate, to further optimize outcomes. ³⁰

In addition, larger palatine tonsils were the factor most strongly associated with greater AHI reduction, consistent with previous findings. ³¹ However, subjects without tonsils still achieved promising results. ⁷ Hypoxemia‐related parameters also showed significant improvement, including reductions in both time and percentage spent with oxygen saturation below 90% and the ODI. Moreover, patient‐reported outcomes improved at both 3 months and at 6 months or longer follow‐up, as reflected by enhanced SLEAP and ESS scores. Notably, the improvement in SLEAP scores exceeded the minimal clinically important difference of 12 points, indicating a significant clinical benefit. ³²

Lateral pharyngeal wall collapse is primarily driven by the action of the superior pharyngeal constrictor muscle and, to some extent, by the palatopharyngeus. ³³ Late modifications of UPPP, including PPPP, incorporate lateral pharyngoplasty techniques that follow tonsillectomy. These techniques include retraction and repositioning of the superior pharyngeal constrictor, palatopharyngeus, and palatoglossus in a supero‐anterior direction, which may enhance lateral wall stabilization. ³³ Müller's maneuver, first described by Borowiecki and Sassin, is performed during awake flexible nasopharyngoscopy, during which the patient attempts a forced inspiratory effort against a closed airway. ¹⁴ , ²⁸ This maneuver enables dynamic visualization of upper airway collapse, particularly at the levels of the soft palate, lateral pharyngeal walls, and tongue base. In our cohort, we found that lateral wall collapse observed during Müller's maneuver correlated positively with reductions in AHI following PPPP, suggesting that patients with this collapse pattern may be more responsive to this technique. While absolute indications for this procedure and palate surgery, in general, are still evolving, palate surgery can manage complete obstruction in 61% of palate obstruction and 17% of lateral pharyngeal wall obstruction. ³⁴

Patients with lower preoperative NOSE scores demonstrated a greater likelihood of postoperative AHI reduction. This finding may be attributed to nasal airflow receptors, which modulate upper airway resistance and potentially enhance physiological responses to palatal surgery. ³⁵ Additionally, patients showed significant postoperative improvement in nasal obstruction, as indicated by reductions in NOSE scores, likely due to retropalatal airway expansion during wakefulness. These results highlight an interplay between nasal and palatal anatomy in managing OSA and nasal obstruction. ³⁶

While the results are encouraging, several limitations warrant discussion. The retrospective design and single‐center setting, with a relatively small sample size in the southeastern region of the country may limit the generalizability of the findings. Additionally, the follow‐up period was limited to 6 months and long‐term efficacy and durability of PPPP remain to be evaluated. The tonsils were assessed using a subjective tonsil grading system; future studies should consider incorporating objective volumetric measurements. Finally, the absence of a control group precludes direct comparisons with other surgical techniques. Future studies should focus on validating these predictive factors in larger, prospective cohorts and exploring the integration of PPPP into multimodal treatment pathways, including weight reduction strategies, to optimize outcomes in patients with OSA.

Conclusion

The PPPP is a mucosa‐ and muscle‐sparing surgical technique that significantly improves objective parameters—including AHI, RDI, ODI, and time spent with oxygen saturation <90%—as well as subjective outcomes in patients with moderate to severe OSA. These benefits were observed even in a challenging cohort with elevated BMI and high baseline disease severity. Greater reductions in AHI were associated with larger palatine tonsils, and lateral pharyngeal wall collapse during Müller's maneuver, emphasizing the importance of patient phenotyping in surgical planning. These findings support PPPP as a safe and effective palatal surgical option for appropriately selected patients and underscore its potential role in tailored, multilevel OSA management strategies.

Author Contributions

Mohamed Abdelwahab, conceptualization, data curation, investigation, methodology, project administration, resources, supervision, validation, writing—review and editing; Ahmed Alhussien, data curation, investigation, visualization, formal analysis, methodology, project administration, resources, software, supervision, validation, visualization, writing—original draft; Mohamed F. Kassir, Investigation, supervision; Hank Butehorn, investigation; Claire Munhall, investigation; Shaun A. Nguyen, methodology, formal analysis, writing—review and editing, supervision.

Disclosures

Competing interests

None.

Funding source

None.