Intensive Care Unit Admission Following Cleft Palate Repair in Patients With Pierre Robin Sequence Corrected With Mandibular Distraction

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Pierre Robin Sequence (PRS) is a congenital condition defined by micrognathia, glossoptosis, and associated upper airway obstruction.¹ Decreased oral cavity volume secondary to micrognathia increases the tendency for glossoptosis as the tongue falls back into the pharynx, causing upper airway obstruction. Mandibular distraction osteogenesis (MDO) effectively treats tongue-based airway obstruction in patients with PRS by advancing the mandible and base of the tongue, increasing the volume of the airway.² MDO is commonly performed in the neonatal phase and early infancy, though there is evidence of resolution of airway obstruction following MDO in patients up to 6 years old.³

Patients with PRS frequently present with a cleft palate.^4,5 Cleft palate repair is performed to separate the oral and nasal cavities and to reorient the soft palatal musculature to optimize the development of speech. These goals must be tempered by the deleterious effects of surgery on maxillary growth. Timing is critical to achieve maximal speech outcomes while minimizing the growth disturbances, with patients generally 6 to 18 months old at primary palatoplasty.^5,6 However, the risk for secondary surgery may be increased when surgery is performed at or before 10 months in patients with and without PRS.⁷ Cleft palate associated with PRS has been described as classically U-shaped with greater widths than those seen in patients with isolated cleft palate.^8,9 Palatoplasty in these patients has the same goals as that of isolated cleft palate repair but carries additional safety considerations, including increased difficulty of intubation, and nutritional concerns.⁵ Further, palatoplasty in patients with PRS has been associated with increased rates of adverse airway events perioperatively and respiratory distress following surgery.^10-14

Patients with increased risk for perioperative and postoperative respiratory complications may be admitted to the pediatric intensive care unit (PICU) postoperatively, which has been reported at rates between 6.2% and 9.3% for patients with isolated cleft palate following primary palatoplasty.^15,16 The majority of these admissions are planned, with unplanned PICU admissions and transfers accounting for less than 2% of total admissions following primary palatoplasty surgery. Though there is no standard risk-stratification tool to guide planned PICU admission in patients with PRS undergoing palate repair, polysomnography (PSG) is a useful tool for evaluating the severity of airway obstruction and risk of airway compromise in this patient population. Its use as a screening tool has been effective in decreasing the disparity of rates of airway events in patients with PRS vs isolated cleft palate following palatoplasty, but it has not been shown to reliably identify patients with PRS who are more likely to experience respiratory distress postoperatively.^10,17

There is a lack of practice standardization regarding PICU admission following primary palatoplasty in these patients. This study provides a retrospective review of all primary palatoplasty operations performed following mandibular distraction at a single tertiary care center from 2014 to 2022. A specific examination of the frequency of airway events following palatoplasty in this subset of patients was conducted, and the association with perioperative factors is described.

Following approval by the institutional review board for research involving human subjects at the University of Mississippi Medical Center, a retrospective review was conducted. The study was conducted in accordance with the Declaration of Helsinki and was approved by the ethics committee of the University of Mississippi Medical Center (no. 2020V0408) on April 8, 2022, with the need for written informed consent waived. All patients with PRS who underwent both MDO and cleft palate repair at our institution from 2014 to 2022 met inclusion criteria. Preoperative characteristics including age and weight at palate repair were collected. Clefts were grouped using the Veau classification. Respiratory status was assessed pre- and postoperatively. PSG measures, including apnea-hypopnea index (AHI), were used to evaluate the severity of airway obstruction. Analgesic use was recorded in both intra- and postoperative settings. The presence of comorbid anomalies as well as concomitant operations were noted.

The primary outcomes of this study included length of stay (LOS) following cleft palate repair, presence of peri- and/or postoperative respiratory events, and admission status following palatoplasty. Respiratory events were defined as any peri- or postoperative circumstance that required escalation of respiratory support while admitted after palatoplasty. Patients were admitted to the PICU or the medical/surgical inpatient unit. Chi-square and independent t tests were conducted using a P value of .05.

Twenty-nine patients underwent MDO at the author’s institution during the period of interest, 13 of whom met the inclusion criteria. Three craniofacial surgeons performed all cleft palate repairs and MDO procedures during this time frame. Preoperative characteristics and patient demographics are shown in Table 1, and perioperative data and outcomes are listed in Table 2. Syndromic patients made up 46% of the patients in this study. Most clefts repaired were Veau II (85%). Only 1 patient had cleft involvement of the alveolus. The average age at cleft palate repair was 16.1 months, and the average weight was 9.4 kg. All patients underwent a single-stage Children’s Hospital of Philadelphia modification of the Furlow palatoplasty following mandibular distraction.¹⁸ All patients were breathing comfortably on room air prior to cleft palate repair. Two patients required intubation postoperatively, and both were intubated for a duration of less than 24 hours. All other patients were stable on room air following surgery, with 1 patient requiring low-flow nasal cannula (LFNC) support later in admission.

Analgesic usage was measured in morphine milligram equivalents (MME). Intraoperatively, an average of 5.4 MME was used. In the immediate 24-hour period postoperatively, patients received an average of 5.9 MME. Local anesthetic infiltration was also recorded and outlined in Table 3; bupivacaine was utilized in 54% of cleft palate repairs. The use of bupivacaine was associated with significantly lower MME used postoperatively (P = .019). Comorbid anomalies and concomitant operations were common in this study, as shown in Table 4. Cardiac anomalies were the most frequent comorbid anomaly, affecting 69% of the patients. Congenital learning difficulties and gastrointestinal anomalies were the next most common, affecting 54% and 46% of the patients, respectively. A concomitant operation was performed in 23% of the patients, including myringotomy with tube insertion and tracheobronchoscopy.

The average LOS following cleft palate repair was 2.3 days. Most patients (77%) had a LOS between 1 and 2 days. Longer lengths of stay were associated with postoperative respiratory events (P < .001). Two airway events occurred in this study, and 3 patients were admitted to the PICU following cleft palate repair. PICU admission was more common in patients 10 months or younger at the time of CP repair (P = .041). Patients with a neurological (P = .041) or musculoskeletal abnormality (P = .041) were significantly more likely to be admitted to the PICU following cleft palate repair. PICU admission was not significantly associated with increased AHI measured on preoperative PSG evaluation. Increased intraoperative analgesic usage was associated with the patient remaining intubated following palate repair (P = .020). Remaining intubated following surgery was additionally associated with increased analgesic usage in the immediate 24 hours postoperative (P = .004). Interestingly, time intubated following palatoplasty was significantly longer for patients who were intubated for greater durations following their previous mandibular distractor placement (P = .003). A longer duration of intubation following distractor placement was additionally associated with admission to the PICU (P = .001).

The goal of cleft palate repair is to optimize functional outcomes of speech, eustachian tube function, and maxillofacial growth. In this study, 85% of the patients were between 6 and18 months old at primary repair. Patients who were 10 months or younger at the time of palatoplasty were significantly more likely to be admitted to the PICU following surgery. Though these patients were also considered at increased risk for secondary surgery, all of them received single-stage repair with no secondary fistulae noted at the latest follow-up.⁷ The 2 recorded respiratory events in this study were episodes of respiratory distress, and the rate of airway events in the combined peri- and postoperative periods was 15%. This reflects equivalent (15%) and superior (30%) outcomes compared with similar studies looking specifically at patients with PRS.^10,11 When compared with rates of respiratory events following cleft palate repair in non-stratified populations, the rate demonstrated in this study remains relatively low.^12,19

PICU admission rates in this study were higher (23%) compared with other studies (9.3%, 6.2%) evaluating ICU admissions following cleft palate repair.^15,16 The planned admission rate remains comparatively high at 15%. No surgeries were performed with the expectation that a patient would necessarily require PICU admission postoperatively. Certain circumstances such as a high-risk airway or desaturation on extubation following surgery supported the decision to place patients under the advanced monitoring and care capabilities of an ICU. In all instances of planned PICU admission, concern for airway swelling secondary to difficult intubation or multiple attempts following surgery was present. The only instance of unplanned PICU admission in the immediate 24-hour postoperative period demonstrated initial stability on room air following surgery, but the patient was ultimately admitted due to respiratory distress secondary to upper airway obstruction and concern for pneumonia. The decreased postoperative narcotic usage associated with bupivacaine seen in this study has been demonstrated in similar studies, with additional benefits of reduced complications, hospital costs, and LOS.^20-22

The association of increased intraoperative analgesic use with remaining intubated following cleft palate repair has not been well described in the literature but may be explained by the decreased respiratory drive associated with opiates. High-risk airways and/or repeated extubation attempts may lengthen operative duration and the analgesia necessary for a patient’s comfort. This would also explain the association of remaining intubated following cleft palate repair with increased analgesia use in the immediate 24-hour postoperative period. The influence of MDO on cleft palate repair represents an area where the current literature is limited. MDO has been shown to decrease cleft palate width, elongate the soft palate, and shorten operative times in palatoplasty compared with patients undergoing cleft palate repair without history of MDO.²³ However, MDO has not been evaluated as a risk stratification tool or predictor of respiratory outcomes following palatoplasty. In this study, a longer duration of intubation following initial distractor placement was shown to be significantly associated with both longer duration of intubation following cleft palate repair and admission to the PICU. Identifying patients at high risk for respiratory compromise or prolonged intubation may be beneficial in planning subsequent surgeries following MDO.

Patients with cleft palate are frequently affected by at least 1 comorbidity (17%-43%), with cardiac, neurologic, and gastrointestinal morbidities being the most common. ^24-27 The present study reflects this, with cardiac and gastrointestinal anomalies affecting 69% and 46% of patients, respectively. Neurologic comorbidities occurred at similar rates in this study compared with others.^25,26 The association of neurologic and musculoskeletal anomalies with admission to the PICU, as demonstrated in this study, is supported by the associations with postoperative adverse events and complications described in related articles.^25,26,28 The comorbidity rates recorded in this study were relatively high, with cardiac and developmental anomalies/learning difficulties each present in over 50% of the patients. This may be due to the high rate of syndromic patients demonstrated (46%). However, syndromic status itself was not significantly associated with PICU admission or respiratory events in this study. 

Several limitations exist within this study. All mandibular distractions and cleft palate repairs were performed by 3 surgeons, and individual practices may have imparted considerable influence on outcomes. Additionally, data extraction from the electronic health record may be a source of inconsistency. Even though many objective measures are reliably reported in the record, they are not always reported in the same manner or by the same provider. The length of time covered by this study could contribute to this issue in terms of staff changes and updates in practice. This may lead to the absence of certain measurements in selected patients. However, this study was designed to control for these limitations as much as possible and ensure that data points consistently fit their definitions. Finally, the number of patients meeting inclusion criteria is relatively small despite the time covered. This is a function of both the unique subset of patients at the center of this study and historically low cases of MDO followed by primary palatoplasty at the authors’ institution. Future studies should continue to evaluate admission and respiratory outcomes in these patients as case numbers increase over time.

Cleft palate repair in patients having undergone MDO must be approached on a case-by-case basis. The severity of initial micrognathia and any residual OSA must be accounted for and factored into the decision to admit these patients to the PICU. In patients with comorbidities, more severe presentations are at higher risk for prolonged intubation or respiratory compromise, and PICU admission may be necessary. In high-risk patients, assessment of airway and respiratory status following surgery must ultimately guide postoperative admission status. The findings presented in this study may be helpful to surgeons in terms of surgical planning, risk stratification, and evaluation of outcomes.