A comparison of parotid imaging characteristics and sialendoscopic findings in obstructive salivary disorders

Pediatric Sialendoscopy

Purpose of Review

To describe the pathophysiology, evaluation, and management of sialadenitis as well as the indications for and outcomes of sialendoscopy in the pediatric population.

Recent Findings

Pediatric sialadenitis makes up a small proportion of all salivary gland disease. Acute viral sialadenitis and juvenile recurrent parotitis are the most common forms of the condition. Juvenile recurrent parotitis is thought to be multifactorial in etiology with infectious, behavioral, autoimmune, and structural contributions. Review of the current literature supports a potential benefit from sialendoscopy for children with recurrent acute or chronic sialadenitis. Sialendoscopy can provide both diagnostic and therapeutic benefits with very low associated risks. The most common sialendoscopy findings include intraductal sludge or debris, sialoliths, and ductal strictures.

Summary

In the select pediatric population, sialendoscopy is a safe and effective procedure with associated decreased rates of recurrent acute sialadenitis including juvenile recurrent parotitis.

Simultaneous Application of Ultrasound and Sialendoscopy and its Value in the Management of Sialolithiasis

OBJECTIVE

Ultrasound (US) and sialendoscopy (SE) are routinely used in patients presenting with sialolithiasis in the submandibular (SMG) and parotid gland (PG). The objective was to assess the value of the simultaneous application of US and SE in the management of sialolithiasis.

STUDY DESIGN

Retrospective study.

SETTING

Tertiary referral center for salivary gland diseases.

PARTICIPANTS

Patients in whom US and SE as single investigation tools were neither conclusive nor useful in the management of sialolithiasis were investigated using both methods simultaneously (simUS + SE).

MAIN OUTCOME MEASURES

Establishment of the final diagnosis and/or contribution to the planning/performing of treatment in sialolithiasis.

RESULTS

74 patients were examined by simUS + SE (58.1 % SMG and 41.9 % PG). In all patients (unclear) hyperechoic reflexes were assessed and/or localized by SE-controlled US navigation. 68.9 % of the patients were investigated for diagnostic or differential-diagnostic reasons including distinguishing extraductal from intraductal calcifications and/or to exclude residual stones after therapy. In 52.7 % simUS + SE was used to plan and/or perform further treatment, in 20.3 % to enable performing a combined approach (all PG) and in 29.7 % to evaluate and plan the most adequate therapy (mainly intraductal vs. extracorporeal shock wave lithotripsy, 68.2 % of these SMG). In two cases SE-controlled and US-guided stone extraction was performed.

CONCLUSION

SimUS + SE is an innovative approach which proved to be very useful in managing sialolithiasis. It added valuable information regarding the establishment of a diagnosis or differential diagnosis, planning and performing the most adequate treatment, intraoperative control of therapy and postoperative follow-up.

Practical Salivary Ultrasound Imaging Tips and Pearls

Ultrasound imaging is a valuable and effective clinical tool for salivary gland disorder evaluation and management. Pathologies including salivary duct stenosis, sialolithiasis, neoplasms, and autoimmune disorders have characteristic sonographic features. Maneuvers such as bimanual palpation and oral administration of sialagogues during the ultrasound examination can enhance examination findings. Ultrasound guidance is useful for targeting needle biopsies of neoplasms, ensuring appropriate intraparenchymal gland injections, and augmenting salivary duct instrumentation and intraoperative management.

Ultrasound in the diagnosis of parotid duct obstruction not caused by sialolithiasis: diagnostic value in reference to direct visualization with sialendoscopy

OBJECTIVES

The aim of this study was to evaluate the diagnostic value of ultrasound in the obstructive pathology of the parotic gland not caused by sialolithiasis using sialendoscopy as reference standard.

METHODS

Retrospective analysis of all patients who presented with suspected diagnosis of obstructive ductal pathology of the parotid gland other than sialolithiasis between January 2011 and December 2017. 538 patients, for a total of 691 parotid glands were included in the study. Ultrasound was performed, followed by sialendoscopy in all cases. Duct diameter and parenchyma echogenicity were assessed. Direct sialendoscopic examination of the parotid duct was regarded as the reference standard.

RESULTS

Parotid glands with normal sialendoscopic findings (21.6%, n = 149) had a duct diameter of 0.3 mm (0-2.7 mm) and homogeneous hyperechoic parenchyma on ultrasound in 98.7%. Ductal inflammation/sialodochitis (32.9%, n = 227) on sialendoscopy had significantly larger ductal diameter of 0.7 mm (0-4.3 mm, p = 0.001) and hypoechoic parenchyma in 78.0% (p < 0.001). Parotid glands with stenosis (45.6%, n = 315) had hypoechoic parenchyma in 52.6% and a ductal diameter of 4.1 mm (0-19.0 mm; p = 0.001). The ductal diameter was ≥2.7 mm in 95.6% of the stenosis (AUC 0.886, p = 0.001). Using 5.1 mm as benchmark ductal diameter, stenosis with ductal anomaly (68/315) were identifiable with a sensitivity of 92.6% and a specificity of 96.8% (AUC 0.986, p = 0.001).

CONCLUSION

Ultrasound parameters can be used to distinguish different types of obstructive ductal pathology of the parotid gland, supporting the use of this imaging modality as diagnostic tool of first choice.

Dual-Source Dual-Energy CT in Submandibular Sialolithiasis: Reliability and Radiation Burden

OBJECTIVE. This study aims to compare the diagnostic accuracy of virtual unenhanced CT images derived from dual-source dual-energy contrast-enhanced CT with that of standard unenhanced CT images for evaluation of sialolithiasis. MATERIALS AND METHODS. All dual-energy CT studies of the neck performed during the preceding 5 years were reviewed for submandibular gland calculi. Only patients who had unenhanced CT and contrast-enhanced CT performed as part of the same evaluation were included in this study. This review yielded 30 patients. Virtual unenhanced CT images were derived from the dual-energy dataset and compared with the true unenhanced CT images by two separate radiologists who assessed the total number of calculi encountered, their location, the largest dimension, and the attenuation of the calculi. The radiation burden incurred for true unenhanced CT and virtual unenhanced CT and the total radiation burden were calculated. RESULTS. Our analysis revealed that measurements of stone size showed good interobserver agreement. The mean stone size was 7.9 ± 5.9 (SD) mm on virtual unenhanced CT and 8.4 ± 5.9 mm on true unenhanced CT (range, 2.0-31.8 mm); the difference was statistically insignificant. The mean stone attenuation differed considerably (p < 0.01) between the virtual and true unenhanced CT images (494.8 ± 187.5 HU and 924.4 ± 374.9 HU, respectively), but correlated well. The mean radiation dose for a dual-phase IV contrast-enhanced CT study was 23.13 mGy (volume CT dose index). The mean dose was 10.93 mGy for the true unenhanced CT phase, thereby suggesting a 47.25% reduction in administered radiation dose when a single-phase contrast-enhanced CT study with virtual unenhanced image reconstructions is performed. CONCLUSION. Virtual unenhanced CT images derived from dual-source dual-energy CT scans of the neck provide accurate assessment of sialolithiasis akin to that provided by conventional CT protocols but at only a fraction of the radiation dosage.

Ultrasound Supplemented by Sialendoscopy: Diagnostic Value in Sialolithiasis

Objective

To assess the value of ultrasound, if indicated, supplemented by sialendoscopy, in the diagnosis of sialolithiasis.

Study Design

Retrospective study.

Setting

Referring center for salivary gland diseases.

Subjects and Methods

All patients who presented with a suspected diagnosis of obstructive sialopathy between January 2011 and April 2017 and had not undergone any treatment were retrospectively evaluated. A total of 2052 patients and 2277 glands were included in the study. Ultrasound examinations were carried out initially and followed by sialendoscopy in all cases. Direct demonstration of sialothiasis by sialendoscopy, transoral ductal surgery, and discharge of concrements/observation of fragments during sialendoscopy after extracorporeal shock-wave lithotripsy were regarded as definitive evidence of sialolithiasis.

Results

Ultrasound had an accuracy, sensitivity, specificity, positive predictive value, and negative predictive value of 94.77%, 94.91%, 94.57%, 96.14%, and 92.89%, respectively, for the diagnosis of sialolithiasis. All false-positive findings were correctly diagnosed, and in all false-negative findings, stones/fragments were visualized by sialendoscopy. Over 95% of the false-negative findings in major salivary glands (64/67) had visible ductal dilation in sonography, and in 73.1%, the stones not detected on ultrasound were located in the distal part of the duct, which is easily accessible with the sialendoscope.

Conclusion

This study shows that sialolithiasis can be diagnosed using ultrasonography with a high degree of certainty. If supplemented by sialendoscopy, the correct diagnosis could be established in virtually all cases of sialolithiasis. Ultrasound supplemented by sialendoscopy has the potential to serve as an alternative diagnostic standard in the future.

The Diagnostic Accuracy of Contrast-Enhanced CT of the Neck for the Investigation of Sialolithiasis

BACKGROUND AND PURPOSE

Sialolithiasis is a common benign pathology affecting the salivary glands but it is unclear if contrast-enhanced CT, which is commonly used for investigation of head and neck pathology, can identify calculi as accurately as noncontrast CT. The aim of this study was to assess the diagnostic accuracy of contrast-enhanced CT of the neck in the diagnosis of sialolithiasis compared with noncontrast CT of the neck used as the criterion standard.

MATERIALS AND METHODS

This was a retrospective, case-control study of 92 consecutive cases in 90 patients who underwent both noncontrast CT of the neck and contrast-enhanced CT of the neck in 2 tertiary referral centers from January 2011 to December 2015 for investigation of sialolithiasis. Axial 3-mm-section images were assessed by a fellowship-trained diagnostic neuroradiologist and diagnostic neuroradiology fellow in consensus. Blinded assessment of the contrast-enhanced CT of the neck was performed first, followed by noncontrast CT of the neck after a 2-week interval. The presence or absence of a stone and stone location and size were documented. Statistical analysis was undertaken to assess the agreement between CT protocols and calculate the sensitivity and specificity of contrast-enhanced CT of the neck.

RESULTS

Fifty calculi were identified on noncontrast CT of the neck in 31 cases; and 48 calculi, in 31 cases on contrast-enhanced CT of the neck. No calculi were identified in the remaining 61 cases. The sensitivity and specificity of contrast-enhanced CT of the neck in the detection of sialolithiasis was 96% (95% CI, 86.3%-99.5%) and 100% (95% CI, 94.1%-100%), respectively. The positive predictive value of contrast-enhanced CT of the neck was 100% (95% CI, 92.6%-100%), and the negative predictive value was 96.8% (95% CI, 89%-99.6%). The accuracy of contrast-enhanced CT of the neck in diagnosing the presence or absence of salivary calculi was 98%.

CONCLUSIONS

Contrast-enhanced CT of the neck is accurate in the detection of sialolithiasis, with no difference in diagnostic accuracy compared with noncontrast CT of the neck.

Value of Sonography in the Diagnosis of Sialolithiasis: Comparison With the Reference Standard of Direct Stone Identification

OBJECTIVES

The aim of this study was to assess the effectiveness of sonography for diagnosing sialolithiasis in comparison with the existing reference standard of direct identification of a stone.

METHODS

A total of 659 glands with signs of obstructive sialadenopathy were evaluated retrospectively. Sonographic examinations of the large head salivary glands had been performed initially in all cases. Direct depiction of a stone during sialoendoscopy or transoral ductal surgery or observation of stone fragmentation with discharge of concrements after extracorporeal shock wave lithotripsy, was regarded as definitive evidence and as the reference standard for the presence of sialolithiasis. The sonographic results were compared with those for direct identification of stones.

RESULTS

The sensitivity of sonography was 94.7%, with specificity of 97.4%, a positive predictive value of 99.4%, and a negative predictive value of 79.6%. Stones that were not diagnosed correctly on sonography were most often located in the distal area of the duct.

CONCLUSIONS

These results show that sialolithiasis can be diagnosed by sonography with a high degree of certainty. Sonography thus appears to be highly appropriate as the examination method of choice.

Surgeon-Performed Ultrasound for Chronic Obstructive Sialadenitis Helps Predict Sialendoscopic Findings and Outcomes

Objective

To determine the accuracy of surgeon-performed ultrasound (SP-US) features for predicting intraoperative sialendoscopic findings and to correlate ultrasound features with short-term symptomatic outcomes following sialendoscopy-assisted salivary duct surgery (SASDS).

Study Design

Case series with chart review.

Setting

The practices of 2 academic sialendoscopy surgeons.

Subjects and Methods

Between February 2014 and September 2015, 82 patients with 105 symptomatic glands underwent SASDS, of whom 56 patients (75 glands) met inclusion criteria. SP-US and sialendoscopic findings were reviewed for patients with chronic obstructive sialadenitis who underwent SASDS and who had been prospectively evaluated with the University of California–San Francisco Chronic Obstructive Sialadenitis Symptoms (COSS) questionnaire (scored 0-100) administered preoperatively and 3 months postoperatively.

Results

The positive predictive value (PPV) and negative predictive value (NPV) of SP-US for identifying sialoliths intraoperatively were 94% (33/35) and 91% (39/43), respectively. Of glands with sialoliths on SP-US, 97% (34/35) had complete symptom resolution (COSS ≤10) after SASDS. The PPV and NPV of salivary duct dilation on SP-US for finding a corresponding stenosis on sialendoscopy were 93% (14/15) and 50% (14/28), respectively. Nonsialolith SP-US features with the highest PPV for complete or partial symptom resolution (COSS ≤25) following SASDS included distal duct dilation of all glands (86%; 6/7) and dilation of both distal and proximal parotid ducts (75%; 6/8).

Conclusion

SP-US has high accuracy for ruling in and ruling out sialoliths, as well as for ruling in but not for necessarily ruling out stenosis presence and location. Ultrasound is helpful in estimating degree of short-term symptom response following SASDS.

Accuracy of Ultrasonography and Computed Tomography in the Evaluation of Patients Undergoing Sialendoscopy for Sialolithiasis

Objective

To determine the accuracy of the 2 most utilized imaging modalities in obstructive sialadenitis secondary to sialolithiasis—computed tomography (CT) and ultrasonography (US)—using sialendoscopic findings as a comparison standard. To review the impact of CT and US on the management of sialolithiasis managed with sialendoscopy alone and through combined approaches.

Study Design

Retrospective cohort study.

Setting

Quaternary academic referral center.

Subjects and Methods

All cases of patients undergoing sialendoscopy by a single surgeon for suspected parotid and submandibular gland pathology between the October 2013 and April 2016 were reviewed.

Results

Sixty-eight patients were in this cohort, of whom 44 underwent US, CT, and sialendoscopy; 20 underwent CT and sialendoscopy only; and 4 underwent US and sialendoscopy only. The sensitivity and specificity were 65% and 80% for US and 98% and 88% for CT, respectively. These 68 patients had 84 total stones addressed, with 79 being removed and 5 remaining in situ. The methods of stone removal were sialendoscopy alone (34 stones), open transoral approaches (36 stones), and an external approach: transcervical for submandibular and transfacial for parotid (11 stones).

Conclusion

US had a lower sensitivity (65%) than what has been reported in the literature (70%-94%), and the majority of missed stones were anterior Wharton’s duct stones. These sialoliths were likely missed due to an incomplete examination. US and CT were complementary in this study, and the findings suggest that both modalities can be utilized to optimize the outcome of sialendoscopy and combined approaches.

Chronic parotitis with multiple calcifications: Clinical and sialendoscopic findings

OBJECTIVES/HYPOTHESIS

To characterize clinical, imaging, and sialendoscopy findings in patients with chronic parotitis and multiple parotid calcifications.

STUDY DESIGN

Retrospective review.

METHODS

Clinical history, radiographic images and reports, lab tests, and operative reports were reviewed for adult patients with chronic parotitis and multiple parotid calcifications who underwent parotid sialendoscopy.

RESULTS

Thirteen of 133 (10%) patients undergoing parotid sialendoscopy for chronic sialadenitis had more than one calcification in the region of the parotid gland. Seven patients (54%) were diagnosed with immune-mediated disease from autoimmune parotitis (positive Sjögren's antibodies or antinuclear antibodies) or human immunodeficiency virus (HIV) disease. The six patients (46%) who did not have an immune-mediated disorder had most calcifications located anterior or along the masseter muscle. Eight of 13 patients (61%) had at least one calculus found in the parotid duct on sialendoscopy. Four patients (38%) had multiple punctate calcifications within the parotid gland, all of whom had either autoimmune parotitis or HIV. None of the proximal or punctate parotid calcifications posterior to the masseter were visualized on sialendoscopy.

CONCLUSIONS

Chronic parotitis in conjunction with multiple parotid calcifications is uncommon and was identified in 10% of our cohort. We contrast two classifications of parotid calcifications: 1) intraductal stones that cause recurrent duct obstruction and are often located within the main parotid duct along or anterior to the masseter and 2) punctate intraparenchymal parotid gland calcifications that are not visualized on sialendoscopy and may represent underlying inflammatory disease.

LEVEL OF EVIDENCE

4 Laryngoscope, 127:1565-1570, 2017.

Nonvisualization of Sialoliths during Sialendoscopy

Objectives

Analyze the characteristics of patients undergoing interventional sialendoscopy for sialolithiasis whose stones were not visualized intraoperatively.

Study Design

Case series with chart review.

Setting

Tertiary care hospital.

Subjects and Methods

Patients (n = 276) undergoing sialendoscopy between June 2008 and December 2014 were reviewed for patient characteristics, imaging characteristics, and outcomes. Nonvisualization was defined as a sialolith that was documented on imaging preoperatively but not visualized intraoperatively during sialendoscopy, despite successful ductal cannulation and evaluation.

Results

A total of 337 sialendoscopy procedures were preformed. Preoperative imaging documented a sialolith in 203 (60%) cases. Nonvisualization occurred in 31 (15%) cases with sialolith. The parotid gland was involved in 58% (18 of 31) of nonvisualization cases, as opposed to 21% (43 of 203) of all sialolith cases. The submandibular gland was involved in 42% (13 of 31) of nonvisualization cases, as compared with 79% (160 of 203) of all sialolith cases. Nonvisualization occurred in 42% (18 of 43) of parotid cases versus 8% (13 of 160) of submandibular cases, a statistically significant difference ( P < .001). Parotid stones located posterior to the plane of insertion of the posterolateral edge of the masseter were significantly more likely to experience nonvisualization (73%) than those along and anterior to the masseter (25% and 0%, respectively; P = .009).

Conclusions

Intraoperative nonvisualization of a sialolith is more likely to occur in the parotid gland. Proximal stone location may predict nonvisualization. These factors should be considered during treatment planning and counseling for patients with sialolithiasis.