International Consensus Statement on Allergy and Rhinology: Sinonasal Tumors

BACKGROUND

Sinonasal neoplasms, whether benign and malignant, pose a significant challenge to clinicians and represent a model area for multidisciplinary collaboration in order to optimize patient care. The International Consensus Statement on Allergy and Rhinology: Sinonasal Tumors (ICSNT) aims to summarize the best available evidence and presents 48 thematic and histopathology-based topics spanning the field.

METHODS

In accordance with prior International Consensus Statement on Allergy and Rhinology documents, ICSNT assigned each topic as an Evidence-Based Review with Recommendations, Evidence-Based Review, and Literature Review based on the level of evidence. An international group of multidisciplinary author teams were assembled for the topic reviews using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses format, and completed sections underwent a thorough and iterative consensus-building process. The final document underwent rigorous synthesis and review prior to publication.

RESULTS

The ICSNT document consists of four major sections: general principles, benign neoplasms and lesions, malignant neoplasms, and quality of life and surveillance. It covers 48 conceptual and/or histopathology-based topics relevant to sinonasal neoplasms and masses. Topics with a high level of evidence provided specific recommendations, while other areas summarized the current state of evidence. A final section highlights research opportunities and future directions, contributing to advancing knowledge and community intervention.

CONCLUSION

As an embodiment of the multidisciplinary and collaborative model of care in sinonasal neoplasms and masses, ICSNT was designed as a comprehensive, international, and multidisciplinary collaborative endeavor. Its primary objective is to summarize the existing evidence in the field of sinonasal neoplasms and masses.

A natural language processing approach to uncover patterns among online ratings of otolaryngologists

BACKGROUND

Patients increasingly use physician rating websites to evaluate and choose potential healthcare providers. A sentiment analysis and machine learning approach can uniquely analyse written prose to quantitatively describe patients' perspectives from interactions with their physicians.

METHODS

Online written reviews and star scores were analysed from Healthgrades.com using a natural language processing sentiment analysis package. Demographics of otolaryngologists were compared and a multivariable regression for individual words was performed.

RESULTS

This study analysed 18 546 online reviews of 1240 otolaryngologists across the USA. Younger otolaryngologists (aged less than 40 years) had higher sentiment and star scores compared with older otolaryngologists (p < 0.001). Male otolaryngologists had higher sentiment and star scores compared with female otolaryngologists (p < 0.001). 'Confident', 'kind', 'recommend' and 'comfortable' were words associated with positive reviews (p < 0.001).

CONCLUSION

Positive bedside manner was strongly reflected in better reviews, and younger age and male gender of the otolaryngologist were associated with better sentiment and star scores.

Exclusively endoscopic surgical resection of esthesioneuroblastoma: A systematic review

Background

Historically sinonasal malignancies were always addressed via open craniofacial surgery for an oncologic resection. Increasingly esthesioneuroblastomas are excised using an exclusively endoscopic approach, however, the rarity of this disease limits the availability of long‐term and large scale outcomes data.

Objective

The primary objective is to evaluate the treatment modalities used and the overall survival of patients with esthesioneuroblastoma managed with exclusively endoscopic surgery.

Methods

In accordance with PRISMA guidelines, PubMed was queried to identify studies describing outcomes associated with endoscopic management of esthesioneuroblastomas.

Results

Forty‐four out of 2462 articles met inclusion criteria, totaling 399 patients with esthesioneuroblastoma treated with an exclusively endoscopic approach. Seventy‐two patients (18.0%) received adjuvant chemotherapy and 331 patients (83.0%) received postoperative radiation therapy. The average age was 50.6 years old (range 6–83). Of the 399 patients, 57 (16.6%) were Kadish stage A, 121 (35.2%) were Kadish stage B, 145 (42.2%) were Kadish stage C, and 21 (6.1%) were Kadish stage D. Pooled analysis demonstrated that 66.0% of patients had Hyams histologic Grade Ⅰ or Ⅱ, while 34.0% of patients had Grade Ⅲ or Ⅳ disease. Negative surgical margins were achieved in 86.9% of patients, and recurrence was identified in 10.3% of patients. Of those with 5‐year follow‐up, reported overall survival was 91.1%.

Conclusion

Exclusively endoscopic surgery for esthesioneuroblastoma is performed for a wide range of disease stages and grades, and the majority of these patients are also treated with adjuvant chemotherapy or radiation therapy. Reported overall recurrence rate is 10.3% and 5‐year survival is 91.1%.

Incorporating Virtual Reality to Improve Otolaryngology Resident Wellness: One Institution's Experience

OBJECTIVE

Burnout is defined as work-related emotional exhaustion, depersonalization, and decreased sense of accomplishment. Virtual reality (VR) has emerged as an effective treatment modality for various conditions related to anxiety, however, few studies have assessed its role for stress management in residents. We hypothesize that VR-based mindfulness meditation can reduce resident burnout in real-world settings.

STUDY DESIGN

Prospective randomized crossover trial.

METHODS

Resident participants completed the validated Maslach Burnout Inventory (MBI). One group used a VR-based meditation app; the second group received no intervention. After a 2-month rotation, all subjects completed an MBI and crossed over to the other arm. Wilcoxon rank-sum tests were used to compare MBI scores before and after intervention, and to compare results by gender and postgraduate year. Mann-Whitney U tests were used to assess qualitative differences between participants.

RESULTS

Eighteen residents completed the study. Five participants were female and 13 were male. Weekly use of VR-guided meditation and paced breathing was associated with a significant decrease in emotional exhaustion (P = .009), and on subgroup analysis, male gender specifically was associated with a decrease in emotional exhaustion (P = .027). In the post-intervention survey, 42.9% subjects reported that VR encouraged them to employ paced breathing techniques, 71.4% reported that they would use the technology if regularly available, and 21.4% reported they would use paced breathing in the future.

CONCLUSION

VR-based therapy may serve as a successful tool in stress management and reduce the rate of burnout among otolaryngology residents.

LEVEL OF EVIDENCE

NA Laryngoscope, 131:1972-1976, 2021.

Long Term Olfactory Outcomes Following Frontal Sinus Surgery in Chronic Rhinosinusitis

OBJECTIVES/HYPOTHESIS

No studies have evaluated the impact of the types of frontal sinus surgery (FSS) on objective olfaction scores. This study evaluated olfactory function and quality of life (QOL) in chronic rhinosinusitis (CRS) patients before and after total ethmoidectomy with frontal sinusotomy (FS).

STUDY DESIGN

Prospective cohort study.

METHODS

A prospective study of adult CRS patients undergoing FSS (Draf 2 or Draf 3 procedures) was conducted at a tertiary care center. Primary outcomes included brief smell identification test (BSIT) and sinonasal outcome test-22 (SNOT-22), which were assessed during preoperative evaluation, 6 to 9 weeks postoperatively, and 12 to 24 weeks postoperatively. Normosmia was defined as BSIT ≥9. Statistical significance was determined using the Wilcoxon signed-rank test with α = .05.

RESULTS

Thirty-eight patients followed up 12 to 24 weeks after FSS. The differences between baseline and long-term outcomes for BSIT (6.11 vs. 8.24, P = .00034) and SNOT-22 (55.49 vs. 24.32, P < .00001) scores were found to be statistically significant. Although both subgroups had clinically significant olfactory improvements, only the Draf 2 cohort experienced a statistically significant improvement in olfaction at long-term follow-up. There was no statistically significant change in data from 6 to 9 weeks to 12 to 24 weeks postoperatively.

CONCLUSIONS

Patients undergoing total ethmoidectomy with FS demonstrated statistically significant increases in olfaction and QOL at long-term postoperative follow-up. This study demonstrated that FS does not negatively impact the olfactory improvement seen in sinus surgery. The lack of statistically significant changes in these olfactory metrics from short to long-term follow-up suggests that there is no additional negative effect of FSS in the long term.

LEVEL OF EVIDENCE

3 Laryngoscope, 2021.

Virtual Reality as Distraction Analgesia and Anxiolysis for Pediatric Otolaryngology Procedures

OBJECTIVES/HYPOTHESIS

While virtual reality (VR) has been used as analgesia and anxiolysis for invasive procedures, no literature exists on the use of VR in the pediatric otolaryngology setting. The purpose of this study was to determine the efficacy of VR in reducing pain and anxiety for pediatric otolaryngology patients.

STUDY DESIGN

Randomized controlled trial.

METHODS

A total of 53 patients aged 7-17 undergoing in-office nasal endoscopies were included. Patients were randomized to receive VR or standard of care. Procedural pain, anxiety, and satisfaction scores were recorded from patients and caregivers. The physician filled out a childhood emotional manifestation scale (CEMS).

RESULTS

Patients in VR group reported a significant decrease in pain (0.80 ± 1.06 vs. 2.26 ± 2.38, P = .018) and anxiety (9.50 ± 12.48 vs. 38.48 ± 29.83, P = .0002) and increase in procedural satisfaction (6.40 ± 0.77 vs. 4.74 ± 1.74, P = .0002) compared to patients in control group. CEMS scores were significantly reduced in VR group (5.15 ± 0.46 vs. 9.64 ± 5.66, P = .0001) and caregiver anxiety levels were significantly reduced in VR group (11.50 ± 17.67 vs. 27.39 ± 30.48, P = .041) compared to control group. There were no reported side effects. Procedural time did not significantly differ between groups.

CONCLUSIONS

For pediatric otolaryngology patients undergoing in-office nasal endoscopies, VR is a safe and effective form of distraction analgesia and anxiolysis, significantly reducing pain and increasing procedural satisfaction for patients. In addition, VR significantly reduces anxiety for both patients and caregivers without disrupting procedural efficiency and workflow.

LEVEL OF EVIDENCE

2. Laryngoscope, 131:E1714-E1721, 2021.

The Role of Advanced Endoscopic Resection of Diverse Skull Base Malignancies: Technological Analysis during an 8-Year Single Institutional Experience

Background Resection of skull base malignancies poses complex pathological and treatment-related morbidities. Recent technological advancements of endoscopic endonasal surgery (EES) offer the ability to reexamine traditional treatment paradigms with endoscopic procedures. The utility of EES was quantitatively examined in a longitudinal series with attention to morbidities and postoperative outcomes.

Methods A single-center retrospective review was performed of all malignant sinonasal tumors from 2010 to 2018. Patients with purely EES were selected for analysis. Disease features, resection extent, complications, adjuvant treatment, recurrence, and survivability were assessed. Despite the mixed pathological cohort, analysis was performed to identify technical aspects of resection.

Results A total of 68 patients (47.6% males and 52.4% females, average age: 60.3 years) were included. A diversity of histotypes included clival chordoma (22.1%), olfactory neuroblastoma (14.7%), squamous cell carcinoma (11.8%), and adenoid cystic carcinoma (11.8%). Gross total resection (GTR) was achieved in 83.8% of cases. Infection (4.4%) and cerebrospinal fluid leak (1.5%) were the most common postoperative complications. Total 46 patients (67.6%) underwent adjuvant treatment. The average time between surgery and initiation of adjunctive surgery was 55.7 days.

Conclusion In our 8-year experience, we found that entirely endoscopic resection of mixed pathology of malignant skull base tumors is oncologically feasible and can be accomplished with high GTR rates. There may be a role for EES to reduce operative morbidity and attenuate time in between surgery and adjuvant treatment, which can be augmented through recent mixed reality platforms. Future studies are required to systematically compare the outcomes with those of open surgical approaches.

Surgical outcomes in patients with endoscopic versus transcranial approach for skull base malignancies: a 10-year institutional experience

Object: The authors performed an extensive comparison between patients treated with open versus an endoscopic approach for skull base malignancy with emphasis on surgical outcomes.Methods: A single-institution retrospective review of 60 patients who underwent surgery for skull base malignancy between 2009 and 2018 was performed. Disease features, surgical resection, post-operative morbidities, adjuvant treatment, recurrence, and survival rates were compared between 30 patients who received purely open surgery and 30 patients who underwent purely endoscopic resection for a skull base malignancy.Results: Of the 60 patients with skull base malignancy, 30 underwent open resection and 30 underwent endoscopic resection. The most common hisotype for endoscopic resection was squamous cell carcinoma (26.7%), olfactory neuroblastoma (16.7%), and sarcoma (10.0%), and 43.3%, 13.3%, and 10.0% for the open resection cohort, respectively. There were no statistical differences in gross total resection, surgical-associated cranial neuropathy, or ability to achieve negative margins between the groups (p > 0.1, all comparisons). Patients who underwent endoscopic resection had shorter surgeries (320.3 ± 158.5 minutes vs. 495.3 ± 187.6 minutes (p = 0.0003), less intraoperative blood loss (282.2 ± 333.6 ml vs. 696.7 ± 500.2 ml (p < 0.0001), and shorter length of stay (3.5 ± 3.7 days vs. 8.8 ± 6.0 days (p < 0.0001). Additionally, patients treated endoscopically initiated adjuvant radiation treatment more quickly (48.0 ± 20.3 days vs. 72.0 ± 20.5 days (p = 0.01).Conclusions: An endoscopic endonasal approach facilitates a clinically meaningful improvement in surgical outcomes for skull base malignancies.

Detection of Cerebrospinal Fluid Leaks: Is There a Radiologic Standard of Care? A Systematic Review

INTRODUCTION

Diagnosis of cerebrospinal fluid (CSF) leaks traditionally involves laboratory testing of markers and appropriate imaging. Surgical localization can be difficult, and the inability to accurately localize skull base defects leads to increased rates of repair failure and complications. Many imaging techniques localizing and identifying CSF leaks have been proposed. Comparisons of current and investigational imaging techniques used to localize CSF leaks are reviewed.

METHODS

A comprehensive and systematic search through PubMed, Scopus, and reference lists from relevant articles was completed to identify literature on sensitivities of different imaging methods for localization and detection of CSF leaks. Prospective, retrospective, and case series published since 1995 that addressed imaging techniques for CSF leaks confined to the skull base were included. Sensitivities of each major imaging technique proposed were recorded and analyzed.

RESULTS

In total, 133 studies initially were screened from 2125 studies on preliminary search. Of these, 38 studies were included based on inclusion criteria. Studies were segregated by imaging modality. A total of 1000 patients with CSF leaks subsequently were evaluated.

CONCLUSIONS

Although radionuclide cisternography has been the historical standard, recent imaging techniques have emerged considering the low sensitivity. Computed tomography cisternography with contrast also has low sensitivity, even in active leaks. Although high-resolution computed tomography is commonly the initial study of choice, magnetic resonance imaging methods, particularly 3-dimensional imaging, may prove to be a more sensitive study of choice. Computed tomography/magnetic resonance imaging combination methods may show promise in localizing CSF leaks. Stratifying by status and etiology may be an important determinant. Further studies investigating various imaging techniques for localizing CSF leaks are needed.

The impact of nasal airflow on sinus mucosa: A radiographic review

BACKGROUND

Chronic rhinosinusitis (CRS) is a disease of widespread prevalence and high morbidity. Many suggest that the introduction of toxins and allergens via nasal airflow plays a significant role in the development of CRS. In patients who have undergone total laryngectomy, nasal airflow is disrupted, providing an opportunity to examine the role of nasal airflow in sinonasal pathology.

METHODS

All patients who received a total laryngectomy between 2002 and 2012 with preoperative and postoperative computed tomography (CT) scans were retrospectively reviewed. The Lund-Mackay (LM) score for each sinus was recorded for both scans. The assessment of differences in pre-operative and post-operative LM scores was analyzed utilizing paired t-tests.

RESULTS

56 patients underwent total laryngectomy and had both preoperative and postoperative CT scans. There were no significant differences in the LM scores between pre-operative and post-operative scans within each sinus (frontal sinus, p = 1.0; anterior ethmoid sinus, p = 0.77; posterior ethmoid sinus, p = 0.45; maxillary sinus, p = 0.90; sphenoid sinus, p = 0.63; ostiomeatal complex, p = 0.78) or in the total LM scores (p = 0.97). Furthermore, patients with pre-operative sinonasal mucosal thickening (total LM score > 0) showed no significant change in their total LM score post-operatively (p = 0.13).

CONCLUSION

In total laryngectomy patients, studies demonstrate that a disruption in nasal airflow is correlated to altered sinonasal physiology and decreased subjective symptoms. However, our study shows that the disruption of nasal airflow results in no significant change in radiographic evidence of sinonasal mucosal thickening.

Costs in Pituitary Surgery: Racial, Socioeconomic, and Hospital Factors

Objective  To investigate the influence of patient demographic factors and hospital factors on cost and length of stay in patients undergoing pituitary surgery. Design/Setting  A retrospective cross-sectional study of the 2008 to 2012 Nationwide/National Inpatient Sample. Participants  Patient demographics and hospital characteristics for patients undergoing pituitary surgery were compared between white, black, and Hispanic patients. Main Outcome Measures  Variables associated with increased cost and increased length of hospital stay were ascertained and compared against each racial and ethnic group via multiple linear regression analysis. Results  Of 8,812 patients who underwent pituitary surgery, 5,924 (67.2%) patients were white, 1,590 (18.0%) were black, and 1,296 (14.7%) were Hispanic. Patient variables found to be significantly different between racial groups via univariate analysis were age, chronic conditions, gender, income, and primary payer. Hospital variables found to be significantly different were location/teaching status, region, and ownership. Hospitalization cost was significantly lower for whites (-$3,082, 95% confidence interval [CI] -$3,961 to -$2,202) and significantly higher for both blacks ($1,889, 95% CI $842-$2,937) and Hispanics ($2,997, 95% CI $1,842-$4,152). Length of hospital stay was also significantly lower in whites (-1.01, 95% CI -1.31 to -0.72) and significantly higher for both blacks (0.65, 95% CI 0.30 to 1.00) and Hispanics (0.96, 95% CI 0.57-1.35). Conclusions  Racial and ethnic factors contribute to differences in hospital utilization and cost for patients undergoing pituitary surgery. Further investigations are necessary to uncover the sources of these disparities in an effort to provide safer and more affordable care to all patients.

A Systematic Review of Secondary Cerebrospinal Fluid Leaks

Background

Secondary cerebrospinal leaks (CSF) are leaks that recur after an initial endoscopic repair of CSF leaks. Identification of characteristics that could predict secondary leaks may allow surgeons to plan repairs with the knowledge that these defects are more likely to fail.

Objective

To identify characteristics that could predict secondary CSF leaks.

Methods

A search of all studies that reported outcomes after endoscopic repair of CSF leaks was conducted by using medical literature data bases. Studies with the following criteria were included: written in the English language, secondary CSF leaks after primary repair, and assessment of success of fistula repair. Data extracted included the etiology of the leak, site of the leak, reconstructive materials used, and success of the repair.

Results

Ninety-four studies, from 1988 to 2015, with a total of 3149 primary CSF leaks were included. Sixty-three studies (67%) had a success rate of ≥80%; 77 studies (82%) had secondary leak rates of <40%. For 88 of the 94 studies (94%), the success rate after secondary repair improved to 81.0–100%. Of 48 studies that included leaks of more than one site, the sphenoid was the most common site of leak in 26 studies (55%), the ethmoid was the most common site in 16 studies (34%), and the cribriform was the most common site in 11 studies (23%).

Conclusion

The rate of secondary CSF leaks was low due to advances in endoscopic repair techniques. Spontaneous and iatrogenic CSF leaks were more likely to recur, especially without adequate control of underlying factors, such as increased intracranial pressure and obesity. Further studies with consistent reporting are required for more definitive conclusions about secondary CSF leaks.

Evaluation of Patients with Sinonasal and Ventral Skull Base Malignancies

A wide variety of tumors present in the sinonasal and ventral skull base. Patients often have nonspecific symptoms initially and present with advanced tumors, affecting the orbit and other adjacent structures. Evaluation of these malignancies with modern imaging techniques can define tumor invasion, but biopsy is often required to establish a diagnosis because most have a nonspecific appearance. A thorough understanding of the anatomy is the key to treatment planning, and a multidisciplinary approach determines the optimal strategy.

Prognostic significance of Kadish staging in esthesioneuroblastoma: An analysis of the National Cancer Database

BACKGROUND

Given the rarity of esthesioneuroblastoma, it is difficult to validate a staging system. The purpose of this study was to investigate the utility of the Kadish staging system in esthesioneuroblastoma using the National Cancer Database (NCDB).

METHODS

One thousand one hundred sixty-seven patients with esthesioneuroblastoma were identified from the NCDB.

RESULTS

Five-year survival was 80.0% for Kadish A, 87.7% for Kadish B, 77.0% for Kadish C, and 49.5% for Kadish D. Kadish B had higher survival than Kadish A. More Kadish B patients received surgery with adjuvant therapy than Kadish A patients (41.6% vs 32.5%; P = .0038) and also had more positive margins (21.6% vs 11.3%; P = .03). There was no difference in age distribution, sex, race, or neck dissection status between the 2 groups.

CONCLUSION

Kadish B had greater survival than Kadish A, but the treatment characteristics could not account for this difference. The utility of early-stage Kadish staging is uncertain and requires further study.

The presentation and outcomes of mucosal melanoma in 695 patients

BACKGROUND

Most data on sinonasal mucosal melanoma come from small institutional studies, and therefore optimal treatment methods are not well understood. The purpose of this study was to analyze the association between treatment and survival in sinonasal mucosal melanoma.

METHODS

Six hundred ninety-five patients diagnosed with sinonasal mucosal melanoma between 2004 and 2010 were identified from the National Cancer Data Base. Treatment modalities and overall survival rates were determined.

RESULTS

The 5-year overall survival was 21.7%, with a mean survival of 38.4 ± 1.7 months. The majority of patients were treated with surgery alone (31.5%) or surgery with adjuvant radiotherapy (41.4%). There was no statistical difference between survival with surgery alone and surgery with adjuvant radiation therapy (25.1% vs 25.1%, p = 0.93). Between the surgery and surgery-with-adjuvant-therapy groups, there was no difference in the number of patients with positive margins (p = 0.54), regional lymph node metastases at diagnosis (p = 0.55), morbidity scores (p = 0.58), insurance status (p = 0.13), age > 60 years (p = 0.24), or treatment at academic centers (p = 0.12).

CONCLUSIONS

Based on this large review of patients with sinonasal mucosal melanoma, adjuvant radiation therapy may not provide a survival benefit as patients tended to do poorly regardless of adjuvant radiation status.

Sinus Disease following Total Laryngectomy: A Radiographic Review

Objectives:

(1) Compare the incidence of radiographic sinus disease before and after laryngectomy by retrospective analysis of preoperative and postoperative computed tomography (CT) scans. (2) Analyze the change in pre-existing radiographic sinus disease via a subset analysis.

Methods:

A single-institution retrospective chart review was conducted. Patients who received a total laryngectomy or total laryngopharyngectomy between 2002 and 2012 with preoperative and postoperative CT scans were included. The Lund-Mackay (LM) Scores for each sinus as well as the total LM score were recorded for both scans. The assessment of differences in these scores is based on McNemar’s statistic for each sinus and on a paired t-test for the total LM score.

Results:

Surgical removal of the larynx creates an anatomical disconnect between the sinonasal cavity and distal respiratory tract. Normal nasal airflow is disrupted, resulting in alterations to the nasal mucosa, mucociliary clearance, and nasal flora. While the incidence of sinonasal disease in patients undergoing total laryngectomy has been studied via subjective scoring methods, this study is the first to evaluate radiographic sinusitis via an objective measure by comparing Lund-Mackay scores before and after total laryngectomy. There were no significant differences in the LM scores between preoperative and postoperative scans within each sinus ( P value >.05) or in the total LM score ( t statistic >0.56).

Conclusions:

In patients undergoing total laryngectomy, disruption in nasal airflow has been correlated with altered sino-nasal physiology and decreased subjective symptoms. However, our study shows no significant change in radiographic evidence of sinonasal disease after laryngectomy.

Videoconferencing for the pre-operative interaction between patient and surgeon

We studied the use of videoconferencing for the pre-operative patient-surgeon interaction. Subjects were recruited from otolaryngology patients undergoing surgery at a tertiary hospital. They were randomised to a conventional face-to-face interaction with their surgeon or a videoconference call via tablet computer. Afterwards, subjects and surgeons completed questionnaires about the experience. Various time points in patient flow were also recorded. Thirty-one patients were enrolled and 25 completed the study; five surgeons participated. The mean overall patient satisfaction scores were similar in the face-to-face and videoconferencing groups (9.88 and 9.89, respectively), as were mean interaction times (119 and 82 s, respectively); neither difference was significant. The mean waiting times in the pre-operative holding area were not significantly different between the groups. Surgeons were satisfied with the videoconferencing and 60% indicated they were somewhat likely to incorporate the technology into their daily practice. Overall patient satisfaction with a pre-operative patient-surgeon interaction via videoconferencing did not differ significantly from that for a conventional face-to-face discussion. It is feasible to incorporate videoconferencing into a busy surgical practice and there is the potential for improved efficiency.