Abstract
Background:
This study assessed the relationship between surgeon volume, operative management, and resource utilization in adrenalectomy.
Methods:
Isolated adrenalectomies performed within our health system were identified (2016–2021). High-volume surgeons were defined as those performing ≥6 cases/year. Outcomes included indication for surgery, perioperative outcomes, and costs.
Results:
Of 476 adrenalectomies, high-volume surgeons (n=3) performed 394, while low-volume surgeons (n=12) performed 82. High-volume surgeons more frequently operated for pheochromocytoma (19% vs. 16%, p<0.001) and less frequently for metastasis (6.4% vs. 23%, p<0.001), more frequently used laparoscopy (95% vs. 80%, p<0.001), and had lower operative supply costs ($1,387 vs. $1,636, p=0.037). Additionally, laparoscopic adrenalectomy was associated with shorter length of stay (−3.43 days, p<0.001), lower hospitalization costs (−$72,417, p<0.001), and increased likelihood of discharge to home (OR 17.03, p=0.008).
Conclusions:
High-volume surgeons more often resect primary adrenal pathology and utilize laparoscopy. Laparoscopic adrenalectomy is, in turn, associated with decreased healthcare resource utilization.
Keywords: minimally invasive surgery, endocrine surgery, length of stay, adrenal neoplasms, adrenal metastasectomy
Graphical Abstract
INTRODUCTION
Widespread use of computed tomography (CT) imaging has led to increased identification of adrenal tumors in the general population.1, 2 Concurrently, the rates of adrenalectomy have steadily increased in the United States, facilitated in part due to advances in minimally invasive operative approaches.3 The laparoscopic approach to adrenalectomy was first reported in 1992 and has become the primary surgical approach for most adrenal tumors, with rare exceptions such as large tumors suspicious for malignancy or those in a radiated field.4, 5 As with other applications of minimally invasive techniques, laparoscopic adrenalectomy has multiple advantages, including lower risk of intraoperative blood loss requiring transfusion, decreased length of stay, and more rapid return to normal patient function when compared to open adrenalectomy.4
Across many specialties in healthcare, it has been demonstrated that experts are more likely to adopt minimally invasive techniques quickly and safely. For example, higher-volume surgeons in urology and colorectal surgery are more likely to use robotic and laparoscopic approaches, with associated improvements in the speed of patient recovery, postoperative complications, and costs.6-9 In endocrine surgery, there is an association between higher surgeon volume and shorter lengths of stay and lower complication rates for thyroid, parathyroid, and adrenal procedures.10-14 However, there is a dearth of literature regarding the relationship between surgeon volume and technical approach in adrenalectomy, and the extent to which the use of laparoscopic over open adrenalectomy mediates improvements in outcomes.
Additionally, prior investigations of the role of surgeon volume in adrenalectomy have not examined indication for surgery. As recent advances in immuno- and targeted therapies have improved survival in numerous malignancies, interest in the resection of oligometastatic disease has grown rapidly.15, 16 Yet for adrenal metastasectomy in particular, evidence of a survival benefit appears to be limited to certain subsets of patients, suggesting the importance of preoperative patient selection.17-19
Therefore, in this study, we sought to examine our institution’s experience with surgeon volume, operative management, and resource utilization in a contemporary cohort of patients undergoing adrenalectomy. As higher-volume providers may be more likely to have advanced training in the surgical management of adrenal disease, we hypothesized that surgeon volume may influence operative approach and patient selection in adrenalectomy.
METHODS
Study Population
Patients who underwent adrenalectomy within our large, academic health system over a five-year period (2016–2021) were retrospectively identified from the electronic medical record based on the following Current Procedural Terminology (CPT) codes: 60650, 60650DV, 60545, 60540, 60540DV. To reduce confounding, patients who underwent any concurrent procedure as identified by additional CPT codes in the case log were excluded.
Variables and Outcomes
Data abstracted for each patient included demographics (age, sex, race/ethnicity, primary insurance), clinical characteristics (body mass index, past medical history as documented by International Classification of Diseases, Tenth Revision codes), approach (laparoscopic vs. open), resource utilization (operative time in minutes, operative supply charges, length of stay, total hospitalization charges), clinical outcomes (discharge disposition, 30-day readmission), and final histopathologic diagnosis. Using chart review, the following variables were collected for patients with discrete neoplasms identified on preoperative imaging: tumor size, Hounsfield units (on non-contrast or pre-contrast computed tomography), standardized uptake value on positron emission tomography, and suspicion for malignancy as documented in the surgeon’s preoperative note. For analysis, primary insurance type was categorized as private, Medicare, Medicaid, or other/none. Charlson comorbidity scores were calculated from patients’ past medical histories in R, version 4.2.1 (R Development Core Team, Vienna, Austria) using package icd.20 Discharge disposition was categorized as home without assistive services, home with assistive services, skilled nursing facility, or in-hospital death/transition to hospice.
Patients were divided into a high-volume surgeon group and a low-volume surgeon group, based on the number of cases performed by the attending surgeon. Based on existing literature, surgeons who performed ≥6 adrenalectomies annually in every year of activity were classified as high-volume, while surgeons who performed <6 adrenalectomies in any year of activity were classified as low-volume.14, 21 The primary outcomes included underlying pathologic diagnosis and technical approach. Secondary outcomes included operative time, operative and hospitalization costs, length of stay, discharge disposition, and 30-day readmissions.
Statistical analysis
Summary statistics were reported as means with standard deviations, medians with interquartile ranges, or frequencies with percentages, as applicable. Group comparisons were performed using Student’s t-tests, Wilcoxon rank-sum tests, and chi-square tests, as appropriate. Multivariable linear and logistic regression analyses were used to estimate the associations between surgeon volume and the outcomes. The models for underlying diagnosis were adjusted for patient age, sex, race/ethnicity (dichotomized as non-Hispanic White vs. other race/ethnicity), insurance (dichotomized as private vs. other insurance), Charlson comorbidity score, and body mass index. Subsequently, for the model examining technical approach, documented preoperative suspicion for malignancy and tumor size were added as covariates. Finally, for the models assessing resource utilization, technical approach was also added as a covariate. Discharge disposition was dichotomized as home vs. another disposition.
Statistical analysis was performed using Stata, version 17.0 software (Stata Corporation, College Station, TX). This study was reviewed and deemed to be exempt by the Institutional Review Board of the University of Pennsylvania.
RESULTS
Surgeon Characteristics
A total of 476 cases of isolated adrenalectomy, performed by 14 surgeons, were identified during the study period. Three of 14 surgeons were classified as high-volume. The high-volume surgeons had completed fellowship training in Complex General Surgical Oncology or Endocrine Surgery. Postgraduate training for the low-volume surgeons included Complex General Surgical Oncology, Endocrine Surgery, Minimally Invasive Surgery, Transplantation, Urologic Oncology, and none. The annual case count for the individual high-volume surgeons ranged from 7–62 adrenalectomies, with a median annual case volume of 19.5 (IQR 14.8–28). Among the low-volume surgeons, the annual case count ranged from 1–7, with a median case volume of 1 (IQR: 1–2). Over the course of the study period, the high-volume surgeons performed 83% of all cases. The number of cases per surgeon is shown in Figure 1.
Figure 1. Total case volume of surgeons who performed isolated adrenalectomies, 2016–2021.
Surgeon case volume ranged from 1–229 over the study period. Three surgeons were categorized as high-volume, and 11 surgeons were categorized as low-volume.
Cohort Characteristics
The mean patient age was 53 ± 13 years. The cohort was 52% female and 48% male. The majority of patients identified as non-Hispanic White (62%) and had private insurance (62%) during their hospitalization. The median Charlson comorbidity score was 1 (IQR: 0–2). The mean body mass index was 31.1 ± 7.1 kg/m2. Among the 425 patients with a documented tumor size on preoperative imaging, the mean size was 3.4 ± 2.5 cm. Only 116 patients had tumor Hounsfield units included in a preoperative computed tomography report; among those, the mean radiodensity was 20.4 ± 19.7 units. In 21% of cases, the surgeon documented a suspicion for malignancy in their preoperative note. On surgical pathology, the most common diagnoses were adrenocortical adenoma (54%), pheochromocytoma (18%), and metastatic malignancy (9.2%).
When stratified by operative volume of the attending surgeon, there were no significant differences between cases treated by high- and low-volume surgeons with respect to mean patient age (53 ± 13 years vs. 56 ± 13 years, p=0.102), sex (53% female vs. 49% female, p=0.508), median Charlson comorbidity score [1 (IQR: 0–2) vs. 1 (IQR: 0–2), p=0.067], or mean body mass index (31.0 ± 7.1 kg/m2 vs. 31.7 ± 7.3 kg/m2, p=0.383). The racial/ethnic distribution of patients also did not significantly differ by surgeon volume (p=0.075). However, there was a significant difference in insurance type between the two cohorts; a greater proportion of patients in the high-volume surgeon group had private insurance (62% vs. 54%), while fewer had Medicare (24% vs. 27%) and Medicaid (7.4% vs. 17%, p=0.017).
When assessing whether high- and low-volume surgeons operated for different underlying diagnoses, we found that the distribution of surgical pathology differed significantly between the two cohorts. High-volume surgeons tended to operate more frequently for adenoma (57% vs. 37%), pheochromocytoma (19% vs. 16%), adrenal hyperplasia (7.4% vs. 2.4%), and neoplasm of uncertain potential (1.8% vs. 1.2%) (p<0.001). Conversely, high-volume surgeons less frequently removed normal glands (0.5% vs. 1.2%), other benign lesions such as myelolipoma (4.8% vs. 13%), and metastatic malignancies (6.4% vs. 23%), compared to low-volume surgeons (p<0.001). These demographic and clinical characteristics are summarized in Table 1.
Table 1.
Demographic and clinical characteristics of patients who underwent isolated adrenalectomy, 2016–2021. Bold indicates p<0.05.
| Characteristic | All Cases N=476 |
High-Volume Surgeon Cases N=394 |
Low-Volume Surgeon Cases N=82 |
p-value |
|---|---|---|---|---|
| Age | ||||
| Mean (SD) | 53 (13) | 53 (13) | 56 (13) | 0.102 |
| Sex, N (%) | ||||
| Male | 228 (48) | 186 (47) | 42 (51) | 0.508 |
| Female | 248 (52) | 208 (53) | 40 (49) | |
| Race/ethnicity, N (%) | ||||
| Non-Hispanic White | 295 (62) | 246 (62) | 49 (60) | 0.075 |
| Non-Hispanic Black | 122 (26) | 104 (26) | 18 (22) | |
| Hispanic | 20 (4.2) | 15 (3.8) | 5 (6.1) | |
| Asian or Pacific Islander |
17 (3.6) | 10 (2.5) | 7 (8.5) | |
| Other or Unknown | 22 (4.6) | 19 (4.8) | 3 (3.7) | |
| Insurance type,, N (%) | ||||
| Private | 289 (61) | 245 (62) | 44 (54) | 0.017 |
| Medicare | 116 (24) | 94 (24) | 22 (27) | |
| Medicaid | 43 (9.0) | 29 (7.4) | 14 (17) | |
| Other or None | 28 (5.9) | 26 (6.6) | 2 (2.4) | |
| Charlson comorbidity index | ||||
| Median (IQR) | 1 (0–2) | 1 (0–2) | 1 (0–2) | 0.067 |
| Body mass index | ||||
| Mean (SD) | 31.1 (7.1) | 31.0 (7.1) | 31.7 (7.3) | 0.383 |
| Histopathology, N (%) | ||||
| Normal gland | 3 (0.6) | 2 (0.5) | 1 (1.2) | 0.459 |
| Benign lesion | 30 (6.3) | 19 (4.8) | 11 (13) | 0.004 |
| Hyperplasia | 31 (6.5) | 29 (7.4) | 2 (2.4) | 0.100 |
| Adenoma | 255 (54) | 224 (57) | 30 (37) | 0.001 |
| Adrenocortical carcinoma | 14 (2.9) | 11 (2.8) | 3 (3.7) | 0.673 |
| Pheochromocytoma | 88 (18) | 75 (19) | 13 (16) | 0.499 |
| Distant metastasis | 44 (9.2) | 25 (6.4) | 19 (23) | <0.001 |
| Neoplasm of uncertain potential | 8 (1.7) | 7 (1.8) | 1 (1.2) | 0.721 |
| Unclear or No gland identified | 3 (0.6) | 1 (0.3) | 2 (2.4) | 0.023 |
Treatment Characteristics
Overall, 92% of cases were performed laparoscopically. The mean tumor size was significantly larger for the cases that were performed via open approach compared to those performed laparoscopically (7.3 ± 4.0 cm vs. 3.0 ± 2.0 cm, p<0.001), and 62% of cases performed open had a preoperative suspicion for malignancy compared to 17% of the cases performed laparoscopically (p<0.001). For the total cohort, the median operative time was 102 (IQR: 82–130) minutes, and median operative supply charges were $1,400 (IQR: $1,007–$1,973). The median length of stay was 1 (IQR: 1–2) day, and median total hospitalization charges were $75,667 (IQR: $64,855–$99,498). Most patients (75%) were discharged home without services, while 0.6% of the cohort died or were placed on hospice during the index hospitalization. Few (1.1%) patients were readmitted within 30 days of adrenalectomy.
When stratified by surgeon volume, there were significant differences between the highland low-volume cohorts with regard to treatment characteristics and resource utilization. First, for the primary outcome of surgical approach, high-volume surgeons more frequently used laparoscopy (p<0.001), both when malignancy was suspected preoperatively (81% vs. 69%) and when malignancy was not suspected preoperatively (98% vs. 88%). Additionally, patients treated by high-volume surgeons had significantly lower operative supply charges [$1,387 (IQR: $989–$1906) vs. $1,636 (IQR: $1,141–$2,698), p=0.037]. However, there were no statistically significant differences between groups in median operative time [103 (IQR: 83–131) minutes vs. 95 (80–129) minutes, p=0.195], median length of stay [1 (IQR: 1–2) day vs. 2 (IQR: 1–3) days, p=0.117], total hospitalization charges [$75,569 (IQR: $63,724ȓ$96,125) vs. $97,527 (IQR: $68,438–$107,075), p=0.329], or 30-day readmission rate (1.0% vs. 1.2%, p=0.869). There was also no significant difference in the distribution of discharge disposition between the two groups (p=0.497). These treatment characteristics are summarized in Table 2.
Table 2.
Treatment characteristics of patients who underwent isolated adrenalectomy, 2016–2021. Bold indicates p<0.05.
| Characteristic | All Cases N=476 |
High-Volume Surgeon Cases N=394 |
Low-Volume Surgeon Cases N=82 |
p-value |
|---|---|---|---|---|
| Operative approach, N (%) | ||||
| Laparoscopic | 439 (92) | 373 (95) | 66 (80) | <0.001 |
| Open | 37 (7.8) | 21 (5.3) | 16 (20) | |
| Operative time, minutes | ||||
| Median (IQR) | 102 (82–130) | 103 (83–131) | 95 (80–129) | 0.195 |
| Operative supply charges, dollars | ||||
| Median (IQR) | 1,400 (1,007–1,973) | 1,387 (989–1906) | 1,636 (1,141–2,698) | 0.037 |
| Length of stay | ||||
| Median (IQR) | 1 (1–2) | 1 (1–2) | 2 (1–3) | 0.117 |
| Total hospitalization charges, dollars | ||||
| Median (IQR) | 75,667 (64,855–99,498) | 75,569 (63,724–96,125) | 97,527 (68,438–107,075) | 0.329 |
| Discharge disposition, N (%) | ||||
| Home without services | 354 (75) | 288 (73) | 66 (80) | 0.497 |
| Home with services | 113 (24) | 98 (25) | 15 (18) | |
| Skilled nursing facility | 5 (1.1) | 4 (1.0) | 1 (1.2) | |
| Hospice or expired | 3 (0.6) | 3 (0.8) | 0 (0.0) | |
| 30-day readmission, N (%) | ||||
| Yes | 5 (1.1) | 4 (1.0) | 1 (1.2) | 0.869 |
| No | 471 (99) | 390 (99) | 81 (99) | |
Operative Management
On multivariable regression analysis, the relationship between surgeon volume and underlying diagnosis persisted. Specifically, high-volume surgeons were less likely to resect normal glands or non-adrenal tissue (OR 0.18, 95% CI 0.03–0.94, p=0.043) and were less likely to resect metastatic disease compared to low-volume surgeons (OR 0.22, 95% CI 0.10–0.48, p<0.001). Notably, resection of metastases was also more likely among male patients (OR 2.62, 95% CI 1.23–5.59, p=0.013) and those with a non-Hispanic White background (OR 5.69, 95% CI 2.14–15.18, p=0.001). There was no significant association between surgeon volume and resection of adrenocortical carcinoma (OR 0.92, 95% CI 0.24–3.61, p=0.908) or pheochromocytoma (OR 1.15, 95% CI 0.59–2.21, p=0.687).
Additionally, after adjusting for patient characteristics, tumor size, and suspicion for malignancy, the likelihood of undergoing a laparoscopic procedure was significantly greater when the procedure was performed by a high-volume surgeon (OR 4.43, 95% CI 1.74–11.30, p=0.001). Laparoscopy was also more likely to be utilized in patients with greater body mass index (OR 1.09, 95% CI 1.01–1.18, p=0.025), while less likely in increasing tumor size (OR 0.61, 95% CI 0.52–0.71, p<0.001) and in patients with a preoperative suspicion for malignancy (OR 0.20, 95% CI 0.08–0.54, p=0.001) (Table 3).
Table 3.
Multivariable regression analysis of factors associated with likelihood of laparoscopic approach to adrenalectomy. Bold indicates p<0.05.
| Characteristic | Odds Ratio | 95% Confidence Interval | p-value |
|---|---|---|---|
| Surgeon volume | |||
| Low-volume | Reference | Reference | 0.002 |
| High-volume | 4.43 | 1.74–11.30 | |
| Age | |||
| Each additional year | 1.03 | 1.00–1.06 | 0.093 |
| Sex | |||
| Male | 0.63 | 0.25–1.58 | 0.326 |
| Female | Reference | Reference | |
| Race/ethnicity | |||
| Non-Hispanic White | 0.89 | 0.34–2.35 | 0.816 |
| Other race/ethnicity | Reference | Reference | |
| Insurance type | |||
| Private | 0.75 | 0.27–2.06 | 0.578 |
| Other or None | Reference | Reference | |
| Charlson comorbidity index | |||
| Each additional point | 0.90 | 0.60–1.36 | 0.623 |
| Body mass index | |||
| Each additional unit | 1.09 | 1.01–1.18 | 0.025 |
| Tumor size | |||
| Each additional cm | 0.61 | 0.52–0.71 | <0.001 |
| Preoperative suspicion for malignancy | |||
| No | Reference | Reference | 0.001 |
| Yes | 0.20 | 0.08–0.54 | |
Resource Utilization
The relationship between surgeon volume and resource utilization was mixed. After adjusting for patient characteristics and operative technique, high-volume surgeons were associated with slightly longer operative time (+13.51 minutes, 95% CI +2.13–+24.89, p=0.020). Operative time was also linked to private insurance (−11.77 minutes, 95% CI −20.88–−2.65, p=0.012), increasing body mass index (+1.28 minutes, 95% CI +0.69–+1.88, p<0.001), presence of malignancy (+25.94 minutes, 95% CI +11.41–+40.47, p<0.001), and laparoscopic approach (−30.95 minutes, 95% CI −47.37–−14.54, p<0.001).
In contrast, high-volume surgeons were associated with lower operative supply charges (−$358, 95% CI −$598–−$117, p=0.004). Interestingly, private insurance was also associated with lower operative costs (−$173, 95% CI −$327–−$17, p=0.029). On further examination of total hospitalization charges, there was no longer a significant relationship with surgeon volume (+$5,138, 95% CI −$10,544–+$20,821, p=0.520). However, lower hospitalization costs were associated with private insurance (−$22,465, 95% CI −$35,655–−$9,276, p=0.001) and laparoscopic technique (−$72,417, 95% CI −$96,588–−$48,245, p<0.001), while higher costs were associated with increasing Charlson score (+$6,131, 95% CI +$463–+$11,798, p=0.034). The distributions of operative supply costs and total hospitalization charges, stratified by technical approach, are shown in Figure 2.
Figure 2. Distribution of (A) operative supply costs and (B) total hospitalization charges, stratified by technical approach. * indicates p-value <0.01.
Laparoscopic adrenalectomies incurred lower median operative supply costs ($1,362 vs. $1,638) and lower total hospitalization charges ($74,531 vs. $122,407) compared to open adrenalectomies.
Similarly, length of stay was not significantly associated with surgeon volume (−0.09 days, 95% CI −0.89–+0.71, p=0.824). Rather, shorter length of stay was associated with private insurance (−0.89 days, 95% CI −1.53–−0.25, p=0.006) and laparoscopic technique (−3.43 days, 95% CI −4.59–−2.28, p<0.001). Furthermore, surgeon volume was not directly associated with likelihood of discharge to home (OR 0.13, 95% CI 0.01–1.70, p=0.119). However, likelihood of discharge to home was higher for patients who underwent a laparoscopic technique (OR 17.03, 95% CI 2.10–137.91, p=0.008) and lower for patients with increasing Charlson scores (OR 0.51, 95% CI 0.28–0.91, p=0.024) and increasing body mass index (OR 0.89, 95% CI 0.81–0.98, p=0.021). Finally, readmission within 30 days was not associated with surgeon volume (OR 0.92, 95% CI 0.09–9.57, p=0.944) or any other measured characteristic.
DISCUSSION
In this study, we sought to assess the relationship between surgeon volume, operative management, and resource utilization in adrenalectomy. Compared to prior work in this area, this study is one of the first to include detailed operative and clinical data, including underlying pathologic diagnosis, in its analysis. We found that the performance of adrenal surgery within our large health system has been effectively centralized among a few surgeons with relevant specialty training, who each have an annual case volume well above the threshold of ≥6 as defined in the literature. There were no significant differences in access to the high-volume surgeons by patient race/ethnicity, though high-volume surgeons treated a greater proportion of privately-insured individuals. On multivariable analysis, high-volume surgeons were less likely to operate for metastatic disease to the adrenal glands; they were also more likely to use a laparoscopic approach. In turn, the use of a laparoscopic technique was associated with conservation of health system resources, including operative time, total charges, length of stay, and discharge home, when compared with an open approach.
One of the strengths of our study is that it represents a distinctly modern cohort compared to prior investigations of surgeon volume in adrenalectomy. With the considerable changes in healthcare organization over the past decade, including increased hospital consolidation and regionalization of surgical care, there has been a synergy between the evidence regarding the volume-outcome relationship for rare and/or complex procedures and the financial pressures that have driven the restructuring of care delivery in the United States.22-25 This study of contemporary practices within a large, academic health system reveal how our institution has successfully integrated the recommendation to centralize adrenalectomy with high-volume specialists. However, this process has occurred organically and thus has not been comprehensive, as evidenced by the 11 low-volume surgeons who performed at least one adrenalectomy during the study period. Moving forward, our department is in the process of creating a more formal “preferred provider” system, such that new patient visits for complex or rare procedures can be consistently directed to the high-volume surgeons.
An important finding from this study is that high-volume surgeons are significantly more likely to utilize a laparoscopic approach to isolated adrenalectomy. The relationship between surgeon volume and technical approach has not previously been well-defined, as several of the seminal studies of surgeon volume in adrenalectomy utilized the National Inpatient Sample, which does not include reliable data on technical approach.14, 21, 26, 27 However, the association between volume and technique is not surprising, as evidence suggests that 20–40 cases are required to overcome the learning curve for laparoscopic adrenalectomy – a threshold which could take a decade to reach for surgeons performing just a few cases per year.28, 29 Notably, the overall proportion of cases that were performed laparoscopically was significantly higher and the median length of stay substantially shorter in our study compared to prior work, reflecting broader trends in minimally invasive techniques and early postoperative discharge across surgical specialities.26, 30, 31
The use of laparoscopy had several downstream implications for resource utilization in this study. Laparoscopic technique was associated with a reduction in total hospitalization charges by over $70,000, a reduction in length of stay by over 3 days, and a 17 times greater odds of discharge to home. These findings build upon prior work investigating the role of surgeon volume in adrenalectomy. Several studies have demonstrated that higher surgeon volume is associated with shorter length of stay as well as decreased costs.21, 27, 32 While these associations may be partially mediated by a lower likelihood of complications in cases performed by high-volume surgeons, they are likely primarily driven by the greater usage of minimally invasive approaches among high volume surgeons.21, 30, 32 Beyond technical approach, high-volume surgeons also have the opportunity to increase efficiency throughout the perioperative continuum. As described in one detailed example of costs in thyroidectomy, high-volume providers can leverage economies of scale to standardize more efficient practices and reap significant cumulative healthcare savings.33 However, it is important to remember that the benefits of centralizing specialized surgical care must be weighed against the potential disadvantages of more limited access. While conservation of healthcare resources is an important goal, ensuring that patients can be seen in a manner that is timely and convenient is also critical.
It is interesting to note that high-volume surgeons were less likely to perform adrenalectomy in the setting of metastatic disease from extra-adrenal primary cancers. The role of adrenal metastasectomy in oncologic care is controversial and likely benefits a limited subset of patients.17-19 While our dataset did not contain granular information regarding the disease distribution, symptoms, or care team composition of patients who underwent adrenalectomy for distant metastasis in this study, we suspect that this finding may represent referral bias, where surgical specialists involved in the care of the primary tumor were enlisted to perform adrenalectomy procedures which were outside of their typical scope of practice. Alternatively, this result may represent selection bias, as high-volume surgeons may be more selective in choosing to proceed with adrenal metastasectomy in cases where evidence suggests a likelihood of meaningful benefit.34 We also observed that male patients and those from non-Hispanic White backgrounds were more likely to undergo adrenal metastasectomy, consistent with findings from other cancer subtypes in which male and White patients with metastatic disease are more likely to receive treatment.35, 36 Together, these findings may represent an increased desire for and/or access to aggressive intervention among this subset of patients, as well as a possible greater responsiveness among low-volume surgeons to patient preferences. Alternatively, these findings may reflect the integration of adrenalectomy into the oncologic care of the primary tumor. However, further investigation of the role of patient and provider preferences in this setting is warranted.
Lastly, another interesting finding in this study is that there was no significant difference in access to the high-volume surgeons according to patient race/ethnicity. This result stands in contrast to several other studies which revealed substantial racial/ethnic disparities in access to high-volume surgeons and hospitals, both for endocrine and non-endocrine procedures.37-40 This encouraging finding from the present study may be indicative of one of the benefits of studying the local context in health systems research. Our health system’s tertiary referral center is situated in a geographically-compact urban environment, where the population is 41% non-Hispanic Black followed by 35% non-Hispanic White; within this context, many social determinants of unequal access to specialty care, such as transportation barriers, may be less salient.41
There are several important limitations to this study. First, its generalizability is inherently limited given that its scope was confined to a single academic health system in a diverse, urban environment. Second, our inability to quantify postoperative complications prevented us from assessing an important outcome of particular interest to patients. Furthermore, our evaluation of costs in this study was based on charges, not reimbursements. While these variables likely travel together, reimbursements may be more meaningful to patients, payors, and health systems and should be investigated in future work.
In summary, this contemporary assessment of the role of surgeon volume in adrenalectomy reveals significant centralization of care among several high-volume specialists in our health system, with an associated increase in the use of laparoscopy and decrease in operative supply costs. Laparoscopic adrenalectomy, in turn, is associated with shorter length of stay and lower hospitalization costs, suggesting that high surgeon volume improves healthcare resource utilization and optimizes patient care.
Supplementary Material
HIGHLIGHTS:
We assessed the relationship between surgeon volume and outcomes in adrenalectomy.
High-volume surgeons more frequently operated on primary adrenal pathology.
High-volume surgeons were more likely to use a laparoscopic approach.
Laparoscopy was associated with reduced resource utilization.
Funding:
This work was partially supported by the NIH National Cancer Institute award number K08 CA270385 to Dr. Heather Wachtel.
Footnotes
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Meeting information: A portion of the work reported in this manuscript was presented as a Quickshot presentation at the 2023 Academic Surgical Congress in Houston, TX.
Disclosures: The authors have no conflicts of interest to disclose.
Sara P. Ginzberg, Julia A. Gasior, Lauren R. Kelz, Jesse E. Passman, Jacqueline M. Soegaard Ballester, Robert E. Roses, Douglas L. Fraker, and Heather Wachtel have no conflicts of interest to disclose.
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