ORIGINAL RESEARCH
Perioperative outcomes of adrenal surgery Does surgical specialty matter?
Basil Ahmad’, Duva Karunakaran’, Naji J.Touma2
‘Queen’s University School of Medicine, Kingston, ON, Canada; 2Department of Urology, Queen’s University, Kingston, ON Canada
Cite as: Ahmad B, Karunakaran D, Touma NJ. Perioperative outcomes of adrenal surgery: Does surgical specialty matter? Can Urol Assoc J 2025;19(2):53-7. http://dx.doi.org/10.5489/cuaj.7852
Published online December 9, 2024
ABSTRACT
INTRODUCTION: Management of adrenal disease requires a multidisciplinary approach often involving varied specialists. Surgical management has often overlapped between gen- eral surgeons, usually with an interest in surgical endocrinology, or urologists with minimally invasive surgical skills. The objectives of this study were to define perioperative outcomes of contemporary Canadian adrenal surgery and determine whether those outcomes are impacted by surgical subspecialty. As a secondary outcome, an assessment of the variability in the indications for adrenal surgery was carried out between the two surgical subspecialties.
METHODS: A retrospective chart review of all adrenalectomies performed at our center from August 2013 to August 2023 was conducted. The only exclusion criterion was when an adrenalectomy was performed secondary to the main procedure. Data was collected and grouped under four categories: patient characteristics, indications for an adrenalectomy, procedural statistics, and perioperative patient outcomes.
RESULTS: A total of 121 adrenalectomies were performed in a period of just over 10 years. Of these, 103 were included in the analysis. Thirty-seven were performed by general surgery, whereas 66 were performed by urology. There were no significant differences in patients’ age and Charlson comorbidity score between the two surgical specialties. The indications for the adrenalectomy were similar between the specialties, and were as follows: 32 (31.1%) for pheo- chromocytoma, 24 (23.3%) for a cortical functional lesion, 19 (18.4%) for a metastatectomy, 16 (15.5%) for size or growth, and 10 (9.7%) for adrenocortical carcinoma. There were no differences in overall operating room time or type of procedure. Most (89.3%) of the proce- dures were performed laparoscopically. Patients that were operated on by general surgeons were more likely to be readmitted within 30 days than those operated on by urologists (five patients [13.5%] vs. one patient [1.5%], respectively, p=0.04), and more likely to require inten- sive care unit (ICU)/stepdown ICU admission (19 patients [51.4%] vs. 19 [28.8%], respectively, p=0.04). There was no difference in length of stay or postoperative complications. There was, however, one Clavien-Dindo 5 complication after a procedure performed by general surgery.
CONCLUSIONS: Most adrenalectomies at this one Canadian center are performed by urology. Indications for adrenalectomy are similar between the specialties. Although post- operative complication rates are similar, rates of 30-day readmission and ICU/stepdown admission were decreased when urologists performed adrenalectomies. Adrenalectomies may be performed safely by either specialty, and factors such as local expertise and surgical volumes are likely important.
INTRODUCTION
Adrenal masses are being diagnosed with increasing frequency, which is partially attributed to the increased use of axial cross-sectional imaging.’ Combined with the development of minimally invasive surgical techniques, this has led to an increase in the rate of adrenalectomies performed over the past several decades.2 Adrenalectomies have historically been performed by general surgeons and urologists, with both specialties having expertise in the surgical anat- omy of the retroperitoneum; how- ever, proportionately fewer adre- nalectomies have been performed by urologists over time,3 despite the lack of strong evidence to sug- gest that surgical subspecialty has an impact on patient outcomes following adrenalectomy.3,4 In a Canadian con- text, adrenalectomies are performed by both specialties but very little is known about outcomes, trends over time, and patterns of practice.
The role of surgical specialty on patient outcomes has been docu- mented in several other types of operations. Thoracic surgeons had lower operative mortality rates after esophageal cancer resection and lung resection than did other surgeons.5,6 In addition, vascular surgeons were found to have lower in-hospital mor- tality rates after carotid endarterec- tomy than did neurosurgeons and general surgeons.7
Over the last decade, Kingston Health Sciences Centre (KHSC) has been the setting of over 100 adrenal- ectomies performed by both urolo- gists and general surgeons. Using a single-center, retrospective chart
review, a comparative analysis of differences between specialties was carried out. The parameters examined included patient demographics and comorbidities, perioperative and postoperative outcomes, as well as complications rates. In addition, the indications for adre- nalectomies were examined to determine whether any variability exists in practice between specialties.
METHODS
Data collection
This study was conducted as a single-center, retrospec- tive, observational investigation at KHSC. We retro- spectively examined the medical records of patients who underwent adrenalectomy between August 8, 2013, and August 8, 2023. The study did not limit participants based on age or other demographic char- acteristics; however, cases where adrenalectomy was a secondary procedure were excluded.
Comprehensive data were collected from clinical electronic medical records, pathology reports, and laboratory findings of all enrolled patients. Variables collected included patient age, indication for adrenal- ectomy, type of surgical procedure (open vs. laparo- scopic), operating room duration, comorbidities, com- plications, interventions for complications, intensive care unit (ICU) admissions, 30-day readmissions, and the medical specialties involved in patient care. Additionally, the Clavien-Dindo classification and Charlson comor- bidity index scores were determined for each patient.
Adrenalectomies At KHSC 2013-2023 n = 121
18 Excluded Adrenalectomy is a secondary procedure
n = 103 Eligible for inclusion
Urology n = 66 (64%)
General Surgery n = 37 (36%)
The study protocol, amendments, and related docu- ments received approval from the Queen’s University Health Sciences & Affiliated Teaching Hospitals Research Ethics Board on July 19, 2023.
Outcomes
The primary objective was to investigate the variation in perioperative patient outcomes and operative met- rics based on the surgical subspecialty performing the adrenalectomy. Key perioperative outcomes of interest included mortality, 30-day readmissions, ICU admissions, and postsurgical complications. Operative metrics of interest encompassed the type of surgical procedure (open vs. laparoscopic) and operating room time. A secondary aim was to explore the differences in indica- tions for adrenalectomy between procedures performed by urologists compared to those by general surgeons.
Statistical analysis
Continuous variables were described as means and standard deviations (SD), or as median and range val- ues between patients who received adrenalectomies at KHSC based on surgical subspecialty. Categorical variables were expressed as counts and percentages. Pearson’s Chi-squared test and Welch two-sample t-test were used to compare patient perioperative outcomes, operative statistics, and indications for adre- nalectomy between surgical subspecialties. All statistical analyses were performed using R V.4.2.0 software, with p<0.05 considered statistically significant.
RESULTS
Between August 8, 2013, and August 8, 2023, 121 adrenalectomies were performed at KHSC. Of these, 103 were eligible for inclusion in our study, with 18 excluded due to their designation as sec- ondary procedures. Figure 1 indicates the breakdown of procedures performed by urologists and general surgeons. The demographic and clinical characteris- tics of the included patients are detailed in Table 1. Statistical analysis indicated no significant differences in sex (p=0.7), age (p=0.3), tumor size as measured by preoperative cross-sectional imaging, laterality, or Charlson comorbidity index (p=0.7) between the two groups.
Operative room parameters are outlined in Table 2 and were found to be similar between the two groups; 89.3% of the procedures were performed laparoscopically. Operating room times, which reflect surgical, anesthesia, and changeover time, were also similar between the procedures.
Outcomes of adrenal surgery by surgeon specialty
| Characteristic | General (n=37) | Urology (n=66) | p |
|---|---|---|---|
| Female (%) | 59.5% | 55.7% | 0.7 |
| Age | 0.3 | ||
| Range | 13-78 | 26-79 | |
| Median (IQR) | 56 (47, 67) | 60 (50.2, 66.8) | |
| Adrenal mass size (cm) | 0.9 | ||
| Range | 0-15 | 0-14.1 | |
| Median (IQR) | 3 (1.7, 5.5) | 3.5 (1.7, 5.0) | |
| Laterality (% right) | 40.5% | 48.5% | 0.8 |
| Charlson comorbidity score | 0.7 | ||
| Range | 0-10 | 2-12 | |
| Median (IQR) | 4.0 (3.0, 6.0) | 4.5 (3.0, 6.0) |
IQR: interquartile range.
| Characteristic | General (n=37)a | Urology (n=66)a | pb |
|---|---|---|---|
| Operating room time (minutes) | 0.7 | ||
| Range | 158 - 618 | 123 - 490 | |
| Median (IQR) | 235 (206, 296) | 256 (211, 302) | |
| Surgical approach | 0.4 | ||
| Laparoscopic | 31 (83.78%) | 61 (92.42%) | |
| Open | 5 (13.51%) | 4 (6.06%) | |
| Open/laparoscopic | 1 (2.70%) | 1 (1.52%) |
ân (%). bWelch two sample t-test; Pearson’s Chi-squared test. IQR: interquartile range.
Perioperative outcomes, as shown in Table 3, revealed that six patients required readmission within 30 days postoperation. A higher likelihood of readmis- sion was observed in patients who underwent surgery by general surgeons (five patients or 13.5%) compared to those by urologists (one patient or 1.5%) (p=0.04). Additionally, the need for ICU/stepdown unit admission was significantly higher in the general surgery group (19 patients or 51.4%) than in the urology group (19 patients or 28.8%) (p=0.04). No significant differences were noted in the length of hospital stay or in the occurrence of postoperative complications; however, one instance of a Clavien-Dindo grade 5 complication
| Characteristic | General (n=37)a | Urology (n=66)a | pb |
|---|---|---|---|
| 30-day readmission | 5 (13.5%) | 1 (1.5%) | 0.04 |
| ICU/Stepdown admission | 0.04 | ||
| Yes | 19 (51.4%) | 19 (28.8%) | |
| No | 18 (48.6%) | 47 (71.2%) | |
| Clavien-Dindo score | 0.4 | ||
| 0 | 23 (62.2%) | 49 (74.2%) | |
| 1 | 6 (16.2%) | 8 (12.1%) | |
| 2 | 5 (13.5%) | 6 (9.1%) | |
| 3 | 2 (5.4%) | 1 (1.5%) | |
| 4 | 0 (0.00%) | 2 (3.0%) | |
| 5 | 1 (2.7%) | 0 (0.0%) | |
| Length of stay (days) | 0.07 | ||
| Range | 1.00 - 50.00 | 1.00 - 9.00 | |
| Median (IQR) | 3.0 (2.0, 4.0) | 2.0 (1.0, 3.0) |
ªn (%). “Pearson’s Chi-squared test; Welch two sample t-test. ICU: intensive care unit; IQR: interquartile range.
| Table 4. Indications for adrenalectomy by surgical specialty | |||
|---|---|---|---|
| Indication | General (n=37) | Urology (n=66) | p |
| 0.2 | |||
| Pheochromocytoma | 12 (32.4%) | 20 (30.3%) | |
| Functional adrenal lesion | 5 (13.5%) | 19 (28.8%) | |
| Metastases | 9 (24.3%) | 10 (15.2%) | |
| Size/growth | 5 (13.5%) | 11 (16.7%) | |
| Primary adrenocortical carcinoma | 4 (10.8%) | 6 (9.1%) | |
| Other | 2 (5.4%) | 0 (0.0%) | |
was reported following a procedure performed by the general surgery department.
The indications for adrenalectomy were broadly consistent across both surgical specialties, including pheochromocytoma (32 cases or 31.1%), cortical func- tional lesions (24 cases or 23.3%), metastatectomy (19 cases or 18.4%), size or growth concerns (16 cases or 15.5%), and adrenocortical carcinoma (10 cases or 9.7%) (Table 4).
DISCUSSION
This is a retrospective report on 103 adrenalecto- mies performed at one Canadian center over the last 10 years, comparing outcomes between procedures performed by urologists and general surgeons. There was no statistically significant difference between the groups in most outcomes of interest, including surgical approach, operative room time, length of stay, and, Clavien-Dindo complication scores. Adrenalectomies may be performed safely by either specialty.
In this Canadian center, most adrenalectomies are performed by urologists (64%) as opposed to general surgeons (36%). There are differences in the literature regarding the proportion of adrenalectomies performed by urologists. National trends observed in the U.S. from 2003-2009 demonstrated that 60% of 23 746 adrenal- ectomies were performed by urologists and 40% by general surgeons, but there was a 15% decrease in the proportion of adrenalectomies performed by urolo- gists over the study period.3 Conversely, a Nationwide Inpatient Sample from 1999-2005 identified that 28% of adrenalectomies were carried out by urologists.8 More recent studies have shown figures ranging from 10-47% of adrenalectomies being performed by urologists.9,10
Overall, complication rates for adrenalectomy are low at our center, which may be attributed to its high-volume status and the fact that 89% of the procedures were performed laparoscopically. A laparoscopic approach has been found to result in lower complications;11 however, there have been mixed results regarding the hospital- volume outcome relationship, with a high-volume center being defined as >10 cases per year.12-14 Adrenal disease requires a multidisciplinary approach with the involve- ment of specialties such as endocrinology, advanced anesthesia, and genetics, which are more likely to be available at high-volume centers.
No differences in complications, operating room time, and length of stay were observed between the specialties. Conversely, postoperative ICU/stepdown unit admission and 30-day readmission were higher when general surgeons performed the procedure. There have been conflicting reports on this in the lit- erature. Complications and length of stay were found to be higher when urologists performed the proce- dure in one series;8 however, this effect disappeared on multivariate analysis, and only surgical volume mat- tered. Conversely, no differences were observed in complications and length of stay between specialties in a more contemporary series.1º A recent survey of Canadian practice indicated that up to 11.5% of prac- titioners routinely admit pheochromocytoma cases to
the ICU as a personal preference or as a result of an institutional practice.1
Independent of specialty, surgeon volume has been found to positively impact patient outcomes in adrenal surgery.8,9,15 With high-volume generally being defined as >4 cases per year, high-volume surgeons tended to have lower complication rates, decreased length of stay, and lower costs.14 Some series found that urologists were more likely to be lower-volume and less likely to perform the procedure at academic institutions.8.9 This is in contrast to our series, where only one surgeon, a urologist, was found to maintain the high-volume defini- tion of >4 cases per year over the entire study period.
One unique aspect of this study is that the propor- tion of adrenalectomies performed laparoscopically is elevated at 89%, with no difference between the two specialties. Other reports on this topic found the rate of minimally invasive adrenalectomy to range from 14-27%.3,9,14 The rate seems to go up when the pro- cedure is performed by high-volume surgical endocri- nologists compared to urologists and general surgeons, but even then, that rate remains low at 34.8%.9 One report observing trends found that the uptake of mini- mally invasive adrenalectomy lags behind other extir- pative procedures, with a 4% increase over a 10-year period (2002-2011).3 In addition, no increase in the laparoscopic approach was observed for adrenalecto- mies performed for malignant indications. There is a need for more contemporary series to keep track of this trend of uptake of laparoscopy for adrenalectomy.
In this series, no statistically meaningful differences were observed between urologists and general sur- geons in indications for adrenalectomies. It appears the pattern of practice is similar. A previous report found that urologists performed higher proportions of malignant cases than general surgeons.8 In the current series, as opposed to a large national database, we had the ability of eliminating secondary adrenalectomies, such as removal of the adrenal gland during a radi- cal nephrectomy. This may partially explain the similar number of adrenalectomies performed for malignant indications observed here.
Being a shared procedure, concerns have been raised that both general surgery and urology residents are underexposed to adrenalectomies during their training. In 1996, Harness et al examined the Resident Statistic Summaries (Report C) of the Residency Review Committee for general surgery from 1986- 1994. They found that the average number of adrena- lectomies performed per general surgery resident was 0.98.16 An updated analysis of the same data source
Outcomes of adrenal surgery by surgeon specialty
from 1994-2004 showed an increase in the average number of adrenalectomies performed per general surgery resident to 1.46.17
A 2005 survey of 372 residents and 56 program dir- ectors in urology throughout the U.S. showed that only 52% of urology chief residents had performed a laparo- scopic adrenalectomy during their training.18 Another report suggested that the number of minimally invasive adrenalectomies performed by Canadian and American urology residents has increased between 2004 and 2009;19 however, those numbers remain low on both sides of the border, with an increase from 0.68 to 2.53 cases per resident per year for Canadian residents, and 1.65 to 1.79 cases per resident per year for American residents. With such low exposure numbers for both specialties during residency training, adrenalectomy may be best reserved for fellowship-trained specialists in sur- gical treatment of adrenal disease. That expertise can be gained by a general surgeon through a surgical endocrin- ology fellowship or a urologist with a minimally invasive fellowship with exposure to adrenal surgery.
Limitations
The limitations of our findings include those inherent to any retrospective, single-center study. The results of this one academic institution may not be generalizable to other Canadian centers. Local expertise, regardless of surgical specialty, may matter more. Despite this, this report provides interesting and revealing data on a procedure claimed by two surgical specialties, yet not entirely owned by either. Future reports from large Canadian databases or multicenter studies are needed to provide a fuller picture of the state of contemporary adrenal surgery in Canada.
CONCLUSIONS
Most adrenalectomies at this one Canadian center are performed by urologists. Indications for adrenalec- tomy are similar between the specialties, with a high penetration of minimally invasive surgery. Although postoperative complication rates are similar, rates of 30-day readmission and ICU/stepdown admission were decreased when urologists performed adrenalectomies. Adrenalectomies may be performed safely by either specialty, and factors such as local expertise and sur- gical volumes are likely more important. Larger and multicenter series of surgical management of adrenal disease are needed to draw a more wholesome picture of contemporary Canadian practice.
COMPETING INTERESTS. The authors do not report any competing personal or financial interests related to this work.
This paper has been peer reviewed.
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CORRESPONDENCE: Dr. Naji J. Touma, Department of Urology, Queen’s University, Kingston, ON Canada; naji.touma@kingstonhsc.ca