Comparison of postoperative biochemical indicators and surgical result between partial adrenalectomy and total adrenalectomy: a systematic review and meta-analysis

Introduction

According to GLOBOCAN’s 2020 data, adrenal tumors, coupled with kidney neoplasms, ranked 15th among cancers that pose a threat to human life (1). They have an incidence rate of 4% in East Asia and a worldwide rate of about 4.6% (1). According to the Chinese urology and andrology guidelines 2023, the probability of pheochromocytoma in Chinese citizens is 0.002–0.008% (2,3). The probability of hypercorticosis is 0.002–0.005%, and the probability of adrenocortical cancer is 0.001–0.002% (4-6). Currently, laparoscopic surgery is upheld as the gold standard for adrenal tumor treatment. However, the selection and extent of application for both total adrenalectomy (TA) and partial adrenalectomy (PA) within this surgical approach continue to be a matter of debate.

TA, often utilized as a surgical intervention for adrenal disorders, is suitable for a diverse range of conditions, including adrenal adrenocortical cancer, aldosteronism, and pheochromocytoma. Its merits are highlighted by lessened perioperative complications and reduced postoperative fatality rate (7,8). TA holds the advantage of triggering notable alterations in the postoperative biochemical markers for functional tumors (9). However, making a hasty decision to opt for bilateral TA may result in lifelong reliance on steroids and thus diminishing the patient’s quality of life after the surgery. Inadequate corticosteroid replacement treatment can also lead to a life-threatening Addisonian crisis (10). Research has further indicated that a decrease in quality of life and an increase in mortality rates in patients may be associated with the lifelong utilization of steroid hormones (11).

PA can avoid lifelong steroid use. In dealing with more prevalent small functional tumors such as sporadic pheochromocytoma, aldosterone, or cortisol-secreting adenomas, the strategy helps to conserve normal adrenal tissue and significantly reduce the likelihood of future adrenal crises. However, PA is comparatively less effective than TA in mitigating long-term complications (12-14). We discovered that most research papers usually limit their focus to the post-surgery index comparison of a single illness, and articles with relevant data from recent years have not been included in previous research papers. However, our study has broadened its scope by including multiple diseases and incorporating the latest research, thus improving the validity and reliability of our findings.

Based on this debate, this article aims to compare the postoperative indicators and functional indicators of PA and TA, compare the safety and effectiveness of these surgical methods, and help clinical doctors make cautious choices when making surgical treatment plans. We present this article in accordance with the PRISMA reporting checklist (available at https://gs.amegroups.com/article/view/10.21037/gs-24-345/rc) (15,16).

Methods

This review has obtained proactive registration in the PROSPERO database, identified as CRD42023467287.

Search strategy

Five databases, namely PubMed, Cochrane, Web of Science, China National Knowledge Infrastructure (CNKI), and Embase, were utilized in the search process. The search criteria included articles up to December 2023 with keywords: “Partial adrenalectomy” and “Total adrenalectomy”, and inclusion criteria were as follows: (I) the study focused on the comparison of PA and TA in the literature. (II) Non-univariate comparison. (III) Comparative safety and efficacy articles. (IV) Randomized controlled trials ought to be incorporated, as well as both prospective controlled trials and retrospective studies. (V) Full papers containing at least one outcome parameter, such as operating time (OT), blood loss, hospital stay, serum aldosterone, plasma renin activity, postoperative aldosterone to renin ratio (ARR), blood potassium. (VI) Adrenal tumor types are not restricted, etc. Exclusion criteria were as follows: (I) studies that are not relevant to the topic or lack complete data. (II) Letters, case reviews, and conference abstracts. (III) Animal experiments, and animal case studies. (IV) Non-comparative safety and efficacy articles. (V) Univariate comparison.

Data extraction

Baseline data were collected based on the original data provided by the included literature, focusing on common baseline characteristics found in most included studies, and categorized the data by article type, tumor size, tumor location, gender, age, Newcastle-Ottawa Quality Assessment Scale (NOS) score, and tumor type (Table 1). The indicators for comparison included OT, blood loss, length of hospital stay, serum aldosterone and plasma renin activity levels, postoperative ARR, systolic and diastolic blood pressure, early postoperative complications, and blood potassium concentration. In processing the data, we also obtained some data with no original data but a clear classification of clinical remission and non-remission. In order to avoid bias, we did not use those data as the content of data analysis but chose to use other data with raw data for data analysis. As for the data of some early complications, we compared the Clavien-Dindo classification of early complications and found that most of their articles did not provide detailed descriptions of complication data, only verbal descriptions of no complications or only grade 1 complications. We selected articles with original data and selected grade 1 complications with more data as the data for comprehensive analysis.

Statistical analysis

The article’s original data definition served as a foundational reference for data recording. In terms of data gathering, this document utilized the Cochran-Mantel-Haenszel approach using the RevMan software, version 5.3. Data that were not immediately usable, such as median values, range metrics, and interquartile spreads, were transformed into a usable format through specific statistical methodologies (26,27). Continuous variables were computed using the weighted mean difference (WMD), while binary variables were assessed using odds ratios (ORs) with the same level of confidence. Both were calculated with 95% confidence intervals (CIs). The variance across the different studies was examined utilizing chi-square analysis along with the I-squared test for a comprehensive evaluation of heterogeneity. The random effects model is used to process all data models, while the fixed effects model is used to process subgroup analysis models. The criterion for high heterogeneity is I²>50%. Finally, a value of P<0.05 is considered statistically significant.

Subgroup analysis

When processing data on OT and blood loss, we found significant heterogeneity in the data. In order to obtain accurate data results for analysis, we combined the data with subgroup classification: year, age, sample size, tumor size. Based on its data characteristics, we selected 2012, 50 years old, 100 sample size, and 2 cm as the cut-off point for data analysis. To enhance the rigor of the article, we categorized the tumor types into Conn’s and mixed based on the inclusion criteria, allowing us to conduct a more detailed subgroup analysis. We also categorized the data into transperitoneal and retroperitoneal types, identifying three studies transperitoneally, three retroperitoneally, and the remainder as mixed. However, significant discrepancies in the original data led us to abandon this grouping approach.

Bias assessment

In this paper, the data processing function of RevMan 5.3 was used to draw a funnel plot and evaluate the bias of data with high heterogeneity (Figure 1). The random effects model was used to process the data. Concurrently, ROBINS-I was used to assess for bias risk in non-randomized controlled (RCTs), including bias: (I) pre-intervention: (i) confounding, (ii) selection of participants; (II) intervening: (i) classification of exposures; (III) post-intervention: (i) departures from intended exposures, (ii) missing data, (iii) measurement of outcomes, (iv) selection of the reported result (Table 2) (28). The NOS was employed to examine the quality of non-randomized studies. Evaluations were conducted on three dimensions: selection, comparability, and exposure/outcome. Studies scoring at least 7 were categorized as high quality (Table 2).

Figure 1 Funnel plot. SE, mean difference; MD, mean difference.

Results

We searched for a total of 1,751 screening records. Firstly, 319 duplicate articles were excluded, and then we screened out articles without relevant intervention, as well as reviews and individual case reports, Further screening was conducted to identify articles without original literature, perioperative and postoperative data, and relevant comparisons. Finally, 10 articles were preliminarily screened. After studying 10 data articles, we manually screened out 1 article without high-quality data and finally included 9 articles. Among them, we included a total of 8 retrospective studies and 1 prospective study included six Conn’s articles and three mixed articles. The mixed articles including pheochromocytoma and Cushing or Conn’s disease (Figure 2). Through the above screening process, we eliminated 1,063 irrelevant articles, 1 article without original literature, and eliminated letters, reviews, and 175 articles without results, a total of 9 projects were ultimately included in our study. The specific process is shown in Figure 3. The data and characteristics included in the study are shown in Table 1.

Figure 2 Screening process. CNKI, China National Knowledge Infrastructure.

Figure 3 Surgical results and functional indicators. (A) PA vs. TA: operation time. (B) PA vs. TA: blood loss. (C) PA vs. TA: hospital stay. (D) PA vs. TA: diastolic blood pressure. (E) PA vs. TA: systolic blood pressure. (F) PA vs. TA: serum aldosterone. (G) PA vs. TA: potassium. (H) PA vs. TA: plasma renin activity. (I) PA vs. TA: ARR. (J) PA vs. TA: early complication. PA, partial adrenalectomy; TA, total adrenalectomy; SD, standard deviation; IV, inverse variance; CI, confidence interval; M-H, ARR, aldosterone to renin ratio.

Surgical results

In the surgical results, we compared the OT, blood loss, and hospital stay between PA and TA. In data analysis, we found significant heterogeneity in the results of OT and blood loss, to reduce its heterogeneity and bias, we divided the two sets of data into four subgroups for analysis. The results were as follows:

Operation time

In Figure 3A, the comparison of OT: PA had a shorter OT compared to TA (WMD =−12.16; 95% CI: −19.42, −4.89; I²=96%; P=0.001, Figure 3A). Subgroups were included sample size, age, study year, and tumor size were included. The use of the appeal statistics method for subgroup analysis showed differences in the results compared to the ungrouped data. In the data results of OT, the OT of PA in subgroup ≤50 years old was shorter than that of TA (WMD =−19.71; 95% CI: −35.99, −3.42; I²=95%; P=0.02, Figure 4A), which was consistent with the conclusion of ungrouped data. However, there was no statistically significant difference between subgroups >50 years old. Furthermore, the results of the subgroup analysis did not show statistical significance based on year and tumor size (P>0.05).

Figure 4 Subgroup result. (A) PA vs. TA: operation time. (B) PA vs. TA: blood loss. (C) PA vs. TA: Conn’s vs. mixed. Mixed: included pheochromocytoma, Cushing or Conn’s disease. PA, partial adrenalectomy; TA, total adrenalectomy; SD, standard deviation; IV, inverse variance; CI, confidence interval.

Blood loss

In Figure 3B, data about blood loss were extracted from five studies (18,19,21,22,24). Our final meta-analysis indicated that there was no significant difference in blood loss between PA and TA (WMD =0.48; 95% CI: −16.92, 17.88; I²=94%; P=0.96, Figure 3B). Similarly, we used the appellate subgroup analysis and concluded. The analysis results show that age and sample size data were not statistically significant, which was the same as that of ungrouped data. In the subgroup of tumor size, there was no statistically significant difference in the results of data with tumor size >2.0 cm, which was the same as the ungrouped data. However, for tumor size ≤2.0 cm, the intraoperative blood loss associated with PA surpasses that of TA (WMD =16.76; 95% CI: 3.62, 29.90; I²=37%; P=0.01, Figure 4B).

Hospitalization time

Referring to Figure 3C, after the collective analysis of four studies (18,21,22,25), a high degree of heterogeneity among the studies was noted, warranting the use of a random effect model. Consequently, there was no discernable difference in the duration of hospital stays between partial resection and full resection (WMD =−0.34; 95% CI: −0.91, 0.22; I²=89%; P=0.23, Figure 3C).

Functional indicators

In assessing the follow-up prognosis between PA and TA, we evaluated functional indicators including systolic and diastolic blood pressure, serum aldosterone levels, post-surgery potassium concentration, plasma renin activity, along with ARR. The displayed results were as follows:

Postoperative diastolic blood pressure and systolic blood pressure

In Figure 3D, to further reduce heterogeneity, we used a random effect model, compared with PA, TA had better diastolic blood pressure recovery (WMD =2.12; 95% CI: 0.42, 3.81; I²=0%; P=0.01, Figure 3D), When comparing the postoperative follow-up indicators of systolic blood pressure between PA and TA, it was also found that there was no significant difference between them (WMD =−1.65; 95% CI: −4.83, 1.53; I²=0%; P=0.31, Figure 3E).

Serum aldosterone

Upon comparing the postoperative follow-up indicators of serum aldosterone between PA and TA, the random-effect model was used, there is no significant disparity was identified (WMD =2.00; 95% CI: −2.80, 6.80; I²=53%; P=0.41, Figure 3F).

Postoperative potassium concentration

When assessing postoperative potassium concentrations, a random-effects model was implemented to diminish heterogeneity. Notably, there also did not appear to be a statistically significant difference between PA and TA (WMD =0.07; 95% CI: −0.05, 0.19; I²=10%; P=0.24, Figure 3G).

Plasma renin activity

In our comparison of plasma renin activity following PA and TA surgery, we deployed a random-effects model and concluded that no statistically significant difference existed (WMD =0.08; 95% CI: −0.27, 0.43; I²=0%; P=0.66, Figure 3H).

ARR

We used the ratio of aldosterone to renin to compare postoperative functional measures to more accurately reflect changes in postoperative functional measures. When we compared the ARR, there was also no significant difference between PA and TA. The random-effects model was used (WMD =13.58; 95% CI: −26.03, 53.18; I²=58%; P=0.50, Figure 3I).

Early postoperative complications

In this paper, the classification and grading data of early complications were compared and classified according to Clavien-Dindo’s complications. Combined with the data of early complications, there was no statistical significance between PA and TA in early complications (OR =0.78; 95% CI: 0.40, 1.51; I²=0%; P=0.45, Figure 3J).

Tumor types

In our baseline data analysis, we identified six articles focused on Conn’s, while the remaining articles included mixed cases of pheochromocytoma and conditions such as Cushing’s or Conn’s disease. To address this, we conducted an additional subgroup analysis, focusing on OT due to the availability of more data. A total of seven articles were included in this analysis. It was concluded that the OT of PA in the Conn’s tumor group was short with TA (WMD =−15.19; 95% CI: −24.05, −6.33; I²=97%; P=0.0008, Figure 4C). In the mixed tumor group, the results were not statistically significant (WMD =−6.37; 95% CI: −15.02, 2.29; I²=96%; P=0.15, Figure 4C).

Bias situation

Figure 1 shows that the funnel plot has significant bias and the graph is not symmetrical. We have created a deviation evaluation form to evaluate the reasons for this deviation (Table 2). We think that the possibility of data dispersion was due to significant differences in the years of the article.

Discussion

In this section, we examine the comparative results of PA and TA based on nine studies. Several key findings from this analysis merit further discussion.

We began by evaluating surgical outcomes, including OT, blood loss, and length of hospital stay. Our analysis revealed that PA typically had a shorter OT compared to TA, aligning with findings from most of the cited studies. Given the significant variability in the data, we performed a subgroup analysis to address this heterogeneity. We examined OT across different factors, including age, tumor size, year of publication, and total number of patients. The results showed no significant differences in operation time between PA and TA when being analyzed by tumor size, publication year, and total patient count. However, among patients ≤50 years old, PA had a shorter operation time than TA, with a high heterogeneity of 96%. To investigate the sources of this heterogeneity, we identified the study by Ishidoya et al., which focused on a cohort with an average age under 50 years. This study included patient data collected between 1995 and 2004 (20). We observed a significant difference in operation time between the two groups in the study of Ishidoya et al., with PA demonstrating a shorter operation time than TA. However, after excluding this article from our analysis, the heterogeneity was reduced to 66%, and the results were no longer statistically significant. This outcome may be attributed to factors such as the early publication date, the inclusion of data from varied tumor sites, differences in surgical techniques, and the varying proficiency of the operators involved. Next, we examined blood loss and length of stay. Our findings indicated minimal differences in blood loss between the two groups, consistent with the majority of the cited studies. However, to ensure the rigor of our analysis, we conducted a subgroup analysis for blood loss. This analysis revealed that for tumors smaller than 2.0 cm, blood loss was lower in the TA group compared to the PA group.

Finally, we compared the data of other articles with differences, for example, in study of Li et al., they came to a different conclusion from ours: compared to TA, PA had fewer hospital stays, blood loss, and complications when dealing with unilateral aldosterone tumors (29). The reason for this difference may be that we have included more types of tumors, and there are also differences in the inclusion of surgical approaches, the difference between the peritoneal and retroperitoneal approaches may lead to heterogeneity in surgical results and affect data results. Furthermore, the site of adrenal tumor development could introduce additional heterogeneity and influence the outcome of the data. For example, Ishidoya et al. reported that if the tumor in PA is small enough and located on the periphery, especially at the top of the adrenal gland, the OT is shorter (20). Data from Fu et al. suggest that PA for tumors of the inferior adrenal pole or lower extremity requires more surgical and hemostatic time than for tumors of the upper extremity or outer surface (21).

Regarding the issue of most of the functional indicators appearing in our data being meaningless, when referring to the data from the Pengli et al. article, the biochemical data in the article also showed meaningless results. The write-up also highlighted that postoperative shifts in biochemical markers between PA and TA were not significantly different. Therefore, it cannot be concluded that PA had a higher recurrence rate compared to TA, our results also confirm this (29).

The dimensions of the tumor along with its functionality largely dictate the treatment strategy chosen. It has been reported that adrenal adenoma size is quantitatively positively correlated with cortisol autonomy and metabolic parameters (30). For tumors with biochemical function, incidental tumors with biochemical function are indications for laparoscopic surgery (31). However, most articles do not make a distinction between PA and TA, and the scope of application of PA and TA remains controversial. As to the question of choosing PA vs. TA, Kaye et al., also noted in a 2010 article that the idea of preserving adrenal glands for patients with isolated adrenal or bilateral disease is supported by benefits that differ from chronic steroid replacement therapy. Addison’s crisis has been reported in up to 35% of patients after bilateral adrenalectomy, with a mortality rate of 3% (32-35). However, in the past 10 years, the PA has been more and more respected. In article of Zawadzka et al., it was pointed out that the main advantage of PA over complete adrenalectomy is that it reduces the incidence of steroid dependence and thus reduces the risk of adrenal crisis (36). Fu et al. also pointed out that adenomas produced by aldosterone were an ideal choice for PA (21). Liu et al. also noted that PA can help preserve more adrenal function in younger patients. How much of the adrenal cortex can be retained to achieve this goal, other articles have suggested that a third of the gland can be retained to achieve this goal (24,37). However, our data results did not provide much functional indicators data to prove the difference between the two. Some articles have also pointed out that TA is superior to PA in certain conditions, such as Simforoosh et al., who recommended that patients with unilateral aldosterone adenoma and primary aldosteronism should undergo TA instead of PA (23). But Kaye also pointed out that PA had not been fully utilized and advocated the use of PA to remove small, functional tumors, Chen et al. also held the same view on PA as Kaye expressing optimism about its prospects (18,38). Balci et al. also indicated that PA was safe and feasible in short term research (17).

The limitations of this article are as follows: firstly, this article is a retrospective study, and there are notable differences in the years of the included studies. These temporal variations may have introduced inconsistencies in surgical techniques and the skill levels of the surgeons, potentially impacting the results. Some studies did not conduct RCT trials, but instead selected appropriate treatment methods based on the patient’s condition, Secondly, there are significant differences in sample size in the literature we included, and there are also slight differences in data in follow-up time. In addition, different literature has different imaging criteria for inclusion and exclusion of patients.

Conclusions

Our findings indicate that PA has a shorter OT than TA, while TA shows more effectiveness in diastolic blood pressure recovery. No significant differences were observed between the PA and TA ungrouped data in terms of blood loss, duration of hospital stay, levels of serum aldosterone and potassium, systolic blood pressure, plasma renin activity, early complications, and postoperative ARR. In the subgroup analysis, when the patient was 50 years old or younger, the OT of PA was less than that of TA, and the tumor size was 2.0 cm or smaller, PA resulting in more surgical bleeding than TA. PA offers advantages in surgical outcomes compared to TA. However, for tumors ≤2 cm, TA may yield greater benefits for patients. Moreover, TA shows better recovery of diastolic blood pressure than PA when assessing functional indicators.

Acknowledgments

Funding: None.

Footnote

Reporting Checklist: The authors have completed the PRISMA reporting checklist. Available at https://gs.amegroups.com/article/view/10.21037/gs-24-345/rc

Peer Review File: Available at https://gs.amegroups.com/article/view/10.21037/gs-24-345/prf

Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://gs.amegroups.com/article/view/10.21037/gs-24-345/coif). The authors have no conflicts of interest to declare.

Ethical Statement: The authors are accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved.

Open Access Statement: This is an Open Access article distributed in accordance with the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International License (CC BY-NC-ND 4.0), which permits the non-commercial replication and distribution of the article with the strict proviso that no changes or edits are made and the original work is properly cited (including links to both the formal publication through the relevant DOI and the license). See: https://creativecommons.org/licenses/by-nc-nd/4.0/.

References

1. Sung H, Ferlay J, Siegel RL, et al. Global Cancer Statistics 2020: GLOBOCAN Estimates of Incidence and Mortality Worldwide for 36 Cancers in 185 Countries. CA Cancer J Clin 2021;71:209-49. [Crossref] [PubMed]
2. Kiernan CM, Solórzano CC. Pheochromocytoma and Paraganglioma: Diagnosis, Genetics, and Treatment. Surg Oncol Clin N Am 2016;25:119-38. [Crossref] [PubMed]
3. Chen H, Sippel RS, O'Dorisio MS, et al. The North American Neuroendocrine Tumor Society consensus guideline for the diagnosis and management of neuroendocrine tumors: pheochromocytoma, paraganglioma, and medullary thyroid cancer. Pancreas 2010;39:775-83. [Crossref] [PubMed]
4. Barwick TD, Malhotra A, Webb JA, et al. Embryology of the adrenal glands and its relevance to diagnostic imaging. Clin Radiol 2005;60:953-9. [Crossref] [PubMed]
5. Stuijver DJ, van Zaane B, Feelders RA, et al. Incidence of venous thromboembolism in patients with Cushing's syndrome: a multicenter cohort study. J Clin Endocrinol Metab 2011;96:3525-32. [Crossref] [PubMed]
6. Schulick RD, Brennan MF. Long-term survival after complete resection and repeat resection in patients with adrenocortical carcinoma. Ann Surg Oncol 1999;6:719-26. [Crossref] [PubMed]
7. Sommerey S, Foroghi Y, Chiapponi C, et al. Laparoscopic adrenalectomy--10-year experience at a teaching hospital. Langenbecks Arch Surg 2015;400:341-7. [Crossref] [PubMed]
8. Coste T, Caiazzo R, Torres F, et al. Laparoscopic adrenalectomy by transabdominal lateral approach: 20 years of experience. Surg Endosc 2017;31:2743-51. [Crossref] [PubMed]
9. Assalia A, Gagner M. Laparoscopic adrenalectomy. Br J Surg 2004;91:1259-74. [Crossref] [PubMed]
10. Partial laparoscopic adrenalectomy. Journal of Endourology 2004;18:A28.
11. Oprea A, Bonnet NCG, Pollé O, et al. Novel insights into glucocorticoid replacement therapy for pediatric and adult adrenal insufficiency. Ther Adv Endocrinol Metab 2019;10:2042018818821294. [Crossref] [PubMed]
12. Walz MK, Peitgen K, Hoermann R, et al. Posterior retroperitoneoscopy as a new minimally invasive approach for adrenalectomy: results of 30 adrenalectomies in 27 patients. World J Surg 1996;20:769-74. [Crossref] [PubMed]
13. Imai T, Tanaka Y, Kikumori T, et al. Laparoscopic partial adrenalectomy. Surg Endosc 1999;13:343-5. [Crossref] [PubMed]
14. Steichen O, Amar L, Chaffanjon P, et al. SFE/SFHTA/AFCE consensus on primary aldosteronism, part 6: Adrenal surgery. Ann Endocrinol (Paris) 2016;77:220-5. [Crossref] [PubMed]
15. Page MJ, McKenzie JE, Bossuyt PM, et al. The PRISMA 2020 statement: an updated guideline for reporting systematic reviews. BMJ 2021;372: [Crossref] [PubMed]
16. Shea BJ, Reeves BC, Wells G, et al. AMSTAR 2: a critical appraisal tool for systematic reviews that include randomised or non-randomised studies of healthcare interventions, or both. BMJ 2017;358:j4008.
17. Balci M, Tuncel A, Aslan Y, et al. Laparoscopic Partial versus Total Adrenalectomy in Nonhereditary Unilateral Adrenal Masses. Urol Int 2020;104:75-80. [Crossref] [PubMed]
18. Chen SF, Chueh SC, Wang SM, et al. Clinical outcomes in patients undergoing laparoscopic adrenalectomy for unilateral aldosterone producing adenoma: partial versus total adrenalectomy. J Endourol 2014;28:1103-6. [Crossref] [PubMed]
19. Liu JH, Wei XD, Fu CC, et al. Long-Term Results of Laparoscopic Partial Versus Total Adrenalectomy for Aldosterone Producing Adenoma. Urol J 2020;17:4981. [Crossref] [PubMed]
20. Ishidoya S, Ito A, Sakai K, et al. Laparoscopic partial versus total adrenalectomy for aldosterone producing adenoma. J Urol 2005;174:40-3. [Crossref] [PubMed]
21. Fu B, Zhang X, Wang GX, et al. Long-term results of a prospective, randomized trial comparing retroperitoneoscopic partial versus total adrenalectomy for aldosterone producing adenoma. J Urol 2011;185:1578-82. [Crossref] [PubMed]
22. Billmann F, Billeter A, Thomusch O, et al. Minimally invasive partial versus total adrenalectomy for unilateral primary hyperaldosteronism-a retrospective, multicenter matched-pair analysis using the new international consensus on outcome measures. Surgery 2021;169:1361-70. [Crossref] [PubMed]
23. Simforoosh N, Soltani MH, Shemshaki H, et al. Symptom Resolution and Recurrence Outcomes after Partial Versus Total Laparoscopic Adrenalectomy: 13 years of Experience with Medium-Long Term Follow up. Urol J 2020;18:165-70. [Crossref] [PubMed]
24. Walz MK, Peitgen K, Diesing D, et al. Partial versus total adrenalectomy by the posterior retroperitoneoscopic approach: early and long-term results of 325 consecutive procedures in primary adrenal neoplasias. World J Surg 2004;28:1323-9. [Crossref] [PubMed]
25. Anceschi U, Tuderti G, Fiori C, et al. Minimally Invasive Partial Versus Total Adrenalectomy for the Treatment of Primary Aldosteronism: Results of a Multicenter Series According to the PASO Criteria. Eur Urol Focus 2021;7:1418-23. [Crossref] [PubMed]
26. Luo D, Wan X, Liu J, et al. Optimally estimating the sample mean from the sample size, median, mid-range, and/or mid-quartile range. Stat Methods Med Res 2018;27:1785-805. [Crossref] [PubMed]
27. Wan X, Wang W, Liu J, et al. Estimating the sample mean and standard deviation from the sample size, median, range and/or interquartile range. BMC Med Res Methodol 2014;14:135. [Crossref] [PubMed]
28. Sterne JA, Hernán MA, Reeves BC, et al. ROBINS-I: a tool for assessing risk of bias in non-randomised studies of interventions. BMJ 2016;355:i4919. [Crossref] [PubMed]
29. Li KP, Duan X, Yang XS, et al. Partial versus total adrenalectomy for the treatment of unilateral aldosterone-producing adenoma: a systematic review and meta-analysis. Updates Surg 2021;73:2301-13. [Crossref] [PubMed]
30. Bleier J, Pickovsky J, Apter S, et al. The association between adrenal adenoma size, autonomous cortisol secretion and metabolic derangements. Clin Endocrinol (Oxf) 2022;96:311-8. [Crossref] [PubMed]
31. Zeiger MA, Thompson GB, Duh QY, et al. The American Association of Clinical Endocrinologists and American Association of Endocrine Surgeons medical guidelines for the management of adrenal incidentalomas. Endocr Pract 2009;15:1-20. [Crossref] [PubMed]
32. van Heerden JA, Sizemore GW, Carney JA, et al. Surgical management of the adrenal glands in the multiple endocrine neoplasia type II syndrome. World J Surg 1984;8:612-21. [Crossref] [PubMed]
33. de Graaf JS, Lips CJ, Rütter JE, et al. Subtotal adrenalectomy for phaeochromocytoma in multiple endocrine neoplasia type 2A. Eur J Surg 1999;165:535-8. [Crossref] [PubMed]
34. Lairmore TC, Ball DW, Baylin SB, et al. Management of pheochromocytomas in patients with multiple endocrine neoplasia type 2 syndromes. Ann Surg 1993;217:595-601; discussion 601-3. [Crossref] [PubMed]
35. Asari R, Scheuba C, Kaczirek K, et al. Estimated risk of pheochromocytoma recurrence after adrenal-sparing surgery in patients with multiple endocrine neoplasia type 2A. Arch Surg 2006;141:1199-205; discussion 1205. [Crossref] [PubMed]
36. Zawadzka K, Tylec P, Małczak P, et al. Total versus partial adrenalectomy in bilateral pheochromocytoma - a systematic review and meta-analysis. Front Endocrinol (Lausanne) 2023;14:1127676. [Crossref] [PubMed]
37. Brauckhoff M, Nguyen Thanh P, Bär A, et al. Subtotal bilateral adrenalectomy preserving adrenocortical function. Chirurg 2003;74:646-51. [Crossref] [PubMed]
38. Kaye DR, Storey BB, Pacak K, et al. Partial adrenalectomy: underused first line therapy for small adrenal tumors. J Urol 2010;184:18-25. [Crossref] [PubMed]