Certification of a Rural Endometriosis Clinic Leads to Improvement in the Diagnosis and Treatment of Endometriosis – a Retrospective Analysis

Abstract

Introduction

Endometriosis is a very common benign condition in women. In recent years certification of health care institutions has led to a more standardized care for endometriosis patients, aiming at improving the quality of diagnosis and treatment. The introduction of a common classification system facilitates quantification of disease extent. This study investigated whether certification of a rural endometriosis clinic ameliorated care in endometriosis patients.

Methods and Material

A single-center retrospective data analysis was performed of all endometriosis patients that underwent surgery at the investigated institution, certified in 2019, for the years 2018–2022.

Results

Between 2018 and 2022, a total of 812 surgeries were performed, with certification significantly improving diagnostic and surgical outcomes. Post-certification, there was an increase in ultrasound utilization (47.7% vs. 35.6%, p = 0.007), greater recognition of adenomyosis (65.8% vs. 57.0%, p = 0.035), and higher rates of complete lesion removal (92.5% vs. 87.8%, p = 0.011). Pain outcomes also improved, with more patients achieving pain relief 12 months postoperatively (40.5% vs. 34.5%, p = 0.196 vs. < 0.001). Additionally, certification enhanced follow-up assessments (64.1% vs. 40.7%, p < 0.001) and documentation of rectal lesions in patients with dyschezia (p < 0.001), indicating a positive impact on overall care quality.

Conclusion

This study shows that certification significantly improved care for endometriosis patients. Certification enhanced diagnostic precision, increased the use of ultrasound, improved surgical outcomes, and enabled more nuanced application of the #Enzian scoring system. Follow-up assessments became more consistent, reflecting stronger quality control. Despite remaining challenges, certification elevated the clinic’s standard of care and emphasized patient-centered management.

Zusammenfassung

Einleitung

Die Endometriose ist eine gutartige, sehr häufige Erkrankung. In den letzten Jahren hat die Zertifizierung von Gesundheitseinrichtungen zu einer standardisierteren Versorgung von Endometriosepatientinnen geführt, mit dem Ziel, die Qualität der Diagnosestellung und Behandlung zu verbessern. Eine Quantifizierung der Häufigkeit dieser Erkrankung wurde durch die Einführung eines weitverbreiteten Klassifizierungssystems vereinfacht. Die Studie untersucht, ob die Zertifizierung einer Endometrioseklinik im ländlichen Raum zu einer Verbesserung der Versorgung von Patientinnen mit Endometriose führte.

Methoden und Material

Es wurde eine monozentrische retrospektive Datenanalyse aller Patientinnen mit Endometriose, die in der hier untersuchten Institution zwischen 2018–2022 operiert wurden, durchgeführt. Die Einrichtung wurde im Jahre 2019 zertifiziert.

Ergebnisse

Zwischen 2018 und 2022 wurden insgesamt 812 chirurgische Eingriffe durchgeführt. Als Folge der Zertifizierung haben sich die diagnostischen und operativen Ergebnisse signifikant verbessert. Nach der Zertifizierung wurde die Sonografie vermehrt eingesetzt (47,7% vs. 35,6%, p = 0,007), Fälle mit Adenomyose wurden häufiger erkannt (65,8% vs. 57,0%, p = 0,035), und die Anzahl der Komplettresektionen von Läsionen nahm zu (92,5% vs. 87,8%, p = 0,011). Die Schmerzlinderung hat sich ebenfalls verbessert, und mehr Patientinnen meldeten eine weitgehende Linderung ihrer Schmerzen 12 Monate nach der Operation (40,5% vs. 34,5%, p = 0,196 vs. < 0,001). Dazu kommt noch, dass die Zertifizierung zu einer Verbesserung der Nachbeobachtungen (64,1% vs. 40,7%, p < 0,001) sowie der Dokumentation anorektaler Läsionen bei Patientinnen mit Dyschezie (p < 0,001) führte, was sich positiv auf die Qualität der allgemeinen Versorgung dieser Patientinnen auswirkte.

Schlussfolgerung

Die Studie zeigt, dass eine Zertifizierung die Versorgung von Patientinnen mit Endometriose signifikant verbessert. Die Zertifizierung hat die Präzision der Diagnosestellung verbessert, den Einsatz von Ultraschall gesteigert, die chirurgischen Ergebnisse verbessert, und erlaubt eine differenziertere Anwendung der #Enzian-Klassifikation. Nachuntersuchungen wurden konsistenter, was auf eine stärkere Qualitätssicherung hinweist. Trotz noch bestehender Herausforderungen hat die Zertifizierung den Behandlungsstandard der Klinik verbessert mit stärkerer Betonung auf ein patientenzentriertes Management.

Keywords

endometriosis - endometriosis certification - endometriosis outcome - EuroEndoCert - EuroEndoCert Certification

Schlüsselwörter

Endometriose - Endometriose-Zertifizierung - Endometriose-Outcome - EuroEndoCert - EuroEndoCert-Zertifizierung

Introduction

The presence of endometrial tissue outside the uterus is known as endometriosis [1]. Approximately 10 percent of women of reproductive age are affected worldwide [2].

Usually located in the pelvis, endometrial lesions can develop at different sites, including the peritoneum, bladder, and other neighboring organs of the uterus as well as regions outside the pelvic cavity. Symptoms vary depending on location, depth of invasion, number of adhesions, size, and histopathological features, amongst others, and are very heterogeneous. They range from minimal to heavy periodic or continuous pain, from dysmenorrhea and dyspareunia to dyschezia, from infertility to fatigue and more, and may affect physical, mental, and sexual health [1] [3] [4]. As symptoms are very variable, partially non-specific and do not reliably correlate with the extent and severity of endometrial lesions, diagnosis of endometriosis is very challenging and definitive proof of endometriosis lesions often requires surgery [5]. However, throughout the last decade diagnosis has significantly improved. When in the right hands, two-dimensional transvaginal sonography is highly accurate for diagnosing pelvic endometriosis and is well-tolerated, making it suitable for patients of all ages. It allows for a noninvasive assessment of endometriosis type and extent, providing a valuable tool for diagnosis and treatment planning, with MRI used as a secondary option if needed [6]. While surgery may not always be the initial treatment choice, as medical options are also available, careful planning is essential when removing endometriosis lesions. Patients should receive comprehensive information about all potential procedures (such as intestinal segment resection), an interdisciplinary team (including specialists like visceral surgeons) should be on hand if needed, and skilled endometriosis surgeons are crucial to ensure optimal outcomes.

Certification Requirements

To standardize and improve patient care and treatment quality, EuroEndoCert was founded in 2013 by the European Endometriosis League (EEL). EuroEndoCert is a certification program established to set and maintain high standards for the treatment of endometriosis across Europe. Its purpose is to certify medical centers that deliver high-quality, interdisciplinary care for endometriosis patients, ensuring consistent standards and improving health outcomes across certified centers [7]. To achieve certification from EuroEndoCert, medical facilities must meet specific structural, and personnel requirements set by the certification commission of the Endometriosis Research Foundation (SEF) [8]. Certification is possible in three categories: Endometriosis Practice, requiring specialized consultations and adherence to diagnostic guidelines; Endometriosis Clinic, which provides advanced diagnostic and surgical treatments and maintains interdisciplinary collaboration with fields such as pathology, radiology, and surgery; and Endometriosis Center, which offers comprehensive care within a network, including reproductive medicine, pain management, and rehabilitation, and participates actively in research and education. All certified institutions must document and report regularly on their endometriosis treatments [7]. The certification process is supported by a positive vote from Germany’s highest decision-making body for healthcare – Gemeinsamer Bundesausschuss (G-BA), or Federal Joint Committee [9].

Established Changes in Medical Processes

There are advanced training opportunities to become an endometriosis specialist, as defined by the Working Group for Endometriosis under the German Society for Gynecological Endoscopy (AGEM). These programs ensure medical professionals gain specialized expertise in diagnosing and treating endometriosis through interdisciplinary and evidence-based approaches, ultimately enhancing the quality of care for patients [10].

A standardized classification system is essential to ensure consistency and comparability in the assessment of endometriosis. Different methods for the classification of endometriosis have been introduced. The #Enzian classification is a comprehensive system for describing endometriosis, encompassing superficial, deep, and extragenital manifestations. Unlike the revised American Society for Reproductive Medicine (rASRM) classification, it is applicable in both diagnostic imaging (such as ultrasound and MRI) and during surgical procedures. This system divides the pelvis into specific compartments, categorizing endometriotic lesions based on their location and size, thereby facilitating a more precise description of the disease, and aiding interdisciplinary treatment planning. Studies have demonstrated that the affected compartments and the number of involved areas correlate with patient symptoms. Additionally, there is a strong concordance between anatomical findings and imaging results. Overall, the #Enzian classification provides a detailed and standardized approach to documenting endometriosis, enhancing diagnostics, and enabling effective treatment planning [11] [12] [13].

Furthermore, the establishment of a dedicated endometriosis outpatient clinic, along with the implementation of standardized patient history questionnaires (e.g., those recommended by AGEM), contributes to a more structured and uniform approach to patient care. This single-center study aimed to assess whether the quality of care for endometriosis patients improved following certification, as part of a quality assurance initiative.

Methods and Material

Objective

A monocenter retrospective analysis of data of all patients undergoing surgery for the diagnosis and removal of endometriosis lesions in the EuroEndoCert certified endometriosis clinic (since May 10^th, 2019) at the Department of Gynecology of the St. Marien Hospital, Amberg, Germany, between 2018 and 2022 was performed. All data were retrieved from the Clinical Information System, from established standardized questionnaires for the assessment of patient history, and from follow-up telephone interview protocols 12 months post-surgery to collect data on pain progression (no more pain, less pain, more pain, no pain improvement), fertility, pain medication usage, contraceptive pill intake and other measures (e.g. physiotherapy). Documentation was executed in a standardized data base. In this longitudinal study a comparison between patients treated before and after the official certification was conducted.

Ethics

The investigation was approved by the ethics committee of the University of Regensburg, Germany (22‑2862‑104).

Statistics

Statistical analysis was performed using the SPSS software version 29.0.0.0 from IBM, using Pearson’s Chi-Square tests.

Data protection

Patient data was pseudonymized. Data processing and analyses were done in accordance with the Declaration of Helsinki and the General Data Protection Regulation of the European Union.

Results

Description of patient cohort

Between 2018 and 2022, a total of 812 surgeries were performed on endometriosis patients, of which 92.1% (n = 748) represented primary surgeries of each patient at the investigated institution. The proportion of follow-up surgeries increased over the years ([Fig. 1]).

Fig. 1 Primary and following surgeries performed at the institution. The bar chart depicts the number of patients undergoing endometriosis surgeries between 2018 and 2022, categorized into primary surgeries and surgeries following prior interventions. The y-axis represents the number of patients, while the x-axis corresponds to the years of surgery.

Most surgeries occurred in patients aged 30 to 49, accounting for 54.5% of cases. Regarding Body Mass Index (BMI), most patients had a BMI between 20 and 29.9, comprising 68.7% of the cohort, indicating a normal to slightly elevated BMI range among the patients. The primary reason for clinic presentation was pain, reported by 56.3% of patients, followed by infertility at 24.1%, indicating that pain and reproductive concerns were the most common issues among patients ([Fig. 2], Online-Supp. Table S1).

Fig. 2 Main reason for presentation at the endometriosis clinic. The pie chart illustrates the reasons for patient presentation at the clinic, categorized into four main groups: pain, infertility, hypermenorrhea, and other reasons.

Among the patients presenting at the institution for the first time, 83.7% had no prior diagnosis of endometriosis at the time of presentation, while 16.3% were already known to have the condition (Online-Supp. Table S4). Most patients (82.4%) required inpatient care for their treatment, while 17.6% received outpatient care (Online-Supp. Table S1).

Comparison before and after certification – Outcome data

Only patients who received their first endometriosis-related surgery at the institution were considered for the following analysis (n = 748). Of these, a total of 172 patients underwent surgery before certification, while 576 patients were operated on after certification ([Fig. 3], Online-Supp. Table S2).

Fig. 3 Certification timeline. The diagram represents a timeline of patient data collection before and after certification.

Infertility increases as main reason for presentation

Post-certification, there was a significant increase in patients presenting mainly due to infertility (from 14.0% to 27.1%), while the percentage presenting with mainly pain remained relatively stable (from 52.9% to 57.3%). This shift was confirmed by a significant Chi-square test result (p < 0.001) (Online-Supp. Table S2).

Ultrasound findings increasingly lead to indication for surgery

The data show a significant increase in the use of ultrasound as an indication for endometriosis after certification, with 47.7% of cases utilizing ultrasound compared to 35.6% before certification (p = 0.007) (Online-Supp. Table S2).

After certification, there was a notable shift in the focus of ultrasound diagnoses for endometriosis-related conditions. The diagnosis of adenomyosis increased significantly, from 36.8% in non-certified cases to 56.3% in certified cases, highlighting a greater emphasis on identifying this condition. Diagnoses of endometriosis on the adnexa remained relatively stable (21.1% vs. 21.7%), while endometriosis cysts, location not specified, decreased from 21.1% to 11.0% following certification. These changes were supported by a significant Chi-square result (p < 0.001) (Online-Supp. Table S2).

Shift in procedures for endometriosis removal

After certification, there was a notable shift in the frequency of certain surgical procedures for endometriosis. Partial peritonectomy increased from 67.4% to 80.7% post-certification (p < 0.001), and the removal of peritubarian endometriosis lesions decreased on both the left side (from 5.8% to 1.7%, p = 0.003) and right side (from 4.7% to 1.7%, p = 0.017). Salpingectomy rates decreased from 29.7% to 23.8% (p = 0.009), while ovariectomy rates also fell from 5.8% to 3.1% (p = 0.048) (Online-Supp. Table S3).

In terms of rectal procedures, the use of rectum shaving increased from 2.3% before certification to 7.5% after certification, with a significant result (p = 0.015). Other rectal interventions, such as discoid dissection and segmental resection with or without anastomosis, were rare but showed minor increases post-certification (Online-Supp. Table S3).

#Enzian Score correlates with rectal procedure

Regardless of certification, the data show a significant association between the #Enzian-classification for rectal endometriosis and the type of rectal surgical procedure performed. Rectum shaving was more common in cases with smaller lesions, with 38.6% of cases classified as C1 (< 1 cm) and 27.3% as C2 (1–3 cm) undergoing this procedure, compared to only 18.2 % of C3 (> 3 cm) cases (p < 0.001). Discoid dissection, although rare overall, was primarily performed on medium sized lesions, specifically C2 (p < 0.001). Segmental dissection with anastomosis was associated with larger lesions, predominantly in the C2 and C3 categories, with significant results (segmental dissection with anastomosis: p < 0.001). Of note, no patient received an anus praeter (Online-Supp. Table S4).

Certification leads to an increase in rectum shaving for the removal of rectal endometriosis

Considering only patients with rectal endometriosis (classified as #Enzian C1–C3, n = 121), the data reveal an increase in the use of rectum shaving after certification. Specifically, rectum shaving was performed in 16.7% of cases without certification, compared to 39.2% with certification, with this difference reaching statistical significance (p = 0.038). Procedures such as discoid dissection and segmental dissection with anastomosis remained rare among this group, showing only slight increases post-certification, which were not statistically significant. These results suggest that certification may have led to a more frequent use of rectum shaving for managing rectal lesions in patients with confirmed rectal involvement (Online-Supp. Table S3).

Certification leads to a decrease in uterosacral ligament resection

For patients with pelvic endometriosis involving the uterosacral ligaments (#Enzian B1–3, n = 511), there was a significant decrease in the frequency of ligament resection after certification. Before certification, 86.4% of patients underwent resection of the uterosacral ligaments, which decreased to 63.5% post-certification, showing a statistically significant difference (p < 0.001). This indicates a reduction in the use of ligament resection for treating pelvic endometriosis in the uterosacral ligaments (Online-Supp. Table S3).

#Enzian-Scoring more nuanced

After certification, notable shifts were observed in the categorization of endometriosis lesions, particularly in peritoneal and pelvic involvement. For peritoneal lesions (#Enzian P), there was a significant change: cases classified as P1 (< 3 cm) increased from 41.3% to 45.5%, and those classified as P3 (> 7 cm) rose substantially from 7.0% to 17.9% (p < 0.001). In contrast, the distribution for ovarian (#Enzian O) and tubal adhesions (#Enzian T) remained largely consistent, indicating no significant changes post-certification (Online-Supp. Table S5).

Certification influenced the documentation of endometriotic manifestation in the pelvis as shown in Enzian Scoring (#Enzian B) on both the left and right sides. For the left side, cases with no detected lesions (B0) decreased from 48.3% to 36.3%, while lesions smaller than 1 cm (B1) increased from 25.0% to 31.8%, and larger lesions (> 3 cm, B3) rose from 6.4% to 12.7% (p = 0.001). On the right side, cases with no lesions (B0) dropped from 53.5% to 46.5%, lesions between 1–3 cm (B2) increased from 14.0% to 18.4%, and larger lesions (> 3 cm, B3) rose from 5.8% to 12.0% (p = 0.022). Meanwhile, classifications for vaginal involvement (#Enzian A) and rectal involvement (#Enzian C) showed no significant changes (Online-Supp. Table S6).

Also, notable changes were observed in the #Enzian F classification for certain anatomical sites. The prevalence of adenomyosis (#Enzian FA) increased significantly, from 57.0% in cases without certification to 65.8% post-certification (p = 0.035). Interestingly, bladder involvement (#Enzian FB) decreased from 14.5% to 6.4% following certification – a significant reduction (p < 0.001). No significant differences were identified in the classification distribution for intestinal, ureter, or other involvements (#Enzian FI, FU, FO) (Online-Supp. Table S7).

Certification leads to higher complete removal rates at primary surgery

The surgical outcomes data reveal a significant improvement in the complete removal of endometriosis lesions following certification. In cases without certification, 87.8% of surgeries resulted in the removal of all lesions, compared to 92.5% in certified cases; the proportion of cases with remaining endometriosis decreased from 11.0% without certification to 7.5% with certification. These findings suggest that certification is associated with a higher rate of complete lesion removal during surgery (p = 0.011) (Online-Supp. Table S3).

In patients with rectal involvement (#Enzian C1–3), certification was also associated with significant changes in surgical outcomes. Prior to certification, complete removal of all lesions was achieved in 78.3% of cases, with 21.7% of surgeries leaving residual endometriosis (no significant correlation). Post-certification, the rate of complete lesion removal increased to 83.5%, while cases with remaining endometriosis decreased to 16.5% (p < 0.001). Adversely, the rate of surgery abortion in patients with rectal involvement increased from 12.5% (p < 0.001) before certification to 14.6% after certification (p < 0.001). However, the Chi-Square test did not show significance for abortion of surgery (p = 0.793) nor for removal of all lesions (p = 0.552) when comparing outcomes before versus after certification ([Table 1]).

Table 1 Result of surgery and abortion of surgery depending on #Enzian C category.

		Certification
		without certification							with certification
		#Enzian C1–3							#Enzian C1–3
		No		Yes		Total		χ²	No		Yes		Total		χ²
		n	%	n	%	n	%	p	n	%	n	%	n	%	p
χ² = Pearson’s Chi Square Test
Result of surgery	Removal of all lesions	132	90.4	18	78.3	150	88.8	0.086	452	94.4	81	83.5	533	92.5	< 0.001
	Endometriosis left over	14	9.6	5	21.7	19	11.2		27	5.6	16	16.5	43	7.5
	Total	146	100.0	23	100.0	169	100.0		479	100.0	97	100.0	576	100.0
Abortion of surgery	No	147	100.0	21	87.5	168	98.2	< 0.001	476	99.4	82	85.4	558	97.0	< 0.001
	Yes	0	0.0	3	12.5	3	1.8		3	0.6	14	14.6	17	3.0
	Total	147	100.0	24	100.0	171	100.0		479	100.0	96	100.0	575	100.0

More follow-up assessments

A significant improvement in the rate of 12-month follow-up assessments after certification was observed. Before certification, 40.7% of patients underwent a 12-month assessment, compared to 64.1% post-certification (p < 0.001). This demonstrates that certification is associated with a notable increase in the completion of follow-up evaluations one year after surgery, suggesting enhanced adherence to postoperative monitoring protocols (Online-Supp. Table S3).

Pain upon first clinic presentation

Following certification, significant changes were observed in preoperative pain and other related symptoms at first presentation. The proportion of patients reporting “no pain” decreased from 11.5% before certification to 4.8% post-certification, while those experiencing “pain” increased to 95.2% (p = 0.004). The distribution of pain intensity on the numeric rating scale (NRS) shifted significantly (p = 0.008), with an overall increase in reported pain levels, including higher frequencies of extreme pain scores (9 and 10). Additionally, the prevalence of dysuria rose from 4.8% to 13.3% (p = 0.002), and dyschezia increased markedly from 3.0% to 20.2% (p < 0.001). In contrast, no significant changes were observed in the prevalence of dysmenorrhea or dyspareunia (Online-Supp. Table S8).

Detailed pain development analysis before and after certification

For this analysis, only patients who experienced pain before surgery and completed a 12-month follow-up were included, missing data were excluded (n = 366). The study compared pain outcomes before and after certification.

Before certification, 55 patients were evaluated. Of these, 34.5% (19 out of 55) reported being pain-free 12 months after surgery, while 65.5% (36 out of 55) continued to experience pain. Among those with persistent pain, 91.7% (33 out of 36) reported a reduction in pain, while 8.3% (3 out of 36) reported no improvement. No patients reported an increase in pain during this period ([Fig. 4]).

Fig. 4 Pain development at 12-month follow-up if pain is still present. This figure evaluates changes in pain severity among patients who reported pain before surgery and at the 12-month follow-up, categorized as “less pain”, “more pain,” or “no improvement” (n = 230).

After certification, 311 patients were evaluated. Of these, 40.5% (126 out of 311) reported being pain-free 12 months postoperatively, showing an increase in the proportion of patients achieving pain relief compared to the pre-certification group. Meanwhile, 59.5% (185 out of 311) continued to experience pain. Among these, 77.3% (143 out of 185) reported less pain, 22.2% (41 out of 185) reported no improvement, and 0.5% (1 out of 185) reported worsening pain ([Fig. 4]).

The statistical analysis revealed no significant difference in pain outcomes before certification (p = 0.196), whereas the difference after certification was highly significant (p < 0.001).

In summary, certification was associated with improved pain outcomes at the 12-month follow-up. A higher proportion of patients achieved pain relief after certification, while the rate of worsening pain remained negligible (Online-Supp. Table S9).

For the following analysis only patients that had a reduction in pain (no pain or less pain) after 12 months were considered (n = 321). The comparison of pain outcomes at 12 months between patients treated with and without certification showed a higher proportion of patients without pain in the certified group (46.8%) compared to the non-certified group (36.5%). Conversely, the proportion of patients reporting continued pain was higher in the non-certified group (63.5%) compared to the certified group (53.2%). Overall, certification appears to be associated with a slight shift toward better pain outcomes. However, the difference between the certified and non-certified groups did not reach statistical significance (p = 0.172) (Online-Supp. Table S8).

Dyschezia and rectal involvement before and after certification

Among patients reporting dyschezia, the relationship with documented rectal involvement showed notable changes before and after certification. Prior to certification, most patients with dyschezia (80.0%) did not have rectal involvement based on the postoperative #Enzian classification (C1–3), and only 20.0% were confirmed to have rectal lesions (p < 0.930).

After certification, the diagnostic association between dyschezia and rectal involvement improved. Among patients reporting dyschezia, the proportion with confirmed rectal lesions increased to 31.9%, while 68.1% still did not have documented rectal involvement. This improvement is supported by a statistically significant chi-square test (p < 0.001), reflecting enhanced recognition and documentation of rectal lesions post-certification (Online-Supp. Table S10).

Age is associated with pain reduction after surgery

For the following only patients with pain at primary surgery and an assessment after 12 months were considered (n = 388), regardless of certification, not-specified included.

A significant association between age at surgery and pain development 12 months postoperatively was observed (p = 0.042). The middle-aged group (20.0–49.9 years) benefited from surgery, with the highest rate of pain reduction (84.1%) and the lowest rates of no improvement (10.4%) or worsening pain (0.3%). Young patients (< 20 years) also showed benefits, with 62.5% reporting pain reduction; however, a higher proportion of this group reported no improvement (37.5%) compared to older groups. Older patients (50+ years) showed 100% improvement in pain, though their small sample size (n = 7) limits the generalizability of this result ([Fig. 5], Online-Supp. Table S11).

Fig. 5 Age and pain outcome. The bar chart illustrates the percentage of pain reduction 12 months after surgery, categorized by the age of the patients at the time of surgery.

Discussion

This study shows that certification according to EuroEndoCert may lead to an improvement in surgical endometriosis patient care which has been described by others [14] [15] [16].

A comparison between patients before and after the certification shows an increase in infertility as the main reason for presentation. This may reveal that the clinic received more referrals from fertility centers after obtaining certification for the diagnosis and treatment of infertility associated with endometriosis. This increase can be attributed to the certification, which likely enhanced the clinic’s visibility, credibility, and the associated assurance of quality. However, like before certification, pain remained the main reason for presentation.

Notably, the role of ultrasound for the indication to proceed to surgery increased with certification, and ultrasound findings were described more precisely. This suggests that the physicians became more experienced and better trained in performing ultrasound as a diagnostic method within the context of the endometriosis consultation.

A shift in frequency of specific surgical measures to remove endometriosis was observed: peritonectomy, and rectum shaving increased, while removal of paratubarian lesions, ovariectomy and tubectomy decreased. This shift indicates a move toward more conservative and fertility-preserving approaches in the treatment of endometriosis. It may also reflect a more cautious and selective approach to surgical decision-making, focusing on balancing disease management with the preservation of reproductive potential.

The lower frequency of uterosacral ligament removal in patients after certification with confirmed endometriosis in the uterosacral ligaments (classified as #Enzian B1–3) could be attributed to limitations in documentation or potential misclassification. It is possible that cases of peritoneal endometriosis in the vicinity of the uterosacral ligaments were misinterpreted or documented as uterosacral involvement. Such inconsistencies might lead to an underreporting of surgical interventions specifically targeting the uterosacral ligaments. This highlights the need for precise diagnostic and documentation practices to ensure accurate assessment and management. Still, the lower frequency of uterosacral ligament removal in patients with confirmed endometriosis might reflect the increased use of nerve-sparing techniques, which aim to preserve the autonomic nerves near the uterosacral ligaments to minimize complications such as chronic pelvic pain or bladder and bowel dysfunction. Additionally, surgeons may aim to preserve pelvic structures that play a critical role in pelvic stability and function, particularly in cases where complete removal might not be deemed necessary for effective disease management. This trend suggests a shift toward more precise, patient-centered surgical strategies that balance effective treatment with the preservation of quality of life.

With certification, the #Enzian scoring system was applied with greater nuance. A decrease in the number of patients classified with no peritoneal (P0) or uterosacral (B0) involvement was observed, accompanied by an increase across nearly all #Enzian subcategories for uterosacral involvement (B1–3) and peritoneal involvement (P1 and P3). Additionally, a significant rise in the diagnosis of adenomyosis uteri (FA) was noted. No notable changes were observed for ovarian, tubarian, vaginal, or rectal involvement. Interestingly, bladder endometriosis (FB) was diagnosed less frequently, although the overall number of patients with bladder involvement remained small. The trends observed could suggest that with certification, more severe cases of endometriosis were identified. The increase in diagnoses across subcategories for uterosacral and peritoneal involvement, as well as the rise in adenomyosis uteri cases, indicates a greater focus on detecting complex or advanced disease. Certification likely enhanced diagnostic precision and awareness, enabling physicians to recognize and classify more severe forms of endometriosis that might have previously gone undetected. This is further supported by the nuanced application of the scoring system, with fewer patients classified as having no peritoneal or uterosacral involvement. However, the decrease in diagnoses of bladder endometriosis, despite small patient numbers, suggests that certain subtypes of endometriosis remain challenging to detect.

Certification was positively correlated with achieving the complete removal of all endometriosis lesions. Notably, this was also confirmed for rectal lesions. However, certification was also associated with an increase in surgery terminations in patients with rectal involvement. The positive correlation between certification and the achievement of complete removal of endometriosis lesions suggests some improvement in surgical precision and planning. Better patient history-taking may have contributed to improved surgical planning and slightly better outcomes overall.

However, the increase in surgery terminations for patients with rectal involvement raises questions. It could reflect more cautious decision-making, where surgeons opted to stop procedures due to high risks or complexities. Alternatively, it may point to gaps in interdisciplinary support, as the absence of a specialized team can limit the ability to manage challenging cases effectively. Additionally, some patients may not have been fully informed about the potential complexity and risks of surgery, which might have contributed to decisions to halt operations. Finally, certification may have led to an increase in the number of complex cases seen, which could have strained available resources or highlighted limitations in handling more advanced disease. To address these issues, ensuring the availability of interdisciplinary teams, improving patient counseling on surgical risks, and enhancing preoperative planning and training for complex cases are essential [17] [18].

The increased frequency of patients presenting with pain, particularly severe pain, and conditions like dysuria and dyschezia, after certification could indicate a more thorough and systematic evaluation process, as well as an improved ability to identify complex and severe cases. This trend may also reflect a shift in patient demographics, with certification attracting patients with more advanced or complicated symptoms. Also, the fact that dyschezia in the patient’s history more increasingly led to rectal or intestinal endometriosis involvement after certification may contribute to this observation.

A positive development was observed concerning follow-up assessments which were performed more often after certification. This suggests improved quality control and stronger integration of patients within the clinic’s care framework. With certification, more patients were seen pain-free at the 12-month follow-up compared to when uncertified. However, when pain continued one-year post-surgery, less patients reported a reduction in pain after certification. When analyzed by age groups, regardless of certification, it was evident that older patients benefited more from surgery, as they more frequently achieved pain relief. This highlights the importance of considering the patient’s age when determining the timing of surgical intervention to minimize the need for repeated operations. Menopause emerges as a critical factor, as it typically prevents the recurrence of endometriosis. In contrast, younger patients remain at risk of recurrence despite measures such as long-term use of hormonal contraceptives, making their management more challenging.

The improvement in healthcare delivery for endometriosis patients at the investigated clinic may largely be attributed to the certification process. The observed certification effect stems from meeting specific criteria, including specialized training, a more structured clinical examination approach, the use of bivalved specula, targeted anamnesis, the selective application of transvaginal sonography, assessment of the gliding sign, and a more detailed evaluation of the uterine ligamentous apparatus, the rectovaginal septum, and the Plica vesicouterina. Additionally, routine kidney ultrasound examinations were implemented to enhance the accuracy of preoperative staging, thereby supporting more precise surgical planning and reducing the likelihood of multiple surgeries.

Furthermore, the structured setup of an endometriosis consultation ensured that patients were increasingly referred to specialized personnel who had undergone dedicated training in diagnostics and therapy. Another key factor was the introduction of certified ultrasound training for physicians, which contributed to a more precise diagnostic process and the introduction of a standardized questionnaire.

With certification, surgeries were exclusively performed by designated surgeons holding the required qualifications (Qualification for minimally invasive surgery Level II or III), in accordance with the criteria of the German Working Group for Gynecological Endoscopy. This likely contributed to the improved surgical outcomes observed. Additionally, the use of adhesion barrier agents increased post-certification, reflecting a stronger emphasis on adhesion prevention. Regarding ovarian suspension immediately postoperatively, while this approach was frequently used in the past based on the hypothesis that it might reduce adhesion formation, we remain unconvinced of its benefit. It represents an additional surgical step, potentially leading to increased postoperative pain. Moreover, to our knowledge, no large-scale randomized studies have demonstrated a clear advantage of this technique.

Overall, certification appears to have enhanced both the diagnostic accuracy and surgical management of endometriosis patients, leading to more precise treatment strategies, improved patient outcomes, and a more structured approach to long-term care.

Conclusion

Certification according to EuroEndoCert appears to have significantly improved the quality of care in the investigated endometriosis clinic. It enhanced diagnostic precision, particularly through more nuanced use of the scoring system, better documentation, and improved identification of complex cases. Surgical planning and execution benefited as well, resulting in higher rates of complete lesion removal and more frequent pain-free states at follow-up. The increase in follow-up assessments further reflects stronger quality control and patient integration within the clinic’s care framework. However, the certification process also highlighted areas for improvement, such as ensuring consistent interdisciplinary support, enhancing patient counseling, and developing tailored strategies for patients. Overall, EuroEndoCert certification has elevated the clinic’s standard of care, while emphasizing the importance of individualized, patient-centered management. All the same, the study is limited by its single-center, retrospective design, which may reduce the generalizability of findings.

Supplementary Material

Supplementary Tables S1–S11 are provided with all analyzed data as referred to in the above results section.

• Supp. Table S1 Patient characteristics in complete cohort (n = 748, primary surgery).

• Supp. Table S2 Comparison of patient and diagnostic characteristics before and after certification (missings excluded for “Ultrasound was indication for endometriosis”).

• Supp. Table S3 Comparison of surgical procedures before and after certification.

• Supp. Table S4 Comparison of #Enzian category C and rectal procedure, regardless of certification.

• Supp. Table S5 Comparison of #Enzian categorization of peritoneal, ovarian and tubarian endometriosis lesions before and after certification.

• Supp. Table S6 Comparison of #Enzian categorization of vaginal, ligamentous (Lgg.), and rectal endometriosis lesions before and after certification.

• Supp. Table S7 Comparison of #Enzian categorization of adenomyosis, vesical, intestinal, ureteral and other endometriosis lesions before and after certification.

• Supp. Table S8 Comparison of pain symptoms before and after certification (missings excluded).

• Supp. Table S9 Assessment after 12 months and pain development, if pain was present at diagnosis (missings excluded).

• Supp. Table S10 Comparison of #Enzian C classification according to dyschezia yes versus no before and after certification (missings for dyschezia excluded).

• Supp. Table S11 Pain development 12 months after diagnosis according to age at surgery (388 patients with assessment, Chi-square p = 0.42), if pain was present at diagnosis.

Conflict of Interest

The authors declare that they have no conflict of interest.

Acknowledgement

We would like to thank Maria Donutiu (Hospital of St. Marien Amberg) for providing part of the data.

• References

• 1 Zondervan KT, Becker CM, Missmer SA. Endometriosis. N Engl J Med 2020; 382: 1244-1256
• 2 Shafrir AL, Farland LV, Shah DK. et al. Risk for and consequences of endometriosis: A critical epidemiologic review. Best Pract Res Clin Obstet Gynaecol 2018; 51: 1-15
• 3 Mechsner S. Endometriosis, an Ongoing Pain-Step-by-Step Treatment. J Clin Med 2022; 11: 467
• 4 Gruber TM, Mechsner S. Pathogenesis of Endometriosis: The Origin of Pain and Subfertility. Cells 2021; 10: 1381
• 5 Hickey M, Ballard K, Farquhar C. Endometriosis. BMJ 2014; 348: g1752
• 6 Exacoustos C. Sonography for pelvic endometriosis. Gynakol Endokrinol 2023; 21: 165-175
• 7 EuroEndoCert EN. EuroEndoCert – Certification by EuroEndoCert. 2021 Accessed November 10, 2024 at: https://www.euroendocert.de/en/
• 8 Stiftung Endometriose-Forschung (SEF). Information on Certification Categories and Requirements for Endometriosis Centers. 2023 Accessed November 10, 2024 at: https://endometriose-sef.de/aktivitaeten/zertifizierungen/
• 9 G-BA Pressemitteilungen. Meldung 828. 2019 Accessed November 10, 2024 at: https://www.g-ba.de/presse/pressemitteilungen-meldungen/828
• 10 AG Endometriose. Aus- und Fortbildung. 2024 Accessed December 09, 2024 at: https://www.ag-endometriose.de/aus-und-fortbildung
• 11 Keckstein J, Saridogan E, Ulrich UA. et al. The #Enzian classification: A comprehensive non-invasive and surgical description system for endometriosis. Acta Obstet Gynecol Scand 2021; 100: 1165-1175
• 12 Vermeulen N, Abrao MS, Einarsson JI. International working group of AAGL, ESGE, ESHRE and WES. et al. Endometriosis classification, staging and reporting systems: a review on the road to a universally accepted endometriosis classification. Hum Reprod Open 2021; 2021: hoab025
• 13 Zondervan KT, Missmer S, Abrao MS. International Working Group of AAGL, ESGE, ESHRE and WES. et al. Endometriosis classification systems: an international survey to map current knowledge and uptake. Hum Reprod Open 2022; 2022: hoac002
• 14 Hudelist G, Korell M, Burkhardt M. et al. Rates of severe complications in patients undergoing colorectal surgery for deep endometriosis-a retrospective multicenter observational study. Acta Obstet Gynecol Scand 2022; 101: 1057-1064
• 15 Meinhold-Heerlein I, Zeppernick M, Wölfler MM. et al. QS ENDO Pilot – A Study by the Stiftung Endometrioseforschung (SEF) on the Quality of Care Provided to Patients with Endometriosis in Certified Endometriosis Centers in the DACH Region. Geburtshilfe Frauenheilkd 2023; 83: 835-842
• 16 Zeppernick F, Zeppernick M, Janschek E. et al. QS ENDO Real – A Study by the German Endometriosis Research Foundation (SEF) on the Reality of Care for Patients with Endometriosis in Germany, Austria and Switzerland. Geburtshilfe Frauenheilkd 2020; 80: 179-189
• 17 Burghaus S, Schäfer SD, Beckmann MW. et al. Diagnosis and Treatment of Endometriosis. Guideline of the DGGG, SGGG and OEGGG (S2k Level, AWMF Registry Number 015/045, August 2020). Geburtshilfe Frauenheilkd 2021; 81: 422-446
• 18 Becker CM, Bokor A, Heikinheimo O. et al. ESHRE guideline: endometriosis. Hum Reprod Open 2022; 2022: hoac009

Publication History

Received: 20 December 2024

Accepted after revision: 17 April 2025

Article published online:
19 May 2025