Enteral contrast administration in abdominal computed tomography – Expert recommendations from the Abdominal Workgroup of the German Roentgen Society

Abstract

Purpose

There is a lack of clear recommendations regarding enteral contrast agent administration in the context of abdominal computed tomography (CT). A survey among members of the German Radiological Society (DRG) identified a very heterogeneous and indication-specific approach in the clinical routine. The goal of this study is to develop generally applicable recommendations.

Materials and Methods

Recommendations for enteral contrast agent administration were developed by members of the Abdominal Workgroup within the DRG, using methodology comparable to that of an S1 guideline with informal consensus. Relevant clinical indications were systematically identified, categorized, and assessed considering current evidence in the literature and guidelines.

Results and Conclusion

There are specific clinical scenarios in which enteral contrast is indicated. Respective recommendations are presented in terms of good clinical practice (GCP). In this context, especially the administration of positive enteral contrast agents for abdominal CT examination is obsolete for many clinical indications.

Key Points

• For many indications, enteral contrast agent administration is not necessary

• In the case of esophageal or gastric tumors, enteral contrast should be achieved using the “hydro-technique”

• Positive enteral contrast agents are primarily recommended for diagnosis of gastrointestinal fistulas and anastomoses

Citation Format

• Stadelmann J, Grenacher L, Juchems MS et al. Enteral contrast administration in abdominal computed tomography – Expert recommendations from the Abdominal Workgroup of the German Roentgen Society. Rofo 2025; DOI 10.1055/a-2750-0204

Keywords

abdomen - contrast agents - recommendations

Introduction

Computed tomography (CT) plays a central role in abdominal imaging and has high diagnostic significance for a broad range of indications. While intravenous contrast administration is established for most indications and is supported by corresponding evidence, the use of supplementary enteral contrast administration in the daily radiology routine is a topic of ongoing debate (including among referring colleagues). A recent survey regarding the status quo in Germany, which included more than 1000 members of the German Radiological Society, showed a very heterogeneous, selective, and indication-dependent approach to decisions about the use of enteral contrast administration and to technical procedure and implementation [1]. Moreover, the results confirmed that there is a significant desire for generally valid recommendations with the possibility for integration in corresponding standard operating procedures (SOPs). Therefore, the goal of the present study is to develop corresponding recommendations for the use of enteral contrast agents for abdominal CT imaging.

The use of enteral contrast agents in CT imaging

In the past, abdominal CT was regularly performed after supplementary enteral contrast administration in order to improve the diagnostic significance of the examination [2]. Due to the transition from conventional film-based image interpretation to digital screen-based image interpretation and due to further technical developments resulting in improved image quality, the indications for enteral contrast administration have changed in the last decades. The use of enteral contrast agent has become obsolete in many cases and even disadvantageous in some cases [3] [4].

Enteral contrast agents amplify density differences between the gastrointestinal tract and surrounding tissues. Contrast agents are fundamentally classified as positive, neutral, and negative [5] ([Fig. 1]). It should be noted here that contrast agents are often only categorized as either positive or negative in the German-language literature, with neutral contrast agents being included with the negative contrast agents (e.g., in the national S3 guidelines on gastric carcinoma) [6]. Positive contrast agents are compounds with a high atomic number, resulting in greater X-ray absorption. As a result, positive contrast agents appear hyperdense (= bright appearance). These contrast agents are typically water-soluble ionic iodine compounds (e.g., gastrografin) or barium sulfate. Negative contrast agents, like CO₂ or air, absorb X-rays to a lesser extent and are used, for example, in CT colonography. These contrast agents appear hypodense (= dark appearance). Neutral contrast agents are more widely used, have water-equivalent (isodense) density values, and differ from the other contrast agents particularly with respect to their viscosity. The neutral contrast agents most commonly used in CT imaging include water, mannitol, and methyl cellulose. Different contrast agents (types) can be combined with one another. Depending on the indication, enteral contrast can be administered orally or rectally or via a tube, stoma, or fistula. These methods can be used alone or in combination. The contrast is administered prior to the start of the examination. Administration must be timed properly with respect to the particular indication and clinical situation.

Fig. 1 Common enteral contrast agents for abdominal CT. Negative contrast agents appear hypodense on CT (dark image impression), positive contrast agents appear hyperdense (bright image impression), and neutral contrast agents are characterized by water-equivalent density values (isodense). Especially in German-language literature, a distinction if often made only between positive and negative contrast agents. Neutral contrast agents, such as water, are then classified as negative contrast agents.

Depending on the type of administration and the amount of contrast that is administered, patients often find enteral contrast administration rather unpleasant. Moreover, a not insignificant delay in diagnosis can occur [7]. Finally, enteral administration is associated with potential contrast-associated risks, which will not be discussed in greater detail here [8]. However, the main risks include gastrointestinal side effects (nausea, vomiting, diarrhea), fluid-electrolyte imbalances due to the osmotic effect, aspiration, and allergic reactions. Hollow organ perforation has even been described as a complication in individual cases. Even if the mentioned side effects are primarily known from intravascular administration, they can also occur after oral or rectal administration due to enteral absorption and the associated systemic effect. For these reasons, a careful risk-benefit analysis should always be conducted under consideration of patient-specific factors and the overall context.

Method

The authors of this publication represent Abdominal Workgroup of the German Roentgen Society. The recommendations presented here are the result of a national gathering of experts who met with the goal of developing recommendations for enteral contrast administration in the context of abdominal CT examinations. The Abdominal Workgroup considers itself as a body of radiology. Therefore, we were very pleased about the high level of interest in this topic. Using the classification of the Association of the Scientific Medical Societies in Germany as a basis, the method is comparable to that of an S1 guideline in terms of an informal expert consensus [9] based on good clinical practice (GCP). The target group includes all radiologists and radiology technicians, who perform abdominal CT examinations regularly or even only occasionally. This publication is also intended to promote understanding of technical aspects of these examinations on the part of referring colleagues. Recommendations for or against enteral contrast administration are presented on the basis of clinical indications and scenarios ([Fig. 2]). These recommendations are given under consideration of current evidence in the literature and national and international guidelines.

Fig. 2 Indication-specific recommendations for the use of enteral contrast agents for abdominal CT. CA = contrast agent; eGIST = extraintestinal gastrointestinal stroma tumor; HCC = hepatocellular carcinoma; CCA = cholangiocarcinoma; AID = acute inflammatory bowel disease; CID = chronic inflammatory bowel disease; GI = gastrointestinal. The recommendations regarding the colon do not apply for dedicated CT colonography.

Indication-dependent recommendations regarding enteral contrast administration in CT

Scenario 1: Enteral contrast administration in the context of CT imaging for oncological indications (tumor screening, primary staging, follow-up)

As the imaging method of choice in most cases, CT assumes a central role in the oncological diagnostic workup. In the case of a nonspecific indication (suspicion of tumor or tumor screening), enteral contrast enhancement in the form of oral contrast administration can be considered. However, in the literature there is no or only weak evidence to support this so that the decision to administer enteral contrast is primarily based on a subjective sense of security with the goal of better differentiating the bowel wall from adjacent (intra- or extraluminal) pathologies [10]. The administration of positive contrast agents is not recommended since an inhomogeneous mixture can result in pseudolesions and beam hardening artifacts [11]. Moreover, the evaluation of mucosal enhancement is limited and subtle findings, e.g., small neuroendocrine tumors, can be masked [11] [12]. If enteral contrast enhancement is desired, neutral contrast agents should be administered orally. Still water should be given preference here as the neutral contrast agent since the bowel distension that is achieved is comparable to that of mannitol, for example, but tolerability is better, patient acceptance is higher, and the costs are lower [13]. As an example, international guidelines of the European Society of Medical Oncology (ESMO) or the National Comprehensive Cancer Network (NCCN) primarily recommend IV contrast administration for tumor screening in the case of unclear primary tumor. No statement regarding supplementary enteral contrast administration is made [14] [15]. Due to the lack of evidence and for reasons of practicality, the authors of this article in the majority do not administer enteral contrast agents in the clinical routine when performing CT imaging in the context of tumor screening.

CT is known to be limited with respect to evaluating the T-stage in patients with tumors of the upper gastrointestinal tract. However, with adequate distension of the lumen, the ability to evaluate this region can be significantly improved [16] [17] ([Fig. 3]). Based on the recommendations of the national S3 guidelines on esophageal cancer and adenocarcinomas of the stomach and the esophagogastric junction, CT should always be performed with optimal wall distension, especially by means of a neutral contrast agent. It should be noted here again that water is considered a negative contrast agent in the guidelines referenced above. Patients should drink approximately 1 l of water over a period of approximately 25–40 minutes prior to the examination and an additional 150–200 ml immediately before image acquisition on the examination table (hydro-technique) [6] [18]. This concrete recommendation is certainly an exception since most guidelines do not provide such specific details about the examination technique. This guideline recommendation is based on studies that showed that the local tumor finding can be better visualized and tumor growth outside the organ can be better evaluated using this technique (correct T-staging on CT in 77–89 % of cases) [19]. Moreover, we recommend that the same examination position as in prior imaging should be used for follow-up imaging (preferably supine position) in order to optimize comparability.

Fig. 3 CT with optimized luminal distension for the evaluation of gastric cancer. For the evaluation of gastric tumors, CT images should be acquired after oral administration of a neutral contrast agent (water). CT without (a) and with (b) enteral contrast enhancement. The patient drank 1 l of water approximately 25–40 minutes prior to the CT scan and an additional 200 ml on the CT table. The hyperdense (bright) mass lesion on the greater curvature of the stomach (arrow in b) can only be adequately assessed against the darker background of water with appropriate use of the “hydro-technique”.

MRI is the primary imaging method used for diagnosing small bowel imaging and should be given preference over CT due to the comparable sensitivity and lack of radiation (in a patient population that is often young). From a technical point of view, in general enterography (drinking contrast agent with passive filling of the bowel) and enteroclysis (contrast administration via a GI tube) can been differentiated in both MRI and CT imaging. Even if there are no specific national guidelines for diagnosing tumors in the small bowel, we can refer to the guidelines for Crohn’s disease [20]. As such, CT enterography (not enteroclysis!) should be performed as an alternative only when MRI is contraindicated. Oral intake of 1.5 l of a neutral contrast agent (preferably 2.5 % mannitol or 0.5 % methyl cellulose) should begin approximately 45 minutes prior to the examination. Water does not seem advantageous here due to the proximal absorption possibly resulting in less distension of the distal small bowel [21] [22]. In principle, the recommendation to perform enterography coincides with the international guidelines of the NCCN on small bowel adenocarcinoma in which CT with IV and oral contrast is recommended. However, the exact contrast administration technique is not specified in greater detail [23]. In summary, we recommend CT enterography with oral administration of a neutral contrast agent for evaluation of tumors in the small bowel only when MRI is contraindicated.

As mentioned earlier, CT is an important part of oncological imaging and plays a role in tumor screening, primary staging, follow-up imaging during treatment, and aftercare. Oral contrast enhancement with a neutral contrast agent can be considered for general tumor screening. However, on the whole, evidence is only weak or lacking [10] [13]. Particularly in the case of colon cancer, the primary goal is not to fill the colon. In the context of abdominal staging (exclusion of distant metastases) as in other tumor entities, oral contrast enhancement with water can be considered with the goal of better delimiting the bowel wall from adjacent (intraluminal or extraluminal) pathologies including the peritoneum [10]. This recommendation explicitly does not relate to dedicated CT colonography. The evaluation of local tumor extent in rectal carcinoma is a clear indication for MRI [24]. Rectal contrast administration should not be performed.

With regard to other tumor entities, the national guidelines on gastrointestinal stromal tumors (GIST) [25], exocrine pancreatic cancer [26], hepatocellular carcinoma (HCC), and cholangiocarcinoma (CCA) [27] do not contain any specific recommendations with respect to the use of enteral contrast agents. In the case of GISTs of the stomach or small bowel, we recommend enteral contrast administration as performed in hydro-CT and CT enterography (see recommendations 1.2 and 1.3). Oral contrast administration with water can be considered in the case of extraintestinal GISTs (eGISTs) as in other tumor entities. Even if individual studies postulate potential advantages of positive contrast agents compared to neutral contrast agents with regard to detecting peritoneal metastasis, the administration of positive substances can also have disadvantages, e.g., with respect to the detection of calcified (including mucinous) lesions [28]. On an international level, the NCCN advises in their guidelines on pancreatic cancer against the administration of positive oral contrast agents and instead recommends the administration of neutral contrast agents since initial 3D and maximum intensity projections (MIPs) could otherwise be affected [29]. However, on the whole, there is insufficient evidence for the use of enteral contrast administration for the staging of the indicated tumor entities. Therefore, the authors of this article in the majority do not use it in the clinical routine for reasons of practicality.

Scenario 2: Enteral contrast administration when performing CT in the case of acute non-traumatic abdomen or nonspecific abdominal pain

CT is typically the imaging method of choice for the diagnostic workup of patients with an acute abdomen or nonspecific abdominal pain. The main reasons for this are the very good availability, quick image acquisition, and high diagnostic accuracy. Even if CT plays a central role in the diagnostic workup of an acute abdomen or nonspecific abdominal pain, there are currently no standardized recommendations regarding details about the examination technique in Germany. An examination protocol that is adapted to the suspected clinical diagnosis and usually includes IV contrast administration is generally recommended [30]. This approach coincides with the appropriateness criteria of the American College of Radiology (ACR) [31]. In contrast, supplementary enteral contrast administration is generally not recommended since a diagnostic gain is usually not to be expected [5]. In fact, the administration of enteral contrast agents can even be disadvantageous in a number of ways. Use of these contrast agents typically results in an unnecessary delay in diagnosis and can worsen clinical symptoms in some patients [32] [33]. Moreover, especially positive contrast agents can mask important findings (e.g., in the intestinal mucosa) [34]. For these reasons, we do not recommend enteral contrast administration in patients with an acute abdomen or nonspecific abdominal pain.

Scenario 3: Enteral contrast administration when performing CT examinations for more specific indications

In the case of nonspecific presentation, enteral contrast enhancement in the form of oral contrast administration can be considered. However, in the literature there is no or only weak evidence to support this so that the decision to administer enteral contrast is primarily based on a subjective sense of security with the goal of better differentiating the bowel wall from adjacent (intra- or extraluminal) pathologies. Accordingly, the ACR primarily recommends IV contrast administration depending on the exact clinical context and does not discuss supplementary enteral contrast administration [35]. For reasons of practicability and because of the lack of evidence, the authors of this article in the majority do not administer enteral contrast in the clinical routine when performing CT examinations for focus identification.

In addition to symptoms and laboratory tests, diagnosis of diverticular disease is largely based on imaging. According to the current S3 guidelines, CT (or alternatively sonography) should be used for imaging in patients with suspected diverticulitis [36]. According to the current state of practice in Germany as described in the background text of the guidelines, CT is currently typically performed with IV and positive oral contrast administration. Moreover, additional rectal contrast administration is described as the current "actual state" in Germany. However, at the same time, the guidelines state that there is an increasing number of studies showing equivalent diagnostic accuracy without any enteral contrast administration even with respect to the correct staging of diverticulitis [10] [37] [38] [39] [40] [41]. The accompanying text of the guidelines explicitly states that the level of evidence of the individual studies is not sufficient for a general recommendation against the use of oral and rectal contrast administration. Publications on this topic [10] [37] [38] [39] [40] [41] were not yet available when the S3 guidelines were created. Therefore, a critical reevaluation of the current evidence is urgently needed here. To achieve greater clarity, we would like to take this opportunity on behalf of Abdominal Workgroup to clearly recommend against the use of enteral contrast administration in the context of diagnostic CT workup of diverticulitis with evidence-based reference to the more recent literature ([Fig. 4]).

Fig. 4 CT imaging and classification of diverticular disease (CDD). Enteral contrast administration is not recommended. Axial CT in the portal venous phase without enteral contrast administration (a, b) in two different patients. a Phlegmonous diverticulitis (*; CDD type 1b). b Acute complicated diverticulitis (arrow; CDD type 2b).

MRI is the primary imaging method used for diagnosing inflammatory bowel diseases and should be given preference over CT due to the comparable sensitivity and lack of radiation (in a patient population that is often young). According to the national guidelines on Crohn’s disease, routine CT enterography using the technique described above (not enteroclysis) should only be performed as an alternative in acute or chronic inflammatory bowel diseases when MRI is contraindicated [20].

CT has very high sensitivity and specificity for detecting acute gastrointestinal bleeding or mesenteric ischemia both in the preoperative and postoperative context. The administration of positive enteral contrast agents can have a significant negative impact by masking bleeding or mucosa-related findings. Moreover, residual contrast agent in the lumen can simulate false-positive findings or can be superimposed on 3D or MIP reconstructions [34] [42] [43] [44]. The national S2k guidelines on gastrointestinal bleeding, which are currently being revised, clearly state that positive enteral contrast administration should not be performed prior to CT examinations [45]. However, the administration of neutral contrast agents is also problematic when determining the cause of bleeding , since an extravasate can be masked as a result of dilution effects [44]. Therefore, we would recommend against the administration of any enteral contrast agent when performing CT to investigate vascular pathologies (e.g., bleeding, mesenteric ischemia).

CT has a sensitivity of up to 100 % for the diagnosis of hollow organ perforation. Direct signs on imaging are the detection of free air in the abdomen, a gastrointestinal wall defect, or extraluminal contrast agent. However, the fact that the sensitivity for extraluminal contrast agent is very low in spite of adequate filling (19–41 % in the literature) is problematic [46] [47]. This means that the detection of free air without extraluminal contrast agent on imaging indicates a hollow organ perforation with high probability. Performing enteral contrast administration prior to the examination is disadvantageous since it often leads to an unnecessary delay in the diagnosis of diseases that are often time-critical. In addition, the lack of documentation of extraluminal contrast agent in spite of a hollow organ perforation can result in a false sense of security([Fig. 5]). Accordingly, we do not recommend any type of enteral contrast administration in the context of diagnostic CT workup of a hollow organ perforation.

Fig. 5 60-year-old female patient presenting with an acute abdomen due to a perforated gastric ulcer. For the evaluation of hollow-viscus perforation, enteral contrast administration is not recommended. Axial (a) and coronal (b) CT in the portal venous phase after the patient drank diluted positive contrast (Gastrografin diluted 1:10, total volume approximately 400 ml). The stomach and downstream small bowel loops are filled with contrast (hyperdense = bright image impression), without evidence of extraluminal contrast. However, free air is visible intraperitoneally adjacent to the gastric antrum (arrows in a and b) consistent with hollow organ perforation, which was subsequently confirmed surgically. Enteral contrast administration does not help to exclude hollow-viscus perforation and is therefore not recommended, as the lack of extraluminal contrast is misleading.

In patients with suspicion of impaired intestinal motility, the corresponding national guidelines recommend a step-by-step diagnostic workup including laboratory testing and imaging to determine the cause but they do not provide any details regarding imaging [48]. In patients with reduced intestinal motility, regardless of the cause, the corresponding bowel loops are typically fluid-filled and distended. This means that there is intrinsically already very high contrast between the intestinal wall, intestinal lumen, and surrounding tissue on CT. The administration of enteral contrast agents can even aggravate clinical symptoms [31] [32] [33] [49] [50]. Moreover, many patients are not capable of drinking large quantities of fluid due to their clinical condition in this scenario. In addition, passage of the contrast agent is significantly delayed because of the reduced intestinal motility so that sufficient contrast enhancement of the intestinal tract cannot be achieved in an appropriate time period in some cases [33] [51].

In the clinical routine, the osmotic effect of positive contrast agents is used not infrequently by referring colleagues in a therapeutic capacity to stimulate intestinal peristalsis among other things in the postoperative phase. Moreover, this provocation with contrast agent in the so-called "open loop" situation (in terms of an obstruction with only one transition point) can help to differentiate between reversible obstructions to be treated conservatively and cases requiring surgery. However, the passage of contrast agent is evaluated primarily with the help of plain films of the abdomen 12 to 24 hours after contrast administration (oral or, e.g., via gastrointestinal tube) [52]. Even if CT with a water-soluble enteral contrast agent is mentioned in the Bologna guidelines from 2018 [53] as an option for the diagnostic workup of a small bowel obstruction, the current evidence argues against routine application of positive contrast agents for CT examination in patients with suspicion of an obstruction [52] [54] [55].

Scenario 4: Enteral contrast administration in the case of abdominal trauma

With regard to special aspects of diagnostic CT imaging in the context of polytrauma/treatment of severe injuries, the national S3 guidelines [56] make reference to the guidelines of the German Medical Association on quality assurance in CT [57] and the guidelines of the European Society of Emergency Radiology (ESER) [58]. Enteral contrast agent is not mentioned in the corresponding chapter on the diagnostic workup of polytrauma patients in the guidelines of the German Medical Association [57]. The ESER comment in the recommendations regarding examination technique that oral or rectal contrast administration is not appropriate or is obsolete primarily for time reasons [58], even though a potential added value particularly in the case of penetrating injuries of the abdomen is discussed in the background text [59], with reference to recommendations from the Royal College of Radiologists (RCR) [60]. However, this potential added value is not reflected in the current literature. There is increasing evidence that dispensing with enteral contrast administration (also in the case of penetrating injuries) has significant advantages. In particular, unnecessary delays in diagnosis and subsequent treatment are avoided while reducing costs and, more importantly, achieving the same diagnostic significance as CT imaging [61] [62] [63]. The musculoskeletal radiology workgroup of the German Radiological Society published protocol recommendations regarding whole-body CT of patients with multiple injuries or polytraumatized patients in 2017 [64]. Only IV contrast administration is recommended here. In summary, we do not recommend enteral contrast administration when performing CT imaging for blunt or penetrating abdominal trauma.

Scenario 5: Enteral contrast administration in a postoperative or postinterventional context

Gastrointestinal fistulas (GI) include enterocutaneous fistulas, interenteric fistulas, and fistulas between the GI tract and other organ systems (e.g., pleura, pancreas, bile ducts). They are often postoperative effects or complications. The abnormal connections are usually relatively subtle and narrow so that detection and adequate evaluation of the extent are best accomplished by direct visualization [65] [66]. Since the financial, personnel, and time expenditure is comparatively low, we recommend enteral contrast administration depending on the specific situation. We concretely recommend using water-soluble iodine compounds that are diluted based on the size of the fistula and the access in order to minimize beam hardening artifacts (from 1:10 to 1:2; the smaller the fistula, the lower the dilution). In the case of enterocutaneous fistulas, contrast agent is injected externally ([Fig. 6]). To visualize interenteric fistulas or fistulas into which contrast agent cannot be externally injected, contrast is administered orally, via a GI tube, rectally, or via an existing stoma, depending on the (assumed) location of the fistula. Various means of administration can be combined depending on the specific situation.

Fig. 6 58-year-old female with multiple prior surgeries for cervical cancer and persistent enterocutaneous fistula. For the evaluation of gastrointestinal fistulas, administration of positive enteral contrast, depending on the specific setting, is recommended. Axial (a) and sagittal (b) CT (without i.v. contrast) after probing two cutaneous fistula tracts and injection of 30 ml of diluted contrast agent (Imeron 300, diluted 1:5). Hyperdense (bright) enhancement of the small bowel lumen and direct visualization of the fistula (arrow in b) by means of corresponding contrast agent overflow.

Free air or fluid near a GI anastomosis is a possible indirect sign of anastomotic insufficiency. The insufficiency can be identified directly or with the greatest specificity by detecting extraluminal contrast agent after administration of a positive enteral contrast agent [67]. Depending on the location of the anastomosis, water-soluble iodine compounds (1:10 dilution) are administered orally, via a GI tube or stoma, or rectally ([Fig. 7]). Sufficient filling of the region of the anastomosis at the time of the examination is essential in order to avoid misinterpretations [67] [68]. In a study from the year 2013, for example, contrast agent was detected in the region of the anastomosis in only 36.8% of the cases with false-negative findings regarding an insufficiency [69]. We therefore recommend enteral administration of a diluted positive contrast agent in the context of dedicated evaluation of gastrointestinal anastomoses. Sufficient filling of the region of the anastomosis at the time of imaging must be ensured.

Fig. 7 46-year-old female patient after sigmoidectomy following diverticulitis. For the evaluation of gastrointestinal anastomoses, enteral application of diluted positive contrast is recommended, depending on the specific setting. Axial (a, b) and sagittal (c) CT following rectal contrast administration (Gastrografin diluted 1:10, total volume approximately 200 ml) via a rectal tube (* in c). Extraluminal contrast appears hyperdense (=bright) and proves insufficiency of the colorectal anastomosis.

Summary

CT is a central component of abdominal radiology and is the method of choice for many indications. Enteral contrast agents were routinely used in the past but are usually no longer necessary today as a result of technical advancements in particular. The recommendations of the Abdominal Workgroup presented here depend on the individual situation and are intended to support the clinical routine. They are based on a national expert consensus with a literature search and are not intended to serve as interdisciplinary guidelines. They merely represent good clinical practice.

Conflict of Interest

The authors declare that they have no conflict of interest.

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Publication History

Received: 06 August 2025

Accepted after revision: 10 November 2025

Article published online:
08 December 2025