The known complex anatomic geometry that goes into the reflux barrier and that needs to be addressed during any surgical procedure includes: the crural diaphragm or hiatal canal, the LES, especially its overall and intra-abdominal length, and the musculomucosal flap valve controlled by the angle of His. All work in concert to constitute a functioning anti-reflux barrier [6,7,8]. At GE-endoscopy, this valve can be graded according to Hill into four grades [9]; that is with progressive effacement or shortening of the valve length, there is a correlative loss of the valve function. This has been shown to be more predictive of the severity of GERD than LES pressure, likely because the Hill grading reflects the sum of all components of anti-reflux barrier rather than simply measuring LES pressure [6, 10].

Surgical fundoplication remains a mainstay in the stepwise management of the disease, as it addresses the underlying incompetence of the GE valve rather than merely reducing the acid production [11,12,13]. The two basic types being performed are the ‘total wrap,’ which includes the Nissen fundoplication, and the ‘partial wrap,’ which includes the Thal and Toupet fundoplications. Selecting the best technique, though, is still debatable [14].

In children, partial fundoplication resulted in more favorable outcomes compared to total fundoplication, including reductions in long-term dysphagia, the need for upper GI endoscopy with or without dilation, and postoperative PPIs use by 2.2%, 9.3%, and 3.2%, respectively. However, the only undesirable outcome associated with partial fundoplication was a 10% increase in wrap failures [3]. Moreover, promising results of the Hill-Snow repair in children have been documented [15]. As a central tenet, performing the right operation correctly on a given patient requires a thorough understanding of the underlying pathophysiology and the anatomic and physiologic components of the reflux barrier [16].

Considering additional components working to support the anti-reflux barrier is essential in the context of anti-reflux surgery. The gastrointestinal tract, from mouth to anus, generally exhibits a continuous tubular configuration, deviating only in the instances of the stomach and cecum. In these latter structures, the organoaxial alignment exclusively assumes an angulated disposition relative to the axis of their respective preceding segments. Such an alignment might operate as a physical barrier akin to valves, precluding an otherwise free ‘orad’ flow of luminal contents into their preceding segments. Failure to do so would have deleterious backwash consequences on the distal esophagus and the terminal ileum, respectively [5].

Further, the anatomical configuration and geometry of the stomach enable it to play a crucial role in handling the laminar flow pattern of digesta within its parts, contributing significantly to the anti-reflux mechanism [17]. The gastric fundus, characterized by a lack of myenteric interstitial cells of Cajal, is predominantly electrically quiescent. This feature allows for gastric accommodation reflexes, facilitating proximal stomach expansion without a substantial increase in intragastric pressure—a mechanism supporting temporary food storage [18,19,20,21,22]. Impaired gastric accommodation is often linked to disorders such as GERD and dyspepsia [17]. The normal muscle tone of the proximal stomach is restored during gastric emptying, maintaining the common cavity pressure levels [23]. Accordingly, alterations in gastric geometry can markedly impact gastric biomechanics, influencing gastric flow, motility, and emptying [24, 25].

Bouras used single photon emission computed tomography to examine gastric volumes in patients who underwent previous fundoplication [26]. The study revealed a notable decrease in postprandial adaptive relaxation of the proximal stomach following Nissen fundoplication, despite preserved receptive relaxation. This abnormality is suggested to play a role in the development of frequently reported dyspeptic symptoms, as supported by another study using an intragastric barostatic balloon [27].

However, the specific contributions to this abnormal postprandial pattern—whether it stems from fundal detachment and denervation, the wrap itself, or the preoperative GERD—are still unclear. Additionally, in patients with prior Nissen fundoplication, there is a significantly faster return of intragastric volume to preprandial levels, likely resulting in the swift emptying of liquids from the stomach, as frequently documented in the literature [28,29,30].

In the same context of understanding how gastric geometry impacts biomechanics, literature identifies four types of the fundal gastric bubble: the hemispherical dome type, irregular type, stomach type (outlining the stomach), and undetected type. The type of fundal bubble serves as an informative marker for assessing upper digestive tract functional disorders, including decreased LES pressure, delayed gastric emptying, or impaired proximal stomach accommodation. Individuals with GERD symptoms are most frequently associated with the stomach-type bubble, followed by undetected-type, irregular-type, and unlikely with the dome-type [31]. Moreover, it has been reported that the air–liquid interface within the dome-shaped fundus plays a crucial role in maintaining gastric mucosa homeostasis [32]. These findings underscore the importance of preserving normal gastric geometry, particularly that of the fundus, during anti-reflux surgery.

Further, the diverse modes of presentation of GERD in children, as documented in the literature and observed within the studied cohort, may underscore the imperative to tailor surgical approaches to address the specific needs of such a growing anatomy to mitigate surgery-related pathophysiology. Consequently, this study, aligning with the Nissen-Hill Hybrid technique in the adult’s literature [4], implements a hybrid approach, utilizing a partial wrap, along with its attendant favorable outcomes in children, complemented by Hill’s gastropexy to fortify the axial integrity of the repair.

From another perspective, given the established efficacy of the crura as an anti-reflux mechanism [33,34,35], there is prevalent advocacy among surgeons for its closure [36]. However, the conventional approach of employing robust, through-and-through muscle sutures—often utilizing non-absorbable materials—suitable for adult cruroplasty may not be appropriate for the continually developing anatomy of a child. In a growing body, even a seemingly loosely applied suture today may pose a risk of strangulation in the future. Therefore, the proposed ‘Eversion Cruroplasty’ is designed to safeguard the muscle excursion of the crural pillars by mitigating the segmentation effect induced by traditional suturing. Additionally, it maintains the mass contractility and sliding properties of the muscle fibers within their fascial compartments.

Overall, in the pursuit of biomimicry, this study addresses the imperative objective of restoring the anatomical recline of the GEJ and preserving the muscle excursion of the crural pillars during anti-reflux surgery. Hence, a nuanced approach ‘ECCO’ is adopted through a sided partial wrapping over the esophagus, involving the bloated gastric fundus working against the right crus and caudate lobe of the liver. This dynamic interplay is meticulously controlled by the pars condensa of the gastrohepatic ligament in the normal anatomy. Such multifaceted interventions collectively contribute to a comprehensive strategy for addressing the functional dynamics within the GE region.

The reported 90% success rate in the presented series, and the follow-up endoscopic evaluations proved the ability to reproduce an augmented anatomical alignment of the GE-junction while preserving the geometry of the fundic pouch. The preserved capacity for belching may itself serve to safeguard the surgical repair by functioning as a pop-off valve, counteracting increments in the common cavity pressure. It is noteworthy that the cohort under consideration exhibited a restored ability to belch within a period of 2–6 weeks postoperatively, with some cases (n = 3) reported episodes of emesis exclusively during systemic illness, similar to their non-refluxing peers. Additionally, the two reported recurrences in the enrolled series were associated with a well-manifested violent retching behavior in the postoperative period.

The study’s limitations include the need for more comprehensive research with long-term follow-up, particularly involving a control group of children who have undergone more standard procedures, such as Nissen or Hill-Snow procedures.