Device for retraction of the fibers of a segment of a uterine body, set of devices, uses and methods

Abstract

The present invention describes a novel device and a set of devices for retraction of the fibers of a segment of a uterine body, particularly useful for single-port endoscopic-assisted tubular surgery for fetal myelomeningocele repair. The invention pertains to the technical fields of surgical medicine and medical devices.

Description

Device for retracting the fibers of a segment of the uterine body, Set of Devices, Uses and Methods Technical Field of the Invention

[0001] This patent application describes a device and a set of devices for retracting the fibers of a segment of the uterine body. The invention falls within the technical fields of surgical medicine and medical devices. Background of the Invention

[0002] Myelomeningocele (MM) is the most common open spinal dysraphism, affecting approximately 1 in 1000 live births. In 1998, Bruner and Tulipan (Bruner JP, Tulipan N, Paschall RL, et al. Fetal surgery for myelomeningocele and the incidence of shunt-dependent hydrocephalus. JAMA. 1999;282(19):1819-1825) performed the first surgery to repair MM during the fetal period at Vanderbilt University. This procedure completely changed the treatment philosophy for this disease. In 2011, a multicenter prospective randomized clinical trial, the Myelomeningocele Management Study (MOMS), showed that when surgery is performed at a gestational age <26 weeks, it provides significant benefits to the fetus. Since then, the number of centers recommending this treatment during the fetal period has multiplied. Several changes have been proposed to improve the original technique, mainly aiming to preserve the uterus and reduce maternal morbidity.Endoscopic procedures have become widespread and are performed by obstetricians, fetologists and pediatric surgeons with diverse results and objectives.

[0003] Thus, a low-cost and easily reproducible solution to the Bruner and Tulipan procedure for preserving uterine muscle fibers becomes of substantial importance. Summary of the Invention

[0004] In this sense, the present patent application presents a low-cost and easily reproducible device and method of the Bruner and Tulipan procedure for preserving uterine muscle fibers.

[0005] Thus, a new device is presented for retracting the fibers of a segment of a uterine body comprising a tubular shape and which comprises at least one of its ends a section of its structure with a slope (3) starting at the outer wall of the tubular structure (1) and ending at the inner wall of the tubular structure (2). Optionally, the slope (3) starts at the outer wall of the tubular structure (1) and is towards the inner wall of the tubular structure (2), thus being able to end the slope in an intermediate position in the structure or followed by a horizontal section up to the inner wall after reaching the required angulation or size of the structure.

[0006] One of the objects of the present patent application is a new set of devices for retracting the fibers of a segment of a uterine body, comprising a first device as defined in claim 1 and at least one subsequent device as in claim 1, in which the one or more subsequent devices of the set each have an internal cylindrical segment that fits outside another of the set, and in which at least one of the subsequent devices has an internal cylindrical segment that fits outside the first device of the set.

[0007] In one embodiment of the present invention, the first device of the assembly comprises the smallest diameter cylindrical segment of the assembly.

[0008] In one embodiment of the present invention, the assembly further comprises a tubular retractor of diameter that fits outside of at least one of the devices of the assembly.

[0009] In one embodiment of the present invention, the first device of the assembly further comprises at least one guide wire.

[0010] One of the objects of this patent application is the use of the device or set of devices for retracting the fibers of a segment of a uterine body.

[0011] In one embodiment of the present invention, the fibers of a segment of a uterine body are for tubular retraction of circular fibers of the uterine body.

[0012] In one embodiment of the present invention, the use is for progressive dilation of the myometrium.

[0013] One of the objects of the present patent application is a new method for retracting the fibers of a segment of a uterine body which comprises introducing into a section of a uterine body a device as defined in the patent application or a set of devices as defined in the patent application.

[0014] In one embodiment of the present invention, the use is of a tubular device for retraction without cutting the uterine muscle fibers or of a set of devices with progressively larger diameters for retraction without cutting the uterine muscle fibers or uterine wall.

[0015] The single-port endoscopy-assisted tubular approach allows an accurate, rapid, universally reproducible, and low-cost procedure for the treatment of fetal spinal dysraphism and is a first step toward future single-port correction using robotic techniques. Description of Figures

[0016] Figure 1: Illustrations showing a procedure that can be performed using the device defined in this patent application. Left: Final appearance after the dilation process and the plastic ring retractor held in place. Right: A plastic ring retractor is held in place with the endoscope and microsurgical instruments.

[0017] Figure 2: Left: Surgical photograph shows the uterine wound immediately after fetal surgery using the device of the present invention. Right: Surgical photograph shows the uterus after cesarean section at 37 weeks of gestation and a small scar on the body of the uterus (white arrow).

[0018] Figure 3: Progressive use of dilators in the uterus. C: Photograph of instruments used to progressively dilate the myometrium: 16-gauge, 3.5-inch epidural anesthesia needle (Procare) (A); first device (dilator) with a guidewire (B); the devices (dilators) separated from each other within the array (C); and configuration of the array of devices (dilators) when all nested within each other (D).

[0019] Figure 3A: Detail of the dilators (Figure 3-C) indicating that the diameter of the outer wall of the tubular structure (1) is greater than the diameter of the inner wall of the tubular structure (2) and the section with the slope at the end of the structure (3).

[0020] Figure 4: Surgical photographs illustrating the steps of the procedure. The entry point is demarcated by the dot within the circle (A) and a line drawn to demarcate the placenta (B).

[0021] Figure 5: Final image after introduction of all dilation devices, obtaining a final opening of 25 mm, without sectioning the uterine muscle fibers.

[0022] Figure 6: Tubular retractor positioned after progressive dilation of the inlet through the placental muscle fibers.

[0023] Figure 7: Another example, showing the final positioning of all dilating devices.

[0024] Figure 8: Surgical photographs depicting MM at different time points. A: Initial endoscopic view of the MM, exposed through the plastic retractor ring. B: Final endoscopic view after MM closure. C: Scar at birth. D: Scar 30 days after birth. Detailed Description of the Invention

[0025] This detailed description of the invention establishes some non-limiting definitions of the main terminologies and technical characteristics used throughout this patent application, as well as providing examples of some of the embodiments of the present invention so that it can be reproduced by a person skilled in the art.

[0026] In the context of the present patent application, the structure of the uterine body can be divided into several layers and anatomical components, consisting mainly of the endometrium: internal mucosal layer, responsible for receiving the embryo during pregnancy; myometrium: intermediate muscular layer, composed of smooth muscle; and; perimetrium: outer serous layer, composed of connective tissue and covered by the peritoneum.

[0027] In the context of this patent application, the aforementioned sets of devices feature an arrangement of multiple tubes or cylindrical segments of different diameters that fit together, which can be defined as external concentric segmentation or nested segmentation. This type of arrangement occurs when the cylindrical segments are arranged progressively, with each tube or element positioned around the previous one, forming a structure with external layers.

[0028] In one embodiment of the present patent application, said sets of devices have as characteristics the external concentric arrangement, where the segments maintain a common axial alignment, but overlap externally; increasing diameters, where each layer has a slightly larger diameter than the internal one to allow fitting; structural overlap, where the shape improves mechanical resistance and allows controlled expansion or retraction; and; fixation or sliding, where it is designed for fixed locking or to allow movement between the segments.

[0029] In one embodiment of the present invention, instead of multiple devices in a set, a single device with an expandable diameter can be used, which can perform the same function of retracting the uterine fibers efficiently and in a controlled manner during fetal surgery. In this embodiment of the invention, the single device has an expandable tubular shape, with a mechanism that allows a gradual increase in diameter after insertion. This mechanism could be, in an exemplary embodiment, based on: A mechanical expansion system (e.g., an adjustable ring that expands through an external control). Pneumatic or hydraulic system (e.g., controlled inflation to increase the diameter). Shape memory materials (e.g., polymers or metal alloys that expand at a certain temperature). The said device can thus be inserted into the The uterine incision is still at its minimum diameter, facilitating insertion into the uterine region. Once inside the uterus, the device is gradually expanded until it reaches the diameter necessary to provide adequate access to the fetus, eliminating the need for multiple sequential insertions. After reaching the ideal diameter, the device maintains a stable uterine inlet, and a retractor can optionally be inserted to maintain the opening and remove the device. Optionally, after the procedure is completed, the device returns to its original diameter to facilitate removal from the uterine region.

[0030] In one embodiment of the present invention, the slope in the cross-section or at least one of the ends of the device, starting at the outer wall and ending at the inner wall of the tubular structure, can be achieved, for example, by inclined machining, progressive molding of the material, controlled oblique cuts, or by using flexible materials that allow gradual deformation under pressure, ensuring a smooth transition for the retraction of the uterine fibers. This angular transition between the outer and inner part of the tube, forming a gentle ramp, is also a region of progressive slope that facilitates fiber retraction by promoting a gradual adaptation of the tubular structure to the surrounding tissue. Alternatively, the adjustable slope structure may have smoothly rounded edges to minimize friction and impact on the tissues.

[0031] In one embodiment of the present invention, the set of multiple devices can be inserted sequentially into the uterine incision, with the first device of smaller diameter being positioned initially for initial fiber retraction, followed by subsequent devices, which fit externally to the previous one, progressively expanding the surgical access in a controlled manner and minimizing mechanical stress on the uterus. This method allows for gradual adjustment of the surgical field, optimizing fetal exposure for myelomeningocele repair while reducing the risk of uterine injury.

[0032] In one embodiment of the present invention, the fitting forms between an anterior and a posterior device of a set of devices may include, for example, a sliding cylindrical fitting, where the subsequent device fits externally to the previous one by friction or light locking, a screw or bayonet system, allowing secure fixation by turning, or an expandable compression mechanism, where the posterior device expands to fix firmly on the previous one, ensuring stability and precise control of the retraction of the uterine fibers.

[0033] In one embodiment of the present invention, each subsequent device has a progressively larger diameter, allowing for controlled expansion of the uterine opening until sufficient or deemed necessary space is achieved for surgery.

[0034] In one embodiment of the present invention, the internal cavity of the tubular structure of the device refers to the hollow central space that allows the passage or fitting of subsequent devices. In one embodiment, the first device to be inserted is solid and may also contain a guide wire or other additional element to aid insertion. From the second and subsequent devices onward, the external wall of each device connects with the internal cavity (internal wall) of the next device through a progressive cylindrical fit, where the subsequent device has an internal cylindrical segment that slides and fits externally to the previous device. This connection may be made by controlled friction, thread, snap-fit, or an expandable mechanism, ensuring a stable and uniform transition in the expansion of the uterine inlet.

[0035] Examples

[0036] Example 1: General procedure for applying the device set in intrauterine myelomeningocele surgery via the Bruner and Tulipan procedure

[0037] The Bruner and Tulipan technique is an intrauterine surgical method developed for the correction of myelomeningocele before birth, reducing neurological complications and improving the baby's quality of life. The set of devices described can be adapted to assist in separating the uterine fibers during this surgery, improving access and minimizing damage to the uterus.

[0038] Incision and Insertion of the First Device

[0039] The surgeon performs a hysterotomy (incision in the uterus) to expose the necessary fetal area. The first device in the set, with a smaller diameter, is inserted into the uterine incision to initiate retraction of the muscle fibers, ensuring minimal space for progression. If the device model includes a guidewire, it can be used for stabilization.

[0040] Gradual Expansion with Subsequent Devices

[0041] Subsequent devices, each with larger internal cylindrical segment, are sequentially fitted to progressively expand the uterine inlet, avoiding excessive tension on the myometrium. This controlled retraction minimizes risks such as uterine rupture or excessive bleeding.

[0042] Use of the Tubular Retractor

[0043] If necessary, a tubular retractor can be attached externally to the devices, keeping the opening stable for intervention in the fetal spine. The devices can then be removed with the opening maintained by the tubular retractor.

[0044] Myelomeningocele Correction

[0045] With the fetus safely positioned and exposed, the surgical team repositions the spinal cord and closes the meninges and skin, reducing the risk of neurological damage. Surgery may follow the Bruner and Tulipan techniques.

[0046] Closure and Recovery

[0047] Removal of Devices

[0048] After myelomeningocele repair, the devices and / or tubular retractor are removed, optionally in reverse order of insertion, allowing the uterus to return to its natural state without trauma.

[0049] Uterine suture

[0050] The uterus is carefully closed, minimizing the risk of complications such as uterine rupture in future pregnancies.

[0051] Maternal and Fetal Recovery

[0052] The patient remains hospitalized for monitoring of contractions and signs of premature labor.

[0053] The present set of invention can also be applied in other uterine surgeries, such as correction of malformations, removal of polyps or treatment of intrauterine adhesions, hysteroscopic myomectomy (removal of uterine fibroids), always facilitating access and improving surgical precision.

[0054] Example 2: Single-port endoscope-assisted tubular surgery for fetal myelomeningocele repair

[0055] We present a retrospective cohort of 10 pregnant women whose fetuses developed lumbosacral myelomeningocele (LMM). The LMM was repaired through a fetal neurosurgical procedure using a single-port endoscopy-assisted tubular technique. The procedure consisted of tubular retraction of circular fibers from the uterine body without excision of the uterine wall. Tubular devices with progressively larger diameters were used for retraction without cutting the uterine muscle fibers, and a 25-mm diameter tubular retractor was used to allow endoscopically assisted closure of the LMM using microsurgical techniques.

[0056] Results: The mean age at birth was 36 and 3 days. Repair of the defect was possible in all cases. The mean surgical time was 130 minutes. Two patients developed hydrocephalus. One patient was treated with ventriculoperitoneal shunt, and the other underwent endoscopic third ventriculostomy with choroid plexus coagulation.

[0057] Conclusions: This is an easy and reproducible procedure that avoids excision of the uterine wall and provides working space for surgical techniques. endoscopically assisted microsurgery, and is the first step towards future single-port repair using robotic techniques.

[0058] Methods:

[0059] Surgical procedure

[0060] The pregnant women were anesthetized with general and spinal anesthesia, with the addition of magnesium sulfate for tocolytic action, administered at an initial dose of 4 g at the time of induction and maintained thereafter at 1 g / day for 12 hours. The fetuses were anesthetized with transplacental general anesthesia. Bladder catheterization was performed. The patient was placed on a gynecological operating table, and her legs were gently spread apart. The uterus was exteriorized through a Joel-Cohen abdominal incision.

[0061] The placenta was mapped under ultrasound guidance, and the procedure was performed on the opposite wall. The entry point was chosen based on placental implantation, the presence of amniotic fluid space, identification of fetal parts, and ultrasound measurement of uterine wall thickness. A sterile surgical pen marked the uterine entry point, and a 25-mm diameter retractor was used (Figure 4). Four external and equidistant sutures were placed along this circumference, using O-polyglactin 910 sutures to anchor the myometrium and amniotic membrane. A 16Gx3.5 epidural anesthesia needle (PROCARE®) was used to puncture the uterus (Figures 3 and 5), reaching the amniotic cavity and aiming for the larger fluid space at the center of the previously described circumference. The Seldinger technique was used to insert the guidewire through the needle.Once the needle was removed, a sharp, cone-shaped trocar with cylindrical extensions and a pencil-like end was inserted through the guidewire to separate the uterine fibers without incisions. The trocar tip was 1 mm long and progressively reached a diameter of 5 mm for the trocar body to enter the uterine cavity (Figures 3 and 5).

[0062] Aluminum tubes with a larger external diameter than the previous ones were inserted externally into the trocar, favoring progressive separation of the uterine circular muscle fibers. The tips of the aluminum tubes were thin, allowing the uterine fibers to be separated without causing damage. Eight tubes were inserted following the steps described above until the opening reached the desired diameter of 25 mm. The last tube, a 25 mm thick plastic cylinder, similar to the uterine wall, previously measured by ultrasound, was inserted and fixed to the uterine wall with polyglactin 910 sutures (Figures 1, right, and 6). All these steps of the procedures were guided by ultrasound to monitor the uterine wall, amniotic membranes, and fetal viability.

[0063] A 4 mm, 0-angle cold-light neuroendoscope owas introduced into the amniotic cavity through this tube (Figures 1). Using fetal movement maneuvers, it was possible to visualize the MM and adequately secure and stabilize the fetal position. With the aid of a neuroendoscope and microsurgical techniques, the spinal cord was gently released. The edges of the placode, which appears as an "open book," were released and approximated, allowing it to return to its cone shape. The apical ligament, often identified on the superior part of the placode between the spinal cord and the dura mater, was divided to release the spinal cord. The dura mater attached to the lateral fascia of the quadratus lumborum was incised and firmly closed to reconstruct the spinal canal with 5-0 poliglecaprone sutures. The skin was sutured with absorbable sutures, and if the defect was large, myocutaneous flaps were created to completely close the spinal dysraphism (Figure 8).The tubular retractor was removed after closure of the MM, and the edges of the uterine wall were closed with 4-0 poliglecaprone sutures, including the amniotic membranes and part of the myometrium. This was a second-layer closure performed with anchored continuous polyglactin 910 sutures. A 16-Fr Foley bladder catheter was placed to fill the amniotic cavity with 0.9% saline at body temperature, and 2 g of cefazolin were added before the uterine walls were completely closed. A third closure was performed using. polyglactin 910 sutures to separate the sutures in the outer uterine layer. The uterus was returned to the abdominal cavity, and the abdominal wall was reconstructed. The uterus was returned to the abdominal cavity, and abdominal wall reconstruction was performed.

[0064] Tocolysis with magnesium sulfate was maintained at 1 g / h for 12 hours. Subsequently, 20 mg of nifedipine was administered every 8 hours until the day of delivery.

[0065] The uterus was evaluated by ultrasound after closure of the abdominal cavity. The evaluation included the placenta, the uterine suture site, the closure of the MM, the degree of hindbrain herniation, and the fetal heart rate. The patients began walking at 1 e day after the operation. However, they were evaluated daily by an obstetrician, and an ultrasound was performed on the 3rd e day after the operation. They were discharged from the hospital on the 3rd e or 4 S day and were evaluated weekly by ultrasound until delivery.

[0066] Fetal inclusion criteria: Fetuses with a gestational age <26 weeks with open spinal dysraphism diagnosed by ultrasound and / or MRI and with lesions located between L1 and S2 were included. Additionally, the presence of hindbrain herniation through the foramen magnum (Chiari type II malformation) was noted.

[0067] All patients had normal genetic findings and no other abnormalities. The patients were followed by the same neurosurgical team postoperatively for at least 6 months.

[0068] Fetal exclusion criteria: fetuses with spinal dysraphism at gestational age >26 weeks, thoracic or cervical spinal dysraphism, genetic diseases, or those undergoing the procedure but not followed up postoperatively. Furthermore, fetuses with closed spinal dysraphism and absence of radiological signs of Chiari malformation, defects below S2, presence of kyphoscoliosis, and diastematomyelia were excluded.

[0069] Maternal inclusion criteria: Healthy pregnant women with a single fetus with a cervix > 25 mm and body mass index < 40 kg / m 2 .

[0070] Maternal exclusion criteria: Mothers with clinical and / or obstetric comorbidities, psychiatric disorders, under 18 years of age, twin pregnancies and cervix smaller than 25 mm.

[0071] Ten pairs of patients (mother and fetus) with gestational age <26 weeks met the maternal and fetal inclusion criteria.

[0072] Results:

[0073] Maternal Aspects

[0074] This was a study involving 10 patients. Six pregnant women took folic acid preventively for more than 3 months before becoming pregnant. At the time of surgery, gestational age was 23 to 26 weeks. Five cases presented with placenta previa. The uterine wall thickness at the entry site measured at the time of surgery ranged from 12 to 23 mm (mean, 18 mm). Tubular retractors of two sizes were used: 15 and 20 mm in height, with a diameter of 25 mm. The procedure time ranged from 120 to 140 minutes (mean, 130 minutes). Furthermore, no mothers experienced uterine dehiscence (Figure 2), pulmonary edema, or placental abruption, or died. However, 1 patient developed oligohydramnios due to separation of the chorioamniotic membrane. The general characteristics of the mothers and fetuses are shown in Table 1.

[0075] Table 1: General characteristics of mothers and fetuses. DVP = Ventriculoperitoneal shunt. 3ETV + CPC = Endoscopic Third Ventriculostomy with Choroid Plexus Coagulation.

[0076] Fetal Aspects

[0077] Five fetuses had MM, while the remainder had myeloschisis. In all cases, the defect was repaired without artificial membranes or parallel releasing incisions. In all fetuses, the Chiari type 2 malformation was anatomically reversed, and none of the patients presented Chiari symptoms after birth. All patients were delivered by cesarean section. Gestational age at birth ranged from 33 to 38 weeks, with a mean of 36 3 / 7; no neonate required respiratory assistance. The mean postnatal hospital stay was 5 days. One patient, who was 33 weeks premature, had premature rupture of membranes and developed oligohydramnios. A cesarean section was indicated after corticosteroids were administered, and the newborn did not require intubation after delivery. birth. All fetuses had reversal of the hindbrain herniation.

[0078] Neonatal Aspects

[0079] The follow-up period ranged from 6 to 39 months after birth. No patient required additional spinal intervention due to scar dehiscence, tethered spinal cord, or inclusion cysts. Motor function improved based on anatomical sensory level in 5 patients. One patient required a VP shunt after birth and had a 14-mm lateral ventricle during fetal surgery. However, another developed hydrocephalus and transependymal edema at 6 months of age. The newborn underwent ETV with choroid plexus coagulation and did not require a VP shunt (Fig. 6). The follow-up time was too short to complete the urological evaluation. One patient required bladder catheterization, and no deaths occurred during this study. The results are summarized in Table 2. Table 2. Comparison of maternal outcomes between prenatal correction cohorts treated by different groups and techniques.

[0080] NA = not applicable; Values ​​are shown as number, number (%), or average unless otherwise indicated.

[0081] Discussion

[0082] The uterus is a smooth muscle organ consisting of longitudinal and circular muscle fibers. Fujimoto et al. (Fujimoto K, Kido A, Okada T, Uchikoshi M, Togashi K. Diffusion tensor imaging (DTI) of the normal human uterus in vivo at 3 Tesla: comparison of DTI parameters in the different uterine layers. J Magn Reson Imaging. 2013;38(6):1494-150). used the diffusion tensor imaging technique to show the presence of many circular and longitudinal fibers in the uterine body and fundus, respectively. The present technique was proposed to elongate the uterine fibers without cutting based on the elastic capacity of uterine myocytes. Retraction was performed in the uterine body; in all cases, this comprised primarily circular fibers. Maintaining uterine fibers should help the uterine wall and ad integrum return to normal and allow pregnancy to be carried to term, thus facilitating future pregnancies and vaginal delivery.In our series, all deliveries were performed by cesarean section, not for fear of uterine rupture, but to preserve fetal surgery. Furthermore, of the 10 patients included in the series, only 1 was born preterm (33 weeks) due to rupture of the amniotic membrane.

[0083] MOMS showed that the need for a shunt decreases by up to 50% when surgery is performed early in the fetal period. Remarkably, only 2 of 10 patients required treatment for hydrocephalus with this procedure. technique. In this study, Chiari type II malformation was reversed in all patients. Different series have shown complete reversal in 60%–80% of cases.

[0084] Many centers began treating these patients based on the MOMS results. Several changes to the initial surgical procedure were proposed, primarily endoscopic techniques and including transabdominal or transuterine laparoscopy with two or three ports. Transabdominal or hybrid endoscopic surgery requires a long learning curve. The costs of these procedures are high due to the use of disposable trocars and heated and humidified carbon dioxide gas.

[0085] This technique was, on average, faster than the results of the International Fetoscopic Neural Tube Defect Repair Consortium (Sanz Cortes M, Chmait RH, Lapa DA, et al. Experience of 300 cases of prenatal fetoscopic open spina bifida repair: report of the International Fetoscopic Neural Tube Defect Repair Consortium. Am J Obstet Gynecol. 2021 ;225(6):678. e1 -678.e1 1 ), and its time was very similar to that of open techniques. Placental abruption rates were higher with endoscopic techniques (25 of 280 cases); however, this was not seen in our cases. Premature rupture of the amniotic membrane, a determining factor for prematurity, was seen in all series; in contrast, the lowest rates were found in our series, and in that of Belfort et al (Belfort MA, Whitehead WE, Shamshirsaz AA, et al. Fetoscopic open neural tube defect repair: development and refinement of a two-port, carbon dioxide insufflation technique. Obstet Gynecol. 2017;129(4):734-743).Regarding uterine rupture at the suture site, these were not found in endoscopic cases; however, they were more common in open techniques. Moron et al (Moron AF, Barbosa MM, Milani H, et al. Perinatal outcomes after open fetal surgery for myelomeningocele repair: a retrospective cohort study. BJOG. 2018; 125(10):1280-1286). found a 3.8% rate of complete dehiscence at the uterine suture site. In their series, the uterine fiber rupture site was intact during delivery. The results were also superior. when comparing prematurity. In the cooperative study (Sanz Cortes et al), the mean gestational age at birth was 34.3 weeks, while in our series, the gestational age was 36.3 weeks. The worst results were reported by Lapa Pedreira et al. (Lapa Pedreira DA, Acacio GL, Gonçalves RT, et al. Percutaneous fetoscopic closure of large open spina bifida using a bilaminar skin substitute. Ultrasound Obstet Gynecol. 2018; 52(4):458-466) with the purely endoscopic technique. These results also differed regarding the need for shunts: the cooperative study used shunts or ETV in 43.8% of cases. However, in the series, 2 / 10 patients required treatment for hydrocephalus: one with a shunt and the other underwent successful ETV.

[0086] Conceptually, MM is characterized by a tethered spinal cord, given the low position of the conus medullaris. Therefore, releasing the spinal cord is key to improving motor and sphincter functions in these patients during fetal surgery. Surgeons should not be content with performing a superficial procedure by simply repairing the defect using various types of adhesives. Neurosurgeons need to release the spinal cord and restore its normal anatomy, leaving the placode in a tubular shape, unlike an open book. Furthermore, releasing the spinal cord prevents the future development of tethered cord syndrome.

[0087] Single-port tube endoscopy-assisted procedures are inexpensive and can be performed at any neurosurgery center because they rely on traditional microsurgery materials. Many pediatric neurosurgeons are proficient in this surgery, as it is routinely performed to remove deep-seated or intraventricular brain tumors and skull base tumors, such as pituitary tumors, craniopharyngiomas, and clivus chordomas.

[0088] The study's limitations are recognized, resulting from its retrospective nature, the relatively small number of cases included, and the short postnatal follow-up. However, despite these limitations, this technique is simple and reproducible. It allows for the presentation of a field of work. relatively wide (e.g. 25 mm) by means of a tubular retractor, which maintains the fetus with sufficient stability and provides a first step towards assisted correction with robotic techniques in a single portal.

[0089] Finally, Adzick et al. (Adzick NS, Thorn EA, Spong CY, et al. A randomized trial of prenatal versus postnatal repair of myelomeningocele. N Engl J Med. 2011;364(11):993-1004) and Degenhardt et al. (Degenhardt J, Schürg R, Winarno A, et al. Percutaneous minimal-access fetoscopic surgery for spina bifida aperta. Part II: maternal management and outcome. Ultrasound Obstet Gynecol. 2014;44(5):525-531) showed that they have distinct techniques and do not describe or suggest the advantages of the present invention.

[0090] Conclusions

[0091] Advances in fetal medicine have improved the quality of life of MM patients who undergo surgery during the fetal period. The single-port tubular endoscopy-assisted approach allows for the treatment of fetal spinal dysraphism and is potentially the first step toward future single-port correction using robotic techniques.

[0092] The examples revealed here are intended to merely exemplify some of the numerous forms of realization and use of the present invention, without limiting the interpretation of its scope and breadth, as well as, on possible alternative forms and configurational variations thereof that will be defined from the claims presented here.

Claims

Claims 1. Device for retracting the fibers of a segment of a uterine body, characterized by having a tubular shape and comprising at least one of its ends a section of its structure with a slope starting (3) at the external wall of the tubular structure (1) towards the internal wall of the tubular structure (2).

2. Device, according to claim 1, characterized by comprising means for gradual and controlled increase of its internal and / or external diameter.

3. Set of devices for retracting the fibers of a segment of a uterine body, characterized by comprising a first device as defined in claim 1 or 2 or at least one subsequent additional device as defined in claim 1 or 2, in which the one or more subsequent devices of the set each have an internal cylindrical segment that fits outside another of the set, and in which at least one of the subsequent devices has an internal cylindrical segment that fits outside the first device of the set.

4. Assembly, according to claim 3, characterized in that the first device of the assembly comprises the smallest diameter of the cylindrical segment of the assembly.

5. Assembly according to claim 3 or 4, characterized in that it additionally comprises a tubular spacer of diameter that fits outside at least one of the devices of the assembly.

6. Assembly according to any one of the preceding claims, characterized in that the first device of the assembly additionally comprises at least one guide wire.

7. Use of the device as defined in claim 1 or 2 or of the set of devices as defined in claims 3 to 6, characterized in that it is for retracting the fibers of a segment of a body uterine.

8. Use according to claim 7, characterized in that the fibers of a segment of a uterine body are for tubular retraction of circular fibers of the uterine body.

9. Use according to claim 7 or 8, characterized in that it is for progressive dilation of the myometrium.

10. Method for retracting fibers from a segment of a uterine body, characterized by comprising introducing a device as defined in claim 1 or 2 or the set of devices as defined in claims 3 to 6 into a section of a uterine body.

11. Method according to claim 10, characterized by comprising the use of a tubular device for retraction without cutting uterine muscle fibers or a set of devices with progressively larger diameters for retraction without cutting uterine muscle fibers or uterine wall.

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