Ultrastructural changes in esophageal tissue undergoing stretch tests with possible impact on tissue engineering and long gap esophageal repairs performed under tension.

Esophageal biomechanical studies are being performed to understand structural changes resulting from stretches during repair of esophageal atresias as well as to obtain biomechanical values for tissue-engineered esophagus. The present study offers insights into ultrastructural changes after stretching of the ovine esophagus using uniaxial stretch tests. In vitro uniaxial stretching was performed on esophagi (n = 16) obtained from the abattoir within 4-6 h of 1-month-old lambs. Esophagi were divided into 4 groups (4 esophagi/group): control, Group1 (G1), Group2 (G2), Group3 (G3) stretched to 20%, 30% and 40% of their original length respectively. Force and lengthening were measured with 5 cycles performed on every specimen. Transmission electron microscopic (TEM) studies were performed on the 4 groups. During observational TEM study of the control group there were no significant differences in muscle cell structure or extracellular matrix. In all stretched groups varying degrees of alterations were identified. The degree of damage correlated linearly with the increasing level of stretch. Distance between the cells showed significant difference between the groups (control (µ = 0.41 µm, SD = 0.26), G1 (µ = 1.36 µm, SD = 1.21), G2 (µ = 2.8 µm, SD = 1.83), and G3 (µ = 3.01 µm, SD = 2.06). The diameter of the cells (control µ = 19.87 µm, SD = 3.81; G1 µ = 20.38 µm, SD = 4.45; G2 µ = 21.7 µm, SD = 6.58; G3 µ = 24.48 µm, SD = 6.69) and the distance between myofibrils (control µ = 0.23 µm, SD = 0.08; G1 µ = 0.27 µm, SD = 0.08; G2 µ = 0.4 µm, SD = 0.15; G3 µ = 0.61 µm, SD = 0.2) were significantly different as well ( p < 0.05 was considered to be significant). Esophageal stretching > 30% alters the regular intracellular and extracellular structure of the esophageal muscle and leads to disruption of intra- and extracellular bonds. These findings could provide valuable insights into alterations in the microscopic structure of the esophagus in esophageal atresias repaired under tension as well as the basis for mechanical characterization for tissue engineering of the esophagus.

Esophagus stretch tests: Biomechanics for tissue engineering and possible implications on the outcome of esophageal atresia repairs performed under excessive tension.

BACKGROUND: Esophageal biomechanical studies are important to understand structural changes resulting from stretches during repair of esophageal atresias as well as to obtain values to compare with the biomechanics of tissue-engineered esophagus in the future. This study aimed to investigate light microscopic changes after uniaxial stretching of the ovine esophagus. METHODS: In vitro uniaxial stretching was performed on esophagi (n = 20) of 1-month-old lambs within 4-6 h post-mortem. Esophagi were divided into 5 groups: control and stretched (1.1, 1.2, 1.3 and 1.4). Force and lengthening were measured with 5 cycles performed on every specimen using a PBS organ bath at 37 °C. Histological studies were performed on the 5 groups. RESULTS: Low forces of ~ 2 N (N) were sufficient for a 1.2-1.25 stretch in the 1st cycle, whereas a three times higher force (~ 6 N) was needed for a stretch of 1.3. In the 2nd to 5th cycle, the tissue weakened and a force of ~ 3 N was sufficient for a stretch of 1.3. Histologically, in the 1.3-1.4 stretch groups, rupture of muscle fibers and capillaries were observed, respectively. Changes in mucosa and collagen fibers could not be observed. CONCLUSIONS: These results offer norm values from the native esophagus to compare with the biomechanics of future tissue-engineered esophagus. Esophageal stretching > 1.3 leads to tears in muscle fibers and to rupture of capillaries. These findings can explain the decrease in microcirculation and scarring in mobilized tissue and possibly offer clues to impaired motility in esophagus atresias repaired under excessive tension.

Cystic lesions of the testis in infancy ­ case series of four patients / A here cysticus elváltozásai csecsemokorban - négy eset ismertetése.

Összefoglaló. Csecsemokorban a here cysticus elváltozásai ritka entitásnak számítanak. Az angol nyelvu szakirodalom kevés hasonló esetrol számol be, a 2000-es évek elejéig publikált esetek harmadában orchiectomia történt. A hisztológia a leggyakrabban teratomát, a legritkábban egyszeru cystát igazol. Mindkét elváltozás jóindulatú, egyéves kor alatt a leggyakoribb. Közleményünkkel arra szeretnénk felhívni a figyelmet, hogy ezen esetek kezelése során törekedni kell a here megtartására. A Pécsi Tudományegyetem Klinikai Központ Gyermekgyógyászati Klinikájának Manuális Tanszékén és a Heim Pál Országos Gyermekgyógyászati Intézet I. Gyermek Ssebészeti és Traumatológiai Osztályán 2015 és 2018 között 4 csecsemoben észleltük a here cysticus elváltozását. A betegek kórtörténeti adatainak részletes retrospektív elemzését és a szakirodalom áttekintését végeztük. Mind a 4 alkalommal a csecsemo féléves kora elott észleltek egyoldali, panaszokat nem okozó herezacskófél-megnagyobbodást. Az ultrahangvizsgálat 3 esetben szoliter cysticus képletet talált. 1 esetben szeptált, suru folyadékkal telt cysticus képletet véleményezett, számottevo hereállomány nem mutatkozott. Ennél a betegnél mágnesesrezonancia-vizsgálat is készült, mely teratoma lehetoségét vetette fel. A feltárás során mindegyik csecsemoben cysticus képletet találtunk. 3 betegnél hereszövet-megtartó mutétet (enucleatiót) végeztünk. 1 esetben az érdemben megtartható hereszövet hiánya, valamint teratoma gyanúja miatt orchiectomia történt. A kórszövettan két esetben egyszeru cystát, két esetben praepubertalis teratomát igazolt, melyek jóindulatú elváltozások. A here cysticus elváltozásai csecsemokorban dönto többségben benignusak. Az egyszeru cysta és a praepubertalis teratoma egyaránt jóindulatú elváltozás, malignus transzformációra nem hajlamosak. A képalkotó eljárások közül az ultrahangvizsgálat elegendo lehet a kezelési terv felállításához. Mindig törekedni kell a here megtartására, a leheto legtöbb hereszövet megkímélésére. Kórszövettani vizsgálat nélkül a here eltávolítása ebben az életkorban nem javasolt. Orv Hetil. 2020; 161(48): 2043-2048. Summary. Cystic lesions of the testis are rare in infancy. Few similar case-series were published in the English literature. Orchiectomy was reported in one-third of the cases until the early 2000s. Histology mostly confirms teratomas, rarely simple cysts. Both are benign and most common under the age of one year. Our aim is to draw attention to the importance of testicular sparing surgery (enucleatio), whenever possible. At the Medical Centre of the Department of Pediatrics of the Division of Paediatric Surgery, Pécs and at the Department of Pediatric Surgery and Traumatology of the Heim Pal Children's Hospital, Budapest, four cystic testicular lesions were treated in infancy between 2015 and 2018. We performed retrospective analysis and reviewed relevant literature. Our patients were under six months and an unilateral, painless scrotal enlargement appeared. Ultrasound described cystic lesion in the testis in three cases. In one case a septated, echogenic, liquid-filled cystic lesion was detected, with no significant amount of testicular tissue. Magnetic resonance imaging scan of this patient predicted the diagnosis of teratoma. During the surgeries, cystic lesions were found in all cases. Enucleatio was performed in three patients. Orchiectomy was carried out once due to the suspicion of teratoma and the lack of salvageable testicular tissue. Histopathology confirmed simple cysts in two babies and prepubertal teratomas in the others. Testicular cystic lesions are predominantly benign in infancy. Simple cysts and prepubertal teratomas are benign, not prone to malignant transformation. Ultrasound is reliable for preoperative planning. Testicular tissue sparing surgery must be considered and without histopathology orchiectomy should not be performed. Orv Hetil. 2020; 161(48): 2043-2048.