Internal Ring Research Articles

The application of the percutaneous suturing technique in thoracoscopic repair of congenital diaphragmatic hernia.

Thoracoscopic surgery of congenital diaphragmatic hernia (CDH) is connected with a higher incidence of recurrence than open repair is. This is usually caused by the dehiscence of sutures in the lateral part of the defect. This area is characterized by increased tension on proximate tissues and difficult thoracoscopic suturing. For more effective repair, the authors adopted a variant of percutaneous internal ring suturing (PIRS) technique. To present and evaluate the efficacy of the PIRS technique for the repair of CDH. The study is based on retrospective analysis of the medical data of patients with CDH treated in the Department of Pediatric Surgery of the Jagiellonian University Medical College (Kraków, Poland) from January 2013 to July 2019. The PIRS technique was applied when thoracoscopic repair under acceptable tension appeared impossible. Fifty-one patients were identified. Of these, 11 children died before surgery and 1 after, leaving 39 (76%) who were operated on and survived. Thoracoscopy was used in 27 cases (69%), with 3 conversions. The recurrence rate in patients who underwent thoracoscopic closure of the defect with intermittent sutures was 27% (3 out of 11 children), while in the group that underwent thoracoscopic repair with the additional use of percutaneous suturing, the recurrence rate was 6.25% (1 out of 16 patients). The follow-up periods ranged from 4 months to 6 years. The applied PIRS technique permits safe and effective closure of intermediate-size diaphragmatic defects under acceptable tension. The method is feasible and can be listed among countermeasures against recurrence.

Reaction pathways of molecular growth for bay-region methyl-substituted polycyclic aromatic hydrocarbons during supercritical pyrolysis of n-decane, as determined from experiments with 4-methylchrysene dopant

To investigate the molecular-growth reactions of bay-region methyl-substituted polycyclic aromatic hydrocarbons (PAH) in the supercritical n-alkane-fuel pyrolysis environment, we have performed supercritical n-decane pyrolysis experiments with and without the dopant 4-methylchrysene (dopant concentration, 0.684 mg/g n-decane), in an isothermal, silica-lined stainless-steel flow reactor at 568 °C, 94.6 atm, and 133 s, conditions of rapid PAH growth. Analyses of the reaction products by high-pressure liquid chromatography with diode-array ultraviolet-visible absorbance and mass-spectrometric detection reveal that in the supercritical n-decane pyrolysis environment—where the aliphatic growth species methyl, ethylene, propene, and 1-butene are abundant—molecular growth of the four-ring 4-methylchrysene to high-ring-number PAH occurs chiefly through two routes, both of which take advantage of the bay-region position of 4-methylchrysene's methyl substituent. In the first route, 4-methylchrysene's resonance-stabilized arylmethyl radical 4-chrysenylmethyl attacks the aryl carbon just across the bay of 4-methylchrysene's structure to form the C19H12 methylene-bridged PAH 4H-cyclopenta[def]chrysene, whose resonance-stabilized radical 4-cyclopenta[def]chrysenyl reacts with methyl and ethylene in ring-expansion reactions that selectively produce the five-ring C20H12 benzo[a]pyrene and its derivatives 4- and 5-methylbenzo[a]pyrene. The arylmethyl radicals 4- and 5-benzo[a]pyrenylmethyl then undergo a series of reactions with n-decane's high-yield C2C4 1-alkenes to selectively produce particular six- to nine-ring peri‑condensed benzenoid PAH such as dibenzo[a,e]pyrene, benzo[a]naphtho[2,3-e]pyrene, dibenzo[e,ghi]perylene, benzo[a]coronene, and naphtho[8,1,2-abc]coronene—all of whose yields increase dramatically with 4-methylchrysene doping. In 4-methylchrysene's second major route of molecular growth, 4-chrysenylmethyl's attack of the aryl carbon across the bay is followed by an intramolecular rearrangement that produces 4H-benzo[cd]fluoranthene, a non-fully aromatic C19H12 PAH with an internal five-membered ring. Reactions of the resonance-stabilized benzo[cd]fluoranthenyl radicals with methyl, propene, and 1-butene selectively produce the six-ring C22H12 indeno[1,2,3-cd]pyrene and four particular seven-ring C26H14 benzindeno[1,2,3-cd]pyrenes—each of which contains an internal five-membered ring, evidencing the distinctive molecular-growth pathways of bay-region methyl-substituted PAH in the supercritical n-alkane-fuel pyrolysis environment.

Experimental and numerical buckling analysis of cylindrical pressure hulls with multi-circular openings

Experimental and finite element analyses are performed to identify the buckling strength of a large-scale specimen of tourist submarine subjected to external hydrostatic pressure. The tourist submarines are designed with multi-windows, built up of structural openings, affecting the buckling and ultimate strength of their pressure hulls. The hydrostatic pressure experiment is conducted in a pressure chamber, recording the external pressure and the structural strains. The experimental structural response and permanent deformation show a good agreement with the finite element analysis performed by the ABAQUS finite element solver. The numerical analysis presents some aspects of particular relevance to the buckling failure behaviour of the submarine hull subjected to a uniform external pressure. Additional analyses are performed to investigate the effect of material properties, structural openings and reinforcing rings. The buckling and ultimate strength of the prototype submarines are also evaluated to explore the critical design aspects of internal and external ring stiffeners.

Subinguinal orchiectomy-A minimally invasive approach to open surgery.

ObjectivesTo determine the rate of morbidity and assess the oncological outcomes for the subinguinal orchidectomy technique.BackgroundRadical inguinal orchiectomy is the definitive management for a testicular mass suspicious for malignancy. The standard approach involves the division of the spermatic cord at the internal inguinal ring. In addition to the morbidity of a significant incision through skin and fascia, a known complication is damage to the nerves within the canal leading to local hypoesthesia or persistent inguinal and scrotal neuralgia. The subinguinal orchiectomy technique avoids opening the inguinal canal by excising the spermatic cord at the external inguinal ring.MethodsPatient data from three urologists who routinely perform subinguinal orchiectomies for suspected testicular malignancy was collected. A retrospective analysis between March 2011 and March 2019 was undertaken evaluating demographic, clinical, and histological data points. Descriptive analysis of oncological and surgical outcomes of subinguinal orchiectomy for testicular mass was performed. Descriptive analysis of oncological and surgical outcomes of subinguinal orchiectomy for testicular mass was performed.ResultsAbout 42 orchiectomies performed via the subinguinal approach were identified. The median age was 38 years (range 22‐72) and mean follow‐up time was 18.4 months (range 0.59‐61). Of the 38 patients with testicular cancer, histopathology showed 26 with pT1, 9 with pT2, and 3 with pT3 disease. Three patients had involvement of the cord, with one patient having a positive surgical margin secondary to venous invasion. No patients experienced neuropathic complications, hernia, or wound break down.ConclusionThese data suggest that subinguinal orchiectomy provides acceptable oncological outcomes, comparable to a traditional technique, and may decrease the risk of neuropathic injury and incisional/inguinal hernia. Further investigation with a larger, prospective series is required.

Cross coupled interlinked split ring resonator based epsilon negative metamaterial with high effective medium ratio for multiband satellite and radar communications

In this paper, a cross coupled interlinked split ring resonator based (CCI-SRR) based metamaterial has been presented. Epsilon negative (ENG) with a highly effective medium ratio (EMR) is attained in this metamaterial. The metamaterial unit cell consists of one square shaped split ring resonator and two rectangular rings. The rectangular rings reside within the outer square split ring. Two internal rings are coupled together by using a cross-shaped metal segment. These inner rings are also interlinked to the outer ring by using metal strips. Coupling causes to increase the electrical length and modifies the inductance of the unit cell. Multiple resonances covering C, X and Ku-band are achieved due to the interconnection of rings. The symmetric nature of the CCI-SRR unit cell exhibits unique quality to minimize noise and harmonics effect. The unit cell is designed on FR4 substrate with a thickness of 1.6 mm. The overall dimension of the unit cell is 0.124λ × 0.124λ, where λ is the wavelength calculated at a lower resonance frequency of 4.15 GHz. Three resonances are obtained for |S21| at frequencies of 4.15 GHz, 10.38 GHz and 14.93 GHz performing numerical simulation in CST microwave studio. Permittivity, permeability, refractive index and impedance are explored by using the Newton-Ross-Weir (NRW) method. ENG performance is observed in frequencies ranging from 3.95 to 5.65 GHz, 9.57–11.46 GHz, 13.68–16 GHz. Near-zero refractive index is attained within the frequency ranges, 4.16–5.75 GHz, 10.16–11.58 GHz, 14.46–16 GHz. An LC equivalent circuit is designed, and component values are achieved by Advanced Design Software (ADS) justifying |S21| with CST result. The study of electromagnetic wave interaction between the unit cell and the double positive medium reveals that the unit cell exhibits evanescent wave properties. The compact nature of the unit cell is confirmed by calculating EMR with a value of 8.03. The electromagnetic coupling effect is examined for 2 × 2 array in various orientations. The |S21| performance of 2 × 2, 4 × 4 and 8 × 8 is matched with the unit cell. Due to symmetric patterns, near-zero refractive index, negative permittivity and high EMR, the proposed unit cell can be used to enhance the performance of microwave devices used for C, X and Ku-bands, especially Satellite and Radar communications.

Three-step tumescent local anesthesia technique for inguinal hernia repair.

The optimal method of anesthesia for inguinal hernia repair is still controversial. We have developed “three‐step tumescent local anesthesia (TLA) technique” for inguinal hernia repair, and recently showed that this technique is acceptable in view of short‐ and long‐term clinical outcomes. Our study included 273 consecutive cases (290 sides) of elective inguinal hernia repair performed under the newly developed technique between September 2003 and May 2019, and overall clinical outcomes were considered to be safe and feasible. Herein, we report the surgical procedure of “three‐step TLA technique.” Briefly, we rapidly inject the diluted solution of local anesthetic and epinephrine step‐by‐step into the three following closed tissue space. Initially, 80 mL injection into the subcutaneous tissue before skin incision (Step 1). After the external oblique fascia is exposed, injection of 20 mL into the inguinal canal before the external oblique fascia is incised and opened (Step 2). The hernia sac and spermatic cord are then dissected, and the blunt dissection of the preperitoneal space is made by injecting 20 mL under the internal inguinal ring (Step 3), followed by placing a gauze into the preperitoneal space, creating the space for mesh placement. We consider that the most important point of this technique is achieved through the rapid injection of TLA solution into each closed tissue space, which makes for easier dissection, hemostasis, and good pain control.

Laparoscopic Abdominoscrortal Hydrocele: A Case Series

ObjectiveTo evaluate the effect of laparoscopic percutaneous extraperitoneal closure (LPEC) of the internal inguinal ring for the treatment in pediatric abdominoscrotal hydrocele (ASH) and to assess the feasibility and safety of the procedures. Patients and MethodsData were collected from the charts of patients with ASH who underwent surgery in Kokura Medical Center from April 2014 to December 2019. The patients’ characteristics, preoperative diagnosis, forms of abdominal components, presence of patent processus vaginalis (PPV), associated pathologies, and postoperative results were evaluated. ResultsThe study population included 10 patients (4.3% of all 230 hydroceles). The mean age of 10 patients was 3.5 years (range, 7 months to 7 years). A preoperative diagnosis of ASH was made in 3 patients. In the other 7 patients, ASH was detected during laparoscopic repair of the scrotal hydrocele. The abdominal forms of hydrocele were monolocular cysts (n = 6) and multilocular cysts (n = 4). PPV was detected by laparoscopy in all cases. Six patients had contralateral pathologies, including PPV (n = 4), inguinal hernia (n = 1), and scrotal hydrocele (n = 1). One patient had ipsilateral undescended testis. Preoperative ultrasonography showed some degree of testicular dysmorphism on the affected side in 4 cases. In all cases, treatment was accomplished by closing the PPV at the internal inguinal ring by LPEC procedures. No patients had postoperative complications, including recurrent ASH or hydrocele after ASH repair (mean follow-up, 2.6 years). ConclusionLPEC may be an adequate and minimally invasive method for the treatment of the pediatric ASH.

Percutaneous hernia repair in children: Safe to introduce.

In 2014 we introduced percutaneous internal ring suture as an alternative to open surgery for the treatment of inguinal hernia. This study aims to evaluate the introduction of the procedure at our institution. In total, 100 consecutive patients operated with percutaneous internal ring suture were compared with 100 consecutive patients operated with open surgery. The patients were operated from August 2014 until November 2017. Patient demographics, clinical history, operative time, time in theater, and postoperative complications were extracted from charts. The mean operative time for percutaneous internal ring suture was 26.54 min and for open surgery 39.94 min, P < 0.0001. The total mean operative theater time for percutaneous internal ring suture was 108.95 min and for open surgery 118.4 min, P = 0.0343. During follow-up, two percutaneous internal ring sutures were operated for recurrent hernia. In the open surgery-group, three patients were operated for recurrent hernia, three for secondary testicular retention, and three for metachronous contralateral hernia. Even when established as a new technique, the percutaneous internal ring suture procedure is safe and results in shorter operative time and shorter theater time compared to open surgery.

Gold(I)/Gold(III) Catalysis that Merges Oxidative Addition and π-Alkene Activation.

Heteroarylation of alkenes with aryl iodides was efficiently achieved with a (MeDalphos)AuCl complex through AuI /AuIII catalysis. The possibility to combine oxidative addition of aryl iodides and π-activation of alkenes at gold is demonstrated for the first time. The reaction is robust and general (>30 examples including internal alkenes, 5-, 6-, and 7-membered rings). It is regioselective and leads exclusively to trans addition products. The (P,N) gold complex is most efficient with electron-rich aryl substrates, which are troublesome with alternative photoredox/oxidative approaches. In addition, it provides a very unusual switch in regioselectivity from 5-exo to 6-endo cyclization between the Z and E isomers of internal alkenols.

Long internal ring waves in a two-layer fluid with an upper-layer current

We consider a two-layer fluid with a depth-dependent upper-layer current (e.g. a river inflow, an exchange flow in a strait, or a wind-generated current). In the rigid-lid approximation, we find the necessary singular solution of the nonlinear first-order ordinary differential equation responsible for the adjustment of the speed of the long interfacial ring wave in different directions in terms of the hypergeometric function. This allows us to obtain an analytical description of the wavefronts and vertical structure of the ring waves for a large family of the current profiles and to illustrate their dependence on the density jump and the type and the strength of the current. In the limiting case of a constant upper-layer current we obtain a 2D ring waves' analogue of the long-wave instability criterion for plane interfacial waves. On physical level, the presence of instability for a sufficiently strong current manifests itself already in the stable regime in the squeezing of the wavefront of the interfacial ring wave in the direction of the current. We show that similar phenomenon can also take place for other, depth-dependent currents in the family.

Laparoscopic assisted percutaneous herniorrhapy in dogs using PIRS technique.

In the literature, no studies describe the use of laparoscopic techniques for inguinal hernia repair in canine clinical patients. The surgical technique-Percutaneous Internal Ring Suturing (PIRS) presented in this article is the world's first minimally invasive laparoscopic surgical technique for inguinal canal closure in dogs. The aim of the presented study is to evaluate the possibility of employment of the laparoscopic PIRS technique in clinical practice as well as to technically evaluate its usefulness in the treatment of the inguinal hernia in dogs. The presented study describes the procedure and the results of laparoscopic treatment of 11 inguinal hernias in nine dogs (two bilateral). The whole procedure is performed under camera control introduced through one umbilical trocar. The very closure of the inner inguinal ring is done with the injection needle by a small puncture over the inguinal canal with the help of which the suture material is inserted, and the canal of the operated inguinal hernia is closed. Each operated dog underwent a thorough clinical examination before surgery which was combined with ultrasound examination of the inguinal canals before, immediately after and three months after surgery. There was no hernia recurrence in the study period in the operated dogs and all individuals returned to full mobility immediately after recovery from anesthesia. Due to the low invasiveness and simplicity of performance, the PIRS technique described in the study should be taken into account when choosing a treatment method for non-traumatic inguinal hernia in dogs. At the same time, the possibility of using the described technique in other types of inguinal hernia in dogs requires further research.

Laparoscopic assisted percutaneous internal ring suturing for inguinal hernia repair in pediatrics

Several laparoscopic techniques used in treatment of pediatric inguinal hernia differ in their approach to the internal inguinal ring, suturing and knotting techniques, number of ports, endoscopic instruments used and hernia sac dissection technique. The aim of this study was to evaluate efficacy and safety of laparoscopic assisted percutaneous internal ring suturing for inguinal hernia repair in pediatrics. Laparoscopic assisted percutaneous internal ring suturing was performed under general endotracheal anesthesia on 54 children with 64 hernias during the period from July 2018 to June 2019. Under laparoscopic-guided vision a 2-0 Prolene® thread inside an 18-gauge epidural needle was placed through the abdominal wall into the peritoneal cavity, then the thread passed under the peritoneum around the internal ring. The knot was tightened from outside and placed in the subcutaneous space. The mean operative time was 14.18 min for unilateral and 21.2 min for bilateral hernias. Cosmetic results are excellent with almost invisible scars. There were no intraoperative and six postoperative complications (recurrence in three cases, transient hydroceles in two boys and one patient had stitch sinus). Laparoscopic assisted percutaneous needle repair of congenital inguinal hernia seems to be a simple minimally invasive procedure in small ring diameter with excellent cosmetic results. But I do not recommend this technique due to high rate of complications and recurrence, also simplicity of the technique can be regarded as a hindrance to the surgeons in training from challenging their skills to be ready for the more complex scenarios.

Laparoscopic inguinal hernia repair in children via PIRS (percutaneous internal ring suturing).

The miniinvasive approach is atrend in pediatric surgery nowadays. The new surgical technique called percutaneous internal ring suturing (PIRS) is apromising method bringing all the benefits of miniinvasive surgery. Prospective study of patients operated on using the PIRS technique from 01 January 2018 to 01 January 2020 at the Department of Pediatric Surgery, 2nd Faculty of Medicine, Charles University, University Hospital Motol. 73 patients (25 boys and 48 girls) were operated on using PIRS. The median age was 68 months. 90% of operations were performed by the same team of surgeons. During the procedure there were found 53 right-sided and 38 left-sided inguinal hernias. In 18 cases the hernia was bilateral, but only in 13 cases was this diagnosis made before the operation. Anon-absorbable stitch was used in 57 cases to close the internal ring of the inguinal canal, and anon-absorbable monofilament in 16. The median operating time was 34 minutes. There were 3 recurrences (3.3%) in our study. Conclusion: In our initial study, the PIRS technique proved to be asafe alternative method to the open inguinal hernia surgery. This method provides the benefit of allowing to revise the contralateral inguinal canal as aprevention of ametachronous inguinal hernia. The cosmetic results were excellent.

Initial Experience with Percutaneous Internal Ring Suturing for Indirect Inguinal Hernia in Pediatric Patients.

PurposeThe aim of this study is to review our experience in treating indirect inguinal hernia in pediatric patients.MethodsWe retrospectively studied a total of 43 patients who underwent percutaneous internal ring suturing (PIRS) for indirect inguinal hernia from January 2016 to September 2018. The participants included 29 boys and 14 girls. There were cases of bilateral internal inguinal hernia (n=12), right indirect inguinal hernia (n=16), and left indirect inguinal hernia (n=15). Their mean age was 3.8±2.9 years, and mean body weight was 16 kg. Clinical features and surgical outcomes were analyzed.ResultsMean operating time was 35 min for unilateral inguinal hernia and 40 min for bilateral inguinal hernia. There were five cases of intraoperative bleeding (12%) during needle insertion. In two cases, stress test resulted in escape of gas into the hernial sac and a second suture was inserted. The contralateral patent processus vaginalis was present in six (14% of cases) and closed. Follow-up was 6~30 months. Mean postoperative hospital stay was 1.2 days. No recurrence hernia and postoperative complications were reported.ConclusionAlthough this study investigated a small number of cases and the surgical experience was rather limited, the PIRS technique was shown to have advantages such as a short learning curve and its aid in detecting contralateral hernias. In this study, there were no reports of recurrence, metachronous inguinal hernias, and postoperative complications.

Single-port laparoscopic percutaneous closure of the internal ring for scarless repair of inguinal hernias in girls

Purpose The purpose of this study was to summarize the clinical experience with laparoscopic percutaneous extraperitoneal closure of the internal ring using an epidural needle for inguinal hernias in girls. Material and methods A total of 462 girls with inguinal hernias participated in this study from January 2013 to June 2019. Laparoscopic percutaneous extraperitoneal closure of the internal ring via an epidural needle was used to treat these patients. Results All 462 girls with an inguinal hernia successfully underwent laparoscopic surgery. The operative times for unilateral and bilateral inguinal hernias were 15 (11–25) minutes and 23 (18–33) minutes, respectively. All patients were discharged 1–2 days after the operations. During the hospitalization and follow-up periods, none of the following complications were observed: hernia recurrence, umbilical hernia, abdominal wall vascular injury, intestinal injury or bladder injury. However, there were six patients with complications: two cases of poor healing of the umbilical incision, three cases of suture granulomas and one case of groin traction pain and discomfort. Conclusion Laparoscopic percutaneous extraperitoneal closure of the internal ring using an epidural needle is a safe and feasible method for the treatment of inguinal hernias in girls. This method has the advantages of limited trauma, no scarring and a good cosmetic effect.

Grosor epitelial corneal un año después de la cirugía de LASIK miópico, medido mediante tomografía de coherencia óptica de segmento anterior combinado con disco de Plácido

ObjectiveTo compare corneal epithelial thickness (CET) between patients who underwent LASIK surgery for the correction of myopia at least one year ago and healthy subjects. MethodsA retrospective observational study was conducted that included 93 healthy subjects (186eyes) and 26 subjects (52eyes) that underwent myopic LASIK surgery. OCT-SA, combined with Placido disk, was performed on all subjects, and CET maps were measured. Statistical analysis was performed to analyse differences between groups. Multivariate analysis was also performed to look for possible predictors of final CET. ResultsThere was no statistically significant differences between the groups in the demographic (age, sex) or anterior segment parameters (spherical equivalent, pachymetry) (all P>.05). Statistically significant differences (P<.05) were obtained between both groups when comparing CET, including central, internal, and external rings (higher in patients that underwent LASIK surgery ≥1year). With the exception of the time elapsed since surgery (P=.00), no correlation was found between the CET and age, sex, ablated dioptres, or other variables studied (P<.05). ConclusionsCET values measured by the OCT-SA were higher in patients that underwent LASIK surgery ≥1year. The only variable that correlated with the CET after LASIK was the time elapsed since surgery. CET changes should be taken into consideration when planning refractive surgery due to its implications on the final outcome.

Effects of an HIV-1 maturation inhibitor on the structure and dynamics of CA-SP1 junction helices in virus-like particles

HIV-1 maturation involves conversion of the immature Gag polyprotein lattice, which lines the inner surface of the viral membrane, to the mature capsid protein (CA) lattice, which encloses the viral RNA. Maturation inhibitors such as bevirimat (BVM) bind within six-helix bundles, formed by a segment that spans the junction between the CA and spacer peptide 1 (SP1) subunits of Gag, and interfere with cleavage between CA and SP1 catalyzed by the HIV-1 protease (PR). We report solid-state NMR (ssNMR) measurements on spherical virus-like particles (VLPs), facilitated by segmental isotopic labeling, that provide information about effects of BVM on the structure and dynamics of CA-SP1 junction helices in the immature lattice. Although BVM strongly blocks PR-catalyzed CA-SP1 cleavage in VLPs and blocks conversion of VLPs to tubular CA assemblies, 15N and 13C ssNMR chemical shifts of segmentally labeled VLPs with and without BVM are very similar, indicating that interaction with BVM does not alter the six-helix bundle structure appreciably. Only the 15N chemical shift of A280 (the first residue of SP1) changes significantly, consistent with BVM binding to an internal ring of hydrophobic side chains of L279 residues. Measurements of transverse 15N spin relaxation rates reveal a reduction in the amplitudes and/or timescales of backbone N-H bond motions, corresponding to a rigidification of the six-helix bundles. Overall, our data show that inhibition of HIV-1 maturation by BVM involves changes in structure and dynamics that are surprisingly subtle, but still sufficient to produce a large effect on CA-SP1 cleavage.

Study of Vibration Behaviour of Stiffened Polymer Composite Shells for Underwater Structural Applications

This paper presents vibration behavior of ring stiffened polymer composite thick shells used for underwater structures. Filament wound shells stiffened with internal and external rings and with hemispherical ends were tested for vibration in air and water in free-free boundary condition using roving hammer and fixed response method. Modal testing of the shells was performed under hydrostatic loading in a custom designed buckling tester for determining natural frequency at higher sea depths. Accelerometer was mounted on the inner surface of the shell. It was excited using a plumbob, rope and pulley arrangement. Experimental results were validated by modal analysis using Hyperworks and ANSYS. Vibration behavior in water was simulated by Fluid structure interaction approach. Experimental first natural frequency in water was lesser than that in air. With increase in hydrostatic pressure, the shell showed moderate variation in natural frequency. The experimental and numerical results of natural frequency and mode shapes were in good agreement with each other. Natural frequencies were lower in long and thick shells.

Single-site laparoscopic percutaneous extraperitoneal closure (SLPEC) of hernia sac high ligation using an ordinary taper needle: a novel technique for pediatric inguinal hernia.

Laparoscopic high ligation of the internal inguinal ring is an alternative procedure for treatment of pediatric inguinal hernia (PIH), with a major trend toward increasing use of extracorporeal knotting and decreasing use of working ports. We have utilized this laparoscopic technique to treat the entire spectrum of PIH (including incarcerated cases) for more than 17years, and the technique continues to evolve and improve. We herein report our latest modification of this minimally invasive technique, namely single-site laparoscopic percutaneous extraperitoneal closure (SLPEC) of hernia sac high ligation using an ordinary taper needle, and evaluate its safety and efficacy. From July 2016 to July 2019, 790 children with indirect PIH were treated by laparoscopic surgery. All patients underwent high ligation surgery with a modified single-site laparoscopic technique mainly performed by extracorporeal suturing with an ordinary closed-eye taper needle (1/2 arc 11 × 34). The clinical data were retrospectively analyzed. All surgeries were successful without serious complications. A contralateral patent processus vaginalis (CPPV) was found intraoperatively and subsequently repaired in 190 patients (25.4%). The mean operative time was 15min (8-25min) for 557 unilateral hernias and 21min (14-36min) for 233 bilateral hernias. The mean postoperative stay was 20h. Minor complications occurred in five patients (0.63%) and were managed properly, with no major impact on the final outcomes. No recurrence was noted in the patients who were followed up for 6-42months. No obvious scar was present postoperatively. Modified SLPEC of hernia sac high ligation using an ordinary taper needle for repair of indirect PIH is a safe, reliable, and minimally invasive procedure with satisfactory outcome, with no special device being needed. It is easy to learn and perform and is worthy of popularization in the clinical setting.

Laparoscopic repair of congenital inguinal hernia: a comparative study between purse–string suture and peritoneal disconnection with ligation techniques in bilateral cases

Many laparoscopic surgical techniques were described for management of inguinal hernia in pediatric patients. This prospective study was conducted to compare laparoscopic purse–string suture of hernia sac at the internal ring at one side, leaving the distal sac intact (technique I) and disconnection of the hernia sac with intra-corporeal suture of proximal part at the internal ring (technique II) in the other side in the same case. Thirty three patients with bilateral congenital inguinal hernia (66 repairs) were included in this study. The outcome variables were operative time, intraoperative complications, post-operative complications and recurrence rate. This study included 28 males and 5 females. The age of the patients ranged from 1 to 72 month with a mean of (15.27 ± 19.09). The operative time was shorter in technique I than in technique II and this difference was statistically significant. No intraoperative complications were reported. Five cases (15%) developed hydrocele and two cases (6%) developed recurrence in technique I during the follow up period. Laparoscopic repair of congenital inguinal hernia using laparoscopic disconnection of the sac and closure of the internal ring has lower recurrence rate and hydrocele formation but longer operative time compared to laparoscopic purse–string closure alone. Due to the high rate of recurrence in technique I, there is definite superiority of technique II as a surgical option.