Estimation of corneal thickness ex vivo and in vivo at instillation of photosensitizer solutions in different modifications of UV corneal crosslinking

Objectives: to evaluate the effectiveness of photosensitizer solutions in the experiment in different modifications of standard UV corneal crosslinking. Materials and Methods. Experiments were performed on 32 enucleated porcine eyes ex vivo and 12 rabbits (24 eyes) in vivo, divided into 4 groups depending on instillations of the photosensitizer solutions: Dextralink, Ribolink, Hypolink and Riboflavin. Evaluation of corneal saturation was performed using two modifications of standard UV CXL: in the first case, instillation of the photosensitizer solution was performed during the entire crosslinking procedure (30 min - saturation and 30 min - ultraviolet irradiation); in the second case, instillations lasted only for the first 30 minutes, the precorneal riboflavin film was removed, and instillation of solution was not performed. Results and Discussion. Instillation of photosensitizer solutions within 60 minutes showed that Dextralink significantly reduced the thickness of the cornea by about 24 % ex vivo and 21 % in vivo, while Hypolink, on the contrary, caused its increase by 9 % ex vivo and 23 % in vivo, respectively. The use of Ribolink and Riboflavin did not change the linear parameters of the cornea during the entire follow-up period. The results of the 2nd series of studies showed that effects of solutions on the cornea during their instillation for 30 minutes were generally preserved during the entire observation period up to 60 minutes. In the group where Dextralink and Hypolink solutions were used, there was a slight tendency to normalization of the initial parameters of the cornea. Conclusion. Safe and effective implementation of UV crosslinking of the cornea is possible on the basis of a rational approach to the performing the stages of stroma saturation with photosensitizer solutions, depending on the initial state of the cornea: Dextralink is recommended for a thickness of more than 450 m, Ribolink - at 400-450 m, Hypolink - from 350 to 400 m. Halting of instillations on the saturated stroma during UV irradiation is advisable to be accompanied by intraoperative control of its thickness. When performing a standard crosslinking technique, where instillations of photosensitizer accompany the stage of UV irradiation of the cornea, it is necessary to take into account the presence of a precorneal film that can absorb some of the radiation energy. The peculiarity of this crosslinking technique can be considered as a potential way to protect intraocular tissues from excessive exposure to UV radiation.

Intraoperative Control of Hemoglobin Oxygen Saturation in the Intestinal Wall during Anastomosis Surgery

During surgery for colon cancer, monitoring of the oxygen saturation of hemoglobin in the tissues under study makes it possible to assess the degree of blood supply to the anastomosis areas of the colon. Adequate blood supply in this area is decisive in terms of the consistency of the anastomosis and can significantly reduce the risk leakage of anastomosis. In this work, we propose a new approach to assessing the hemoglobin oxygen saturation based on measuring both the diffuse reflectance and transmittance spectra of the colon wall tissues. The proposed method is based on the use of two fiber-optic tools for irradiation from both sides—the intestinal lumen and the outside of the intestinal wall. The spectra are recorded from the external side. To determine the degree of hemoglobin saturation, two algorithms, both based on the Taylor series expansion of the coefficient of light attenuation by tissues, are proposed. The results of a clinical study of the proposed approach on volunteers were obtained, allowing to draw a conclusion about the applicability of the approach in a clinical setting.

Submandibular approach for orotracheal intubation in Oral and Maxillofacial Surgery and Traumatology

Introduction: Submandibular tracheal intubation is a technique that can be applied in Oral and Maxillofacial Surgery and Traumatology, as well as other surgical specialties. Its main advantages are helping in the surgical manipulation of the middle facial skeleton and jaw and allowing the intraoperative control of dental occlusion. The technique is an alternative to elective tracheostomy. Objective and case report: The article presents the treatment of an adult patient, with sequelae of multiple fractures in the face due to a car accident, with endotracheal intubation using submandibular approach. Final considerations: In large surgical manipulations of the face, the submandibular approach for tracheal intubation allows a faster, facilitated anatomical access with a lower risk of damage to adjacent structures when compared to other pathways. It also guarantees excellent cervical mobility, the possibility of wide manipulation and the use of occlusion as a guide for surgical intervention.

An experiment of using the SonoVue ultrasound contrast agent for focused high-intensity ultrasound ablation of uterine fibroids

BACKGROUND: One of the modern methods of organ-saving non-invasive remote treatment of uterine fibroids is ablation of myomatous nodes with high-intensity focused ultrasound (HIFU). AIM: The aim of this study was to analyze changes in the parameters of ultrasonic ablation when using intraoperative control with the help of an ultrasound contrast agent. MATERIALS AND METHODS: In the period from 2016 to 2018, a total of 208 patients with symptomatic uterine myoma underwent HIFU ablation of myomatous nodes. The two groups of patients were compared: group I included 98 patients aged 36 to 52 years (mean age: 44.39 7.12 years) with intraoperative control with an ultrasound contrast agent (sulfur hexafluoride); group II consisted of 110 patients aged 20 to 55 years (mean age: 38.33 8.72 years), whose treatment was not controlled by the contrast agent. RESULTS: Using the Mann-Whitney test, we obtained statistically significant differences in the following parameters: the duration of ultrasound ablation was 215.28 70.57 min (from 70 to 390 min) in group I, and 610.84 56.26 min (from 290 to 1230 min) in group II (p 0.005); the average energy was 329.06 33.06 W in group I, and 293.68 64.51 W in group II (p 0.001); good tolerance of the operation was shown in 91% of cases in group I, and in 61.8% of cases in group II; satisfactory tolerance of the operation was shown in 7.7% of cases in group I, and in 37.3% of cases in group II (p 0.001). CONCLUSIONS: The data obtained indicate that the performance of HIFU ablation with the use of an ultrasonic contrast agent allowed halving the insonation time, while using submaximal and maximum ultrasound exposure powers with better tolerance of intervention by patients.

Intra-operative diagnosis of an adult ureterocele complicated by hydronephrosis: a case report

Ureterocele is a cystic dilatation of the terminal ureter. Hydronephrosis is less commonly reported in individuals with ureterocele. We report a unique case of an incidental ureterocele with hydronephrosis in a 47-year-old woman; diagnosed with intraoperative control cystoscopy while performing total laparoscopic hysterectomy and bilateral salpingo- oophorectomy.

Dynamics of Freezing and Warming of Soft Tissues with Short-Term Eff ect on Skin with Cryoapplicator

The paper presents the analysis of possibilities and limitations of using the thermal imaging to monitor the dynamics of temperature field caused by a short-term cryoablation of skin. It is shown that the method allows to remote and intraoperative control the dynamics of the freezing zone diameter as well as to estimate the current diameter of primary cryonecrosis zone. The diameter of primary cryonecrosis zone for this type of tissues reaches 13 mm, which makes it possible to destroy small morbid growth by low temperatures even with a short-term (30 s) croexposure. The using of this method to monitor the process of natural warming has shown the presence of long quasi-stable stage in dynamics of the freezing zone diameter with a slight change in the temperature field. This fact is likely due to structural changes in frozen tissues.

Simultaneous Application of Ultrasound and Sialendoscopy and its Value in the Management of Sialolithiasis

Objective Ultrasound (US) and sialendoscopy (SE) are routinely used in patients presenting with sialolithiasis in the submandibular (SMG) and parotid gland (PG). The objective was to assess the value of the simultaneous application of US and SE in the management of sialolithiasis. Study Design Retrospective study. Setting: Tertiary referral center for salivary gland diseases. Participants: Patients in whom US and SE as single investigation tools were neither conclusive nor useful in the management of sialolithiasis were investigated using both methods simultaneously (simUS + SE). Main outcome measures: Establishment of the final diagnosis and/or contribution to the planning/performing of treatment in sialolithiasis. Results 74 patients were examined by simUS + SE (58.1 % SMG and 41.9 % PG). In all patients (unclear) hyperechoic reflexes were assessed and/or localized by SE-controlled US navigation. 68.9 % of the patients were investigated for diagnostic or differential-diagnostic reasons including distinguishing extraductal from intraductal calcifications and/or to exclude residual stones after therapy. In 52.7 % simUS + SE was used to plan and/or perform further treatment, in 20.3 % to enable performing a combined approach (all PG) and in 29.7 % to evaluate and plan the most adequate therapy (mainly intraductal vs. extracorporeal shock wave lithotripsy, 68.2 % of these SMG). In two cases SE-controlled and US-guided stone extraction was performed. Conclusion SimUS + SE is an innovative approach which proved to be very useful in managing sialolithiasis. It added valuable information regarding the establishment of a diagnosis or differential diagnosis, planning and performing the most adequate treatment, intraoperative control of therapy and postoperative follow-up.