Ospan A. Mynbaev

Peritoneal mesothelial hypoxia during pneumoperitoneum is a cofactor in adhesion formation in a laparoscopic mouse model

OBJECTIVE To develop a laparoscopic mouse model to evaluate the hypothesis that mesothelial hypoxia during pneumoperitoneum is a cofactor in adhesion formation. DESIGN Prospective randomized trials. SETTING Academic research center. ANIMAL(S) One hundred thirty female Naval Medical Research Institute (NMRI) mice. INTERVENTION(S) Adhesions were induced by opposing monopolar lesions in uterine horns and pelvic side walls during laparoscopy and evaluated after 7 or 28 days under microscopic vision during laparotomy. The following pneumoperitoneum variables were assessed: duration (10 or 60 minutes), insufflation pressure (5 or 15 cm of water), insufflation gas (CO(2) or helium), and addition of oxygen (0-12%). MAIN OUTCOME MEASURE(S) Adhesions were scored quantitatively and qualitatively for extent, type, and tenacity. RESULT(S) Scoring of adhesions 7 or 28 days after laparoscopic surgery was comparable. Adhesions increased with duration of pneumoperitoneum and with insufflation pressure and decreased with the addition of oxygen. Half-maximal reduction of adhesions was obtained at 1.5% oxygen, whereas a maximal reduction required only 2%-3%. The effect of CO(2) and helium was similar. CONCLUSION(S) These data demonstrate the feasibility of the intubated laparoscopic mouse model and confirm previous observations in rabbits, indicating that mesothelial hypoxia plays a key role in adhesion formation.

Pathogenesis CO2 Pneumoperitoneum-Induced Metabolic Hypoxemia in a Rabbit Model

STUDY OBJECTIVE To investigate the effects of carbon dioxide (CO(2)) pneumoperitoneum-induced changes in blood gases, acid-base balance, and oxygen homeostasis in rabbits. DESIGN Prospective, randomized, controlled study (Canadian Task Force classification I). SETTING University training and teaching center. SUBJECTS Twenty-six adult female New Zealand white rabbits. INTERVENTION Anesthesia and pneumoperitoneum. MEASUREMENTS AND MAIN RESULTS In anesthetized rabbits arterial blood gases, acid-base balance, oxygenation values, and lactate concentrations were assayed during 2 hours. Spontaneous breathing, superficial and optimal ventilation without pneumoperitoneum, and with pneumoperitoneum at low (6 mm Hg) and higher (10 mm Hg) insufflation pressures were compared. The CO(2) pneumoperitoneum profoundly affected blood gases, acid-base balance, and oxygen homeostasis. Carboxemia with increasing end-tidal CO(2) and partial pressure of CO(2) (p <0.001), acidosis with decreasing pH (p <0.001), and base deficiency with decreasing actual base excess (p <0.001), standard base excess and standard bicarbonate and acid excess with increasing hydrogen bicarbonate (p <0.05 and <0.01) were found. Desaturation (p <0.01) with decreasing oxyhemoglobin p <0.05) and hemoglobin oxygen affinity (p <0.01) were also found. Carboxemia with acidosis was more pronounced with higher (p <0.01) than with lower (p >0.05) intraperitoneal pressures, and also with spontaneous breathing (p <0.05) and superficial ventilation (p <0.001) than with optimal ventilation, resulting in metabolic hypoxemia. CONCLUSION In superficially ventilated and spontaneously breathing rabbits, CO(2) pneumoperitoneum profoundly affected blood gases, acid-base balance, and oxygen homeostasis, resulting in metabolic hypoxemia. With optimal ventilation and low intraperitoneal pressure carboxemia, respiratory acidosis, and changes in oxygen metabolism were minimal.

Severe inflammatory reaction induced by peritoneal trauma is the key driving mechanism of postoperative adhesion formation

BackgroundMany factors have been put forward as a driving mechanism of surgery-triggered adhesion formation (AF). In this study, we underline the key role of specific surgical trauma related with open surgery (OS) and laparoscopic (LS) conditions in postoperative AF and we aimed to study peritoneal tissue inflammatory reaction (TIR), remodelling specific complications of open surgery (OS) versus LS and subsequently evaluating AF induced by these conditions.MethodsA prospective randomized study was done in 80 anaesthetised female Wistar rats divided equally into 2 groups. Specific traumatic OS conditions were induced by midline incision line (MIL) extension and tissue drying and specific LS conditions were remodelled by intraperitoneal CO2 insufflation at the 10 cm of water. TIR was evaluated at the 24th, 72nd, 120th and 168th hour by scoring scale. Statistical analysis was performed by the non-parametric t test and two-way ANOVA using Bonferroni post-tests.ResultsMore pronounced residual TIR was registered after OS than after LS. There were no significant TIR interactions though highly significant differences were observed between the OS and LS groups (p < 0.0001) with regard to surgical and time factors. The TIR change differences between the OS and LS groups were pronounced with postoperative time p < 0.05 at the 24th and 72nd; p < 0.01 - 120th and p < 0.001 - 168th hrs. Adhesion free wounds were observed in 20.0 and 31.0% of cases after creation of OS and LS conditions respectively; with no significant differences between these values (p > 0.05). However larger adhesion size (41.67 ± 33.63) was observed after OS in comparison with LS (20.31 ± 16.38). The upper-lower 95% confidential limits ranged from 60.29 to 23.04 and from 29.04 to 11.59 respectively after OS and LS groups with significant differences (p = 0.03). Analogous changes were observed in adhesion severity values. Subsequently, severe TIR parameters were followed by larger sizes of severe postoperative adhesions in the OS group than those observed in the LS group.ConclusionsMIL extension and tissue drying seem to be the key factors in the pathogenesis of adhesion formation, triggering severe inflammatory reactions of the peritoneal tissue surrounding the MIL resulting in local and systemic consequences. CO2 insufflation however, led to moderate inflammation and less adhesion formation.

Prevention of Adhesions with Crystalloids during Laparoscopic Surgery in Mice

STUDY OBJECTIVE To evaluate the effect of saline and Ringers lactate solutions in preventing adhesions during laparoscopic surgery in mice. DESIGN Prospective, randomized trial (Canadian Task Force classification I). SETTING Academic research center. SUBJECTS Ninety-two female Naval Medical Research Institute mice. INTERVENTION Adhesions were induced laparoscopically by opposing bipolar lesions in the uterine horns and pelvic sidewalls, and saline or Ringers lactate solution was added at different times during the procedure. MEASUREMENTS AND MAIN RESULTS Adhesions were scored quantitatively and qualitatively for extent, type, and tenacity after 7 days under microscopic vision during laparotomy. After 45 minutes of pneumoperitoneum, neither solution reduced adhesion formation, but when added immediately after surgery they did (p = 0.002). Coagulation was not significantly different with addition of either solution immediately after coagulation. In the third experiment the presence of fluid during pneumoperitoneum decreased adhesion formation (p = 0.0001) but Ringers lactate was more effective than saline (p = 0.0005). CONCLUSION Crystalloids reduced CO(2) pneumoperitoneum-enhanced adhesion formation in a laparoscopic mouse model, but Ringers lactate solution was more effective than saline.

Lymphocele prevention after pelvic laparoscopic lymphadenectomy by a collagen patch coated with human coagulation factors: a matched case-control study.

Objective Lymphoceles are among the most common postoperative complications of pelvic lymphadenectomy (PL), with a reported incidence of 1% to 50%. Symptoms are pelvic pain, leg edema, gastrointestinal obstruction, obstructive uropathy, and deep vein thrombosis, and severe complications such as sepsis and lymphatic fistula formation. After laparoscopic PL, we tested the prevention of lymphoceles using collagen patch coated with the human coagulation factors (TachoSil, Nycomed International Management GmbH, Zurich, Switzerland) on 55 patients with endometrial cancer stages IB to II who had undergone laparoscopy. Materials and Methods The authors divided the patients into 2 laparoscopy groups: PL plus TachoSil (group 1: 26 patients) and PL without TachoSil in a control group (group 2: 29 patients), as historical cohort of patients who underwent PL between 2010 and 2012. We collected surgical parameters, and the patients underwent ultrasound examination on postoperative days 7, 14, and 28. The main outcome measures were the development of symptomatic or asymptomatic lymphoceles, the need for further surgical intervention, as adverse effect of surgery, and the drainage volume and duration. Results The same number of lymph nodes in both groups was removed; group 1 showed a lower drainage volume. Lymphoceles developed in 5 patients in group 1 and in 15 patients in group 2; of these, only 2 patients were symptomatic in group 1 and 5 patients were symptomatic in group 2, without statistical difference and no percutaneous drainage request. Conclusions In this preliminary investigation, the intraoperative laparoscopy application of TachoSil seems to reduce the rate of postoperative lymphoceles after PL, providing a useful additional treatment option for reducing drainage volume and preventing lymphocele development after PL.

Impact of surgical approach on blood loss during intracapsular myomectomy

Abstract Background: Myomectomy is one of the most common surgical procedures in gynecology and has implications on fertility and subsequent pregnancies. We compared the impact of surgical approach on blood loss during laparoscopic and abdominal intracapsular myomectomy. Material and methods: The evaluation comprised 124 fertile women with subserous or intramural myomas: 66 patients treated by laparoscopy and 58 patients treated by laparotomy. The intracapsular myoma enucleation technique was similar for both approaches. All procedures were analyzed for the evaluation of intra- and post-surgical blood loss and intra- and short-term post-operative surgical outcomes. Results: The operating time for laparoscopic intracapsular myomectomy was longer (95 ± 7.2 min vs. 63 ± 5.6, p < 0.0001), but was associated with reduced intra- (65 ± ml vs. 105 ± 5, p < 0.0001) and post-surgical blood loss (30 ± 5 vs. 60 ± 5 ml, p < 0.0001), as well as diminished application of pain relief medication (8 patients vs. 17, p < 0.05), compared to open intracapsular myomectomy. Conclusions: The surgical approach did not substantially affect the technique of intracapsular myomectomy; however, laparoscopy significantly reduced intra- and postoperative blood loss and resulted in better short-term outcomes than after open surgery. Our results underscore the advantages of trying to reduce the rate of laparotomic myomectomy, one of the leading surgical interventions associated with infertility and sterility.

Reduction of CO2‐pneumoperitoneum‐induced metabolic hypoxaemia by the addition of small amounts of O2 to the CO2 in a rabbit ventilated model. A preliminary study

BACKGROUND CO(2)-pneumoperitoneum used in endoscopic surgery induces system effects by CO(2) absorption. This study investigated the effect of the addition of O(2) to CO(2)-pneumoperitoneum, upon CO(2) absorption. METHODS The effect of a pneumoperitoneum using 100% CO(2) or 94% CO(2) + 6% O(2) upon arterial blood gases, acid base and O(2) homeostasis was evaluated. In series A suboptimal ventilation and a pneumoperitoneum pressure (PP) of 10 mmHg was used. In series B adequate ventilation and PP of 6 mmHg was used. RESULTS CO(2)-pneumoperitoneum profoundly affected blood gases and acid base homeostasis i.e. increasing pCO(2), HCO(3)(P < 0.001) and lactate concentrations (P < 0.05) and decreasing pH, actual base excess and standard bicarbonate (P < 0.001), resulting in metabolic hypoxaemia with desaturation, lower pO(2) (P < 0.001) and O(2)Hb (P < 0.05). These effects were more pronounced with higher PP and suboptimal ventilation. CONCLUSION CO(2)-pneumoperitoneum profoundly affected blood gases and acid base homeostasis resulting in metabolic hypoxaemia. The addition of 6% of O(2) to the CO(2)-pneumoperitoneum prevented these effects to a large extent. If these preliminary data are confirmed in the human, the addition of a few percent of O(2) to CO(2) could become important for endoscopic surgery of long duration, especially in obese patients with limited cardiorespiratory adaptation and steep Trendelenburg.

The opioid neuropeptides in uterine fibroid pseudocapsules: a putative association with cervical integrity in human reproduction

Abstract The myoma pseudocapsule (MP) is a fibro-vascular network rich of neurotransmitters, as a neurovascular bundle, surrounding fibroid and separating myoma from myometrium. We investigated the distribution of the opioid neuropeptides, as enkephalin (ENK) and oxytocin (OXT), in the nerve fibers within MP and their possible influence in human reproduction in 57 women. An histological and immunofluorescent staining of OXT and ENK was performed on nerve fibers of MP samples from the fundus, corpus and isthmian-cervical regions, with a successive morphometric quantification of OXT and ENK. None of the nerve fibers in the uterine fundus and corpus MPs contained ENK and the nerve fibers in the isthmian–cervical region demonstrated an ENK value of up to 94 ± 0.7 CU. A comparatively lower number of OXT-positive nerve fibers were found in the fundal MP (6.3 ± 0.8 CU). OXT-positive nerve fibers with OXT were marginally increased in corporal MP (15.0 ± 1.4 CU) and were substantially higher in the isthmian–cervical region MP (72.1 ± 5.1 CU) (p < 0.01). The distribution of OXY neurofibers showed a slight into the uterine corpus, while are highly present into the cervico-isthmic area, with influence on reproductive system and sexual disorders manifesting after surgical procedures on the cervix.

Occiput posterior position diagnosis: vaginal examination or intrapartum sonography? A clinical review.

Abstract The occiput posterior (OP) position is one of the most frequent malposition during labor. During the first stage of labor, the fetal head may stay in the OP position in 30% of the cases, but of these only 5–7% remains as such at time of delivery. The diagnosis of OP position in the second stage of labor is made difficult by the presence of the caput succedaneum or scalp hair, both of which may give some problem in the identification of fetal head sutures and fontanels and their location in relationship to maternal pelvic landmarks. The capability of diagnosing a fetus in OP position by digital examination has been extremely inaccurate, whereas an ultrasound approach, transabdominal, transperineal and transvaginal, has clearly shown its superior diagnostic accuracy. This is true not only for diagnosis of malpositions, detected in both first and second stage of labor, but also in cases of marked asynclitism.

Mother‐to‐child transmission of HBV: review of current clinical management and prevention strategies

Mother‐to‐child transmission (MTCT) of HBV is responsible for approximately half of the HBV transmission routes and continues to be a challenging problem worldwide. Even after the development of effective vaccines and clear World Health Organization guidelines toward HBV several decades ago, 1–9% newborns of HBV‐carrying mothers still acquire HBV in early life as a result of in utero infection. The prevention of MTCT is of high importance, because chronically infected individuals function as a reserve for sustained HBV transmission, and 25% of them can develop asymptomatic liver cirrhosis and hepatocellular carcinoma. In this article, we review the canonical and novel HBV infection routes/mechanisms, influencing factors, diagnostic criteria, and interruption strategies for HBV MTCT. The preventative strategy of HBV MTCT has evolved from routine postpartum HB immune globulin (HBIG) plus HB vaccine schedules to administration of HBIG or nucleoside analogs during pregnancy and minimizing the exposure of maternal body fluids to the newborn during delivery. Copyright