Genetic Predisposition of Postoperative Adhesions Varies in Substrains of BALB/c Mice.

Postoperative adhesions are a major clinical problem because of the associated infertility, chronic pain, bowel obstruction, and the associated costs. Variability in adhesion formation was suggested by clinical observations that apparently similar interventions can cause little to severe adhesions. This is supported by the presence of polymorphisms and genetic predisposition to develop adhesions in animal models and humans. We previously demonstrated differences in postoperative adhesions between different mouse strains. In this study, we aimed to investigate the variability in adhesion formation in inbred substrains of BALB/c mice. Since genetic differences in inbred substrains are minimal, they might be an opportunity to tackle the genetics of adhesion formation.

N2O strongly prevents adhesion formation and postoperative pain in open surgery through a drug-like effect.

BACKGROUND: Microsurgical tenets and peritoneal conditioning during laparoscopic surgery (LS) decrease postoperative adhesions and pain. For a trial in human, the strong beneficial effects of N2O needed to be confirmed in open surgery (OS). RESULTS: In a mouse model for OS, the effect of the gas environment upon adhesions was evaluated. Experiment I evaluated desiccation and the duration of exposure to CO2, N2O or CO2 + 4%O2. Experiment II evaluated the dose-response curve of adding N2O to CO2. Experiment III compared humidified CO2 + 10% N2O during LS and OS.In OS, 30- and 60-min exposure to non-humidified CO2 caused mortality of 33 and 100%, respectively. Mortality was prevented by humidification, by dry N2O or dry CO2 + 4%O2. Adhesions increased with the duration of exposure to CO2 (p < 0.0001) and decreased slightly by humidification or by the addition of 4% O2. N2O strongly decreased adhesions at concentrations of 5% or greater. With humidified CO2 + 10% N2O, adhesion formation was similar in OS and LS. CONCLUSIONS: The drug-like and strong beneficial effect of low concentrations of N2O is confirmed in OS.

Corifollitropin alfa followed by hpHMG in GnRH agonist protocols. Two prospective feasibility studies in poor ovarian responders.

In two prospective uncontrolled feasibility trials, we examined the effect of corifollitropin alfa (CFA) followed by highly purified human menopausal gonadotrophin (hpHMG) in a short flare-up gonadotropin-releasing hormone (GnRH) agonist and a long GnRH agonist protocol for women with poor ovarian response. Overall, 45 patients were treated with short flare-up and 47 patients with the long agonist protocol. All patients received a single dose of 150 µg CFA, followed by 300 IU hpHMG 7 days later, triggering with 10 000 IU hCG, CSI and day 3 embryo transfer. Ongoing pregnancy rates (OPRs) did not differ between the short 15.6% and the long 17% agonist protocol (p = 0.85). Among patients treated with the short flare-up protocol, OPRs were 20% for younger patients (<40 years old) and 12% in older women (≥40 years old), p = 0.68. Similarly, in patients treated with the long agonist protocol younger women had an OPR of 26.7% versus 12.5% in older women, p = 0.23. Among patients treated with the short flare-up, live births rate were 15% and 4.3% for younger (<40 years old) and older patients (≥40 years old), respectively, p = 0.32. Similarly, in patients treated with the long agonist protocol, live births rate were 25% and 12.9% for younger (<40 years old) and older patients (≥40 years old), respectively, p = 0.41. None of the patients reported any serious adverse event related to treatment. According to our results, CFA followed by hpHMG in a short flare-up or long GnRH agonist protocol appears to be a feasible option for poor ovarian responders. Large phase III trials are mandatory prior to introduction in clinical practice.

A mixture of 86% of CO2, 10% of N2O, and 4% of oxygen permits laparoscopy under local anesthesia: a pilot study.

The aim of this study is to verify that 10 % of N2O in CO2 sufficiently reduces pain to permit laparoscopy under local anesthesia. In nine patients undergoing laparoscopy under local anesthesia for tubal sterilization, a mixture of 86 % of CO2, 10 % of N2O, and 4 % of oxygen (the Gas Mixture) was used for the pneumoperitoneum. For CO2, N2O, and for the Gas Mixture, the pain when blowing over the tongue tip and the pH changes of saline and Hartmann's solution were estimated. In all nine patients, discomfort was minimal and the intervention was well tolerated, similar to 100 % N2O. Tongue tip pain (n = 15), on VAS scale, was lower with 86 % CO2 + 10 % N2O + 4 % O2 (2.4 ± 1.4, P = 0.005) and much lower with 100 % N2O (0.3 ± 0.6, P < 0.0007) than with pure CO2 (3.6 ± 1.7). The pH of saline (n = 5) decreased from 7.00 ± 0.07 to 4.18 ± 0.04 (P = 0.001), 6.98 ± 0.08 (NS), and 4.28 ± 0.04 (P = 0.01) with 100 % CO2, 100 % N2O and the Gas Mixture, respectively. The pH of Hartmann's solution (n = 5) decreased similarly from 7.00 ± 0.07 to 5.18 ± 0.04 (P = 0.01), 7.02 ± 0.19 (NS), and 5.3 ± 0.4 (P = 0.01), respectively. These data demonstrate that a mixture with 10 % of N2O and 4 % of O2 in CO2 permits laparoscopy under local anesthesia. This result cannot be explained by direct irritation estimated by tongue tip pain or by pH changes.

Live birth rates in Bologna poor responders treated with ovarian stimulation for IVF/ICSI.

This retrospective study determined the efficacy of ovarian stimulation for IVF/intracytoplasmic sperm injection (ICSI) in poor ovarian responders fulfilling the Bologna criteria for poor ovarian response and identified predictors of live birth rates. Overall, 485 patients undergoing 823 ovarian stimulation cycles for IVF/ICSI with maximum gonadotrophin dose (≥ 300 IU) between January 2009 and December 2011 were included. Patients were considered eligible, irrespective of the treatment protocol, if they were classified as poor responders based on the recently developed definition for poor ovarian response by the European Society of Human Reproduction and Embryology, the Bologna criteria. Live birth rates did not significantly differ between women aged <40 and women aged ≥ 40 years either per cycle (7.1 versus 5.2%, OR 1.38, 95% CI 0.77-2.46) or per patient (11.6 versus 8.8%, OR 1.36, 95% CI 0.75-2.46). In logistic regression analysis, the number of oocytes retrieved was the only variable significantly associated with live births (OR 1.92, 95% CI 1.03-3.55 for >3 versus 1-3 oocytes). Bologna poor responders demonstrate very low live birth rates, irrespective of age and treatment protocol used. An increase in the number of oocytes retrieved is an independent variable related to live birth rates.

Conditioning of the abdominal cavity reduces tumor implantation in a laparoscopic mouse model.

PURPOSE: The addition of 4 % O2 and 10 % N2O to the CO2 pneumoperitoneum (PP), together with slight cooling and humidification (conditioning), contributes to reducing adhesions by preventing mesothelial damage. We investigated the effect of peritoneal damage during laparoscopy on tumor implantation. METHODS: In Experiment 1, different tumor cell concentrations were injected into control mice without PP and into mice with 60-min dry CO2PP (mesothelial damage). In Experiment 2, tumor cells were injected into control mice (group I) and in mice with mesothelial damage (group II). In groups III to VI, mesothelial damage was decreased by adding humidification, humidification + 10 % N2O, humidification + 10 % N2O + 4 % O2, and conditioning, respectively. RESULTS: In Experiment 1, the tumors increased with the number of cells injected and with mesothelial damage in the abdominal cavity (p = 0.018) and abdominal wall (p < 0.0001). Experiment 2 confirmed that 60 min of dry CO2PP increased the number of tumors in the abdominal cavity and wall (p = 0.026 and p = 0.003, respectively). The number of tumors was decreased in the abdominal cavity by conditioning (p = 0.030) and in the abdominal wall using humidified CO2 (p = 0.032) or conditioning (p = 0.026). CONCLUSIONS: Tumor implantation was enhanced by peritoneal damage (60 min of dry CO2PP and desiccation), but this was prevented by conditioning. If confirmed in humans, conditioning would become important for oncologic surgery.

Peritoneal full-conditioning reduces postoperative adhesions and pain: a randomised controlled trial in deep endometriosis surgery.

BACKGROUND: To translate the concept of full-conditioning (FC) from animal experiments to the human, and to evaluate the efficacy for adhesion prevention. FC consisted of decreasing acute inflammation by 86% CO2+ 10% N2O + 4% O2 for the pneumoperitoneum, cooling of the peritoneal cavity, humidification, heparinized rinsing solution and 5 mg of dexamethasone as demonstrated in animal models. METHODS: A randomized controlled trial (RCT: NCT01344486) comparing standard laparoscopy with full conditioning together with a barrier in a 2/3 ratio in 44 women undergoing deep endometriosis surgery at KULeuven. The primary aim was reduction of adhesions. Secondary aims were CO2 resorption, postoperative pain and recovery. Randomization was performed after signing informed consent. Adhesion scoring during second look laparoscopy and pain scoring were done blindly. RESULTS: In the FC group (n = 16) adhesions were completely prevented in 12/16 women whereas in the control group (n = 11) all women had severe adhesions (P < 0.0005). Also the area, density and severity of adhesions were less. (P <0.001). In the control group, severity, density and area of adhesions were strongly interrelated (P = 0.0001 for all areas) suggesting a common enhancing factor. In the FC group CO2 resorption (P < 0.001), postoperative pain (P < 0.001), and CRP concentrations (P < 0.01) were lower while clinical recovery was faster (P < 0.0001) and time to first flatus (P < 0.002) shorter. IN CONCLUSION: This translational research confirms in the human the efficacy of FC in reducing CO2 resorption and adhesions with in addition less postoperative pain, lower postoperative CRP concentrations and an accelerated recovery.

Addition of nitrous oxide to the carbon dioxide pneumoperitoneum strongly decreases adhesion formation and the dose-dependent adhesiogenic effect of blood in a laparoscopic mouse model.

OBJECTIVE: To evaluate the effect of addition of nitrous oxide (N2O) to the carbon dioxide (CO2) pneumoperitoneum (PP) and the effect of blood, plasma, or red blood cells (RBCs) on postoperative adhesions in a laparoscopic mouse model. DESIGN: Prospective randomized controlled trial. SETTING: University laboratory research center. ANIMAL(S): BALB/c female mice. INTERVENTION(S): The effect of adding to the 60-minute CO2 PP 5%, 10%, 25%, 50%, or 100% N2O on adhesion formation was evaluated. Subsequently the effect of adding 1 mL blood, or RBCs, or plasma and the effect of adding different concentrations of blood were studied. Finally, the effect of adding 10% N2O, 4% O2, or both to the CO2 was evaluated in a control group and after addition of blood. MAIN OUTCOME MEASURE(S): Postoperative adhesions after 7 days. RESULT(S): N2O strongly reduces adhesion formation with a full effect at a concentration of 5% or 10%. Adhesions increase linearly with 0.125 mL to 1 mL blood. In both the control group and after adding blood, 10% N2O is the most effective factor in prevention of adhesions. CONCLUSION(S): N2O, from concentrations of 5% upward, strongly prevents adhesion formation. Blood, mainly the plasma, increases adhesion formation. These data extend the concept of the role of acute inflammation and support the importance of good surgical practice with little bleeding and peritoneal cavity conditioning in adhesion prevention.

Intraperitoneal temperature and desiccation during endoscopic surgery. Intraoperative humidification and cooling of the peritoneal cavity can reduce adhesions.

This study was conducted to document quantitatively the intraperitoneal temperature and desiccation during laparoscopic surgery. The temperature, relative humidity, and flow rate were measured in vitro and during laparoscopic surgery, at the entrance and at the exit of the abdomen. This permitted us to calculate desiccation for various flow rates using either dry CO(2) or CO(2) humidified with 100% relative humidity at any preset temperature between 25 and 37°C. The study showed that desiccation, both in vitro and in vivo, varies as expected with the flow rates and relative humidity while intraperitoneal temperature varies mainly with desiccation. Temperature regulation of bowels is specific and drops to the intraperitoneal temperature without affecting core body temperature. With a modified humidifier, desiccation could be eliminated while maintaining the intraperitoneal temperature between 31 to 32°C.

The impact of the learning curve on adhesion formation in a laparoscopic mouse model.

OBJECTIVE: To evaluate the impact of surgeon training on adhesion formation in a laparoscopic mouse model. Laparoscopic surgery and bowel manipulation was demonstrated to enhance postoperative adhesion formation. DESIGN: Prospective randomized, controlled trial. SETTING: University laboratory research center. ANIMAL(S): 200 BALB/c and 200 Swiss female mice. INTERVENTION(S): Adhesions were induced by opposing bipolar lesions and 60 minutes of pneumoperitoneum. Each surgeon operated on 80 mice (40 Swiss and 40 BALB/c), the only variable thus being his/her increasing experience. Some surgeons were already experienced gynecologists, others were starting their training. MAIN OUTCOME MEASURE(S): End points were the duration of surgery while performing the lesions. The adhesion formation was scored quantitatively (proportion and total) and qualitatively (extent, type, and tenacity) after 7 days. RESULT(S): With training, duration of surgery and adhesion formation decreased exponentially for all surgeons, whether experienced or not. Experienced surgeons had initially a shorter duration of surgery, less adhesion formation, and less de novo adhesions than inexperienced surgeons. CONCLUSION(S): These data suggest that laparoscopic skills improve with training, leading to a decrease in the duration of surgery and formation of adhesions. Therefore completion of a standardized learning curve should be mandatory when initiating adhesion formation studies both in laboratory or clinical setting.

Postoperative inflammation in the abdominal cavity increases adhesion formation in a laparoscopic mouse model.

OBJECTIVE: To investigate acute inflammation in the peritoneal cavity in adhesion formation. DESIGN: Prospective randomized, controlled trial. SETTING: University laboratory research center. ANIMAL(S): 9- to 10-week-old BALB/c female mice. INTERVENTION(S): In a laparoscopic mouse model, acute inflammation in the peritoneal cavity evaluated in CO(2) pneumoperitoneum enhanced adhesions, by CO(2) pneumoperitoneum plus manipulation, and in the latter group plus dexamethasone. MAIN OUTCOME MEASURE(S): Qualitative and quantitative adhesion scores and an acute inflammation score (neoangiogenesis, diapedesis, and leukocyte accumulation). RESULT(S): Adhesions at the lesion site were enhanced by the CO(2) pneumoperitoneum, further enhanced by manipulation, and decreased by the administration of dexamethasone. The acute inflammation scores (total, neoangiogenesis, diapedesis, and leukocyte accumulation) strongly correlated with the total adhesion score. Inflammation scores were similar at both the surgical lesion and the parietal peritoneum. CONCLUSION(S): Acute inflammation of the entire peritoneum cavity is an important mechanism involved in adhesion formation and enhances adhesion formation at the lesion site.

Effect of upper abdomen tissue manipulation on adhesion formation between injured areas in a laparoscopic mouse model.

STUDY OBJECTIVE: These experiments were designed to examine the effect of manipulation during surgery as a cofactor in adhesion formation at trauma sites. DESIGN: Randomized, controlled trial. Canadian Task Force Classification-class 1. SETTING: University laboratory research center. SUBJECTS: A standardized laparoscopic mouse model (Balb\c mice 9-10 weeks old) for adhesion formation after opposing bipolar lesions and 60 minutes of carbon-dioxide pneumoperitoneum. In this model adhesions are known to decrease after the addition of 3% of oxygen, dexamethasone, or both. In addition, adhesions decrease with experience (i.e., with a decreasing amount of manipulation during the learning curve). INTERVENTIONS: A factorial design was used to evaluate the effects of dexamethasone and of adding 3% of oxygen on manipulation-enhanced adhesion formation during a learning curve. Blocks of 4 animals were thus randomized as controls (carbon-dioxide pneumoperitoneum only) or received an additional 3% of oxygen, dexamethasone, or both. In a second experiment, the effects of manipulation on adhesion formation were quantified. In a third experiment we evaluated whether dexamethasone had a specific effect on manipulation-enhanced adhesion formation. MEASUREMENTS AND MAIN RESULTS: Qualitative and quantitative adhesion scoring 7 days after the intervention. The first experiment confirmed that adhesion formation decreased during the learning curve (p <.0001) and after the addition of dexamethasone whether assessed as the total adhesion score (p <.0001 and p =.0009, respectively) or a quantitative score (p <.0001 and p <.0001, respectively). The second experiment showed that adhesion formation increased by standardized touching and grasping of omentum and bowels (proportion score p =.0059 and p =.0003, respectively) and this effect increased with duration of touching (p =.0301). In the third experiment, dexamethasone was confirmed to decreased adhesion formation (p =.0001) but this effect was not specific for manipulation-enhanced adhesion formation. CONCLUSION: Manipulation of intraperitoneal organs in the upper abdomen enhances adhesion formation at trauma sites, confirming that the peritoneal cavity is a cofactor in adhesion formation. Dexamethasone decreases adhesion formation but the effect is not specific for manipulation-enhanced adhesion formation.

Intercoat gel (oxiplex): efficacy, safety, and tissue response in a laparoscopic mouse model.

STUDY OBJECTIVE: To study the efficacy and safety of Intercoat gel in a laparoscopic mouse model with pneumoperitoneum-enhanced adhesion formation. DESIGN: Randomized controlled trial. Evidence obtained from a properly designed, randomized, controlled trial (Canadian Task Force classification I). SETTING: University laboratory research center. SUBJECTS: Balb\c female mice 9 to 10 weeks old. INTERVENTIONS: Two laparoscopic mouse models for adhesion formation were used. In the first model, adhesions following bipolar opposing lesions in the pelvis were enhanced by 60 minutes of carbon-dioxide pneumoperitoneum. In the second model, adhesions were further enhanced by bowel manipulation. The first experiment evaluated the efficacy of Intercoat in both models. The second experiment evaluated the efficacy of Intercoat in the first model, when applied immediately on the lesion, when applied at the end of the pneumoperitoneum, and when applied in the upper abdomen. Biopsy specimens were taken after 7 days and were evaluated after hematoxylin-eosin and CD45 staining. MEASUREMENTS AND MAIN RESULTS: Qualitative and quantitative adhesion scoring. Morphology was evaluated by standard light microscopy. In both models, Intercoat decreased adhesion formation whether applied immediately on the lesion or at the end of the pneumoperitoneum (qualitative and quantitative scoring p <.0001 and p <.0001, respectively). Intercoat application is associated with tissue redness, vascular congestion, and cellular edema but without an inflammatory reaction. Applied in the upper abdomen, Intercoat does not increase adhesions, but decreases adhesions at higher doses (p =.0024). Intercoat in high doses had a toxic effect (p =.0058). CONCLUSION: Intercoat is an effective antiadhesion product. It is associated with tissue edema and vasodilatation as observed after 7 days both macroscopically and by histology.

Pathophysiology of cyclic hemorrhagic ascites and endometriosis.

Massive hemorrhagic ascites (4470 mL, range 1-10 L) in women with endometriosis is a rare condition occurring predominantly in black women. Of the 43 case reports published, 42 are compatible with the hypothesis that the hemorrhagic ascites is predominantly a consequence of excessive ovarian transudation similar to a Meigs syndrome. Indeed, bilateral ovariectomy cures the condition without recurrences, whereas after unilateral ovariectomy or cystectomy recurrence rate is more than 50%; during ovarian suppression by luteinizing hormone-releasing hormone agonist ascites disappears, but reappears after treatment. Superficial pelvic endometriosis also contributes to the ascites because after superficial endometriosis destruction the recurrence rate is only 4 in 14. Based on these data, it is suggested, to scrutinize the ovaries for tumors given the analogy with Meigs syndrome. In women desiring fertility, conservative treatment with destruction of endometriosis only can be attempted given the cure rate of some 20%. It is unknown what the effect of ovulation induction would be.

Tension-free Vaginal Tapes and Pelvic Nerve Neuropathy.

Obturator nerve neuropathies after tension-free vaginal tape or transobturator tape are considered to be caused by nerve trauma, although it is unclear whether these are accidents or whether these injuries are inherent to the procedure of tape insertion. Two cases show that obturator nerve neuropathy can occur after tension-free vaginal tape without direct trauma to the obturator nerve possibly as a consequence of excessive fibrotic reaction or persisting low-grade inflammation. PubMed Entrez, Cochrane Library, and up-to-date databases were searched for obturator and pudendal neuropathy and for neuropathies associated with tension-free vaginal tape-transobturator tape and the symptoms, diagnosis, and therapy of the pudendal and obturator nerve neuropathies are reviewed. Based on data, our experience, and data available in literature, we can conclude that, if conservative obturator nerve block confirms the diagnosis of obturator nerve neuropathy and symptoms recur shortly thereafter, a laparoscopic neurolysis can be proposed as therapy.