Intraperitoneal Pressure Research Articles

The Factors Affectıng The Effıcıency Of Contınuous Ambulatory Perıtoneal Dıalysıs In Chıldren

Objective: Peritoneal dialysis is a complex and variable process. Many factors can affect efficiency of dialysis, and relevant mortality and morbidity rates. Efficient dialysis is important in improving quality of life as well as reducing the morbidity and mortality rates. Dialysis fill volume, intraperitoneal pressure and ultrafiltration (UF) are important variables that determine dialysis efficiency. We aimed to investigate the factors affecting dialysis efficiency and to determine necessities to develop a more effective dialysis program. Methods: Sixteen continuous ambulatory peritoneal dialysis (CAPD) patients between the ages of 7 and 19 years who were followed up in the Pediatric Nephrology Department were included in the study. Patients who had peritonitis, surgical or medical complications in the last 6 months were excluded from the study. Demographic data, duration of dialysis, hemogram, urea, creatinine, albumin, glucose levels, intraperitoneal pressures, peritoneal equilibration test (PET) and Kt/Vurea test results were recorded. Results: Mean Kt /Vurea, dialysis fill volume, UF, intraperitoneal pressure, Hb and serum albumin were found as 2.5±0.93 (1.22-4.64), 1123.4±126.86 (875-1360) ml/m2, 600.1±382.15 (85 -1375) ml, 12.9±2.77 (8.5-19) cm/H2O, 9.0±1.54 (6.3-11.8) gr/dl and 3.6±0.61 (2.45-4.8) gr/dl, respectively. A statistically significant relationship was shown between UF and Kt/Vurea (p=0.04). The mean duration of dialysis was 54±36 months. The majority of the cases had high (37.5%) and medium-high (31.25%) peritoneal permeability. High permeability was found to have a significant relationship with the duration of dialysis (p=0.04). Conclusion: Efficient peritoneal dialysis depends on preserved ultrafiltration. Therefore, the dialysate volume should be calculated according to the intraperitoneal pressure and dialysis should be adjusted according to the permeability properties of the peritoneal membrane.

Expediency of abdominal drainage after operative delivery in severe preeclampsia

One of the leading mechanisms for the development of severe preeclampsia in pregnant women is a decrease in perfusion pressure in the life-supporting organs, followed by the development of multiple organ failure. In recent years, there have been studies indicating the influence of intraperitoneal hypertension on the perfusion pressure of the pelvic and abdominal organs with the subsequent development of obstetric complications [ 4,2] according to the classification of JAN(2006), pregnancy is included in the list of conditions accompanied by an increase in intraperitoneal pressure. Thus, the prevention and treatment of increased intra-abdominal pressure in pathology accompanied by multiple organ dysfunction and insufficiency, which is observed in preeclampsia, is one of the important problems of modern medicine. The purpose of our study was to determine the feasibility of abdominal drainage during operative delivery for severe preeclampsia.

Intraperitoneal pressure: Stability over time and validation of Durand's measurement method.

Intraperitoneal pressure (IPP) is gaining consideration as a relevant parameter of peritoneal dialysis (PD) in adults, although many of its aspects are still pending clarification. We address here its stability over time and the validity of the usual method of clinical measurement, as proposed by Durand in 1992 but never specifically validated. We performed this validation by comparing Durand's method and direct measurements with a central venous pressure system. We performed a total of 250 measurement pairs in 50 patients with different intraperitoneal volumes plus in-vitro measurements with a simulated peritoneum. Absolute differences between the two systems in vivo were 0.87 ± 0.91 cmH2O (range 0-5 cmH2O); only 6.4% of them were ≥3 cmH2O. In vitro results for both methods were identical. We also compared IPP measurements in the same patient separated by 1-4 h (514 measurement pairs in 136 patients), 1 week (92 pairs in 92 patients), and 2 years (34 pairs in 17 patients). Net differences of measurements separated by hours or 1 week were close to 0 cmH2O, with oscillations of 1.5 cmH2O in hours and 2.3 cmH2O in 1 week. IPP measured 2 years apart presented a net decrease of 2.5 ± 4.9 cmH2O, without correlation with body mass index changes or any other usual parameter of PD. In hours, 7% of IPP differences were >3 cmH2O, 22% in 1 week, and 50% in 2 years. In conclusion, Durand's method is precise enough to measure IPP in peritoneal dialysis. This parameter is not stable over long timescales, so it is necessary to use recent measurements.

Effect of initiation of renal replacement therapy on mortality in acute pancreatitis patients.

This study aims to explore effect of initiation of renal replacement therapy (RRT) on mortality in acute pancreatitis (AP) patients. In this study, a total of 92 patients from the surgical intensive care unit (SICU) of the Second Affiliated Hospital of Harbin Medical University who were diagnosed with AP and underwent RRT or not between January 2014 and December 2018 were included in this retrospective study. Demographic and clinical data were obtained on admission to SICU. Patients were divided into early initiation of RRT group (n = 44) and delayed initiation of RRT group (n = 48). Duration of mechanical ventilation (MV), intra-peritoneal pressure, vasopressors infusion, body temperature, procalcitonin, creatinine, platelet counts, length of hospital stay and prognosis were recorded during hospitalization, and then compared between groups. Patients with delayed initiation of RRT exhibited significantly higher APACHE II score, SOFA score and lower GCS score than those with early initiation of RRT (P < 0.001, <0.001, = 0.04, respectively). No difference in the rest of the baseline data and vasopressors infusion was found. Dose of Norepinephrine, maximum and mean PCT, maximum and mean creatinine, maximum and mean intra-peritoneal pressure, length of hospital stay, prognosis of ICU and hospitalization showed significant difference between groups. Early initiation of RRT may be beneficial for AP patients, which can provide some insight and support for patients’ treatment in clinic.

APD or CAPD: one glove does not fit all.

The use of Automated Peritoneal Dialysis (APD) in its various forms has increased over the past few years mainly in developed countries. This could be attributed to improved cycler design, apparent lifestyle benefits and the ability to achieve adequacy and ultrafiltration targets. However, the dilemma of choosing the superior modality between APD and Continuous Ambulatory Peritoneal Dialysis (CAPD) has not yet been resolved. When it comes to fast transporters and assisted PD, APD is certainly considered the most suitable Peritoneal Dialysis (PD) modality. Improved patients’ compliance, lower intraperitoneal pressure and possibly lower incidence of peritonitis have been also associated with APD. However, concerns regarding increased cost, a more rapid decline in residual renal function, inadequate sodium removal and disturbed sleep are APD’s setbacks. Besides APD superiority over CAPD in fast transporters, the other medical advantages of APD still remain controversial. In any case, APD should be readily available for all patients starting PD and the most important indication for its implementation remains patient’s choice.

Effects of Low Intraperitoneal Pressure on Quality of Postoperative Recovery after Laparoscopic Surgery for Genital Prolapse in Elderly Patients Aged 75 Years or Older

Previous clinical trials for laparoscopic surgery have included few elderly patients aged ≥75 years. We aimed to evaluate the quality of postoperative recovery after laparoscopic surgery using low intraperitoneal pressure (IPP) (6 mm Hg) and warmed, humidified carbon dioxide gas for genital prolapse in elderly patients aged ≥75 years. Prospective consecutive case series. University hospital. Consecutive patients (n = 30) aged ≥75 years planning to undergo laparoscopic surgery for genital prolapse by the same surgeon were recruited from October 2016 through December 2019. Laparoscopic promontofixation for the treatment of genital prolapse was performed using low IPP and warmed, humidified carbon dioxide gas. When a promontory could not be easily identified, laparoscopic pectopexy was alternatively performed. The primary outcome was the Quality of Recovery-40 (QoR-40) score at 24 hours postoperatively. The secondary outcomes were postoperative pain using a 100-mm visual analog scale and the length of hospital stay after surgery (LHSS). For the global QoR-40 score and for 4 dimensions of the QoR-40, "emotional state," "physical comfort," "psychologic support," and "pain," no differences were observed between the baseline score and the score at 24 hours. The score for the "physical independence" dimension at 24 hours was significantly lower than the baseline score (p <.001). No patient had visual analog scale pain scores >30 out of 100 at 12 hours or later. LHSS was <48 hours in 22 patients (73.3%) and <72 hours in 8 patients (26.7%). Multivariable analysis showed that the odds of an LHSS >48 hours were more than 8 times higher in patients who were discharged from the operating room in the afternoon compared with those with a morning discharge. The use of a low IPP is feasible, safe, and has clinical benefits for elderly patients aged ≥75 years who undergo laparoscopic surgery for genital prolapse.

Intraperitoneal Pressure in Polycystic and Non-Polycystic Kidney Disease Patients, Treated by Peritoneal Dialysis

Introduction: Intraperitoneal volume (IPV) should be individualized and aimed to maintain an intraperitoneal pressure (IPP) lower than 17 cm H₂O. IPP is very variable, given its relation with body size. However, it is not yet fully understood which anthropometric variable mostly affects IPP and the relation between IPP and organomegaly in polycystic kidney disease (PKD) patients is not known. Objectives: The aim of the present study was to analyse the relation between antropometric variables and IPP in a large cohort of peritoneal dialysis (PD) patients and to identify if a relation between nephromegaly and IPP exists in PKD patients. Methods: IPP was measured in PD patients and data was retrospectively collected. In PKD patients, total kidney volumes were measured in CT scans, and normalized with height (hTKV). Results: Seventy-seven patients were included in the study, 18% affected by PKD. Mean IPP was 14.9 ± 2.9 cm H₂O and it showed significant positive correlation with body mass index (BMI; ρ = 0.42, p < 0.001). No correlation was found between IPP and absolute IPV; conversely, IPP has a significant inverse correlation with IPV normalized with BMI and body surface area (ρ –0.38, p = 0.001 and ρ –0.25, p = 0.02, ­respectively). Patients with IPP >17 cm H₂O have significant larger BMI and lower IPV/BMI compared to those with IPP <17 cm H₂O (29 ± 3.6 vs. 26 ± 4 kg/m², p < 0.05 and 97 ± 15.5 vs. 109 ± 22 mL/kg/m², p < 0.05). PKD patients have a wide variability in hTKV (range 645–3,787 mL/m²) and it showed a significant correlation with IPP/IPV (ρ = 0.6, p < 0.05). Conclusions: Patients with larger BMI have greater IPP, irrespectively to IPV. In PKD patients, hTKV correlate with IPP/IPV ratio. However, given the wide range of distribution of hTKV, increased IPP cannot be presumed because of pre-existing polycystic kidney, but need to be quantified.

Ascites-induced compression alters the peritoneal microenvironment and promotes metastatic success in ovarian cancer

The majority of women with recurrent ovarian cancer (OvCa) develop malignant ascites with volumes that can reach > 2 L. The resulting elevation in intraperitoneal pressure (IPP), from normal values of 5 mmHg to as high as 22 mmHg, causes striking changes in the loading environment in the peritoneal cavity. The effect of ascites-induced changes in IPP on OvCa progression is largely unknown. Herein we model the functional consequences of ascites-induced compression on ovarian tumor cells and components of the peritoneal microenvironment using a panel of in vitro, ex vivo and in vivo assays. Results show that OvCa cell adhesion to the peritoneum was increased under compression. Moreover, compressive loads stimulated remodeling of peritoneal mesothelial cell surface ultrastructure via induction of tunneling nanotubes (TNT). TNT-mediated interaction between peritoneal mesothelial cells and OvCa cells was enhanced under compression and was accompanied by transport of mitochondria from mesothelial cells to OvCa cells. Additionally, peritoneal collagen fibers adopted a more linear anisotropic alignment under compression, a collagen signature commonly correlated with enhanced invasion in solid tumors. Collectively, these findings elucidate a new role for ascites-induced compression in promoting metastatic OvCa progression.

The role of intraperitoneal hypertension in the development of postoperative eventration in cancer patients

Despite the development of modern surgery, postoperative surgery continues to be one of the most dangerous complications, especially in patients with malignant tumors of the abdominal cavity, where there are phenomena of secondary immunodeficiency, cachexia, anemia, etc. occur. One of the many factors that directly lead to postoperative surgery is the sharp increase in intraperitoneal pressure, which is quite common in cancer patients in the early postoperative period. The study of the frequency of development of the postoperative eventration, depending on the level of intraperitoneal and abdominal perfusion pressures in patients with cancer of the abdominal organs, will allow determining the role of the latter in the development of this postoperative complication. The purpose of the research is to study the frequency of postoperative event development in patients with malignant tumors of the abdominal cavity, depending on the level of intraperitoneal and abdominal perfusion pressures.Material and methods. We examined 122 operated patients with malignant tumors of the abdominal cavity, which underwent a median laparotomy. Depending on the average level of HRT patients are divided into three groups. The first group consisted of 57 (46.7%) individuals with a mean IVT level below 12 mmHg. The second group consisted of 40 (32.8%) with an average HFT level of 12 - 17 mmHg. The third group consisted of 25 (20.5%), with an average TBI of over 18 mmHg. Depending on the average level of APT, the first group consisted of 48 (39.3%) individuals with an average level of APT above 90 mmHg. The second group was 43 (35.3%) with an average level of APT - 89 - 56 mmHg. The third group consisted of 31 (25.4%), in whom the average level of APT was less than 55 mmHg.Results. The results of the study indicate a significant difference in the incidence of postoperative events in groups of patients with higher TBI and, respectively, lower APT (study groups 2 and 3). This proves a certain relationship between the levels of HRT, APT and the frequency of postoperative event development.Conclusion. The frequency of development of postoperative events is directly dependent on the levels of intraperitoneal and abdominal perfusion pressures in the early postoperative period, which makes it possible to consider the latter as one of the factors of development of this complication and markers of its prognosis.

SO007OVERHYDRATION TREATMENT WITH COMBINED CRYSTALLOID AND COLLOID PD SOLUTION

Abstract Background and Aims Peritoneal dialysis (PD) fluids used colloid or crystalloid solutions to achieve ultrafiltration. Here we presented our clinical experience with the intraperitoneal (IP) use of mixed solutions (MS) (crystalloid plus colloid) to treat overhydration. Method We studied the kinetics of 4-hour single-dwell exchange using 2L MS in 3 different sessions. We analysed IP fluids and IP pressure at 0,30,60,120 and 240 min plus blood samples at 0, 120 and 240 min. MS kinetics were compared with standard 4-hour 3.86 % glucose (GS) exchange. MS composition. We modified a single-dwell exchange of 2L Icodextrin (Extraneal, Baxter®) by adding a continuous 50% glucose infusion (50g Glucose per 100mL) in an aseptic technique through infusion pump (42 ml/h) over 4 hours. Results MS exchange induced a progressive increase in IP pressure with an inverse decrease in IP sodium, without significant changes in IP glucose or osmolarity. MS exchanges were well tolerated without side effects (total 25 sessions). We did not observe any remarkable change in bloods samples during the MS exchange. The combination fluid enhanced net ultrafiltration (mean 1030 ml) compared with GS (650 ml). Although the net glucose dispensed was slightly higher with MS (79 g MS vs 77.2 g GS), similar net glucose absorption was observed (49.8 g MS vs 49.9g GS) and smaller maximum intraperitoneal glucose levels (1739 mg/dL at 120 min with MS vs 2695 mg/dL with GS at 0 min). GS induced a faster initial reduction in dialysate sodium concentration while MS maintained the sodium sieving over 4-hour dwell enhancing net ultrafiltration due to sustained IP glucose concentration. Conclusion The combination fluid could be a new strategy to enhance ultrafiltration in PD patients, leaded by colloid osmosis at the beginning of PD exchange maintained by crystalloid osmosis. Figure (A) Intraperitoneal kinetics of MIXED SOLUTION for IP sodium (Na+ PF), Osmolarity PF and intraperitoneal pressure. (B, C, D) Comparison between MIXED SOLUTIONS (black line) vs Glucose solution 3,86 % (gray line) intraperitoneal kinetcs for sodium (B), intraperitoneal pressure (C) and glucose (D).

P1158DOES THE PERITONEUM SWELLS OR SHRINK DURING PERITONEAL DIALYSIS?

Abstract Background and Aims The width of the peritoneum (composed mainly of connective tissue and relatively free of vasculature) is increased in patients on peritoneal dialysis compared to healthy subjects. We investigated to what extent increased intraperitoneal (ip) hydrostatic and osmotic pressures following the infusion of dialysis fluid will change hydration status and width of the peritoneum. Method Using linear theory of poroelasticty, clinical data on transport parameters and experimental data on elastic characteristics of the interstitium, the relative change of the width of the poroelastic layer subject to the combined effect of external hydrostatic and effective osmotic pressures (that is, ideal osmotic pressure multiplied by reflection coefficient for osmotic agent) can be described as a function of effective pressure and elastic modulus of the layer: Lmod/L0 = 1/(1-deltaP*/lambda*), where L0 is initial thickness of the tissue, Lmod is modified thickness of the layer, deltaP* is change in effective combined pressure, and lambda* is the elastic modulus of the poroelastic material. The same formula describes also the change in fractional free fluid volume ratio, thetaF. The elastic modulus of the connective tissue was assumed to be 110 mmHg, as measured for the subcutaneous layer of the tip of mouse tail by Swartz et al (J Biomech, 1999), and reflection coefficient for glucose in the interstitium of 0.0035 as estimated by Stachowska-Pietka et al (NDT, 2019) from clinical data for patients on peritoneal dialysis. Results The ip hydrostatic pressure increases by 2-3 mmHg to 15 mmHg at rest depending on infused volume of dialysis fluid (and posture, body weight and location in abdominal cavity), and may increase to 100 mmHg during activities as coughing, whereas the osmotic pressure of glucose 3.86% dialysis fluid is around 400 mmHg above the osmotic pressure of plasma and interstitial fluid (in equilibrium with plasma). However, due to the low reflection coefficient of interstitium, the effective osmotic pressure of dialysis fluid minus the physiological value of interstitial osmotic pressure is only 1.4 mmHg, and is quickly decreasing with dwell time. Therefore, hydrostatic pressure is the dominant factor for interstitial hydration. Assuming ip pressure of 15 mmHg, the stretch of the peritoneum increases its equilibrium width (at 0 mmHg and isotonic interstitial fluid) by 15%. During physical activities peritoneum may transiently thicken even more. Conclusion The peritoneum becomes overhydrated after infusion of dialysis fluid, which increases interstitial hydrostatic pressure; the thickness and fractional free fluid volume of the peritoneum increase by 15% although transiently higher increases may occur following activities that increase intraperitoneal pressure. The mechanical changes in the peritoneum may contribute to the biological changes in cells present there, as fibroblasts and mesothelial cells. The swelling of the peritoneum is in agreement with the increase in the fractional free fluid volume of the intramuscular interstitium behind the peritoneum as reported by Zakaria et al (Am J Physiol Heart Circ Physiol, 1999).

P1232COMPUTED TOMOGRAPHIC PERITONEOGRAPHY - GUARANTYING SAFER SURGICAL STRATEGIES

Abstract Background and Aims Peritoneal Dialysis (PD) is currently the first option as renal replacement therapy to many patients, for several reasons, as personal flexibility, volemic management in cardiorenal patients, poor vascular access to dialysis, among others. Mechanical complications can be a drawback in these patients, which may occur during or after catheter placement. Abdominal wall hernias and dialysate leaks are relatively common and highly related to chronically increased intraperitoneal pressure. In this setting CT peritoneography is the technique of choice as it allows differentiation between a true hernia or a wall leakage. Method We describe a case of a 69-year-old man, with a personal history of polycystic kidney disease, colonic diverticulosis and hypertension, which opted for PD. The patient later developed a mechanical complication for which a proper diagnostic approach, namely through specific imaging, and surgical planning were essential. Results After 15 months without complications, it was detected a bulging in the periumbilical area, exacerbated by orthostatism. Changes in dialytic prescription included lower dialytic volumes during orthostatic period, with some improvements. The limitation of volumes and difficulty of drainage were limiting dialytic prescription and insufficient kt/V. An ultrasound (figure 1) and CT peritoneography (figure 2) were performed, revealing an hernial sac with peritoneal liquid leak, without any intestinal loop, approachable by minimally invasive surgery and local anesthesia. Mini-laparotomy was performed, hernial sac was removed, without peritoneum aperture, with only a 4-day pause on PD technique. Conclusion CT peritoneography allowed the differentiation between this true hernia and a wall leakage, by providing accurate anatomical detail, allowing proper planning of surgical intervention. In this case, the patient had additional predisposing factors, namely polycystic kidney disease. Moreover, only a short pause on PD was necessary. Although some limitations exist, such as the use of iodinated contrast material and ionizating radiations, CT peritoneography is currently the gold standard for the evaluation of mechanical complications in PD; in addition to those mentioned, it is also useful for complications related to the catheter (kinking, entrapment, malposition), intrabdominal adhesions or loculated fluid collections.

Peritoneal Dialysis for Acute Kidney Injury Treatment in the United States: Brought to You by the COVID-19 Pandemic.

The coronavirus disease 2019 (COVID-19) pandemic has created unprecedented strain on health care resources in the United States. Initial reports of AKI rates from Wuhan, China ranged between 3% and 9%, although rates as high as 15% have been reported (1,2). For AKI requiring RRT, intermittent hemodialysis (HD) and continuous RRT (CRRT) have been mainstays of therapy in the United States. However, shortages in supplies, staffing, and available equipment among critically ill patients with COVID-19, particularly in the New York City area, have demanded alternative strategies such as acute peritoneal dialysis treatment for AKI (AKI-PD) that are being implemented. Here, we will review the rationale for the use of AKI-PD and describe potential advantages, criteria for patient selection, and practical considerations on the basis of initial experiences to consider when prescribing and delivering peritoneal dialysis (PD). PD was routine for AKI treatment worldwide well into the 1980s. However, by the 1990s with the development of the central venous catheter for HD and the advent of CRRT, PD became rarely used in higher-resource countries to treat adult patients with AKI (3). The utility and efficacy of PD to treat patients with AKI were re-examined after the publication of a series of articles from Brazil, including a randomized trial, demonstrating that PD provided acceptable care, was not inferior to daily HD in treating acutely ill patients with AKI in terms of patient mortality, and was associated with a shorter duration of AKI and need for RRT (4,5). These findings were confirmed in a randomized trial from Saudi Arabia comparing PD with hemodiafiltration (6). AKI-PD expanded dramatically in lower-resource countries with the advent of the Saving Young Lives Program in 2012, which promoted the use of PD because of minimal infrastructural requirements, including a lack of need for water …

Identification of the Factors Associated With Intraperitoneal Pressure in ADPKD Patients Treated With Peritoneal Dialysis

IntroductionPeritoneal dialysis (PD) is reported to be underused in the autosomal dominant polycystic kidney disease (ADPKD) population because doctors fear technical failure caused by reduced abdominal space and high intraperitoneal pressure (IPP).MethodsWe designed a multicenter retrospective study to be carried out in 15 French centers recruiting 60 patients with ADPKD treated with PD to identify factors associated with IPP. Inclusion criteria were start of PD between 2010 and 2017, available tomodensitometry, and IPP measurement in the first year of dialysis. The clinical and radiological data for each patient were reviewed by the same operator. Total kidney volume (TKV), liver volume, and the volume of the abdominal cavity were measured using contouring.ResultsTKV and the volume of the abdominal cavity in women and men were, respectively, 2397 ml versus 3758 ml and 9402 ml versus 12,920 ml. In the univariate analysis, IPP was significantly and positively associated with body surface area (P = 0.0024), body mass index (BMI) (P < 0.0001), the volume of the abdominal cavity (P = 0.0005), and the volume of the dialysate infused in the peritoneal cavity (IPV) (P = 0.0108). In the multivariate analysis, only BMI was still significantly associated with IPP (P = 0.0004)ConclusionsOur results identified BMI as the main factor linked to IPP in patients with ADPKD. Despite a reliable assessment of the volume of their organs we did not find any correlation between liver and kidney volumes and IPP. To our knowledge, this is the first study designed to identify factors associated with IPP in patients with ADPKD on PD.

Clinical relevance of marginal factors on ultrafiltration in peritoneal dialysis.

Ultrafiltration (UF) in peritoneal dialysis (PD) is mainly driven by the osmotic gradient and peritoneal permeability, but other factors-such as intraperitoneal pressure (IPP)-also have an influence. To assess the clinical relevance of these marginal factors, we studied 41 unselected PD patients undergoing two consecutive 2 h, 2.27% glucose exchanges, first with 2.5 L and then with 1.5 L. IPP, higher in the 2.5 L exchange, had a wide interpatient range, was higher in obese and polycystic patients and their increase with infusion volume was higher for women regardless of body size. UF with 2.5 L correlated inversely with IPP and was higher for patients with polycystosis or hernias, while for 1.5 L we found no significant correlations. The effluent had higher glucose and osmolarity in the 2.5 L exchange than in the 1.5 L one, similar for both sexes. In spite of this stronger osmotic gradient, only 21 patients had more UF in the 2.5 L exchange, with differences up to 240 mL. The other 20 patients had more UF in the 1.5 L exchange, with stronger differences (up to 800 mL, and more than 240 mL for 9 patients). The second group, with similar effluent osmolarity and peritoneal equilibration test (PET) parameters than the first, has higher IPP and preponderance of men. The sex influence is so intense that men decreased average UF with 2.5 L with respect to 1.5 L, while women increased it. With 2.27% glucose, sex and IPP-modulated by obesity, polycystosis, hernias, and intraperitoneal volume-significantly affect UF in clinical settings and might be useful for its management.

Is Minimally Invasive Surgery Safe in Colorectal Signet Ring Cell Adenocarcinoma?

Background: Signet ring cell adenocarcinoma (SRCC) accounts for around 16% of colorectal cancer patients at our centre. Low E-cadherin expression is seen majority of SRCC. E-cadherin expression downregulation correlates with aggressive biology, invasion and poor prognosis. Studies have shown SRCC to have higher incidence of peritoneal recurrences. High intraperitoneal pressure during minimal access surgery (MIS) might lead to dissemination of tumor cells in SRCC due to poor cell to cell adhesion. We evaluated if patients undergoing MIS had higher recurrence rates and decrease survival as compared to those undergoing open surgery.

Overcoming Drug Resistance by Taking Advantage of Physical Principles: Pressurized Intraperitoneal Aerosol Chemotherapy (PIPAC).

Theoretical considerations as well as comprehensive preclinical and clinical data suggest that optimizing physical parameters of intraperitoneal drug delivery might help to circumvent initial or acquired resistance of peritoneal metastasis (PM) to chemotherapy. Pressurized Intraperitoneal Aerosol Chemotherapy (PIPAC) is a novel minimally invasive drug delivery system systematically addressing the current limitations of intraperitoneal chemotherapy. The rationale behind PIPAC is: (1) optimizing homogeneity of drug distribution by applying an aerosol rather than a liquid solution; (2) applying increased intraperitoneal hydrostatic pressure to counteract elevated intratumoral interstitial fluid pressure; (3) limiting blood outflow during drug application; (4) steering environmental parameters (temperature, pH, electrostatic charge etc.) in the peritoneal cavity for best tissue target effect. In addition, PIPAC allows repeated application and objective assessment of tumor response by comparing biopsies between chemotherapy cycles. Although incompletely understood, the reasons that allow PIPAC to overcome established chemoresistance are probably linked to local dose intensification. All pharmacological data published so far show a superior therapeutic ratio (tissue concentration/dose applied) of PIPAC vs. systemic administration, of PIPAC vs. intraperitoneal liquid chemotherapy, of PIPAC vs. Hyperthermic Intraperitoneal Chemotherapy (HIPEC) or PIPAC vs. laparoscopic HIPEC. In the initial introduction phase, PIPAC has been used in patients who were quite ill and had already failed multiple treatment regimes, but it may not be limited to that group of patients in the future. Rapid diffusion of PIPAC in clinical practice worldwide supports its potential to become a game changer in the treatment of chemoresistant isolated PM of various origins.

URINOTHORAX SECONDARY TO UNILATERAL URINOMA CAUSED BY URETERAL STRICTURE

SESSION TITLE: Global Case Report Posters SESSION TYPE: Global Case Reports PRESENTED ON: 10/23/2019 09:45 AM - 10:45 AM INTRODUCTION: Urinothorax is a rare and atypical cause of pleural effusion and it usually involves patient with obstructive uropathy, iatrogenic genitourinary procedure complications or abdominal trauma. CASE PRESENTATION: A 67-year-old male with PMHx of colon cancer s/p right hemicolectomy with entero-colonic anastomosis presented with right flank pain radiating to umbilical/pelvic region for 5 days. He was hemodynamically stable. His P/E showed decrease air entry with decreased percussion in the right mid lung and tenderness in the right flank area. His CXR which was significant for right pleural effusion and CT abdomen showed severe right kidney perinephric fluid, stranding with dilation of the pelvicalyceal system and focal rupture of the superior right renal pelvis and proximal-mid ureter stricture without any present of renal or ureteral calculus. This large perinephric collection is consistent with Urinoma. Patient underwent thoracocentesis yellow color fluid was removed. The analysis showed pH of 7.34, glucose 102, WBC 27 (Lymph: 87), RBC 26, LDH of 53 and protein of 2. Serum chemistry showed protein of 8.1 and LDH of 108.The pleural fluid was transudative which is suggestive of urinothorax. The patient successfully received a right ureteral stent, relieving his obstruction, and was subsequently discharged home. Follow up CXR and CT abdomen after discharge showed resolved pleural effusion and patent ureteral stent. DISCUSSION: In our patient, the cause of the pleural effusion is due to unilateral obstructive uropathy leading to rupture pelvis and accumulation of urine in the retroperitoneal space (Urinoma) that leaked into the pleural space. The most plausible theory that would explain our case is that the urinoma drained into the pleural space via the communication between the retroperitoneal and pleural lymphatic systems due to increased retroperitoneal or intraperitoneal pressure. Urinothorax is mostly a transudative process where the pleural fluid is typically a yellow color with very low total urine protein, pH <7.4 and low cell count as well which correlated with the finding of the pleural fluid analysis in our patient. The diagnosis of urinothorax and its underlying cause can be identified with an ultrasound or CT scan of the abdomen. The management of the urinothorax may require a thoracentesis for diagnostic and symptomatic relief purposes. In our case, the underlying cause was ureteral stricture most likely risen from the complication of his right hemicolectomy. The ureteral stricture was relieved with a ureteral stent resulting in the rapid resolution of the urinothorax. CONCLUSIONS: Unilateral urinothorax is rare entity caused due to genitourinary obstruction, surgical complications and abdominal trauma, which can be resolved once the underlying cause is treated. We highlight this case to show that “zebras” should always remain in the differential diagnosis of pleural effusion. Reference #1: Casallas A, Castañeda-Cardona C, Roselli D. Urinothorax: case report and systematic review of the literature. Urol Ann 2016;8:91-4. 10.4103/0974-7796.164851 Reference #2: Toubes ME, Lama A, Ferreiro L, et al. Urinothorax: a systematic review. Journal of Thoracic Disease. 2017;9(5):1209-1218. https://doi.org/10.21037/jtd.2017.04.22 Reference #3: Garcia-Pachon E, Padilla-Navas I. Urinothorax: case report and review of the literature with emphasis on biochemical diagnosis. Respiration. 2004;71(5):533-36. DISCLOSURES: No relevant relationships by Waheed Abdul, source=Web Response

Feasibility of a Portable Abdominal Insufflation Device for Controlling Intraperitoneal Bleeding After Abdominal Blunt Trauma.

Uncontrolled bleeding contributes to 30% to 40% of trauma-related deaths and is the leading cause of potentially preventable deaths. Currently, there is no effective method available to first responders for temporary control of noncompressible intraabdominal bleeding while patients are transported to the hospital. Our previous studies demonstrated that abdominal insufflation provides effective temporary bleeding control. The study aims to prove the feasibility (insufflation to a target pressure) and safety (cardiovascular and respiratory effects) of a novel portable abdominal insufflation device (PAID) designed to control the intraperitoneal bleeding caused by abdominal trauma. The PAID prototype is based on a patented design and manufactured via additive manufacturing. PAID contains a 16-g CO2 cartridge and an electronic pressure transducer. PAID was tested on a bench top and a swine animal model. For the animal model study, the intraperitoneal pressure as well as cardiorespiratory parameters (hearth rate, SpO2 [peripheral capillary oxygen saturation], and blood pressure) were continuously monitored during the insufflation procedure. The prototype functioned according to specifications on both bench top and animal models. CO2 insufflation of the peritoneal cavity was delivered up the target 20 mm Hg and maintained for 30 minutes from 1 or 2 cartridges in the swine model. No intraoperative incidents were registered, and all the recorded physiological parameters were within normal limits. The PAID prototype is a feasible, easy to use device that provides quick, controlled, and safe insufflation of the peritoneal cavity. Future studies will focus on testing the next-generation, semiautomatic PAID prototype in a severe intraabdominal injury model.

Abstract 1910: Regulation of ovarian tumor microenvironment dynamics by compressive stress

Abstract Ovarian cancer (OvCa) is the most fatal gynecologic malignancy and the fifth leading cause of overall cancer death among American women with a low (27%) 5-year survival rate, as 75% of women are diagnosed with disseminated intra-peritoneal (IP) metastasis. OvCa cells detach from the primary tumor and shed into the peritoneal cavity, adhere to the peritoneal mesothelial cell (MC) monolayer, intercalate within this layer, and invade into the submesothelial matrix, where they proliferate and form secondary lesions. More than one third of OvCa patients develop ascites that correlates with relapse and poor prognosis. The accumulated ascites can reach volumes up to 5 liters, causing a striking elevation in intraperitoneal pressure (IPP) from normally sub-atmospheric ~5 mmHg to as high as 27 mmHg, impacting the tumor microenvironment including host and tumor cells. The pressure created by accumulated ascites alters the force environment in the peritoneal cavity, causing strain and compressive forces on peritoneal structures. Yet, the mechanism through which ascites-induced IPP influences OvCa progression is poorly understood. The aim of this study is to understand how ascites-induced IPP promotes OvCa progression. To model the compressive force present in vivo due to accumulated tense ascites (~27 mmHg), we evaluated the effects of compressive force on primary human and murine MC monolayers and murine peritoneal explants using the Flexcell Compression System. Strikingly, compressed MC and peritoneal explants exhibited phenotypic alterations and formed abundant Tunneling Nanotubes (TNT), which are cell membrane extensions that modulate transfer of organelles between cells under stress. Furthermore, compression of OvCa cells adherent to murine peritoneal explants show intense formation of TNT between OvCa cells and peritoneal MC. Remarkably, TNT formed under compression displayed membrane distension and modulated the transfer of mitochondria from MC to OvCa cells. Moreover, collected peritoneal explants from OvCa murine model with intense ascites showed TNT formation and changes in the peritoneal sub-mesothelial collagen ultrastructure. This study reveals a novel response of OvCa cells and the tumor microenvironment to mechanical compression, uncovering a new mechanism by which OvCa metastatic success may be regulated. Note: This abstract was not presented at the meeting. Citation Format: Marwa Asem, Allison Young Young, Alejandro ClaureDeLaZerda, Matthew Ravosa, Sharon Stack. Regulation of ovarian tumor microenvironment dynamics by compressive stress [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 1910.