Complement terminal pathway inhibition reduces peritoneal injuries in a rat peritonitis model.

Peritonitis and the resulting peritoneal injuries are common problems that prevent long-term peritoneal dialysis (PD) therapy in patients with end-stage kidney diseases. Previously, we have analyzed the relationship between the complement system and progression of peritoneal injuries associated with PD, particularly focusing on the early activation pathways and effects of the anaphylatoxins. We here utilized a novel mAb 2H2 that blocks assembly of the membrane attack complex (MAC) to investigate roles of the complement terminal pathway in PD-associated peritoneal injury. We intraperitoneally injected mAb 2H2 anti-C5b-7 (2.5 or 5 mg/rat) once or twice over the five-day course of the experiment to investigate the effects of inhibiting formation of MAC in a fungal rat peritonitis model caused by repeated intraperitoneal administration of zymosan after methylglyoxal pretreatment (Zy/MGO model). Rats were sacrificed on day 5 and macroscopic changes in both parietal and visceral peritoneum evaluated. Peritoneal thickness, the abundance of fibrinogen and complement C3 and MAC deposition in tissue and accumulation of inflammatory cells were pathologically assessed. The results showed that mAb 2H2, but not isotype control mAb, reduced peritoneal thickness and accumulation of inflammatory cells in a dose and frequency-dependent manner in the Zy/MGO model. These effects were accompanied by decreased C3, MAC, and fibrinogen deposition in peritoneum. In conclusion, in the rat Zy/MGO model, complement terminal pathway activation and MAC formation substantially contributed to development of peritoneal injuries, suggesting that MAC-targeted therapies might be effective in preventing development of peritoneal injuries in humans.

Neutrophils direct preexisting matrix to initiate repair in damaged tissues.

Internal organs heal injuries with new connective tissue, but the cellular and molecular events of this process remain obscure. By tagging extracellular matrix around the mesothelium lining in mouse peritoneum, liver and cecum, here we show that preexisting matrix was transferred across organs into wounds in various injury models. Using proteomics, genetic lineage-tracing and selective injury in juxtaposed organs, we found that the tissue of origin for the transferred matrix likely dictated the scarring or regeneration of the healing tissue. Single-cell RNA sequencing and genetic and chemical screens indicated that the preexisting matrix was transferred by neutrophils dependent on the HSF-integrin AM/B2-kindlin3 cascade. Pharmacologic inhibition of this axis prevented matrix transfer and the formation of peritoneal adhesions. Matrix transfer was thus an early event of wound repair and provides a therapeutic window to dampen scaring across a range of conditions.

Sterile Injury Repair and Adhesion Formation at Serosal Surfaces.

Most multicellular organisms have a major body cavity containing vital organs. This cavity is lined by a mucosa-like serosal surface and filled with serous fluid which suspends many immune cells. Injuries affecting the major body cavity are potentially life-threatening. Here we summarize evidence that unique damage detection and repair mechanisms have evolved to ensure immediate and swift repair of injuries at serosal surfaces. Furthermore, thousands of patients undergo surgery within the abdominal and thoracic cavities each day. While these surgeries are potentially lifesaving, some patients will suffer complications due to inappropriate scar formation when wound healing at serosal surfaces defects. These scars called adhesions cause profound challenges for health care systems and patients. Therefore, reviewing the mechanisms of wound repair at serosal surfaces is of clinical importance. Serosal surfaces will be introduced with a short embryological and microanatomical perspective followed by a discussion of the mechanisms of damage recognition and initiation of sterile inflammation at serosal surfaces. Distinct immune cells populations are free floating within the coelomic (peritoneal) cavity and contribute towards damage recognition and initiation of wound repair. We will highlight the emerging role of resident cavity GATA6+ macrophages in repairing serosal injuries and compare serosal (mesothelial) injuries with injuries to the blood vessel walls. This allows to draw some parallels such as the critical role of the mesothelium in regulating fibrin deposition and how peritoneal macrophages can aggregate in a platelet-like fashion in response to sterile injury. Then, we discuss how serosal wound healing can go wrong, causing adhesions. The current pathogenetic understanding of and potential future therapeutic avenues against adhesions are discussed.

CT Imaging Characteristics and Influence Factors of Renal Dialysis-Associated Peritoneal Injury.

Peritoneal dialysis (PD), as one of the main renal replacement modalities for end-stage renal disease, gets the advantages of better protection of residual renal function and better quality of survival. However, ultrafiltration failure after peritoneal injury is an important reason for patients to withdraw from PD treatment. Peritonitis is a major complication of peritoneal dialysis, which results in an accelerated process of peritoneal injury due to direct damage from acute inflammation and local release of cytokine TGF-ß. In this paper, the application of ultrasound to examine the peritoneum revealed a positive correlation between peritoneal thickness and the development of peritonitis. The results of this study also further confirmed the effect of peritonitis on peritoneal thickening. A multifactorial regression analysis also revealed that peritonitis and its severity were independent risk factors for peritoneal thickening and omental structural abnormalities. This paper reported a correlation between mural peritoneal thickness and peritoneal transit function. In this study, patients with high peritoneal transit and high mean transit were found to be more prone to omental structural abnormalities than patients with low mean and low transit and a higher proportion of patients with mural peritoneal thickening, but this did not reach statistical significance, which may be related to the still small number of cases.

Primordial GATA6 macrophages function as extravascular platelets in sterile injury.

Most multicellular organisms have a major body cavity that harbors immune cells. In primordial species such as purple sea urchins, these cells perform phagocytic functions but are also crucial in repairing injuries. In mammals, the peritoneal cavity contains large numbers of resident GATA6+ macrophages, which may function similarly. However, it is unclear how cavity macrophages suspended in the fluid phase (peritoneal fluid) identify and migrate toward injuries. In this study, we used intravital microscopy to show that cavity macrophages in fluid rapidly form thrombus-like structures in response to injury by means of primordial scavenger receptor cysteine-rich domains. Aggregates of cavity macrophages physically sealed injuries and promoted rapid repair of focal lesions. In iatrogenic surgical situations, these cavity macrophages formed extensive aggregates that promoted the growth of intra-abdominal scar tissue known as peritoneal adhesions.

Causes of peritoneal injury during laparoscopic totally extraperitoneal inguinal hernia repair and methods of repair.

INTRODUCTION: Peritoneal injury during laparoscopic totally extraperitoneal (TEP) inguinal hernia repair is an intraoperative complication that affects accomplishment. We retrospectively examined the causes of peritoneal injury and methods of TEP repair. METHODS: This study examined 58 patients with inguinal hernia (43 unilateral, 15 bilateral) who had undergone TEP repair; all procedures were performed by the same surgeon. The incidence of peritoneal injury, clinical characteristics that could have influenced peritoneal injury, and management of the injury were analyzed. RESULTS: Peritoneal injury was noted in 16 inguinal hernias (21.9%, 16 /73). Injury occurred more frequently in right-sided hernias than in left-sided hernias (31.6% vs 11.4%, P = .049). No other factors were related to injury. Peritoneal injury occurred due to anatomical misrecognition in five hernias (31.3%, 5/16) and unintentional dissection in six hernias (37.5%, 6/16). All injuries due to unintentional dissection occurred in right-sided hernias. The procedures used for peritoneal injury repair were endoscopic suturing for 4 hernias, pre-tied loop ligation for 1 hernia, and ligation clips in 11 hernias. Additional techniques were required in three hernias repaired by endoscopic suturing (75% 3/4). After introduction of the ligation clips, endoscopic suturing was discontinued, and no additional techniques were needed. CONCLUSION: Peritoneal injury more frequently occurred in right-sided inguinal hernia than in left-sided inguinal hernia during TEP repair. The common reasons for peritoneal injury were anatomical misrecognition and unintentional dissection. Repair using ligation clips is the best option for peritoneal injuries that occur during TEP repair.

Can Intraoperative Video Recordings Contribute to Improving Laparoscopic Percutaneous Extraperitoneal Closure in Children with Inguinal Hernia and Prevent Recurrence? A Pilot Study.

Aim: We reviewed intraoperative video recordings (IVRs) of laparoscopic percutaneous extraperitoneal closure (LPEC) for inguinal hernia in children blindly to assess performance. Methods: IVRs of 183 LPEC performed between April 2013 and March 2016, graded by the operating surgeon as difficult (D; n = 8), straightforward (S; n = 96), or easy (E; n = 79), were scored by a panel of reviewers with advanced (group A; >400 LPEC cases; n = 5), intermediate (group I; 50-150 cases; n = 5), and basic (group B; <10 cases; n = 5) experience, according to suturing, dissection plane, vas/vessel dissection, bleeding, and peritoneal injury. They also allocated a recurrence risk rank (RRR; highest = 6; lowest = 1) for each IVR. Mean score variance for each IVR was also compared between reviewers. Results: There was one recurrence (R; 4-year-old male; level E). RRR were: 1, 2, and 2 for reviewers A, I, and B, respectively. Reviewer A scores for "suturing" and "bleeding," and reviewer I scores for "dissection plane" and "peritoneal injury" correlated significantly with RRR. No reviewer B scores correlated with RRR. Score variance between A and I and A and B for cases D1 and D2 were statistically significant. Conclusion: Advanced reviewers showed greatest variance, questioning the validity of whether experience alone improves surgical technique.

"Taken by surprise" - Women's experiences of the first eight weeks after a second degree perineal tear at childbirth.

OBJECTIVE: This study explores women's experience of having a second degree perineal tear and related consequences to daily life during the first eight weeks after childbirth. METHOD: Written responses to open-ended questions in a questionnaire distributed about eight weeks postpartum and completed by 1,007 women with second degree perineal tears were excerpted from the national quality register, Perineal Laceration Register. Inductive qualitative content analysis was applied to the data. RESULT: The theme Taken by surprise illustrates women's experience of the first two months after having a second degree perineal tear at childbirth. Women were not prepared for the inconveniences and expressed concerns about their bodies. Further, they expressed distress about their physical and psychological recovery as well as how to return to a pre-childbirth condition. CONCLUSIONS: Although many women recovered fairly well the first months after a second degree perineal tear at childbirth, it was evident that a substantial number of women were unprepared for the pain and discomfort they experienced. It is apparent that also women with the "minor" perineal tears at childbirth need improved postpartum care with tailored analgesia and improved information, but also check-ups and reassurance of recovery from healthcare professionals. Health care professionals need to identify women with persisting problems so that they can be referred to inpatient care for additional assessments of the injury.

The structural effect of high intensity ultrasound on peritoneal tissue: a potential vehicle for targeting peritoneal metastases.

BACKGROUND: High-intensity ultrasound (HIUS) has been increasingly investigated as a possible tool in the treatment of multiple tumor entities. However, there is only little knowledge on the effect of HIUS on the peritoneum. This preliminary study aims to investigate HIUS' potential for altering the peritoneal surface and potentially improving current treatments for peritoneal metastases. For this purpose, HIUS' qualitative and quantitative structural effects on the peritoneal tissue were analyzed by means of light, fluorescence and electron microscopy. METHODS: Proportional sections were cut from the fresh postmortem swine peritoneum. Peritoneal surfaces were covered with a 6 mm thick liquid film of 0.9% NaCl. HIUS was applied in all tissue samples for 0 (control), 30, 60, 120 and 300 s. Peritoneal tissues were analyzed using light-, fluorescence and electron microscopy to detect possible structural changes within the tissues. RESULTS: Following HIUS, a superficial disruption of peritoneal tissue was visible in light microscopy, which amplified with increased time of HIUS' application. Fluorescence microscopy showed both peritoneal and subperitoneal disruption with tissue gaps. Electron microscopy revealed structural filamentation of the peritoneal surface. CONCLUSION: Our data indicate that HIUS causes a wide range of effects on the peritoneal tissue, including the formation of small ruptures in both peritoneal and subperitoneal tissues. However, according to our findings, these disruptions are limited to a microscopical level. Further studies are required to evaluate whether HIUS application can benefit current therapeutic regimens on peritoneal metastases and possibly enhance the efficacy of intraperitoneal chemotherapy.

Imaging of blunt bowel and mesenteric injuries: Current status.

Blunt abdominal trauma often presents a diagnostic challenge. Clinical examination demonstrates low reliability in detecting abdominal injury (16 %) when there is a history of head injury or loss of consciousness. This can prove detrimental, as delays in the diagnosis of traumatic bowel injury of 8 h or less can result in increased morbidity and mortality, as well as prolonged hospitalization. Although hemodynamically unstable patients will require an urgent laparotomy following clinical assessment, MDCT is the modality of choice for comprehensive imaging of blunt abdominal trauma in hemodynamically stable patients. Despite the use of MDCT, blunt injury to the bowel and mesentery, which accounts for up to 5% of injuries in cases of trauma, may be difficult to detect. The use of a constellation of direct and indirect signs on MDCT can help make the diagnosis and guide clinical management. Direct signs on MDCT, such as bowel wall discontinuity, and extraluminal gas may assist in the diagnosis of traumatic bowel injury. However, these signs are not sensitive. Therefore, the astute radiologist may have to rely on indirect signs of injury, such as free fluid, bowel wall thickening, and abnormal bowel wall enhancement to make the diagnosis. This review will focus on MDCT imaging findings of bowel and mesenteric injuries secondary to blunt abdominal trauma.

Effect of different carbon dioxide (CO2) insufflation for laparoscopic colorectal surgery in elderly patients: A randomized controlled trial.

BACKGROUND: Evidence suggests that dry CO2 insufflation during laparoscopic colorectal surgery results in greater structural injury to the peritoneum and longer hospital stay than the use of warm, humidified CO2. We aimed to test the hypothesis that warm, humidified CO2 insufflation could reduce postoperative pain and improve recovery in laparoscopic colorectal surgery. METHODS: One hundred fifty elderly patients undergoing laparoscopic colorectal surgery under general anesthesia from May 2017 to October 2018 were randomly divided into 3 groups. The primary outcomes were resting pain, cough pain, and consumption of sufentanil at 2, 4, 6, 12, 24, and 48 hours postoperatively. Quality of visual image, hemodynamic changes, esophageal temperature, mean skin temperature, mean body temperature, recovery time, days to first flatus and solid food intake, shivering, incidence of postoperative ileus, length of hospital stay, surgical site infections, patients and surgeon satisfaction scores, adverse events, prothrombin time, activated partial thromboplastin time, and thrombin time were recorded. RESULTS: Group CE patients were associated with significantly higher early postoperative cough pain and sufentanil consumption than the other 2 groups (P < .05). Compared with group CE, patients in both groups WH and CF had significantly reduced intraoperative hypothermia, recovery time of PACU, days to first flatus and solid food intake, and length of hospital stay, while the satisfaction scores of both patients and surgeon were significantly higher (P < .05). Prothrombin time, activated partial thromboplastin time, and thrombin time were significantly higher in group CE from 60 minutes after pneumoperitoneum to the end of pneumoperitoneum than the other 2 groups (P < .05). The number of patients with a shivering grade of 0 was significantly lower and grade of 3 was significantly higher in group CE than in the other 2 groups (P < .05). CONCLUSION: Use of either warm, humidified CO2 insufflations or 20°C, 0% relative humidity CO2 combined with forced-air warmer set to 38°C during insufflations can both reduce intraoperative hypothermia, dysfunction of coagulation, early postoperative cough pain, sufentanil consumption, days to first flatus, solid food intake, and length of hospital stay.

A Case of Spontaneous Intraperitoneal Rupture of an Acute Necrotic Fluid Collection Associated with Necrotizing Pancreatitis.

BACKGROUND An acute necrotic fluid collection is a rare condition that occurs within four weeks of the onset of necrotizing pancreatitis. This report is of a case of spontaneous intraperitoneal rupture of an acute necrotic fluid collection that required emergency laparotomy. CASE REPORT A 61-year-old man presented with worsening symptoms following hospital discharge for necrotizing pancreatitis. On hospital admission, a computed tomography (CT) scan showed changes of pancreatic necrosis and inflammation with a peripancreatic fluid collection. On the sixth day following admission, he developed hemodynamic instability and peritonitis. Repeat CT scan showed a reduction in the size of the peripancreatic collection but free intraperitoneal fluid, consistent with intraperitoneal rupture. At exploratory laparotomy, several liters of necrotic pancreatic fluid were drained from the abdomen, followed by admission to the intensive care unit (ICU) for continued resuscitation. On postoperative day 3, he underwent open cystgastrostomy, cholecystectomy, placement of a jejunostomy tube (J-tube), and abdominal closure. He remained in the ICU for several weeks until ventilatory support could be reduced, and was transferred to the hospital ward when he was able to tolerate J-tube and oral feeding. On postoperative day 35, he was transferred to a long-term care facility. CONCLUSIONS Acute pancreatitis is usually managed conservatively, and surgical management has become less common. A case of acute necrotic fluid collection arising within the first four weeks of onset of acute necrotizing pancreatitis is presented that underwent spontaneous intraperitoneal rupture leading to ascites, peritonitis, and hemodynamic instability, requiring emergency surgical management.

Diagnostic laparoscopy in penetrating abdominal trauma.

BACKGROUND: Penetrating abdominal trauma is uncommon in Australia. There are multiple potential approaches to the patient without an indication for immediate laparotomy. This study examined the management of patients with a penetrating anterior abdominal injury in a Level 1 trauma centre, and in particular investigated the outcomes of those patients who underwent diagnostic laparoscopy. METHODS: A retrospective review was undertaken of all patients presenting to a Level 1 trauma centre with an anterior abdominal stab wound over a 15-year period. Patient demographic, injury, examination, treatment and outcome data were extracted. These data were analysed using SPSS PASW version 20. RESULTS: A total of 318 patients were identified. Immediate laparotomy was performed in 121 of those patients. Of the remaining 197 patients, 146 underwent diagnostic laparoscopy. Peritoneal breach was identified in 87 patients, 79 of whom then had exploratory laparotomy. The laparotomy was therapeutic in 36 of 79 patients (45.6%). Multiple stab wounds were an independent predictor of therapeutic laparotomy (hazard ratio 2.39, 95% CI 1.16-4.93). Diagnostic laparoscopy was 100% sensitive, 60.9% specific and had a negative predictive value of 100% and a positive predictive value of 40%. Non-therapeutic laparotomy was associated with a median length of stay of 5.5 days and a complication rate of 9.3%. CONCLUSION: Diagnostic laparoscopy to detect peritoneal breach is a safe approach in the management of anterior abdominal stab wounds. However, utilizing peritoneal breach as an indication for laparotomy is associated with a moderate incidence of non-therapeutic laparotomy. Measures to decrease the negative laparotomy rate should be considered.

Management of penetrating intraperitoneal colon injuries: A meta-analysis and practice management guideline from the Eastern Association for the Surgery of Trauma.

BACKGROUND: The management of penetrating colon injuries in civilians has evolved over the last four decades. The objectives of this meta-analysis are to evaluate the current treatment regimens available for penetrating colon injuries and assess the role of anastomosis in damage control surgery to develop a practice management guideline for surgeons. METHODS: Using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) methodology, a subcommittee of the Practice Management Guidelines section of EAST conducted a systematic review using MEDLINE and EMBASE articles from 1980 through 2017. We developed three relevant problem, intervention, comparison, and outcome (PICO) questions regarding penetrating colon injuries. Outcomes of interest included mortality and infectious abdominal complications. RESULTS: Thirty-seven studies were identified for analysis, of which 16 met criteria for quantitative meta-analysis and included 705 patients considered low-risk in six prospective randomized studies. Seven hundred thirty-eight patients in 10 studies undergoing damage control laparotomy and repair or resection and anastomosis (R&A) were included in a separate meta-analysis. Meta-analysis of high-risk patients undergoing repair or R&A was not feasible due to inadequate data. CONCLUSIONS: In adult civilian patients sustaining penetrating colon injury without signs of shock, significant hemorrhage, severe contamination, or delay to surgical intervention we recommend that colon repair or R&A be performed rather than routine colostomy. In adult high-risk civilian trauma patients sustaining penetrating colon injury, we conditionally recommend that colon repair or R&A be performed rather than routine colostomy. In adult civilian trauma patients sustaining penetrating colon injury who had damage control laparotomy, we conditionally recommend that routine colostomy not be performed; instead, definitive repair or delayed R&A or anastomosis at initial operation should be performed rather than routine colostomy. LEVEL OF EVIDENCE: Systematic review/meta-analysis, level III.

Pancreatic mucinous cystadenoma doubly complicated by acute pancreatitis and retroperitoneal rupture.

Mucinous cystadenomas are the most frequent cystic benign tumors of the pancreas. They are characterized by a malignant potential. Acute pancreatitis is their most common complication. This manuscript reports a unique complication of mucinous cystadenomas of the pancreas: retroperitoneal rupture associated to acute pancreatitis. After resuscitation, the patient underwent surgery. A cystic mass of the pancreas tail with retroperitoneal rupture was found. Splenopancreatectomy was performed. Outcomes were straightforward. After 3 years of follow-up, no signs of recurrence are highlighted.

Perforation in the peritoneal cavity during transanal endoscopic microsurgery for rectal tumors: a real surgical complication with a challenging prognosis?

BACKGROUND: Perforation in the peritoneal cavity during transanal endoscopic microsurgery represents a major challenge. It is usually treated by primary suture, though some authors propose laparoscopic repair with or without ostomy. It is unclear whether perforation increases the risk of tumor dissemination. AIM: The purpose of the study is to assess the safety of primary suture of peritoneal perforation and the long-term risk of dissemination, also, to determine risk factors for perforation and to propose a predictive model for lesions with risk of perforation. METHOD: This is an observational study with prospective data collection at Parc Taulí University Hospital, Sabadell, of patients undergoing transanal surgery with perforation into the peritoneal cavity from June 2004 to September 2017. The main variable is postoperative morbidity and mortality. The long-term follow-up of local recurrence and peritoneal tumor dissemination is described, and a quantitative predictive model for peritoneal cavity perforation is proposed. RESULTS: Forty-five patients out of 686 (6.6%) presented perforation into the peritoneal cavity. Ten patients (22.2%) in the perforation group had morbidity, a rate similar to the non-perforated group. There was no peritoneal dissemination in patients with adenoma or with carcinoma treated with curative intent. In the quantitative predictive model, risk factors for perforation were proximal edge of tumor > 14 cm from anal verge (6 points), size ≥ 6 cm (2), age ≥ 85 years (4), anterior quadrant (3) , and sex (2). Total scores of ≥ 6 points predicted perforation. CONCLUSIONS: Primary suture after peritoneal cavity perforation during transanal surgery is safe and does not increase the risk of recurrence or peritoneal dissemination. Our predictive model provides guidance regarding the risk of perforation and the need to suture the defect after transanal surgery resection.

Surgical adhesions in mice are derived from mesothelial cells and can be targeted by antibodies against mesothelial markers.

Peritoneal adhesions are fibrous tissues that tether organs to one another or to the peritoneal wall and are a major cause of postsurgical and infectious morbidity. The primary molecular chain of events leading to the initiation of adhesions has been elusive, chiefly due to the lack of an identifiable cell of origin. Using clonal analysis and lineage tracing, we have identified injured surface mesothelium expressing podoplanin (PDPN) and mesothelin (MSLN) as a primary instigator of peritoneal adhesions after surgery in mice. We demonstrate that an anti-MSLN antibody diminished adhesion formation in a mouse model where adhesions were induced by surgical ligation to form ischemic buttons and subsequent surgical abrasion of the peritoneum. RNA sequencing and bioinformatics analyses of mouse mesothelial cells from injured mesothelium revealed aspects of the pathological mechanism of adhesion development and yielded several potential regulators of this process. Specifically, we show that PDPN+MSLN+ mesothelium responded to hypoxia by early up-regulation of hypoxia-inducible factor 1 alpha (HIF1α) that preceded adhesion development. Inhibition of HIF1α with small molecules ameliorated the injury program in damaged mesothelium and was sufficient to diminish adhesion severity in a mouse model. Analyses of human adhesion tissue suggested that similar surface markers and signaling pathways may contribute to surgical adhesions in human patients.

Biocompatible dialysis fluids for peritoneal dialysis.

BACKGROUND: Biocompatible peritoneal dialysis (PD) solutions, including neutral pH, low glucose degradation product (GDP) solutions and icodextrin, have previously been shown to favourably influence some patient-level outcomes, albeit based on generally sub-optimal quality studies. Several additional randomised controlled trials (RCT) evaluating biocompatible solutions in PD patients have been published recently. This is an update of a review first published in 2014. OBJECTIVES: This review aimed to look at the benefits and harms of biocompatible PD solutions in comparison to standard PD solutions in patients receiving PD. SEARCH METHODS: The Cochrane Kidney and Transplant Specialised Register was searched up to 12 February 2018 through contact with the Information Specialist using search terms relevant to this review. Studies in the Specialised Register are identified through searches of CENTRAL, MEDLINE, and EMBASE, conference proceedings, the International Clinical Trials Register Search Portal and ClinicalTrials.gov. SELECTION CRITERIA: All RCTs and quasi-RCTs in adults and children comparing the effects of biocompatible PD solutions (neutral pH, lactate-buffered, low GDP; neutral pH, bicarbonate(± lactate)-buffered, low GDP; glucose polymer (icodextrin)) in PD were included. Studies of amino acid-based solutions were excluded. DATA COLLECTION AND ANALYSIS: Two authors extracted data on study quality and outcomes. Summary effect estimates were obtained using a random-effects model, and results were expressed as risk ratios and 95% confidence intervals (CI) for categorical variables, and mean differences (MD) or standardised mean differences (SMD) and 95% CI for continuous variables. MAIN RESULTS: This review update included 42 eligible studies (3262 participants), including six new studies (543 participants). Overall, 29 studies (1971 participants) compared neutral pH, low GDP PD solution with conventional PD solution, and 13 studies (1291 participants) compared icodextrin with conventional PD solution. Risk of bias was assessed as high for sequence generation in three studies, allocation concealment in three studies, attrition bias in 21 studies, and selective outcome reporting bias in 16 studies.Neutral pH, low GDP versus conventional glucose PD solutionUse of neutral pH, low GDP PD solutions improved residual renal function (RRF) preservation (15 studies, 835 participants: SMD 0.19, 95% CI 0.05 to 0.33; high certainty evidence). This approximated to a mean difference in glomerular filtration rate of 0.54 mL/min/1.73 m2 (95% CI 0.14 to 0.93). Better preservation of RRF was evident at all follow-up durations with progressively greater preservation observed with increasing follow up duration. Neutral pH, low GDP PD solution use also improved residual urine volume preservation (11 studies, 791 participants: MD 114.37 mL/day, 95% CI 47.09 to 181.65; high certainty evidence). In low certainty evidence, neutral pH, low GDP solutions may make little or no difference to 4-hour peritoneal ultrafiltration (9 studies, 414 participants: SMD -0.42, 95% CI -0.74 to -0.10) which approximated to a mean difference in peritoneal ultrafiltration of 69.72 mL (16.60 to 122.00 mL) lower, and may increase dialysate:plasma creatinine ratio (10 studies, 746 participants: MD 0.01, 95% CI 0.00 to 0.03), technique failure or death compared with conventional PD solutions. It is uncertain whether neutral pH, low GDP PD solution use led to any differences in peritonitis occurrence, hospitalisation, adverse events (6 studies, 519 participants) or inflow pain (1 study, 58 participants: RR 0.51, 95% CI 0.24 to 1.08).Glucose polymer (icodextrin) versus conventional glucose PD solutionIn moderate certainty evidence, icodextrin probably reduced episodes of uncontrolled fluid overload (2 studies, 100 participants: RR 0.30, 95% CI 0.15 to 0.59) and augmented peritoneal ultrafiltration (4 studies, 102 participants: MD 448.54 mL/d, 95% CI 289.28 to 607.80) without compromising RRF (4 studies, 114 participants: SMD 0.12, 95% CI -0.26 to 0.49; low certainty evidence) which approximated to a mean creatinine clearance of 0.30 mL/min/1.73m2 higher (0.65 lower to 1.23 higher) or urine output (3 studies, 69 participants: MD -88.88 mL/d, 95% CI -356.88 to 179.12; low certainty evidence). It is uncertain whether icodextrin use led to any differences in adverse events (5 studies, 816 participants) technique failure or death. AUTHORS' CONCLUSIONS: This updated review strengthens evidence that neutral pH, low GDP PD solution improves RRF and urine volume preservation with high certainty. These effects may be related to increased peritoneal solute transport and reduced peritoneal ultrafiltration, although the evidence for these outcomes is of low certainty due to significant heterogeneity and suboptimal methodological quality. Icodextrin prescription increased peritoneal ultrafiltration and mitigated uncontrolled fluid overload with moderate certainty. The effects of either neutral pH, low GDP solution or icodextrin on peritonitis, technique survival and patient survival remain uncertain and require further high quality, adequately powered RCTs.