Impact of intraperitoneal pressure and duration of surgery on levels of tissue plasminogen activator and plasminogen activator inhibitor-1 mRNA in peritoneal tissues during laparoscopic surgery

Impact of Standard Versus Low Pneumoperitoneum Pressure on Peritoneal Environment in Laparoscopic Cholecystectomy. Randomized Clinical Trial

BACKGROUND

High CO 2 pneumoperitoneum pressure during laparoscopy adversely affects the peritoneal environment. This study hypothesized that low pneumoperitoneum pressure may be linked to less peritoneal damage and possibly to better clinical outcomes.

MATERIALS AND METHODS

One hundred patients undergoing scheduled laparoscopic cholecystectomy were randomized 1:1 to low or to standard pneumoperitoneum pressure. Peritoneal biopsies were performed at baseline time and 1 hour after peritoneum insufflation in all patients. The primary outcome was peritoneal remodeling biomarkers and apoptotic index. Secondary outcomes included biomarker differences at the studied times and some clinical variables such as length of hospital stay, and quality and safety issues related to the procedure.

RESULTS

Peritoneal IL6 after 1 hour of surgery was significantly higher in the standard than in the low-pressure group (4.26±1.34 vs. 3.24±1.21; P =0.001). On the contrary, levels of connective tissue growth factor and plasminogen activator inhibitor-I were higher in the low-pressure group (0.89±0.61 vs. 0.61±0.84; P =0.025, and 0.74±0.89 vs. 0.24±1.15; P =0.028, respectively). Regarding apoptotic index, similar levels were found in both groups and were 44.0±10.9 and 42.5±17.8 in low and standard pressure groups, respectively. None of the secondary outcomes showed differences between the 2 groups.

CONCLUSIONS

Peritoneal inflammation after laparoscopic cholecystectomy is higher when surgery is performed under standard pressure. Adhesion formation seems to be less in this group. The majority of patients undergoing surgery under low pressure were operated under optimal workspace conditions, regardless of the surgeon's expertise.

Financial and Inpatient Burden of Adhesion-Related Small Bowel Obstruction: A Systematic Review of the Literature

BACKGROUND

Postoperative adhesions may occur after >90% of laparotomies and is the most common cause of small bowel obstruction (SBO). Despite the high incidence, there is a lack of data related to financial implications of adhesion-related SBO (ASBO). This systematic literature review of in-hospital costs for treatment of ASBO searched PubMed, Scopus and Google Scholar databases according to PRISMA guidelines. Exclusion criteria were reviews, editorials, clinical vignettes, studies of patients <18 years of age, studies with no English full text and studies assessing adhesiolysis for causes other than SBO or that used extrapolations with economic models. Main outcome measures were financial costs per patient and national costs.

RESULTS

Seven studies, published between 1999 and 2016, incorporating a total of 39 573 patients, were identified. Four were undertaken in European countries, one in the USA, 1 in New Zealand and 1 in Nigeria. Overall national costs regarding treatment of patients with ASBO ranged between $3.468 million and $1.77 billion. Median overall cost in the medical management group was $2371.5 ($1814-$2568) vs $12370 ($4914-$25321) in the surgical group. Median length of stay was 4 (3-7) days for patients conservatively treated and 11.5 (8-16.3) days for patients who underwent surgery. Median length of stay of operated patients on was almost triple that of patients conservatively managed.

CONCLUSIONS

Given the major financial implications of ASBO, further initiatives are needed to avoid operations for SBO when clinically appropriate and minimize delays taking patients with high suspicion of complete SBO to the operating room.

How to dissect the pelvic nerves: from microanatomy to surgical rules. An evidence-based clinical review

Background: Advanced gynaecological procedures often include extensive pelvic dissections, with the nervous structures involved in the disease. Nerve-sparing and preservation is a key factor in reducing postoperative morbidity. Objectives: The goal of this review is to describe in detail the structure of the pelvic nerves and to gather information from other surgical specialties to give recommendations for safe nerve dissection applied in different gynaecological subspecialties. Materials and methods: An extensive literature review was carried out in PubMed and Google Scholar. The search included articles concerning peripheral nerve anatomy, mechanisms of injury and different dissection techniques, with the most exhaustive being analysed for the review. Articles from different fields of medicine like orthopaedics, plastic surgery, maxillofacial surgery dealing with peripheral nerve injuries and repair have been reviewed. Results: The following review demonstrates the in-depth anatomy and mechanism of injury of the peripheral nerves, describes the different techniques for neurolysis and proposes some directions for safe nerve dissection. Conclusion: When performing complex gynaecological surgeries, the surgeon should avoid unnecessary nerve handling, apply nerve-sparing techniques whenever possible and use the new devices to preserve the nervous structures. Advanced gynaecological surgeries should be performed in specialised centres by expert surgeons with comprehensive knowledge in neuropelveology. What is new? To our knowledge, this is the first article focused on peripheral nerves that collects data from such a wide range of specialties in order to propose the most comprehensive recommendations that could be applied in pelvic surgery.

The "Dark Side" of Pneumoperitoneum and Laparoscopy

Laparoscopic surgery has been one of the most common procedures for abdominal surgery at pediatric age during the last few decades as it has several advantages compared to laparotomy, such as shorter hospital stays, less pain, and better cosmetic results. However, it is associated with both local and systemic modifications. Recent evidence demonstrated that carbon dioxide pneumoperitoneum might be modulated in terms of pressure, duration, temperature, and humidity to mitigate and modulate these changes. The aim of this study is to review the current knowledge about animal and human models investigating pneumoperitoneum-related biological and histological impairment. In particular, pneumoperitoneum is associated with local and systemic inflammation, acidosis, oxidative stress, mesothelium lining abnormalities, and adhesion development. Animal studies reported that an increase in pressure and time and a decrease in humidity and temperature might enhance the rate of comorbidities. However, to date, few studies were conducted on humans; therefore, this research field should be further investigated to confirm in experimental models and humans how to improve laparoscopic procedures in the spirit of minimally invasive surgeries.

High-Pressure Pneumoperitoneum Aggravates Surgery-Induced Neuroinflammation and Cognitive Dysfunction in Aged Mice

Postoperative cognitive dysfunction (POCD) is a common complication after surgery, especially in aged patients. Neuroinflammation has been closely associated with the development of POCD. While the contribution of pneumoperitoneum to the systemic inflammation has been well documented, the effect of pneumoperitoneal pressure on neuroinflammation and postoperative cognitive function remains unclear. In this study, we showed that high-pressure pneumoperitoneum promoted the postoperative neuroinflammation and microglial activation in the hippocampus and aggravated the postoperative cognitive impairment in aged mice. These results support the requirement to implement interventions with lower intra-abdominal pressure, which allows for adequate exposure of the operative field rather than a routine pressure.

Surgical peritoneal stress creates a pro-metastatic niche promoting resistance to apoptosis via IL-8

Background

The mainstay of treatment of advanced ovarian cancer (AOC) involves chemotherapy, and debulking surgery. However, despite optimal surgical procedure and adjuvant chemotherapy, 60% of patients with AOC will relapse within 5 years. Most recurrences occur in the peritoneal cavity, suggesting the existence of occult sanctuaries where ovarian cancer cells (OCC) are protected. In murine models, surgical stress favors tumor growth; however, it has never been established that surgery may affect OCC sensitivity to subsequent chemotherapy. In this study, we investigated how the surgical stress could affect the chemosensitivity of OCC.

Methods

To avoid bias due to tumor burden in peritoneal cavity and duration of surgery, we used peritoneal biopsies from patients without a malignancy at precise time points. During laparotomies, peritoneal biopsies at the incision site were performed at the time of incision (H0 sample) and 1 h after initiation of surgery (H1 sample). We evaluated the chemoresistance to Taxol (0–20 µM) induced by H0 or H1 incubation (24 h) in two ovarian cancer cell lines OVCAR3 and SKOV3 and a primary cancer cell lines derived in our laboratory.

Results

Our results indicate that stressed peritoneum overexpressed cytokines, resulting in OCC increased resistance to therapy. Among these cytokines, IL8 was responsible for the resistance to apoptosis through the AKT pathway activation. Chemoresistance in OCC persists through the establishment of an autocrine IL8 loop. Finally, in a cohort of 32 patients, we showed an impact of IL8 tumoral overexpression on chemosensitivity and survival outcomes with a significant association to earlier recurrence.

Conclusions

Our study demonstrated that precision surgery where targeted treatment would be used in combination with surgery is essential to obtain better tumor control.

Electronic supplementary material

The online version of this article (10.1186/s12967-018-1643-z) contains supplementary material, which is available to authorized users.

Pelvic adhesions and fertility: Where are we in 2018?

Peritoneal adhesions remain a major public health problem despite the development of laparoscopy. The rules of microsurgery must be known and followed during any pelvic surgery, even in patients who no longer have a desire for pregnancy. Anti-adhesion products are numerous. All have interest, confirmed by anatomical studies showing a smaller extent or a lesser severity of adhesions associated with their use. No studies, however, show clinical benefit in terms of improved pain or postoperative fertility. Pneumoperitoneum parameters, humidification, and lower abdominal pressure should be optimized to limit peritoneal trauma. Peri-operative corticosteroids, whose benefit has been has been demonstrated in at least one randomized trial, should be systematically used.

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.

Effects of low intraperitoneal pressure and a warmed, humidified carbon dioxide gas in laparoscopic surgery: a randomized clinical trial

Laparoscopic surgery technology continues to advance. However, much less attention has been focused on how alteration of the laparoscopic surgical environment might improve clinical outcomes. We conducted a randomized, 2 × 2 factorial trial to evaluate whether low intraperitoneal pressure (IPP) (8 mmHg) and/or warmed, humidified CO₂ (WH) gas are better for minimizing the adverse impact of a CO₂ pneumoperitoneum on the peritoneal environment during laparoscopic surgery and for improving clinical outcomes compared to the standard IPP (12 mmHg) and/or cool and dry CO₂ (CD) gas. Herein we show that low IPP and WH gas may decrease inflammation in the laparoscopic surgical environment, resulting in better clinical outcomes. Low IPP and/or WH gas significantly lowered expression of inflammation-related genes in peritoneal tissues compared to the standard IPP and/or CD gas. The odds ratios of a visual analogue scale (VAS) pain score >30 in the ward was 0.18 (95% CI: 0.06, 0.52) at 12 hours and 0.06 (95% CI: 0.01, 0.26) at 24 hours in the low IPP group versus the standard IPP group, and 0.16 (95% CI: 0.05, 0.49) at 0 hours and 0.29 (95% CI: 0.10, 0.79) at 12 hours in the WH gas group versus the CD gas group.

Humidification during laparoscopic surgery: overview of the clinical benefits of using humidified gas during laparoscopic surgery

PURPOSE

The peritoneum is the serous membrane that covers the abdominal cavity and most of the intra-abdominal organs. It is a very delicate layer highly susceptible to damage and it is not designed to cope with variable conditions such as the dry and cold carbon dioxide (CO2) during laparoscopic surgery. The aim of this review was to evaluate the effects caused by insufflating dry and cold gas into the abdominal cavity after laparoscopic surgery.

METHODS

A literature search using the Pubmed was carried out. Articles identified focused on the key issues of laparoscopy, peritoneum, morphology, pneumoperitoneum, humidity, body temperature, pain, recovery time, post-operative adhesions and lens fogging.

RESULTS

Insufflating dry and cold CO2 into the abdomen causes peritoneal damage, post-operative pain, hypothermia and post-operative adhesions. Using humidified and warm gas prevents pain after surgery. With regard to hypothermia due to desiccation, it can be fully prevented using humidified and warm gas. Results relating to the patient recovery are still controversial.

CONCLUSIONS

The use of humidified and warm insufflation gas offers a significant clinical benefit to the patient, creating a more physiologic peritoneal environment and reducing the post-operative pain and hypothermia. In animal models, although humidified and warm gas reduces post-operative adhesions, humidified gas at 32 °C reduced them even more. It is clear that humidified gas should be used during laparoscopic surgery; however, a question remains unanswered: to achieve even greater clinical benefit to the patient, at what temperature should the humidified gas be when insufflated into the abdomen? More clinical trials should be performed to resolve this query.

Pain medication requirements after sacropexy and combination interventions

BACKGROUND AND OBJECTIVES

Laparoscopic surgery is associated with reduced morbidity, and postoperative pain is reduced. The aim of this study was to assess postoperative pain intensity, analgesic requirements, and the influence of cofactors after laparoscopic sacral colpopexy.

METHODS

The study assessed 287 patients treated with laparoscopic sacropexy for genital prolapse with a Pelvic Organ Prolapse Quantification grade>1. Patients were asked to evaluate their pain postoperatively using a 4-point verbal pain rating scale. In addition, medical records were analyzed regarding the requirement for analgesic medication.

RESULTS

Patients distinguished between abdominal pain and shoulder pain after laparoscopy. Abdominal pain reached maximum severity on day 1 and showed a good response to nonsteroidal antiphlogistics, whereas shoulder pain was rarely found (6.27%). Of the patients, 38% required no pain treatment or required 1 dose at most. The need for pain medication reached its climax on day 1 and decreased during the 5 following days. Non-opioid analgesics provided a sufficient therapeutic effect.

CONCLUSION

Laparoscopic sacropexy is associated with a moderate degree of postoperative pain. Non-opioid analgesics should be preferred as first-line therapy. The typical shoulder-tip pain showed only a low prevalence in our study group. From our point of view, the low rate of shoulder-tip pain corresponded with the low intra-abdominal carbon dioxide pressure.

Peritoneal adhesions after laparoscopic gastrointestinal surgery

Although laparoscopy has the potential to reduce peritoneal trauma and post-operative peritoneal adhesion formation, only one randomized controlled trial and a few comparative retrospective clinical studies have addressed this issue. Laparoscopy reduces de novo adhesion formation but has no efficacy in reducing adhesion reformation after adhesiolysis. Moreover, several studies have suggested that the reduction of de novo post-operative adhesions does not seem to have a significant clinical impact. Experimental data in animal models have suggested that CO₂ pneumoperitoneum can cause acute peritoneal inflammation during laparoscopy depending on the insufflation pressure and the surgery duration. Broad peritoneal cavity protection by the insufflation of a low-temperature humidified gas mixture of CO₂, N₂O and O₂ seems to represent the best approach for reducing peritoneal inflammation due to pneumoperitoneum. However, these experimental data have not had a significant impact on the modification of laparoscopic instrumentation. In contrast, surgeons should train themselves to perform laparoscopy quickly, and they should complete their learning curves before testing chemical anti-adhesive agents and anti-adhesion barriers. Chemical anti-adhesive agents have the potential to exert broad peritoneal cavity protection against adhesion formation, but when these agents are used alone, the concentrations needed to prevent adhesions are too high and could cause major post-operative side effects. Anti-adhesion barriers have been used mainly in open surgery, but some clinical data from laparoscopic surgeries are already available. Sprays, gels, and fluid barriers are easier to apply in laparoscopic surgery than solid barriers. Results have been encouraging with solid barriers, spray barriers, and gel barriers, but they have been ambiguous with fluid barriers. Moreover, when barriers have been used alone, the maximum protection against adhesion formation has been no greater than 60%. A recent small, randomized clinical trial suggested that the combination of broad peritoneal cavity protection with local application of a barrier could be almost 100% effective in preventing post-operative adhesion formation. Future studies should confirm the efficacy of this global strategy in preventing adhesion formation after laparoscopy by focusing on clinical end points, such as reduced incidences of bowel obstruction and abdominal pain and increased fertility.

Preservation of peritoneal fibrinolysis owing to decreased transcription of plasminogen activator inhibitor-1 in peritoneal mesothelial cells suppresses postoperative adhesion formation in laparoscopic surgery

BACKGROUND

Postoperative adhesion formation is regulated by peritoneal fibrinolysis, which is determined by tissue-type plasminogen activator (tPA) and plasminogen activator inhibitor-1 (PAI-1). This study compared peritoneal fibrinolysis and adhesion formation after laparoscopic surgery (LAP) and open surgery (OP).

METHODS

We divided 154 male rats into 3 groups after cecal cauterization: Control, no treatment; LAP, CO2 pneumoperitoneum at 5 mmHg for 60 minutes; and OP, laparotomy for 60 minutes. Adhesions were quantified at day 7. The activity and mRNA level of tPA and PAI-1 were determined by enzyme-linked immunosorbent assay in plasma and peritoneal lavage and by real-time polymerase chain reaction in peritoneal mesothelial cells from omentum. We also examined peritoneal fibrinolysis in human gastric cancer patients treated with LAP (n = 14) or OP (n = 10).

RESULTS

In the animal study, adhesion scores, PAI-1 activity in peritoneal lavage fluid, and PAI-1 mRNA levels in peritoneal mesothelium were significantly greater in the OP group than the control and LAP groups. In the human study, postoperative PAI-1 mRNA levels were significantly greater in the OP group than the LAP group. Additionally, PAI-1 mRNA levels and subsequent adhesion formation were induced by prolonged operative time in the OP group, but not the LAP group.

CONCLUSION

Preservation of peritoneal fibrinolysis owing to decreased PAI-1 expression at the transcriptional level in peritoneal mesothelial cells is associated with suppression of postoperative adhesion formation in LAP. PAI-1 mRNA levels and subsequent adhesion formation were not induced by prolonged operative time in LAP. These results highlight the less invasiveness nature of LAP.

Impact of intraperitoneal pressure of a CO2 pneumoperitoneum on the surgical peritoneal environment

BACKGROUND

Animal experiments have suggested that a high intraperitoneal pressure (IPP) might adversely affect the surgical peritoneal environment. The present experimental study investigates the impact of IPP of a CO(2) pneumoperitoneum on human peritoneum.

METHODS

Patients undergoing laparoscopic surgery were subjected to either low (8 mmHg) or standard (12 mmHg) IPP. Normal peritoneum was collected from the parietal wall at the beginning of surgery and every 60 min thereafter. Expression levels of 168 genes that encode extracellular matrix proteins, adhesion molecules or inflammatory cytokine signaling molecules were measured in peritoneal tissues using real-time polymerase chain reaction (PCR)-based assay panels. Human peritoneal mesothelial cells (HPMCs) and human peritoneal fibroblasts (HPFBs) were incubated in a CO(2) insufflation chamber for 1 h at 12 or 8 mmHg. Hyaluronan (HA) synthesis and mRNA expression levels of hyaluronic acid synthases (HAS) and hyaluronidases (Hyal) in HPMCs and HPFBs were measured at 0, 4, 8, 12, 24 and 48 h after CO(2) gas exposure by ELISA and real-time PCR, respectively.

RESULTS

Expression levels of connective tissue growth factor (CTGF), matrix metalloproteinase-9, E-selectin, chemokine (C-X-C motif) ligand 2 (CXCL-2), Hyal-1 and Hyal-2 were significantly higher and those of HAS-1, HAS-3, thrombospondin-2 (TSP-2) and interleukin-10 were significantly lower in the 12 mmHg group compared with the 8 mmHg group. HA synthesis was significantly lower in the 12 mmHg group compared with the 8 mmHg group in HPMCs and HPFBs throughout the time course.

CONCLUSIONS

A low IPP (8 mmHg) may be better than the standard IPP (12 mmHg) to minimize the adverse impact on the surgical peritoneal environment during a CO(2) pneumoperitoneum.