Intra-peritoneal microdialysis and intra-abdominal pressure after endovascular repair of ruptured aortic aneurysms

NO-Donation Increases Visceral Circulation in a Porcine Model of Abdominal Hypertension

Intraabdominal hypertension (IAH) is negative for outcome after intensive care. Little research has focused on medical intervention to improve visceral circulation during IAH. A nitric oxide (NO)-donor was compared with placebo in 25 pigs; each pig was randomized into three groups: PDNO (NO-donor), Control (placebo), or Sham. IAH was induced by CO2 insufflation to 30 mmHg. Sham group had surgical preparation only. Blood gases, invasive venous and arterial blood pressure, intestinal microcirculation and superior mesenteric blood flow were measured. The PDNO group had significantly increased intestinal microcirculation compared with Controls during IAH (last hour, P = 0.009). The mean arterial pressure and abdominal perfusion pressures (APP) were decreased, and the cardiac index were increased in the PDNO group. Also, systemic and pulmonary vascular resistances were lower in the PDNO group compared with Controls. These experimental findings indicate that NO should be further explored with potential application to improve intestinal microcirculation in IAH patients.

Abdominal Compartment Syndrome-When Is Surgical Decompression Needed?

Compartment syndrome occurs when increased pressure inside a closed anatomical space compromises tissue perfusion. The sudden increase in pressure inside these spaces requires rapid decompression by means of surgical intervention. In the case of abdominal compartment syndrome (ACS), surgical decompression consists of a laparostomy. The aim of this review is to identify the landmarks and indications for the appropriate moment to perform decompression laparotomy in patients with ACS based on available published data. A targeted literature review was conducted on indications for decompression laparotomy in ACS. The search was focused on three conditions characterized by a high ACS prevalence, namely acute pancreatitis, ruptured abdominal aortic aneurysm and severe burns. There is still a debate around the clinical characteristics which require surgical intervention in ACS. According to the limited data published from observational studies, laparotomy is usually performed when intra-abdominal pressure reaches values ranging from 25 to 36 mmHg on average in the case of acute pancreatitis. In cases of a ruptured abdominal aortic aneurysm, there is a higher urgency to perform decompression laparotomy for ACS due to the possibility of continuous hemorrhage. The most conflicting recommendations on whether surgical treatment should be delayed in favor of other non-surgical interventions come from studies involving patients with severe burns. The results of the review must be interpreted in the context of the limited available robust data from observational studies and clinical trials.

Systemic inflammatory response in robot-assisted and laparoscopic surgery for colon cancer (SIRIRALS): study protocol of a randomized controlled trial

Background

Robot-assisted surgery is being increasingly adopted in treating colorectal cancer, and the transition from laparoscopic surgery to robot-assisted surgery is a trend. The evidence of the benefits of robot-assisted surgery is sparse. However, findings are associated with improved patient-related outcomes and overall morbidity rates compared to laparoscopic surgery. This induction is unclear, considering both surgical modalities are characterized as minimally invasive. This study aims to evaluate the systemic and peritoneal inflammatory stress response induced by robot-assisted surgery compared with laparoscopic surgery for elective colon cancer resections in a prospective, randomized controlled clinical trial.

Methods

This study is a single-centre randomized controlled superiority trial with 50 colon cancer participants. The primary endpoint is the level of systemic inflammatory response expressed as serum C-reactive protein (CRP) and interleukin 6 (IL-6) levels between postoperative days one and three. Secondary endpoints include (i) levels of systemic inflammation in serum expressed by a panel of inflammatory and pro-inflammatory cytokines measured during the first three postoperative days, (ii) postoperative surgical and medical complications (30 days) according to Clavien-Dindo classification and Comprehensive Complication Index, (iii) intraoperative blood loss, (iv) conversion rate to open surgery, (v) length of surgery, (vi) operative time, (vii) the number of harvested lymph nodes, and (viii) length of hospital stay. The exploratory endpoints are (i) levels of peritoneal inflammatory response in peritoneal fluid expressed by inflammatory and pro-inflammatory cytokines between postoperative day one and three, (ii) patient-reported health-related quality of recovery-15 (QoR-15), (iii) 30 days mortality rate, (iv) heart rate variability and (v) gene transcript (mRNA) analysis.

Discussion

To our knowledge, this is the first clinical randomized controlled trial to clarify the inflammatory stress response induced by robot-assisted or laparoscopic surgery for colon cancer resections.

Trial registration This trial is registered at Clinicaltrials.gov (Identifier: NCT04687384) on December, 29, 2020, Regional committee on health research ethics, Region of Southern Denmark (N75709) and Data Protection Agency, Hospital Sønderjylland, University Hospital of Southern Denmark (N20/46179).

Supplementary Information

The online version contains supplementary material available at 10.1186/s12893-021-01355-4.

Abdominal compartment syndrome after r-EVAR: a systematic review with meta-analysis on incidence and mortality

INTRODUCTION

Endovascular aneurysm repair for ruptured abdominal aortic aneurysms (r-EVAR) sometimes complicates with abdominal compartment syndrome (ACS) due to extensive retroperitoneal hematoma, with significant prognostic implications. This systematic review aimed to analyze the incidence of the syndrome and assess the impact of ACS on mortality. Mortality after decompressive laparotomy was also assessed.

EVIDENCE ACQUISITION

Two databases were searched: Medline and Web of Science. The search was conducted through October 2019. The titles and abstracts of the retrieved articles were independently reviewed. All studies reporting on the ACS incidence after r-EVAR were initially included. From each study, eligibility was determined and descriptive, methodological, and outcome data was extracted. The incidence was calculated with summary proportion. Odds ratio was used to compare the mortality rate. Meta-analysis was performed with fixed effect model when calculating the ACS incidence in r-EVAR patients and when assessing the impacts of ACS and DL in the mortality rate.

EVIDENCE SYNTHESIS

A total of 46 studies were included, with a cumulative cohort of 3064 patients. Two hundred and fifty-two (8.2%) patients developed ACS. The ACS pooled incidence was 9% with a 95% confidence interval of [0.08; 0.11]. Among the 46 included studies, 19 studies reported data on the mortality rate, corresponding to 1825 of the 3064 patients. Of these, 169 (9.3%) had developed ACS and 94 (55.6%) of them died by multi organ failure. Among the 1656 patients without ACS, 328 died (19.8%). The mortality odds ratio meta-analysis was 6.25 with a 95% confidence interval of [4.44, 8.80]. Decompressive laparotomy was performed in 41 patients, decreasing mortality in 47%.

CONCLUSIONS

ACS affects approximately 9% of patients submitted to r-EVAR, and significantly increases perioperative mortality. Close postoperative surveillance to clinical signs of ACS is vital in these patients.

Results of postoperative microdialysis intraperitoneal and at the anastomosis in patients developing anastomotic leakage after rectal cancer surgery

Introduction: Anastomotic leakage postoperatively in patients operated with rectum resection and primary anastomosis is a common and feared complication. We have studied seven patients with an anastomotic leakage after surgery and compared them with 13 patients without complications.Methods: Metabolic measurements with microdialysis were done during the first seven postoperative days, with measurements of glucose, pyruvate, lactate and glycerol. The lactate/pyruvate ratio was calculated. Measurements were performed subcutaneously, intraperitoneally and at the anastomosis. The inflammatory cytokines, IL 6 and IL 10, were measured intravenously and intraperitoneally 48 hours postoperatively.Results: Intravenous and intraperitoneal IL 6 were higher in the leakage group. Around the small intestine (intraperitoneally), we found that patients developing anastomotic leakage had higher lactate and lactate/pyruvate ratio immediately after surgery. They also showed lower glycerol levels. At the anastomosis, we found higher lactate and lactate/pyruvate ratio in anastomotic leak patients after the fourth postoperative day.Conclusions: The results indicate that a possible mechanism behind an anastomotic leakage is an impaired circulation and thus insufficient saturation to the small intestine peroperatively. This develops into an inflammation both intraperitoneally and intravenously, which, if not reversed, spread within the gastrointestinal tract .The colorectal anastomosis is the most vulnerable part of the gastrointestinal tract postoperatively and hypoxia and inflammation may occur there, and an anastomosis leakage will be the consequence.

Splanchnic Circulation and Intraabdominal Metabolism in Two Porcine Models of Low Cardiac Output

The impact of acute cardiac dysfunction on the gastrointestinal tract was investigated in anesthetized and instrumented pigs by sequential reductions of cardiac output (CO). Using a cardiac tamponade (n = 6) or partial inferior caval vein balloon inflation (n = 6), CO was controllably reduced for 1 h each to 75% (CO_75%), 50% (CO_50%), and 35% (CO_35%) of the baseline value. Cardiac output in controls (n = 6) was not manipulated and maintained. Mean arterial pressure, superior mesenteric arterial blood flow, and intestinal mucosal perfusion started to decrease at CO_50% in the intervention groups. The decrease in superior mesenteric arterial blood flow was non-linear and exaggerated at CO_35%. Systemic, venous mesenteric, and intraperitoneal lactate concentrations increased in the intervention groups from CO_50%. Global and mesenteric oxygen uptake decreased at CO_35%. In conclusion, gastrointestinal metabolism became increasingly anaerobic when CO was reduced by 50%. Anaerobic gastrointestinal metabolism in low CO can be detected using intraperitoneal microdialysis.

Abdominal compartment syndrome after endovascular repair for ruptured abdominal aortic aneurysm leads to acute intestinal necrosis: Case report

INTRODUCTION

Abdominal compartment syndrome (ACS) after endovascular repair (EVAR) of rupture abdominal aortic aneurysm (rAAA) is a rare emergency situation, which has a high mortality. However, the progression of ACS is rapid and the diagnosis is usually been delayed, which increase the difficulties in treatment and affect the prognosis. We describe a case of a sever complication (acute intestinal necrosis) resulting from ACS after endovascular repair of rAAA.

CLINICAL FINDING

An elderly man, 81 years old, complained a sudden lower abdominal and back pain without any predisposing cause. He had a history of hypertension for 20 years without any regular anti-hypertensive therapy. Physical Examination revealed that the blood pressure was 89/54 mmHg, pulse was 120/min, oxygen saturation was 91%. The abdominal ultrasound and the CTA (computed tomography angiography) scan revealed a rAAA. Emergency EVAR under general anesthesia was performed for this patient.

DIAGNOSIS

Fourteen hours after endovascular repair, sudden decreased of blood pressure (70/50 mmHg) and oxygen saturation (70%) was observed. ACS or bleeding of retroperitoneal space was diagnosed.

INTERVENTIONS

Abdominal laparotomy was immediately performed. ACS was verified and a severe complication (acute intestinal necrosis) was observed, intestinal resection was performed for this patient.

OUTCOMES

Unfortunately, this patient died after operation because of multi-organ failure in a very short period, which is very rare regarding to this condition. Surgical pathology, diagnosis and management were discussed.

CONCLUSION

ACS was occurred with a severe complication (acute intestinal necrosis) in a very short period, which is very rare regarding to this condition after EVAR, it reminds us the severe result of ACS and more methods to prevent it happened after surgical management.

Intraperitoneal microdialysis as a monitoring method in the intensive care unit

Studies on surgical patients provide some evidence of prompt detection of enteric ischemia with microdialysis. The purpose of the study was to measure intraperitoneal microdialysis values (glucose, glycerol, pyruvate, and lactate) in patients hospitalized in an intensive care unit (ICU) with an underlying abdominal surgical condition and to correlate these values with patients' outcomes. Twenty-one patients, 10 female, were enrolled in the study. The intraperitoneal metabolite values were measured for 3 consecutive days, starting from the first day of ICU hospitalization. Descriptive and inferential statistics were performed. The t-test, repeated measures analysis, Holm's test, and a logistic regression model were applied. Level of statistical significance was set at P = 0.05. Mean age of participants was 68.10 ± 8.02 years old. Survivors exhibited statistically significantly higher glucose values on day 3 (6.61 ± 2.01 against 3.67 ± 1.62; P = 0.002). Mean lactate/ pyruvate (L/P) values were above 20 (35.35 ± 27.11). All non-survivors had a mean three day L/P values greater than 25.94. Low L/P values were related to increased survival possibilities. High microdialysis glucose concentration, high L/P ratio and low glucose concentration were the major findings during the first three ICU hospitalization days in non-survivors. Intraperitoneal microdialysis may serve as a useful tool in understanding enteric ischemia pathophysiology.

Mild to moderate intra-abdominal hypertension: Does it matter?

This review summarizes the epidemiology, pathophysiological consequences and impact on outcome of mild to moderate (Grade I to II) intra-abdominal hypertension (IAH), points out possible pitfalls in available treatment recommendations and focuses on tasks for future research in the field. IAH occurs in about 40% of ICU patients. Whereas the prevalence of abdominal compartment syndrome seems to be decreasing, the prevalence of IAH does not. More than half of IAH patients present with IAH grade I and approximately a quarter with IAH grade II. However, most of the studies have addressed IAH as a yes-or-no variable, with little or no attention to different severity grades. Even mild IAH can have a negative impact on tissue perfusion and microcirculation and be associated with an increased length of stay and duration of mechanical ventilation. However, the impact of IAH and its different grades on mortality is controversial. The influence of intra-abdominal pressure (IAP) on outcome most likely depends on patient and disease characteristics and the concomitant macro- and microcirculation. Therefore, management might differ significantly. Today, clear triggers for interventions in different patient groups with mild to moderate IAH are not defined. Further studies are needed to clarify the clinical importance of mild to moderate IAH identifying clear triggers for interventions to lower the IAP.

A small case series of aortic balloon occlusion in trauma: lessons learned from its use in ruptured abdominal aortic aneurysms and a brief review

BACKGROUND

EndoVascular and Hybrid Trauma Management (EVTM) is an emerging concept for the early treatment of trauma patients using aortic balloon occlusion (ABO), embolization agents and stent grafts to stop ongoing traumatic bleeding. These techniques have previously been implemented successfully in the treatment of ruptured aortic aneurysm.

AIMS

We describe our very recent experience of EVTM using ABO in bleeding patients and lessons learned over the last 20 years from the endovascular treatment of ruptured abdominal aortic aneurysms (rAAA). We also briefly describe current knowledge of ABO usage in trauma.

METHODS

A small series of educational cases in our hospital is described, where endovascular techniques were used to gain temporary hemorrhage control. The methods used for rAAA and their applicability to EVTM with a multidisciplinary approach are presented.

RESULTS

Establishing femoral arterial access immediately on arrival at the emergency room and use of an angiography table in the surgical suite may facilitate EVTM at an early stage. ABO may be an effective method for the temporary stabilization of severely hemodynamically unstable patients with hemorrhagic shock, and may be useful as a bridge to definitive treatment of the bleeding patients.

CONCLUSION

EVTM, including the usage of ABO, can be initiated on patient arrival and is feasible. Further data need to be collected to investigate proper indications for ABO, best clinical usage, results and potential complications. Accordingly, the ABOTrauma Registry has recently been set up. Existing experiences of EVTM and lessons from the endovascular treatment of rAAA may be useful in trauma management.

Moderate intra-abdominal hypertension leads to anaerobic metabolism in the rectus abdominis muscle tissue of critically ill patients: a prospective observational study

Purpose. We hypothesize that intra-abdominal hypertension (IAH) is associated with the presence of anaerobic metabolism in the abdominal rectus muscle (RAM) tissue of critically ill patients. Methods. We included 10 adult, critically ill patients with intra-abdominal pressure (IAP) above 12 mmHg. Microdialysis catheters (CMA 60) were inserted into the RAM tissue. The samples were collected up to 72 hours after enrollment. Results. The patients' median (IQR) APACHE II at inclusion was 29 (21–37); 7 patients were in shock. IAP was 14.5 (12.5–17.8) mmHg at baseline and decreased significantly over time, concomitantly with arterial lactate and vasopressors requirements. The tissue lactate-to-pyruvate (L/P) ratio was 49 (36–54) at the beginning of the study and decreased significantly throughout the study. Additionally, the tissue lactate, lactate-to-glucose (L/G) ratio, and glutamate concentrations changed significantly during the study. The correlation analysis showed that lower levels of pyruvate and glycerol were associated with higher MAP and abdominal perfusion pressures (APP) and that higher levels of glutamate were correlated to elevated IAP. Conclusions. Moderate IAH leads to RAM tissue anaerobic metabolism suggestive for hypoperfusion in critically ill patients. Correlation analysis supports the concept of using APP as the primary endpoint of resuscitation in addition to MAP and IAP.

Abdominal hypertension and decompression: the effect on peritoneal metabolism in an experimental porcine study

OBJECTIVE

The aim of this study was to investigate the abdominal metabolic response and circulatory changes after decompression of intra-abdominal hypertension in a porcine model.

METHODS

This was an experimental study with controls. Three-month-old domestic pigs of both sexes were anesthetized and ventilated. Nine animals had a pneumoperitoneum-induced IAH of 30 mmHg for 6 hours. Twelve animals had the same IAH for 4 hours followed by decompression, and were monitored for another 2 hours. Hemodynamics, including laser Doppler-measured mucosal blood flow, urine output, and arterial blood samples were analyzed every hour along with glucose, glycerol, lactate and pyruvate concentrations, and lactate-pyruvate (l/p) ratio, measured by microdialysis.

RESULTS

Laser Doppler-measured mucosal blood flow and urine output decreased with the induction of IAH and showed a statistically significant resolution after decompression. Both groups developed distinct metabolic changes intraperitoneally on induction of IAH, including an increased l/p ratio, as signs of organ hypoperfusion. In the decompression group the intraperitoneal l/p ratio normalized during the second decompression hour, indicating partially restored perfusion.

CONCLUSION

Decompression after 4 hours of IAH results in an improved intestinal blood flow and a normalized intraperitoneal l/p ratio.