Clinical and pelvic morphologic correlation after subtotal colectomy with colorectal anastomosis for combined slow-transit constipation and obstructive defecation

BACKGROUND

The treatment of slow-transit constipation combined with outlet obstruction is controversial. Subtotal colectomy with colorectal anastomosis is regarded as a safe and effective surgical option for refractory constipation.

PURPOSE

The clinical and morphologic outcomes of patients who underwent subtotal colectomy with colorectal anastomosis for refractory mixed constipation were prospectively evaluated.

DESIGN

This study is a nonrandomized, prospective review of gathered data.

SETTING

This investigation was conducted at a tertiary-care GI surgical center in China.

PATIENTS

The study prospectively included 42 consecutive patients with refractory constipation who were diagnosed with obstructed defecation syndrome combined with slow colon transit.

MAIN OUTCOME MEASURES

The primary outcomes measured were the Longo obstructive defecation syndrome score and the Wexner constipation scale. The pelvic morphologic changes were determined with defecography before surgery and at 6 and 24 months after surgery.

RESULTS

A significant reduction in the Wexner constipation score was observed between baseline (median 24) and 6 months (median 10), which was maintained until 24 months (median 8, compared with baseline, p < 0.01). Improvement in the constipation score was matched by an overall improvement in the Longo obstructive defecation syndrome score at the 6- and 24-month follow-up times (compared with baseline, p < 0.01). In 17 of 21 patients, preexisting intussusception was no longer visible during defecography. Rectoceles were significantly reduced in depth, from 36 mm to 8 mm (p < 0.01), whereas the number of detectable rectoceles was also significantly decreased, from 29 to 7 (p < 0.01). Incomplete evacuation disappeared in 28 of 38 patients. No stenosis was observed at the colorectal posterior side-to-side anastomosis. Most complications were managed conservatively without significant events.

LIMITATIONS

This study was performed in selected patients with constipation and did not include a comparison group.

CONCLUSIONS

Subtotal colectomy with colorectal anastomosis can correct pelvic anatomical disorders in patients with mixed refractory constipation. The clinical improvement of obstructed defecation syndrome after subtotal colectomy with colorectal anastomosis is highly correlated with the morphologic correction of the rectal redundancy.

Novel insights into the development of portal vein thrombosis in cirrhosis patients

The prognostic impact of portal vein thrombosis (PVT) in liver cirrhosis remains controversial among studies, primarily because the risk stratification of PVT is often lacking. A definition of clinically significant PVT should be proposed and actively improved. Moreover, the risk factors for the development of PVT in liver cirrhosis should be fully recognized to screen and identify high-risk patients. Currently, well-recognized risk factors include a reduced portal vein flow velocity, a worse liver function, splenectomy, liver transplantation, and factor V Leiden and prothrombin G20210A mutations. Novel risk factors include an increased flow volume of portosystemic collateral vessel, thrombopoietin receptor agnonists, and non-selective beta-blockers. In contrast to the traditional perspectives, the abnormalities of procoagulant and anticoagulant factors may not contribute to the development of PVT in liver cirrhosis. Further studies should explore the role of other risk factors, such as antiphospholipid antibodies, methylenetetrahydrofolate reductase C677T gene mutation, hyperhomocysteinemia, and myeloproliferative neoplasms.

Efficacy and safety of damage control in experimental animal models of injury: protocol for a systematic review and meta-analysis

BACKGROUND

Although abbreviated surgery with planned reoperation (damage control surgery) is now widely used to manage major trauma patients, the procedure and its component interventions have not been evaluated in randomized controlled trials (RCTs). While some have suggested the need for such trials, they are unlikely to be conducted because of patient safety concerns. As animal studies may overcome several of the limitations of existing observational damage control studies, the primary objective of this study is to evaluate the efficacy and safety of damage control versus definitive surgery in experimental animal models of injury.

METHODS/DESIGN

We will search electronic databases (Medline, Embase, PubMed, Web of Science, Scopus, and the Cochrane Library), conference abstracts, personal files, and bibliographies of included articles. We will include RCTs and prospective cohort studies that utilized an animal model of injury and compared damage control surgery (or specific damage control interventions or adjuncts) to definitive surgery (or specific definitive surgical interventions). Two investigators will independently evaluate the internal and external/construct validity of individual studies. The primary outcome will be all-cause mortality. Secondary outcomes will include blood loss amounts; blood pressures and heart rates; urinary outputs; core body temperatures; arterial lactate, pH, and base deficit/excess values; prothrombin and partial thromboplastin times; international normalized ratios; and thromboelastography (TEG) results/activated clotting times. We will calculate summary relative risks (RRs) of mortality and mean differences (for continuous outcomes) using DerSimonian and Laird random effects models. Heterogeneity will be explored using subgroup meta-analysis and meta-regression. We will assess for publication bias using funnel plots and Begg's and Egger's tests. When evidence of publication bias exists, we will use the Duval and Tweedie trim and fill method to estimate the potential influence of this bias on pooled summary estimates.

DISCUSSION

This study will evaluate the efficacy and safety of damage control in experimental animal models of injury. Study results will be used to guide future clinical evaluations of damage control surgery, determine which animal study outcomes may potentially be generalizable to the clinical setting, and to provide guidelines to strengthen the conduct and relevance of future pre-clinical studies.

Predictors of critical acute pancreatitis: a prospective cohort study

Critical acute pancreatitis (CAP) has recently emerged as the most ominous severity category of acute pancreatitis (AP). As such there have been no studies specifically designed to evaluate predictors of CAP. In this study, we aimed to evaluate the accuracy of 4 parameters (Acute Physiology and Chronic Health Evaluation [APACHE] II score, C-reactive protein [CRP], D-dimer, and intra-abdominal pressure [IAP]) for predicting CAP early after hospital admission. During the study period, data on patients with AP were prospectively collected and D-dimer, CRP, and IAP levels were measured using standard methods at admission whereas the APACHE II score was calculated within 24 hours of hospital admission. The receiver-operating characteristic (ROC) curve analysis was applied and the likelihood ratios were calculated to evaluate the predictive accuracy. A total of 173 consecutive patients were included in the analysis and 47 (27%) of them developed CAP. The overall hospital mortality was 11% (19 of 173). APACHE II score ≥11 and IAP ≥13 mm Hg showed significantly better overall predictive accuracy than D-dimer and CRP (area under the ROC curve-0.94 and 0.92 vs. 0.815 and 0.667, correspondingly). The positive likelihood ratio of APACHE II score is excellent (9.9) but of IAP is moderate (4.2). The latter can be improved by adding CRP (5.8). In conclusion, of the parameters studied, APACHE II score and IAP are the best available predictors of CAP within 24 hours of hospital admission. Given that APACHE II score is rather cumbersome, the combination of IAP and CRP appears to be the most practical way to predict critical course of AP early after hospital admission.

Effect of acute, slightly increased intra-abdominal pressure on intestinal permeability and oxidative stress in a rat model

Introduction

Intra-abdominal hypertension (IAH) is known as a common, serious complication in critically ill patients. Bacterial translocation and permeability changes are considered the pathophysiological bases for IAH-induced enterogenic endotoxemia and subsequent multiorgan failure. Nevertheless, the effects of slightly elevated intra-abdominal pressures (IAPs) on the intestinal mucosa and the associated mechanisms remain unclear.

Methods

To investigate the acute effects of different nitrogen pneumoperitoneum grades on colonic mucosa, male Sprague-Dawley rats were assigned to six groups with different IAPs (0 [control], 4, 8, 12, 16, and 20 mmHg, n = 6/group). During 90 min of exposure, we dynamically monitored the heart rate and noninvasive hemodynamic parameters. After gradual decompression, arterial blood gas analyses were conducted. Thereafter, structural injuries to the colonic mucosa were identified using light microscopy. Colon permeability was determined using the expression of tight junction proteins, combined with fluorescein isothiocyanate dextran (FD-4) absorption. The pro-oxidant-antioxidant balance was determined based on the levels of malondialdehyde (MDA) and antioxidant enzymes.

Results

IAH significantly affected the histological scores of the colonic mucosa, tight junction protein expression, mucosal permeability, and pro-oxidant-antioxidant balance. Interestingly, elevations of IAP that were lower than the threshold for IAH also showed a similar, undesirable effect. In the 8 mmHg group, mild hyponatremia, hypocalcemia, and hypoxemia occurred, accompanied by reduced blood and abdominal perfusion pressures. Mild microscopic inflammatory infiltration and increased MDA levels were also detected. Moreover, an 8-mm Hg IAP markedly inhibited the expression of tight junction proteins, although no significant differences in FD-4 permeability were observed between the 0- and 8-mmHg groups.

Conclusions

Acute exposure to slightly elevated IAP may result in adverse effects on intestinal permeability and the pro-oxidant-antioxidant balance. Therefore, in patients with critical illnesses, IAP should be dynamically monitored and corrected, as soon as possible, to prevent intestinal mucosal injury and subsequent gut-derived sepsis.

Transjugular intrahepatic portosystemic shunt for Budd-Chiari syndrome: techniques, indications and results on 51 Chinese patients from a single centre

BACKGROUND & AIMS

In Western countries, transjugular intrahepatic portosytemic shunt (TIPS) is widely applied for the treatment of Budd-Chiari syndrome (BCS). However, the outcome of Chinese BCS patients treated with TIPS is extremely limited. Furthermore, the timing of conversion from percutaneous recanalization to TIPS remains uncertain.

METHODS

All consecutive BCS patients treated with TIPS between December 2004 and June 2012 were included. Patients were classified as the early and converted TIPS groups. Indications, TIPS-related complications, post-TIPS hepatic encephalopathy, shunt dysfunction and death were reported.

RESULTS

Of 51 patients included, 39 underwent percutaneous recanalization for 1024 days (0-4574) before TIPS. Early TIPS group (n = 19) has a shorter history of BCS and a lower proportion of prior percutaneous recanalization than converted TIPS group (n = 32). Main indications were diffuse obstruction of three HVs (n = 12), liver failure (n = 2), liver function deterioration (n = 8), refractory ascites (n = 10) and variceal bleeding (n = 19). Procedure-related intraperitoneal bleeding was reversible in three patients. The cumulative 1-year rate of being free of first episode of post-TIPS hepatic encephalopathy and shunt dysfunction was 78.38 and 61.69% respectively. The cumulative 1-, 2-, and 3-year survival rates were 83.82, 81.20 and 76.93% respectively. BCS-TIPS score, but not Child-Pugh, MELD, Clichy or Rotterdam score, could predict the survival. Age, total bilirubin and inferior vena cava thrombosis were also significantly associated with overall survival. Survival was similar between early and converted TIPS groups.

CONCLUSIONS

TIPS can achieve an excellent survival in Chinese patients in whom percutaneous recanalization is ineffective or inappropriate. BCS-TIPS score could effectively predict these patients' survival.

Efficacy of transjugular intrahepatic portosystemic shunt with adjunctive embolotherapy with cyanoacrylate for esophageal variceal bleeding

BACKGROUND

Transjugular intrahepatic portosystemic shunt (TIPS) with adjunctive embolotherapy has recently been reported to be effective in the prevention of variceal hemorrhage of cirrhotic patients. However, further investigation of its long-term efficacy is still needed.

AIM

To examine the rebleeding, survival, and hepatic encephalopathy (HE) after treatment with TIPS alone and TIPS with adjunctive embolotherapy using cyanoacrylate for esophageal variceal bleeding.

METHODS

Patients with refractory to endoscopic therapy for esophageal variceal bleeding were enrolled. TIPS was performed in 101 patients with adjunctive embolotherapy (n = 53) or alone (n = 48) between January 2006 and December 2011. Chart reviews were performed to determine rebleeding, survival rates, and the incidence of HE.

RESULTS

Recurrent hemorrhage occurred in 12 (11.9 %) patients during the mean follow-up periods of 35.8 months. Rebleeding was observed in 9/48 (18.8 %) patients in TIPS alone group and 3/53 (5.7 %) patients in TIPS with adjunctive embolotherapy group (p = 0.042). Death occurred in 30 patients during follow-up (TIPS alone: n = 16, TIPS with adjunctive embolotherapy: n = 14, p = 0.447). Twenty-six episodes of HE occurred in 18 patients in TIPS alone group and 16 episodes occurred in 10 patients in TIPS with embolotherapy group. The probability of HE was significantly higher in TIPS alone group than in TIPS with embolotherapy group (p = 0.019).

CONCLUSIONS

TIPS with adjunctive embolotherapy with cyanoacrylate is relatively safe and effective, with a lower rebleeding and HE incidence in comparison of TIPS alone.

The "Pavia model" of experimental small bowel transplantation in pigs: technical variations for ischemia reperfusion injury studies

Ischemia reperfusion injury (IRI) is a major field of study in small bowel transplantation because of its implications regarding intestinal immunity. In this study, we have introduced some variations to the described models of IRI in pigs to make possible a complete isolation of the small bowel for IRI studies. In swine, two anatomical barriers make impossible a complete isolation of the small bowel at the origin of superior mesenteric artery (SMA) and vein (SMV): the main colic vessels, which originate distally to form SMA and SMV, and the blood supply of the distal portion of the duodenum and the cephalic part of the pancreas. In a group of Large White pigs (n = 5), we have performed a complete isolation of the small bowel, including sub-total colectomy and pancreaticoduodenectomy. Both SMA and SMV were isolated at the origin from the aorta and at the junction of the splenic vein, respectively. Intestinal continuity was restored with duodenojejunal anastomosis and with ileotransverse colon anastomosis. One pig died on postoperative day 5 from intestinal occlusion due to adhesions. The remaining four pigs were killed on postoperative day 7 after an uneventful postoperative course. No complications were found at autopsy. In swine, resection of part of the pancreas and duodenum and removal of the large bowel does not affect short-term survival, allowing a full isolation of the entire small bowel mimicking the transplantation procedure. Thus, this model appears to be attractive for IRI studies in the field of intestinal transplantation.

Selection of treatment modalities for Budd-Chiari Syndrome in China: A preliminary survey of published literature

AIM: To evaluate the frequency of use of various treatment modalities for Budd-Chiari syndrome (BCS) in China by conducting a preliminary survey of relevant literature.

METHODS: All papers regarding the treatment of BCS in Chinese patients were identified by searching PubMed, Chinese Scientific and Technological Journal, and China National Knowledge Infrastructure databases. Data regarding the number of BCS patients treated with different treatment modalities over time were collected. The proportions of BCS patients undergoing various treatment modalities were calculated.

RESULTS: Overall, 300 of 3005 papers initially retrieved were included. These papers included 23352 BCS patients treated with different treatment modalities. The treatment modalities include surgery (n = 8625), interventional treatment (n = 13940), surgery combined with interventional treatment (n = 363), medical therapy (n = 277), other treatments (n = 91), and no treatment (n = 56). After 2005, the number of BCS patients treated with surgery was drastically decreased, but the number of BCS patients who underwent interventional treatment was almost maintained. Shunt surgery was the most common type of surgery (n = 3610). Liver transplantation was rarely employed (n = 2). Balloon angioplasty with or without stenting was the most common type of interventional treatment (n = 13747). Transjugular intrahepatic portosystemic shunt was rarely employed (n = 81).

CONCLUSION: Selection of treatment modalities for BCS might be different between China and Western countries. Further work should be necessary to establish a unanimous therapeutic strategy for BCS in China.

Pre-eclampsia renamed and reframed: Intra-abdominal hypertension in pregnancy

This hypothesis proposes pre-eclampsia is caused by intra-abdominal hypertension in pregnancy. Sustained or increasing intra-abdominal pressure ⩾12mmHg causes impaired venous return to the heart, systemic vascular resistance, ischemia reperfusion injury, intestinal permeability, translocation of lipopolysaccharide endotoxin to the liver, cytotoxic immune response, systemic inflammatory response, pressure transmission to thoracic and intra-cranial compartments, and multi-organ dysfunction. This hypothesis is predicated on Pascal's law, evidence founded in the intra-abdominal hypertension literature, and the adapted equation ΔIAP-P=ΔIAVF/Cab, where ΔIAP-P=change in intra-abdominal pressure in pregnancy, ΔIAVF=change in intra-abdominal vector force (volume and force direction) and Cab=abdominal compliance. Factors causing increased intra-abdominal pressure in pregnancy include: progressive uterine expansion, obstetrical factors that increase intra-uterine volume excessively or acutely, maternal anthropometric measurements that affect intra-abdominal pressure thresholds, maternal postures that increase abdominal force direction, abdominal compliance that is decreased, diminished with advancing gestation, or has reached maximum expansion, habitation at high altitude, and rapid drops in barometric pressure. We postulate that the threshold for lipopolysaccharide translocation depends on the magnitude of intra-abdominal pressure, the intestinal microbiome complex, and the degree of intestinal permeability. We advance that delivery cures pre-eclampsia through the mechanism of abdominal decompression.

Selection of a TIPS stent for management of portal hypertension in liver cirrhosis: An evidence-based review

Nowadays, transjugular intrahepatic portosystemic shunt (TIPS) has become a mainstay treatment option for the management of portal hypertension-related complications in liver cirrhosis. Accumulated evidence has shown that its indications are being gradually expanded. Notwithstanding, less attention has been paid for the selection of an appropriate stent during a TIPS procedure. Herein, we attempt to review the current evidence regarding the diameter, type, brand, and position of TIPS stents. Several following recommendations may be considered in the clinical practice: (1) a 10-mm stent may be more effective than an 8-mm stent for the management of portal hypertension, and may be superior to a 12-mm stent for the improvement of survival and shunt patency; (2) covered stents are superior to bare stents for reducing the development of shunt dysfunction; (3) if available, Viatorr stent-grafts may be recommended due to a higher rate of shunt patency; and (4) the placement of a TIPS stent in the left portal vein branch may be more reasonable for decreasing the development of hepatic encephalopathy. However, given relatively low quality of evidence, prospective well-designed studies should be warranted to further confirm these recommendations.

Intraintestinal drainage as a damage control surgery adjunct in a hypothermic traumatic shock swine model with multiple bowel perforations

BACKGROUND

Temporary bowel ligation (TL) has been proposed to prevent contamination as a damage control procedure in multiple bowel perforations. However, bacteria translocation and intestinal ischemia may develop in a prolonged duration. We here hypothesized that intraintestinal drainage combined with temporary ligation (D-TL) would decrease intestinal injury and improve survivals in a gunshot multiple bowel perforation swine model in the setting of a damage control surgery.

MATERIALS AND METHODS

The abdomen was shot one time with an experimental modified gun whereas pigs were hemorrhaged to a mean arterial pressure of 40 mm Hg and maintained in shock for 40 min. Cold lactated Ringer solution was gradually infused to induce hypothermia. Animals were randomized to primary anastomosis, TL and intraintestinal D-TL groups (n = 8). Animals were resuscitated for 12 h with the shed blood and lactated Ringer solution. Delayed anastomosis was performed in TL and D-TL animals after resuscitation. Surviving animals were humanely killed 24 h after operation. Systemic hemodynamic parameters were recorded and blood samples were obtained for biochemical assays. Intra-abdominal pressure, portal vein and peripheral vein bacterial cultures, small intestine hematoxylin-eosin staining, and transmission electron microscopy examination were performed at 0, 2, 6, 12, and 24 h after the surgery.

RESULTS

All animals suffered extreme physiologic conditions as follows: hypothermia, severe acidosis, hypotension, and depressed cardiac output. Compared with the primary anastomosis and TL group, D-TL animals required less resuscitation fluid, suffered a lower intra-abdominal hypertension and bacterial translocation, normalized lactate levels faster, had lower serum creatine kinase, aspartate aminotransferase levels and tissue TNF-α level, and nuclear factor-kB activations and thus had greater early survival.

CONCLUSIONS

Compared with primary intestinal anastomosis and TL, rapid bowel ligation combined with intraintestinal drainage as a damage control adjunct improved survivals in a multiple bowel perforation swine model in the setting of damage control surgery.

Relevance of induced and accidental hypothermia after trauma-haemorrhage-what do we know from experimental models in pigs?

Recent experimental research has either focused on the role of accidental hypothermia as part of the lethal triad after trauma or tried to elucidate the effects of therapeutically induced hypothermia on the posttraumatic course. Induced hypothermia seems to reduce the mortality in experimental models of trauma-haemorrhage. As potential mechanisms, a decrease of cellular metabolism, beneficial effects on haemodynamic function and an attenuation of the inflammatory response have been described. However, negative side effects of hypothermia have to be considered, such as impairment of the coagulatory function and immunosuppressive effects. Furthermore, the optimal strategy for the induction of hypothermia (magnitude, duration, timing, cooling rate, etc.) and subsequent rewarming remains unclear. Nevertheless, this piece of information is essential before considering hypothermia as a treatment strategy for severely injured patients. This review aims to elaborate the differences between accidental and induced hypothermia and to summarize the current knowledge of the potential therapeutic use of induced hypothermia suggested in porcine models of trauma-haemorrhage.

Early enteral nutrition prevents intra-abdominal hypertension and reduces the severity of severe acute pancreatitis compared with delayed enteral nutrition: a prospective pilot study

BACKGROUND

To investigate the effects of early enteral nutrition (EEN) on intra-abdominal pressure (IAP) and disease severity in patients with severe acute pancreatitis (SAP).

METHODS

Enteral nutrition (EN) was started within 48 h after admission in the EEN group and from the 8th day in the delayed enteral nutrition (DEN) group. The IAP and intra-abdominal hypertension (IAH) incidence were recorded for 2 weeks. The caloric intake and feeding intolerance (FI) incidence were recorded daily after EN was started. The severity markers and clinical outcome variables were also recorded.

RESULTS

Sixty patients were enrolled to this study. No difference about IAP was found. The IAH incidence of the EEN group was significantly lower than that of the DEN group from the 9th day (8/30 versus 18/30; P = 0.009) after admission. The FI incidence of the EEN group was higher than that of the DEN group during the initial 3 days of feeding (25/30 versus 12/30; P = 0.001; 22/30 versus 9/30; P = 0.001; 15/30 versus 4/30; P = 0.002). Patients with an IAP <15 mmHg had lower FI incidence than those with an IAP ≥15 mmHg on the 1st day (20/22 versus 17/38; P < 0.001), the 3rd day (11/13 versus 8/47; P < 0.001), and the 7th day (3/5 versus 3/55; P = 0.005) of feeding. The severity markers and clinical outcome variables of the EEN group were significantly improved.

CONCLUSIONS

Early enteral nutrition did not increase IAP. In contrast, it might prevent the development of IAH. In addition, EEN might be not appropriate during the initial 3-4 days of SAP onset. Moreover, EN might be of benefit to patients with an IAP <15 mmHg. Early enteral nutrition could improve disease severity and clinical outcome, but did not decrease mortality of SAP.

Damage control resuscitation: history, theory and technique

Damage control resuscitation (DCR) represents the natural evolution of the initial concept of damage control surgery. It currently includes early blood product transfusion, immediate arrest and/or temporization of ongoing hemorrhage (i.e., temporary intravascular shunts and/or balloon tamponade) as well as restoration of blood volume and physiologic/hematologic stability. As a result, DCR addresses the early coagulopathy of trauma, avoids massive crystalloid resuscitation and leaves the peritoneal cavity open when a patient approaches physiologic exhaustion without improvement. This concept also applies to severe injuries within anatomical transition zones as well as extremities. This review will discuss each of these concepts in detail.

A modified total colonic exclusion for elderly patients with severe slow transit constipation

BACKGROUND

The aim of this study was to evaluate outcomes of total colonic exclusion with antiperistaltic ileorectal anastomosis (TCE-AIA) for elderly patients with slow transit constipation (STC).

METHODS

Elderly patients (defined as age >65) who underwent TCE-AIA for severe idiopathic STC between 2009 and 2012 at our institution were identified. Postoperative outcomes and routine follow-up were assessed using the Wexner constipation score (WCS), gastrointestinal quality of life index (GIQLI) and four-point postoperative satisfaction scales.

RESULTS

A total of 13 elderly patients were met the inclusion criteria. Five patients (38.5%) were male, and eight patients (61.5%) were female. The mean age of this population was 74 years (range 63-82 years). The mean operative time was 55 min (range 28-32), and blood loss was minimal. The mean postoperative hospital stay was 6.7 days (range 5-12 days). The mean time until the first postoperative bowel movement was 4 days (range 2-8 days). There was no procedure-related mortality and no major in-hospital complications. The median duration of follow-up was 12.4 months (range 6-29 months). None of the 13 patients had fecal incontinence or recurrence of constipation at the follow-up end point. However, eight patients underwent colonoscopy during follow-up, and four patients presented with diversion colitis. The patients' preoperative WCS was 22.8 ± 3.3, and it had significantly improved to 5.4 ± 2.1 on 6 months after operation (p < 0.05). The preoperative GIQLI of 93.6 ± 20.5 had significantly increased to 120.8 ± 13.0 on 6 months after surgery (p < 0.05). Patient satisfaction at 6 months was very high in 11 patients and high in two patients.

CONCLUSIONS

TCE-AIA is a relatively simple procedure. It might be an effective surgical intervention for the selected elderly patients with STC.

Long-term outcomes and quality of life after subtotal colectomy combined with modified Duhamel procedure for adult Hirschsprung's disease

BACKGROUND

Subtotal colectomy combined with modified Duhamel procedure (Jinling procedure) was used in patients with adult Hirschsprung's disease (AHD) at Jinling Hospital in the last decade. The aim of this study is to evaluate the safety, effectiveness and quality of life of Jinling procedure for AHD.

MATERIALS AND METHODS

All the data are from the database of the Jinling Hospital Constipation Registry System. Primary outcomes, including safety (morbidity and adverse events), effectiveness (satisfaction rate, Wexner constipation scale (WCS) and bowel function score (BFS)) and gastrointestinal quality of life index (GIQLI), were all evaluated.

RESULTS

Fifty-nine patients were available for this study and the mean postoperative period was 44 months. Seventeen major complications were found in 11 patients and most of the complications could be managed conservatively. A significant improvement in WCS, BFS and GIQLI at 6 months postoperatively was obtained.

CONCLUSION

Jinling procedure is safe and effective for AHD.

The role of intestinal mucosa injury induced by intra-abdominal hypertension in the development of abdominal compartment syndrome and multiple organ dysfunction syndrome

Introduction

Abdominal distension is common in critical illness. There is a growing recognition that intra-abdominal hypertension (IAH) may complicate nonsurgical critical illness as well as after abdominal surgery. However, the pathophysiological basis of the injury to the intestinal mucosal barrier and its influence on the onset of abdominal compartment syndrome (ACS) and multiorgan dysfunction syndrome (MODS) remain unclear. We measured intestinal microcirculatory blood flow (MBF) during periods of raised intra-abdominal pressure (IAP) and examined how this influenced intestinal permeability, systemic endotoxin release, and histopathological changes.

Methods

To test different grades of IAH to the injury of intestinal mucosa, 96 New Zealand white rabbits aged 5 to 6 months were exposed to increased IAP under nitrogen pneumoperitoneum of 15 mmHg or 25 mmHg for 2, 4 or 6 hours. MBF was measured using a laser Doppler probe placed against the jejunal mucosa through a small laparotomy. Fluorescein isothiocyanate (FITC)-conjugated dextran was administered by gavage. Intestinal injury and permeability were measured using assays for serum FITC-dextran and endotoxin, respectively, after each increase in IAP. Structural injury to the intestinal mucosa at different levels of IAH was confirmed by light and transmission electron microscopy.

Results

MBF reduced from baseline by 40% when IAP was 15 mmHg for 2 hours. This doubled to 81% when IAP was 25 mmHg for 6 hours. Each indicator of intestinal injury increased significantly, proportionately with IAP elevation and exposure time. Baseline serum FITC-dextran was 9.30 (± SD 6.00) μg/ml, rising to 46.89 (±13.43) μg/ml after 15 mmHg IAP for 4 hours (P <0.01), and 284.59 (± 45.18) μg/ml after 25 mmHg IAP for 6 hours (P <0.01). Endotoxin levels showed the same pattern. After prolonged exposure to increased IAP, microscopy showed erosion and necrosis of jejunal villi, mitochondria swelling and discontinuous intracellular tight junctions.

Conclusions

Intra-abdominal hypertension can significantly reduce MBF in the intestinal mucosa, increase intestinal permeability, result in endotoxemia, and lead to irreversible damage to the mitochondria and necrosis of the gut mucosa. The dysfunction of the intestinal mucosal barrier may be one of the important initial factors responsible for the onset of ACS and MODS.

Surveillance of intra-abdominal pressure and intestinal barrier function in a rat model of acute necrotizing pancreatitis and its potential early therapeutic window

OBJECTIVES

To monitor intra-abdominal pressure (IAP) and intestinal barrier function in a rat model of acute necrotizing pancreatitis (ANP) to elucidate a potential relevant therapeutic window.

METHODS

Sprague-Dawley rats were randomly divided into experimental or control groups. The ANP group (n = 40) was injected with 4.5% sodium taurocholate into the pancreatic duct to induce ANP. The controls received only abdominal opening surgery (sham-operated, SO; n = 40) or no treatment or surgery (baseline; 0 h, n = 20). The SO and ANP groups were then randomly subdivided into 3, 6, 12 and 24 h groups (n = 10 each). IAP was measured at each time point and the rats were sacrificed to measure the weight of accumulated ascites fluid and the amylase, endogenous creatinine (Cr), total bilirubin (TB), tumor necrosis factor- alpha (TNF-alpha), diamine oxidase (DAO), and D-lactate. Mortality and the development of pathological changes in the pancreas and intestines were also monitored.

RESULTS

IAP showed a continuous upward trend in the ANP group, with values 2 to 3 times higher than those in the SO group at the corresponding time points and the rising rate was peaking at 6 h. The levels of plasma amylase, TNF-alpha, Cr, TB, DAO, and D-lactate also gradually increased in the ANP group over time and were significantly higher than in the SO group at 3, 6, 12 and 24 h (all P<0.05). Moreover, the rising rate of TNF-alpha, DAO, and D-lactate also peaked at 6 h.

CONCLUSIONS

The ANP-induced changes in IAP, inflammatory factors and intestinal barrier that we observed in the rat model were especially obvious at 6 h post-induction, suggesting an early therapeutic window for the treatment of ANP in humans.

The preventive effect of dopamine infusion in rats with abdominal compartment syndrome

BACKGROUND

The most significant perfusion disorder of the intra-abdominal viscera occurs in the abdominal compartment syndrome (ACS). Free oxygen radicals diffuse into the body during the reperfusion phase of ACS. Our aim was to determine the effects of dopamine infusion (3 μg/kg/min) on renal perfusion, cytokine levels, free oxygen radicals, and renal histopathological changes in the presence of ACS in a prospective randomized manner.

METHODS

Twenty-four male Sprague-Dawley rats were randomly divided into four groups (n = 6). Group 1 was used as control. In group 2, air was inflated until the intra-abdominal pressure (IAP) reached 20 mmHg. In group 3, dopamine was infused for 60 min meanwhile IAP was kept at 20 mmHg. In group 4, dopamine was infused for 60 min before IAP rise. After this phase, renal artery (RA) perfusion was measured continuously. Myeloperoxidase activity (MPO), glutathione (GSH), and lipid peroxidation (MDA) levels were measured in tissue samples and histopathological scoring was performed.

RESULTS

Dopamine treatment before and during ACS significantly decreased MPO and MDA levels and also increased renal blood flow and GSH levels. However, histopathological damage was improved simultaneously.

CONCLUSION

Dopamine infusion before and during ACS, increases renal perfusion and decreases free oxygen radicals. According to our findings, dopamine infusion may be proposed for the treatment of ACS and perfusion disorders in critically ill patients.

Stent-grafts for the treatment of TIPS dysfunction: Fluency stent vs Wallgraft stent

AIM: To evaluate the clinical efficacy of an expanded polytetrafluoro-ethylene-covered Fluency stent compared with that of a polyethylene terephthalate-covered Wallgraft stent for the management of transjugular intrahepatic portosystemic shunt (TIPS) dysfunction.

METHODS: A retrospective review of patients who underwent TIPS revision with stent-grafts between May 2007 and June 2011 was conducted. The patients were divided into two groups according to the stent-grafts implanted: the Fluency stent (Bard Incorporated, Karlsruhe, Germany) and the Wallgraft stent (Boston Scientific, Galway, Ireland). The primary patency rates were calculated and compared using the Kaplan-Meier method.

RESULTS: A total of 73 patients were evaluated in this study: 33 with Fluency stents and 40 with Wallgraft stents. The primary patency rates at 12 and 24 mo were 91% and 85%, respectively, in the Fluency stent group and 78% and 63%, respectively, in the Wallgraft stent group. The primary shunt patency rates after TIPS revision were significantly better with the Fluency stent than with the Wallgraft stent (P = 0.033).

CONCLUSION: TIPS revision with the Fluency stent has higher medium-term patency rates than that with the Wallgraft stent.

Transjugular intrahepatic portosystemic shunt in the treatment of Budd-Chiari syndrome: a critical review of literatures

An increasing number of patients with Budd-Chiari syndrome (BCS) have undergone transjugular intrahepatic portosystemic shunt (TIPS). However, the critical role of TIPS in the treatment of BCS has not been systematically reviewed. The authors identified all relevant literatures via the PubMed, EMBASE and Cochrane library databases. Overall, 160 papers from 29 countries reported the application of TIPS for BCS. The number of publications was increased over time, but the level of evidence in this field was low. Common indications for TIPS in BCS patients included refractory ascites, recurrent variceal bleeding, diffuse hepatic vein thrombosis and progressive liver failure. Successful TIPS insertion could improve the hemodynamic and clinical parameters. TIPS procedure-related complications were not infrequent (range: 0-56%), but procedure-related death was rare. Shunt dysfunction rate appeared to be higher (range: 18-100%). Compared with bare stents, covered stents could significantly decrease the rate of shunt dysfunction. Hepatic encephalopathy rate after TIPS was relatively low (range: 0-25%). Short- and long-term prognosis of BCS-TIPS patients was excellent with 1-year cumulative survival rate of 80-100% and 5-year cumulative survival rate of 74-78%. In conclusions, existing literatures supported the feasibility, safety and efficacy of TIPS in the treatment of BCS. Prospective cohort studies or randomized controlled trials were difficult due to the rarity of BCS, but might be very necessary to precisely identify the timing of transition from medical therapy and/or percutaneous recanalization to TIPS insertion and the real candidates in whom early TIPS should be promptly employed with no need of any prior therapy.

Hemodynamic effects of continuous versus bolus infusion of terlipressin for portal hypertension: a randomized comparison

BACKGROUND AND AIM

The hemodynamics of patients with portal hypertension within 4 h after a single injection of terlipressin has been studied. However, the hemodynamics in a longer phase under different infusion styles is unknown. This study aims to compare the effects of bolus and continuous infusion of terlipressin on systemic and hepatic hemodynamics in patients with portal hypertension.

METHODS

Twenty patients who underwent transjugular intrahepatic portosystemic shunt procedure were randomly assigned to be treated with either intravenous bolus infusion of terlipressin (1 mg) followed by a continuous infusion (4 mg/24 h, n = 10), or intravenous bolus injection of terlipressin (2 mg) followed by intermittent injections (1 mg/6 h, n = 10). The mean arterial pressure, heart rate, and portal venous pressure (PVP) were monitored and recorded at baseline, 1 min, 5 min, 10 min, 30 min, and then once an hour. Serum renin activity, serum angiotensin II, and aldosterone levels were measured prior to and 24 h after the administration of terlipressin.

RESULTS

PVP dropped rapidly in both groups, and reduced 16.46% and 28.22%, respectively, at the 1-h time point. Thereafter, PVP remained stable in continuous group while rebounded obviously in intermittent group. One hour after the start of drug administration, heart rate decreased significantly in both groups (84.1 ± 12.8 vs 73.8 ± 12.6 in intermittent group and 86.7 ± 11.5 vs 77.1 ± 13.6 in continuous group, P < 0.005), and mean arterial pressure increased in both groups, although no statistical differences were found.

CONCLUSION

Continuous infusion of terlipressin reduces PVP stably and may become an alternative to traditional bolus injection.

Lipopolysaccharide-induced bacterial translocation is intestine site-specific and associates with intestinal mucosal inflammation

The present study aimed to determine whether any specific intestinal site or intestinal mucosal inflammation is highly correlated with bacterial translocation (BT). Enterostomy tubes were surgically placed in adult male Sprague-Dawley rats 5 days before induction of experimental model. After surgery, sterile water containing kanamycin (25 mg/L) was injected into each intestinal segment through the tubes for 3 days. Green fluorescent protein (GFP)-transfected Escherichia coli (n = 30 for lipopolysaccharide (LPS) group, and n = 30 for control group) or 0.9 % saline (n = 30 for blank group) were injected into each intestinal segment through the tubes for two consecutive days. Rats were then subjected to LPS-induced endotoxemia; lactulose and mannitol were injected into each intestinal segment through the tubes simultaneously. At 6 h after LPS injection, BT to distant organs and integrity of tight junctions (TJ) were examined by fluorescence and electron microscopy, respectively. The urinary excretion ratio of lactulose/mannitol (L/M) and intestinal mucosal cytokine levels were assessed. We found that the intestinal permeability, reflected by translocation rates of GFP-labeled E. coli, the levels of open TJ, the excretion ratio of L/M, and the inflammatory cytokine levels were higher in the LPS group than in the control and blank groups. The endotoxemia ileum showed the highest levels of both intestinal permeability and inflammatory cytokine, while the colon showed the lowest. The present study of endotoxemia rats suggests that LPS increases gut paracellular permeability and induces BT. The ileum is the site of greatest BT risk, while the colon is the lowest, and the difference in risk between these sites is correlated with intestinal mucosal inflammation.

Tonometry as a predictor of inadequate splanchnic perfusion in an intra-abdominal hypertension animal model

BACKGROUND

The gastrointestinal system is the most sensitive to the presence of intra-abdominal hypertension. We aimed to assess the early prognostic value of gastric air tonometry as a predictor of inadequate splanchnic perfusion and determine its relation with abdominal perfusion pressure (APP).

METHODS

Twenty-five Large White swine were used for this study. A control group and two study groups were included, in which intra-abdominal pressure (IAP) was elevated with Co2 to 20 and 30 mmHg during 5 h. We measured the intramucosal gastric pH (pHim) and determined gastric luminal PCO2 (PgCO2) and PgCO2gap (gastric luminal CO2-arterial CO2) to evaluate gastric acidity. APP was indirectly obtained through IAP and mean arterial pressure. Additionally, histopathologic samples of small intestine were obtained and analyzed.

RESULTS

pHim showed a decrease in IAP groups, with statistical significance in the 30 mmHg group, 90 min after stabilization period (P < 0.01). Serum lactate showed delayed alteration when compared with pHim, with significant increase, 180 min after stabilization (P < 0.05). The values of PgCO2 and PCO2gap were increased in IAP groups, being statistically significant in the 30 mmHg group, 120 and 150 min, respectively, after stabilization. In increased IAP groups, there was a time progressive decrease of APP, with statistically significant differences observed between groups at 20 min (P < 0.001). The histopathology study revealed parenchymal injury of the intestine at 30 mmHg.

CONCLUSIONS

Tonometry is sensitive to the increase in IAP and relates to the reduction of APP generated by splanchnic hypoperfusion.

The importance of timing of decompression in severe acute pancreatitis combined with abdominal compartment syndrome

BACKGROUND

Surgical decompression is widely considered as an important treatment in patients with severe acute pancreatitis (SAP) and abdominal compartment syndrome (ACS). Until now, the indication and optimal time of decompression remain unknown, and no experimental data exist, although extremely high mortality has been repeatedly reported in these patients. The aim of this study was to evaluate the effects of three different time points for decompression in a 24-hour lasting porcine model.

METHODS

Following baseline registrations, 32 animals were divided into four groups (8 animals each group) as follows: one SAP-alone group and three SAP + ACS groups, which received decompression at 6, 9, and 12 hours. We used a N2 pneumoperitoneum to increase the intra-abdominal pressure to 25 mm Hg and retrograde intra-ductal infusion of sodium taurocholate to induce SAP. Global hemodynamic profiles, urine output, systemic oxygenation, and serum biochemical parameters of the animals were studied. At the end of the experiment, histologic examination of the intestine and lung was performed.

RESULTS

The survival time of the 12-hour group was significantly shortened (p = 0.037 vs. 9 hours and p = 0.008 vs. 6 hours). In SAP + ACS animals, decompression at 6 hours restored systemic hemodynamics, oxygen-derived parameters, organ function, and inflammatory intensity to a level comparable with that of the SAP-alone group. In contrast, animals in the 9 hours and 12 hours developed more severe hemodynamic and organ dysfunction. The histopathologic analyses also revealed higher grade injury of the intestine and lung in animals receiving delayed decompression.

CONCLUSION

Well-timed decompression in a porcine model of SAP incorporating 25-mm Hg intra-abdominal hypertension/ACS was associated with significantly reduced mortality, improved systemic hemodynamics and organ function, as well as alleviated histologic injury and inflammatory intensity. According to our results and previous reports, both too early and too late decompression should be avoided owing to significant morbidity for the former and unfavorable outcomes for the latter.

Delayed liver laceration following transjugular intrahepatic portosystemic shunt for portal hypertension

The transjugular intrahepatic portosystemic shunt (TIPS) is an acceptable procedure that has proven benefits in the treatment of patients who have complications from portal hypertension due to liver cirrhosis. Delayed liver laceration is a rare complication of the TIPS procedure. We describe a patient with portal hypertension due to liver cirrhosis, who suddenly presented with abdominal hemorrhage and liver laceration 8 d after TIPS. Few reports have described complications after TIPS placement. To the best of our knowledge, this is the first report describing delayed liver laceration. This potential and serious complication appears to be specific and fatal for TIPS in portal hypertension. We advocate careful attention to the technique to avoid this complication, and timely treatment is extremely important.

Fluctuating portal velocity tracing with rhythmicity: ultrasonic differential diagnosis and clinical significance

Background

To evaluate the usefulness of the routine sonographic evaluation of the pattern of fluctuate portal velocity tracings and the hepatic veins for the diagnosis of arterioportal fistula (APF) and cardiogenic trans-sinusoidal shunting (CTS).

Materials and methods.

Color Doppler flow imaging and pulsed-wave Doppler (PW) examinations of the portal vein were performed in 282 subjects. The waveforms of the velocity tracings in the portal main trunk and its branches were determined to infer APF or CTS. Suspected cases of APFs or CTSs were always confirmed by echocardiography, contrast-enhanced ultrasound, computed tomography, or digital subtraction angiography findings. The portal maximum velocity (V_max), minimum velocity(V_min), V_max/V_min, arterial peak systolic velocity and resistance index, and venous reverse and forward velocities were used to estimate their haemodynamics.

Results

The waveform of the velocity tracing for the draining portal vein of APF was typically arterial-like or diphase, as indicated by a systolic hepatofugal dwarf peak and a diastolic hepatopetal low flat shape. The flow in the affected portal vein was always hepatofugal in an intrahepatic patient, whereas a hepatopetal flow was observed in an extrahepatic APF patient. The waveform of the velocity tracing for the portal vein of CTS patients, especially its intrahepatic branches, showed a typical hump-like shape with or without a transitory hepatofugal tracing. The PW results displayed an increase in the retrograde phase of the hepatic venous flow with increased velocities in the two phases.

Conclusions

Portal velocity tracings should be evaluated during routine detecting for APF or CTS, especially in patients with gastrointestinal upsets.

Clinical outcome and predictors of survival after TIPS insertion in patients with liver cirrhosis

AIM: To determine the clinical outcome and predictors of survival after transjugular intrahepatic portosystemic stent shunt (TIPS) implantation in cirrhotic patients.

METHODS: Eighty-one patients with liver cirrhosis and consequential portal hypertension had TIPS implantation (bare metal) for either refractory ascites (RA) (n = 27) or variceal bleeding (VB) (n = 54). Endpoints for the study were: technical success, stent occlusion and stent stenosis, rebleeding, RA and mortality. Clinical records of patients were collected and analysed. Baseline characteristics [e.g., age, sex, CHILD score and the model for end-stage liver disease score (MELD score), underlying disease] were retrieved. The Kaplan-Meier method was employed to calculate survival from the time of TIPS implantation and comparisons were made by log rank test. A multivariate analysis of factors influencing survival was carried out using the Cox proportional hazards regression model. Results were expressed as medians and ranges. Comparisons between groups were performed by using the Mann-Whitney U-test and the χ² test as appropriate.

RESULTS: No difference could be seen in terms of age, sex, underlying disease or degree of portal pressure gradient (PPG) reduction between the ascites and the bleeding group. The PPG significantly decreased from 23.4 ± 5.3 mmHg (VB) vs 22.1 ± 5.5 mmHg (RA) before TIPS to 11.8 ± 4.0 vs 11.7 ± 4.2 after TIPS implantation (P = 0.001 within each group). There was a tendency towards more patients with stage CHILD A in the bleeding group compared to the ascites group (24 vs 6, P = 0.052). The median survival for the ascites group was 29 mo compared to > 60 mo for the bleeding group (P = 0.009). The number of radiological controls for stent patency was 6.3 for bleeders and 3.8 for ascites patients (P = 0.029). Kaplan-Meier calculation indicated that stent occlusion at first control (P = 0.027), ascites prior to TIPS implantation (P = 0.009), CHILD stage (P = 0.013), MELD score (P = 0.001) and those patients not having undergone liver transplantation (P = 0.024) were significant predictors of survival. In the Cox regression model, stent occlusion (P = 0.022), RA (P = 0.043), CHILD stage (P = 0.015) and MELD score (P = 0.004) turned out to be independent prognostic factors of survival. The anticoagulation management (P = 0.097), the porto-systemic pressure gradient (P = 0.460) and rebleeding episodes (P = 0.765) had no significant effect on the overall survival.

CONCLUSION: RA, stent occlusion, initial CHILD stage and MELD score are independent predictors of survival in patients with TIPS, speaking for a close follow-up in these circumstances.

Dynamic changes of intrinsic brain activity in cirrhotic patients after transjugular intrahepatic portosystemic shunt: a resting-state FMRI study

PURPOSE

The majority of cirrhotic patients who underwent transjugular intrahepatic portosystemic shunt (TIPS) experienced the first post-TIPS hepatic encephalopathy (HE) episode within the first three months after TIPS insertion. However, so far, little is known about the exact neuro-pathophysiological mechanism of TIPS's effects on brain function. We aimed to investigate the dynamics of brain function alteration of post-TIPS patients using resting-state functional MRI (rs-fMRI).

MATERIALS AND METHODS

Sixteen cirrhotic patients who were scheduled for TIPS and 16 healthy controls were included in the rs-fMRI scans. Ten patients repeated the MRI study in a median 8-day follow-up interval following TIPS and seven in a median 3-month follow-up. The amplitude of low frequency fluctuation (ALFF), an index reflecting the spontaneous brain activity, was compared between patients before TIPS and healthy controls as well as patients pre- and post-TIPS.

RESULTS

Compared with healthy controls, patients showed decreased ALFF in frontal and parietal regions and increased ALFF in insula. Patients who underwent the median 8-day follow-up fMRI examinations showed decreased ALFF in posterior cingulate cortex (PCC)/precuneus and increased ALFF in anterior cingulate cortex (ACC). Of 10 patients in this group, 9 had moderate to large increase rate of ALFF value (>20%, mean 49.19%) in ACC, while only one patient with the smallest increase rate of ALFF value (<10%) in ACC, who experienced three episodes of overt HE during the 3-month follow-up. In the median 3-month follow up observation, patients displayed persistently decreased ALFF in PCC, ACC and medial prefrontal cortex (MPFC), while no increased regional ALFF was observed.

CONCLUSION

TIPS insertion alters cirrhotic patients' ALFF patterns in the resting state, which may imply different short-term and moderate-term effects on cirrhotic patients, i.e., both impairment and compensatory mechanism of brain functions in peri-TIPS and continuous impairment of brain function 3 months following TIPS.

The effect of hepatic encephalopathy, hepatic failure, and portosystemic shunt on brain volume of cirrhotic patients: a voxel-based morphometry study

Purpose

To evaluate the effect of hepatic encephalopathy (HE), hepatic failure, and portosystemic shunt (PS) on the brain volume alteration in cirrhotic patients with MRI voxel-based morphometry (VBM).

Methods

Sixty cirrhotic patients (overt HE [OHE], n = 11; minimal HE [MHE], n = 19; non HE [nHE], n = 30) including 12 with pre- and post-transjugular intrahepatic portosystemic shunt (TIPS) scanning and 40 healthy controls were recruited. Neuropsychological and laboratory tests were performed in all patients. VBM was analyzed with ANOVA test among 4 groups, and t-tests for patients with different hepatic function, PS scores, and TIPS. Multiple linear regression was performed to investigate the effect of venous blood ammonia levels, Child-Pugh scores, and PS on the brain volumes in all patients.

Results

Cirrhotic patients exhibited decreased volume in many areas of gray matter (GM), increased volume in thalamus, and increased whiter matter (WM) volume, with the extent of affected brain volume greater in HE patients than nHE patients. Hepatic failure also resulted in decreased GM volume. Patients with high PS scores and TIPS displayed decreased GM and increased WM volume in some regions. Post-TIPS patients displayed increased GM volume in the thalamus. Multiple covariate regression results suggested that Child-Pugh score was a major factor to affect GM volume, while PS mainly affected WM volume.

Conclusion

Brain structure abnormalities appeared bilaterally symmetrical in cirrhotic patients, and the impairment was more extensive in HE patients than those without HE. Increased thalamus volume was not associated with HE progression. Hepatic failure and PS altered cirrhotic patients’ brain structure.

Influence of two different levels of intra-abdominal hypertension on bacterial translocation in a porcine model

BACKGROUND

The purpose of the present study was to quantify bacterial translocation to mesenteric lymph nodes due to different levels of intra-abdominal hypertension (IAH; 15 vs. 30 mmHg) lasting for 24 h in a porcine model.

METHODS

We examined 18 anesthetized and intubated pigs (52.3 ± 4.7 kg) which were randomly allocated to three experimental groups (each n = 6) and studied over a period of 24 h. After preparation and establishing a steady state, the intra-abdominal pressure (IAP) was increased stepwise to 30 mmHg in six animals using a carbon dioxide (CO2) insufflator (IAP-30 group). In the second group, IAP was increased to 15 mmHg (IAP-15 group), while IAP remained unchanged in another six pigs (control group). Using a pulse contour cardiac output (PiCCO®) monitoring system, hemodynamic parameters as well as blood gases were recorded periodically. Moreover, peripheral and portal vein blood samples were taken for microbiological examinations. Lymph nodes from the ileocecal junction were sampled during an intra-vital laparotomy at the end of the observational period. After sacrificing the animals, bowel tissue samples and corresponding mesenteric lymph nodes (MLN) were extracted for histopathological and microbiological analyses.

RESULTS

Cardiac output decreased in all groups. In IAP-30 animals, volumetric preload indices significantly decreased, while those of IAP-15 pigs did not differ from those of controls. Under IAH, the mean arterial pressure (MAP) in the IAP-30 group declined, while MAP in the IAP-15 group was significantly elevated (controls unchanged). PO2 and PCO2 remained unchanged. The grade of ischemic damage of the intestines (histopathologically quantified using the Park score) increased significantly with different IAH levels. Accordingly, the amount of translocated bacteria in intestinal wall specimens as well as in MLN significantly increased with the level of IAH. Lymph node cultures confirmed the relation between bacterial translocation (BT) and IAP. The most often cultivated species were Escherichia coli, Staphylococcus, Clostridium, Pasteurella, and Streptococcus. Bacteremia was detected only occasionally in all three groups (not significantly different) showing gut-derived bacteria such as Proteus, Klebsiella, and E. coli spp.

CONCLUSION

In this porcine model, a higher level of ischemic damage and more BT were observed in animals subjected to an IAP of 30 mmHg when compared to animals subjected to an IAP of 15 mmHg or controls.

Influence of abdominal pressure on respiratory and abdominal organ function

PURPOSE OF REVIEW

Intra-abdominal hypertension (IAH) and abdominal compartment syndrome (ACS) have been realized as severe complications in the intensive care patient. Laparoscopic surgery in older and more obese patients increases the risk of IAH and ACS.

RECENT FINDINGS

The incidence of IAH may be larger than thought of being approximately one-third of mechanically ventilated intensive care patients. In shock/trauma, three-fourths of all patients may suffer from IAH. Kidney and liver may dysfunction and the gut barrier may be impeded, permitting spread of inflammation to other organs. IAH and ACS have an impact on respiratory mechanics and may impede ventilation and require higher ventilation pressures than under normal conditions. Prone position and alternating (asynchronous) ventilation may moderate the IAH. In addition, surgical decompression should be considered.

SUMMARY

In view of the frequent occurrence of IAH in intensive care, the need of better understanding of the mechanisms behind IAH is a prerequisite for better treatment. Respiratory mechanics are affected but may also indicate routes of ventilatory treatment to lower IAH.

Temporary rapid bowel ligation as a damage control adjunct improves survival in a hypothermic traumatic shock swine model with multiple bowel perforations

BACKGROUND

Primary intestinal anastomosis is not the right choice for multiple bowel perforations under hemodynamically stable conditions. Our group has employed temporary rapid bowel ligation as a damage control procedure in a hypothermic traumatic shock swine model with multiple bowel perforations and hypothesized that damage control treatment would improve survival in the setting of a damage control surgery.

MATERIALS AND METHODS

The abdomen was shot one time with an experimental modified gun while pigs were hemorrhaged to a mean arterial pressure of 40 mm Hg and maintained in shock for 40 min. Cold lactated Ringer solution was gradually infused to induce hypothermia. Animals were randomized to control (no resuscitation), primary anastomosis (PA), or temporary rapid bowel ligation (damage control group, DC). Animals were resuscitated for 12 h with the shed blood and lactated Ringer solution. Delayed anastomosis was performed in DC animals after resuscitation. Surviving animals were humanely killed 24 h after operation. Systemic hemodynamic parameters were recorded and blood samples were obtained for biochemical assays. The lung and ileum was harvested at the end of the experiment for pathologic evaluation and test of wet/dry weight ratio, TNF-α level, and nuclear factor-κB activations.

RESULTS

All animals suffered extreme physiologic conditions: hypothermia, severe acidosis, hypotension, and depressed cardiac output. Control animals suffered 100% mortality. Compared with the PA group, DC animals required less resuscitation fluid, normalized lactate levels faster, had lower serum creatine kinase, aspartate amino transferase levels and tissue TNF-α level and nuclear factor-κB activations, suffered less severe histopathology, had greater early survival.

CONCLUSIONS

Multiple bowel perforations under hemodynamically stable conditions seem better managed with DC than with PA. Temporary rapid bowel ligation as a damage control adjunct is important to rapid control of multiple bowel perforations instead of a prolonged operative time.

The effect of intra-abdominal hypertension incorporating severe acute pancreatitis in a porcine model

Introduction

Abdominal compartment syndrome (ACS) and intra abdominal hypertension(IAH) are common clinical findings in patients with severe acute pancreatitis(SAP). It is thought that an increased intra abdominal pressure(IAP) is associated with poor prognosis in SAP patients. But the detailed effect of IAH/ACS on different organ system is not clear. The aim of this study was to assess the effect of SAP combined with IAH on hemodynamics, systemic oxygenation, and organ damage in a 12 h lasting porcine model.

Measurements and Methods

Following baseline registrations, a total of 30 animals were divided into 5 groups (6 animals in each group): SAP+IAP30 group, SAP+IAP20 group, SAP group, IAP30 group(sham-operated but without SAP) and sham-operated group. We used a N₂ pneumoperitoneum to induce different levels of IAH and retrograde intra-ductal infusion of sodium taurocholate to induce SAP. The investigation period was 12 h. Hemodynamic parameters (CO, HR, MAP, CVP), urine output, oxygenation parameters(e.g., S_vO₂, PO₂, PaCO₂), peak inspiratory pressure, as well as serum parameters (e.g., ALT, amylase, lactate, creatinine) were recorded. Histological examination of liver, intestine, pancreas, and lung was performed.

Main Results

Cardiac output significantly decreased in the SAP+IAH animals compared with other groups. Furthermore, AST, creatinine, SUN and lactate showed similar increasing tendency paralleled with profoundly decrease in S_vO₂. The histopathological analyses also revealed higher grade injury of liver, intestine, pancreas and lung in the SAP+IAH groups. However, few differences were found between the two SAP+IAH groups with different levels of IAP.

Conclusions

Our newly developed porcine SAP+IAH model demonstrated that there were remarkable effects on global hemodynamics, oxygenation and organ function in response to sustained IAH of 12 h combined with SAP. Moreover, our model should be helpful to study the mechanisms of IAH/ACS-induced exacerbation and to optimize the treatment strategies for counteracting the development of organ dysfunction.

Effects of different tidal volumes in pulmonary and extrapulmonary lung injury with or without intraabdominal hypertension

PURPOSE

We hypothesized that: (1) intraabdominal hypertension increases pulmonary inflammatory and fibrogenic responses in acute lung injury (ALI); (2) in the presence of intraabdominal hypertension, higher tidal volume reduces lung damage in extrapulmonary ALI, but not in pulmonary ALI.

METHODS

Wistar rats were randomly allocated to receive Escherichia coli lipopolysaccharide intratracheally (pulmonary ALI) or intraperitoneally (extrapulmonary ALI). After 24 h, animals were randomized into subgroups without or with intraabdominal hypertension (15 mmHg) and ventilated with positive end expiratory pressure = 5 cmH(2)O and tidal volume of 6 or 10 ml/kg during 1 h. Lung and chest wall mechanics, arterial blood gases, lung and distal organ histology, and interleukin (IL)-1β, IL-6, caspase-3 and type III procollagen (PCIII) mRNA expressions in lung tissue were analyzed.

RESULTS

With intraabdominal hypertension, (1) chest-wall static elastance increased, and PCIII, IL-1β, IL-6, and caspase-3 expressions were more pronounced than in animals with normal intraabdominal pressure in both ALI groups; (2) in extrapulmonary ALI, higher tidal volume was associated with decreased atelectasis, and lower IL-6 and caspase-3 expressions; (3) in pulmonary ALI, higher tidal volume led to higher IL-6 expression; and (4) in pulmonary ALI, liver, kidney, and villi cell apoptosis was increased, but not affected by tidal volume.

CONCLUSIONS

Intraabdominal hypertension increased inflammation and fibrogenesis in the lung independent of ALI etiology. In extrapulmonary ALI associated with intraabdominal hypertension, higher tidal volume improved lung morphometry with lower inflammation in lung tissue. Conversely, in pulmonary ALI associated with intraabdominal hypertension, higher tidal volume increased IL-6 expression.

Prolonged indwelling time of temporary vascular shunts is associated with increased endothelial injury in the porcine mesenteric artery

BACKGROUND

Temporary intravascular shunts (TIVS) have been used as a damage control surgery (DCS) adjuncts in superior mesenteric artery (SMA) injuries, both experimentally and clinically. However, no study to date has evaluated the relationship between shunt indwelling time and resultant endothelial cell (EC) injury. We hypothesized that prolonged use of TIVS in SMA injuries would jeopardize EC integrity.

METHOD

After laparotomy, the SMA was clamped and transected while pigs were hemorrhaged to 40 mm Hg for 30 minutes. A TIVS was inserted between transected ends of the SMA without systemic anticoagulation. Totally, 24 animals were resuscitated and randomized to different shunt indwelling time groups: A, 3 hours; B, 6 hours; C, 9 hours; and D, 12 hours. Patency of shunts was monitored and recorded. Continuous wave Doppler was used as a determinant of adequacy of flow through the shunts. Transmural SMA biopsies from areas of TIVS placement were examined with electron microscopy for histopathologic injury after staining with hematoxylin and eosin and immunofluorescence using a validated histopathologic injury score (minimum-maximum score: 0-4).

RESULTS

Severity of endothelial injury was observed to be directly related to shunt indwell time. SMA transmural biopsies harvested from group D animals showed the most profound injury, demonstrating extensive EC denudations and marked intimal rupture (injury grade, 3.4 ± 0.2). Sections from group A animals revealed the mildest EC injury (1.3 ± 0.3 vs. group D p < 0.01). No significant difference was detected between group A and B. EC injury grade in group C (2.7 ± 0.6) was higher than that in group B (1.8 ± 0.6) but did not reach statistical significance (p = 0.58).

CONCLUSION

When possible, vascular reconstruction following use of shunts should include an interposition graft after debridement of the arterial edges having interfaced with the shunt. Finally, to minimize intimal injury to the native vessel, this model suggests that indwell times of shunts should be <9 hours.

Comparisons of three surgical procedures on intestine ischemia reperfusion injury in a superior mesenteric artery injury model

BACKGROUND

Temporary ligation, primary anastomosis, and temporary shunt have been reported to deal with superior mesenteric artery (SMA) injuries. We aimed to investigate which brought minimal ischemia reperfusion injury in a hypothermic traumatic shock swine model.

METHODS

SMA was completely clamped while pigs were hemorrhaged to a mean arterial pressure (MAP) of 40 mm Hg. Animals were then randomized into temporary ligation (A, n=8), primary anastomosis (B, n=8), temporary shunt (C, n=8), and control groups (n=4). Animals in group A remained SMA interrupted for additional 1h while the other groups underwent the corresponding procedures immediately. Intestine injury was assessed by histologic examination and measurement of lipid peroxidations at the end of ischemia and experiment.

RESULTS

Overall mortality rate was 50%, 25%, and 0% in groups A, B, and C, respectively (P<0.05). The total intestine ischemia time was predominantly shorter in group C in the other groups. Remarkable elevations of malonaldehyde (MDA) in small intestine were noted after reperfusion in group A. Animals in other groups, however, did not exacerbate during the 6-h reperfusion (resuscitation period). Group C showed the lowest MDA level at the end of experiment. Myeloperoxidase (MPO) levels showed no significant elevations during the ischemia or early reperfusion period; nevertheless, it reached approximately 3- to 6-fold in groups A and B (compared with baseline, P<0.01), and remained unchanged in group C at the end of experiment.

CONCLUSION

Our study suggests that temporary shunt insertion might be preferred as it shortens ischemia time, alleviates intestinal ischemia/reperfusion injury, and thus decreases early mortality in this animal model.

Temporary intravascular shunting improves survival in a hypothermic traumatic shock swine model with superior mesenteric artery injuries

BACKGROUND

Repairs of superior mesenteric artery (SMA) injuries are difficult and often result in high mortality. Our group has employed temporary intravascular shunts (TIVS) as a damage control procedure in a SMA transection model and hypothesized that TIVS would improve survival when compared with primary vascular anastomosis in the setting of a damage control surgery.

METHODS

The SMA was clamped and completely transected while pigs were hemorrhaged to a mean arterial pressure of 40 mmHg and maintained in shock for 30 minutes. Cold lactated Ringer's solution was gradually infused while the abdomen was open to induce hypothermia. Animals were randomized to control (no resuscitation), primary anastomosis (PA), or temporary shunting (TS) of the SMA. Animals were resuscitated for 6 hours with the shed blood and lactated Ringer's solution. Delayed anastomosis was performed in TS animals after resuscitation. Surviving animals were humanely killed 2 days after operation. Systemic hemodynamic parameters were recorded hourly. The ileum was harvested at the end of resuscitation and experiment for pathologic evaluation.

RESULTS

All animals suffered extreme physiologic conditions: hypothermia, severe acidosis, hypotension, and depressed cardiac output and oxygen delivery. Control animals suffered 100% mortality. Compared with the PA group, TS animals required less resuscitation fluid, retained higher SMA flow rates, normalized lactate levels faster, suffered less severe intestine histopathology, and had greater early survival.

CONCLUSION

Damage control surgery in the setting of SMA transection seems better managed with TS than with PA. Further validation of this model is required before generalization to human applications.