Perioperative intravenous contrast administration and the incidence of acute kidney injury after major gastrointestinal surgery: prospective, multicentre cohort study

BACKGROUND

This study aimed to determine the impact of preoperative exposure to intravenous contrast for CT and the risk of developing postoperative acute kidney injury (AKI) in patients undergoing major gastrointestinal surgery.

METHODS

This prospective, multicentre cohort study included adults undergoing gastrointestinal resection, stoma reversal or liver resection. Both elective and emergency procedures were included. Preoperative exposure to intravenous contrast was defined as exposure to contrast administered for the purposes of CT up to 7 days before surgery. The primary endpoint was the rate of AKI within 7 days. Propensity score-matched models were adjusted for patient, disease and operative variables. In a sensitivity analysis, a propensity score-matched model explored the association between preoperative exposure to contrast and AKI in the first 48 h after surgery.

RESULTS

A total of 5378 patients were included across 173 centres. Overall, 1249 patients (23·2 per cent) received intravenous contrast. The overall rate of AKI within 7 days of surgery was 13·4 per cent (718 of 5378). In the propensity score-matched model, preoperative exposure to contrast was not associated with AKI within 7 days (odds ratio (OR) 0·95, 95 per cent c.i. 0·73 to 1·21; P = 0·669). The sensitivity analysis showed no association between preoperative contrast administration and AKI within 48 h after operation (OR 1·09, 0·84 to 1·41; P = 0·498).

CONCLUSION

There was no association between preoperative intravenous contrast administered for CT up to 7 days before surgery and postoperative AKI. Risk of contrast-induced nephropathy should not be used as a reason to avoid contrast-enhanced CT.

Benign intraductal papillary-mucinous neoplasm of the pancreas associated with spontaneous pancreaticogastric and pancreaticoduodenal fistulas

Invasive intraductal papillary-mucinous neoplasms (IPMNs) of the pancreas may be associated with pancreaticogastric fistulas as shown by case reports. We report the case of a benign IPMN associated with pancreaticogastric and pancreaticoduodenal fistulas. A 70-year-old woman was admitted with intestinal obstruction. Computed tomography and MRI showed a large dilatation of the main pancreatic duct (>1 cm) with intraductal nodules, and pancreaticogastric and pancreaticoduodenal fistulas. Several features in imaging were present to support a malignant IPMN, so that the patient underwent a pancreaticoduodenectomy. The histopathological examination of the surgical specimen showed a benign IPMN. This case proves that a benign IPMN can cause pancreaticogastric and pancreaticoduodenal fistulas, probably resulting from mechanical factors.

[Radiofrequency ablation for palliation of soft tissue tumor pain]

PURPOSE

To assess the efficacy of radiofrequency (RF) ablation for palliation of soft tissue tumor pain.

MATERIALS AND METHODS

Retrospective study of 12 patients receiving palliative treatment for soft tissue tumors (5 primary tumors including 4 sarcomas and 1 PEComa and 7 metastatic tumors) with pain refractory to standard management. RF ablation was performed under CT or ultrasound guidance.

RESULTS

The efficacy was determined by using pain scores and treatment regimen modifications after RF ablation. Response was graded as absent, partial or complete. Short term symptomatic relief was observed in 100% of cases, with complete response in 43% of cases ; Mid term and long term symptomatic relief was observed in 70% and 83% of cases respectively. We also observed dosage reduction for narcotics with corresponding reduction in related side-effects and functional improvement in some patients. A single case of complication with serosanguinous collection within a region of necrosis was observed.

CONCLUSION

Radiofrequency ablation for palliation of soft tissue tumor pain may be a useful complement to standard management. It results in symptomatic improvement with few complications.

[Imaging of the postoperative biliary tract]

For a long time, imaging of the biliary tract after surgical procedures was performed with invasive procedures such as endoscopic retrograde cholangiopancreatography or percutaneous transhepatic cholangiography. Due to recent advances in diagnostic imaging, non-invasive techniques are now favored. While US remains the initial imaging modality, it is frequently followed by CT and/or MRCP. Image interpretation should always be performed in keeping with clinical and laboratory findings as well as the type of surgical procedure. The most appropriate imaging modality is selected based on these data. In patients with jaundice or biliary tract stenosis, MRCP, with use of an optimal technique and 3D acquisition, is the imaging modality of choice. In non-jaundiced patients with non-distended biliary tract and suspected bile leak, MRCP should be completed by the injection of a liver-specific contrast agent with biliary excretion to achieve non-invasive biliary tract opacification. In patients with malignancy, CT is preferred due to its high spatial resolution and ability to demonstrate small anastomotic tumor recurrences. CT should also be performed in patients with suspected hepatic artery or portal vein injury in addition to biliary tract injury or to detect distant complications.

The creation of a peritoneal defect in transanal endoscopic microsurgery does not increase complications

INTRODUCTION

During Transanal Endoscopic Microsurgical (TEMS) full-thickness excision of a rectal lesion above the peritoneal reflection, entrance to the peritoneal cavity is inevitable. This has been regarded as a complication that requires conversion to an open procedure. We describe our experience of full thickness intraperitoneal excision of rectal lesions where the peritoneal defect was sutured endoscopically.

METHOD

Data were collected prospectively on 15 patients in whom a peritoneal defect was created intraoperatively during TEMS excision of a rectal lesion. When a defect was recognized, it was closed by endoscopic suture. If there was any doubt regarding security of the closure, a defunctioning loop stoma was fashioned.

RESULTS

Between November 1998 and January 2008, a total of 257 patients underwent TEMS during which a peritoneal defect was created in 15 patients. Six patients had a defunctioning stoma formed at the time of TEMS. No patient was defunctioned postoperatively and there were no deaths. The mean hospital stay was 8 days (range 3 to 19 days). A contrast enema showed sub-clinical leaks in two patients for which no treatment was required. No patient developed pelvic or peritoneal sepsis, but one patient had to return to theatre for postoperative bleeding when a single bleeding vessel was coagulated.

CONCLUSION

Full thickness excision of lesions in the intraperitoneal rectum with endoscopic suture of the defect is a safe procedure. Lesions in the upper rectum should not be excluded from TEMS excision because of the chance of peritoneal breach.

Giant cystic widening of Virchow-Robin spaces: an anatomofunctional study

We describe 2 patients with unusual white matter cystic dilations, which could correspond to widening of the perivascular spaces. They underwent morphologic MR imaging with tractography, functional MR imaging (fMRI), and neuropsychological evaluation. fMRI examination showed no functional reorganization of cortical areas. Tractography showed an apparent decrease of white matter tract vectors into the regions of concern. Findings of the neuropsychological examination were normal. It seems that even an extensive cystic dilation of white matter does not deteriorate brain function.

La douleur biliaire : comment la reconnaître ? Comment l’explorer ?

Biliary colic is the most common clinical presentation of symptomatic gallstone disease, whatever its localisation (cholelithiasis or choledocolithiasis). The pain of biliary colic is unfortunately called "colic", a word suggesting paroxystic bouts and usually described as localised in the right upper quadrant. In fact, biliary pain is most frequently epigastric in location, usually starts abruptly to generally persists without fluctuation and resolve gradually over two to four hours. Biliary lithiasis has a high prevalence in the population, especially in elderly women but only 20% of the patients are symptomatic and among them, only 10 to 20% experience severe pain. Misdiagnosis is frequent with potential disastrous implications, especially with other causes of epigastric pain (atypical myocardial ischemia, perforated ulcer, etc.). Non invasive imaging of the biliary tract is now generally easy to obtain; abdominal ultrasound for gallbladder stones and magnetic resonance cholangiography for the main bile duct and the intrahepatic bile ducts. But, for gallbladder stones, the greatest care must be taken by the radiologist to link up the symptomatology and the cholelithiasis. Precise description of the abdominal pain (nature, intensity, location, duration, irradiation...) is needed and must be searched by the radiologist to prevent misdiagnosis.

Spontaneous hepatic rupture: a report of five cases

BACKGROUND

Spontaneous hepatic rupture is a well recognised but rare condition. Because of the difficulty in diagnosis, it is often associated with a high mortality rate. Pregnant women with HELLP syndrome are more prone to hepatic rupture, but it can also occur with other liver pathology. Different modalities of treatment, including liver resection, packing, hepatic artery ligation and even liver transplantation have been described for this condition.

PATIENTS AND RESULTS

We report a series of five cases, three of which were associated with pregnancy and two with no identifiable pathology. Pre-operative diagnosis was not made in any of these cases.Two of the five patients had hepatic resection, two had peri-hepatic packing and one was treated with laparoscopic drainage.

DISCUSSION

From our experience we conclude that no single form of treatment is applicable to all cases of hepatic rupture.The treatment should be individualised,depending on the extent of hepatic rupture and the expertise available, to obtain best outcome.

In vivo biological effects of various forms of thrombopoietin in a murine model of transient pancytopenia

Thrombopoietin (TPO) is the natural regulator of platelet production in the bone marrow of mammals. This cytokine also seems to play an important role in the development of the erythroid lineage when recovering from anemic conditions. Here we study the effects of various TPO molecules on the recovery of hematopoietic lineages in a mouse model of pancytopenia. Based on previous animal experimentation and clinical experience with other hematopoietic cytokines, we found that daily dosing with TPO augmented the recovery of both the megakaryocyte and erythroid lineages in a mouse model of pancytopenia. However, further experiments showed that no benefit was gained by using more than a single dose of recombinant murine (rm)TPO(335) given 24 h after the initiation of the myelosuppressive treatment. This response to a single dose of rmTPO(335) is dose-dependent. However, the response was attenuated when a truncated, short half-life TPO molecule (rmTPO[153]) was used. Increasing the half-life of the molecule with 10 kDa polyethylene glycol (PEG) does not improve the response. Only when larger PEG molecules (20 kDa or 40 kDa) are linked to the rmTPO(153) is the response to single doses restored to the level of the full-length molecule. These data suggest that, unlike our experience with other cytokines, the commitment of progenitors to a megakaryocytic cell line is accomplished by a single short exposure to TPO.

Performance of serum-free broth media for growth of Renibacterium salmoninarum

Growth of Renibacterium salmoninarum was compared in 14 different broth media; 13 serum-free, and 1 that contained newborn calf serum, KDM2+M. Supplementation with 1% v/v R. salmoninarum MCO4M metabolite was evaluated for 6 of the media that do not utilize it as part of their ingredients. Viable cells were enumerated on Days 10, 20, and 30 post inoculation to evaluate performance. The experiment was repeated 3 times using high, low, and medium (trials 1 to 3, respectively) cell concentrations as inoculum. In general there was no optimal medium and all performed well. The choice of which to employ depends on the ease of preparation and presence of certain ingredients that might affect subsequent assays. In trials 2 and 3, the pH was estimated using test papers at the same time as cells were counted. Maximum pH increase occurred with KDM2+M and those media containing charcoal. For most media, a simple pH determination could be used as a means to check that growth has occurred in a culture, particularly if charcoal was added directly to the media and a visual inspection could not be made to detect growth.

Ischemic stroke injury is reduced in mice lacking a functional NADPH oxidase

BACKGROUND AND PURPOSE

Free radicals account for a significant proportion of the brain damage that occurs during ischemic stroke. Using mutant mice (X-CGD) with a dysfunctional phagocytic NADPH oxidase, we investigated the role of this superoxide-generating enzyme as a mediator of the reperfusion injury in a mouse model of middle cerebral artery occlusion.

METHODS

Transient (2 hour) middle cerebral artery occlusion was performed in X-CGD or wild-type litter mates (8- to 10-week-old). After 22 hours of reperfusion, brains were harvested and infarct volume delineated using 2,3,5-triphenyl-tetrazolium chloride. To elucidate the origin of the damaging NADPH oxidase, transient ischemia was also performed in X-CGD or wild-type mice transplanted with wild-type C57 B1/6J or X-CGD bone marrow, respectively.

RESULTS

The infarct volume induced by transient ischemia was significantly less in X-CGD mice (29.1 +/- 5.6 mm3; n = 13) than wild-type littermates (54.0 +/- 10.6 mm3; n = 10; P < .05). The elimination of a functional NADPH oxidase from either the circulation or the central nervous system, by performing the appropriate bone marrow transplant experiments, did not reduce the infarct size induced by transient ischemia. This suggests that in order to confer protection against transient ischemia and reperfusion, a putative neuronal and circulating NADPH oxidase need to be inactivated.

CONCLUSIONS

Brain injury was reduced in mice lacking a functional NADPH oxidase in both the central nervous system and peripheral leukocytes, suggesting a pivotal role for the NADPH oxidase in the pathogenesis of ischemia-reperfusion injury in the brain.

A role for leptin and its cognate receptor in hematopoiesis

BACKGROUND

Hematopoiesis entails the production of multiple blood cell lineages throughout the lifespan of the organism. This is accomplished by the regulated expansion and differentiation of hematopoietic precursors that originate from self-renewing hematopoietic stem cells. Studies of lineage commitment and proliferation have shown that the cytokine family of growth factors plays an important role in hematopoietic differentiation. However, in hematopoiesis, as in most self-renewing biological systems, the molecules that regulate the stem cells directly remain largely unknown. In this study, we have undertaken a search for novel cytokines that may influence the fate of hematopoietic stem cells.

RESULTS

We have cloned three splice variants of a novel cytokine receptor from human hematopoietic stem cells expressing the CD34 antigen, one of which is identical to the leptin receptor. Expression analysis revealed that the leptin receptor is expressed in both human and murine hematopoietic stem cell populations, and that leptin is expressed by hematopoietic stroma. We show that leptin provides a proliferative signal in hematopoietic cells. Importantly, we demonstrate that leptin provides a proliferative signal in BAF-3 cells and increases the proliferation of hematopoietic stem cell populations. The proliferative effects of leptin seem to be at the level of a multilineage progenitor, as shown by increased myelopoiesis, erythropoiesis and lymphopoiesis. Analysis of db/db mice, in which the leptin receptor is truncated, revealed that the steady-state levels of peripheral blood B cells and CD4-expressing T cells were dramatically reduced, demonstrating that the leptin pathway plays an essential role in lymphopoiesis. Colony assays performed using marrow from db/db and wild-type mice indicated that db/db marrow has a deficit in lymphopoietic progenitors; furthermore, db/db mice are unable to fully recover the lymphopoietic population following irradiation insult, and although the levels of peripheral blood erythrocytes are normal in db/db mice, spleen erythrocyte production is severely compromized.

CONCLUSIONS

We have discovered that leptin and its cognate receptor constitute a novel hematopoietic pathway that is required for normal lymphopoiesis. This pathway seems to act at the level of the hematopoietic stem/progenitor cell, and may well also impact upon erythropoiesis, particularly in anemic states that may require output from the spleen. These findings offer a new perspective on the role of the fat cell in hematopoiesis.

The psychological adjustment of offspring of adults with obsessive-compulsive disorder: a brief report

This study describes the prevalence of emotional and behavioural problems in the offspring of parents who are members of the Obsessive-Compulsive Neurosis Support Group in South Australia. The results suggest that the offspring of adults with obsessive-compulsive disorder do not have more problems than other children and adolescents in the community. The study also highlights potential benefits of collaborative research conducted by research groups and self-help organisations.

Differences between informants' reports describing emotional and behavioural problems in community and clinic-referred children: a research note

This study compared the pattern of reports describing childhood emotional and behavioural problems amongst children in the community with the pattern of reports describing children referred to mental health clinics. Whereas children in the community reported more externalizing and internalizing problems than were reported by their parents, clinic-referred children reported fewer externalizing but more internalizing problems than their parents. The results highlight potential limitations which may arise when reports describing the problems of clinic-referred children are used as the criterion for assessing the clinical significance of reports describing problems amongst children in the community.