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.

Does the Pittsburgh Severity Score predict outcome in esophageal perforation?

Esophageal perforation is an uncommon and challenging surgical emergency associated with high rates of morbidity and mortality. At present, no consensus exists on optimal management of the condition. The Pittsburgh Severity Score (PSS) is a tool intended to stratify perforation severity and guide treatment. However, there is a paucity of literature examining the validity of the score or its application in a UK population. This study aims to validate the PSS and explore its use in stratifying patients with esophageal perforation into distinct subgroups with differential outcomes in an independent UK study population.All patients treated for esophageal perforation at Queen Elizabeth Hospital, Birmingham between September 2003 and October 2017 were included in this study. Cases were identified using a combination of ICD-10 and OPCS informatics search codes and prospective case collection. Data relating to the clinical presentation, diagnosis, management, and outcome of cases were recorded using a preformed data collection form. PSS predictive performance was assessed against five outcomes: rates of post-perforation and post-operative complications, in-hospital mortality, length of intensive care (ICU/HDU) stay, and total length of hospital stay.A total of 87 cases were identified, consisting of 48 (55%) iatrogenic perforations, 24 (28%) cases of spontaneous (Boerhaave's) perforation, and 15 perforations due to other etiologies (17%). Operative management was favored in this series, with 47% of all perforations being treated surgically. Overall in-hospital mortality was 13%, coupled with a median length of hospital stay of 24 days (interquartile range [IQR]: 12-49), of which a median of 2 days was spent in intensive care facilities (IQR: 0-14). A total of 46% of patients developed post-perforation complications, with 59% of the operatively managed cohort developing complications post-operatively.The PSS was not found to be significantly predictive of post-perforation complications (area under the ROC curve [AUROC]: 0.62, p = 0.053) or in-hospital mortality (AUROC: 0.69, p = 0.057) for the cohort as a whole. However, a subgroup analysis found the accuracy of the PSS to vary considerably by etiology, being significantly predictive of post-perforation complications within the subgroup of Boerhaave's perforations (AUROC: 0.86, p = 0.004).In conclusion, we found that the PSS has some utility in stratifying esophageal perforation severity and predicting specific patient outcomes. However, it appears to be of more value when applied to the subgroup of patients with Boerhaave's perforations.

Oxidative Stress and Cardiovascular Risk in Type 1 Diabetes Mellitus: Insights From the DCCT/EDIC Study

Background

Hyperglycemia leading to increased oxidative stress is implicated in the increased risk for the development of macrovascular and microvascular complications in patients with type 1 diabetes mellitus.

Methods and Results

A random subcohort of 349 participants was selected from the DCCT / EDIC (Diabetes Control and Complications Trial/Epidemiology of Diabetes Interventions and Complications) cohort. This included 320 controls and 29 cardiovascular disease cases that were augmented with 98 additional known cases to yield a case cohort of 447 participants (320 controls, 127 cases). Biosamples from DCCT baseline, year 1, and closeout of DCCT , and 1 to 2 years post‐ DCCT ( EDIC years 1 and 2) were measured for markers of oxidative stress, including plasma myeloperoxidase, paraoxonase activity, urinary F 2α isoprostanes, and its metabolite, 2,3 dinor‐8 iso prostaglandin F 2α . Following adjustment for glycated hemoblobin and weighting the observations inversely proportional to the sampling selection probabilities, higher paraoxonase activity, reflective of antioxidant activity, and 2,3 dinor‐8 iso prostaglandin F 2α , an oxidative marker, were significantly associated with lower risk of cardiovascular disease (−4.5% risk for 10% higher paraoxonase, P <0.003; −5.3% risk for 10% higher 2,3 dinor‐8 iso prostaglandin F 2α , P =0.0092). In contrast, the oxidative markers myeloperoxidase and F 2α isoprostanes were not significantly associated with cardiovascular disease after adjustment for glycated hemoblobin. There were no significant differences between DCCT intensive and conventional treatment groups in the change in all biomarkers across time segments.

Conclusions

Heightened antioxidant activity (rather than diminished oxidative stress markers) is associated with lower cardiovascular disease risk in type 1 diabetes mellitus, but these biomarkers did not change over time with intensification of glycemic control.

Clinical Trial Registration

URL : https://www.clinicaltrials.gov . Unique identifiers: NCT 00360815 and NCT 00360893.

Minimising aseptic loosening in extreme bone resections: custom-made tumour endoprostheses with short medullary stems and extra-cortical plates

AIMS

Following the resection of an extensive amount of bone in the treatment of a tumour, the residual segment may be insufficient to accept a standard length intramedullary cemented stem. Short-stemmed endoprostheses conceivably have an increased risk of aseptic loosening. Extra-cortical plates have been added to minimise this risk by supplementing fixation. The aim of this study was to investigate the survivorship of short-stemmed endoprostheses and extra-cortical plates.

PATIENTS AND METHODS

The study involved 37 patients who underwent limb salvage surgery for a primary neoplasm of bone between 1998 and 2013. Endoprosthetic replacement involved the proximal humerus in nine, the proximal femur in nine, the distal femur in 13 and the proximal tibia in six patients. There were 12 primary (32%) and 25 revision procedures (68%). Implant survivorship was compared with matched controls. The amount of bone that was resected was > 70% of its length and statistically greater than the standard control group at each anatomical site.

RESULTS

The mean follow-up was seven years (one to 17). The mean length of the stem was 33 mm (20 to 60) in the humerus and 79 mm (34 to 100) in the lower limb. Kaplan-Meier analysis of survival of the implant according to anatomical site confirmed that there was no statistically significant difference between the short-stemmed endoprostheses and the standard stemmed controls at the proximal humeral (p = 0.84), proximal femoral (p = 0.57), distal femoral (p = 0.21) and proximal tibial (p = 0.61) sites. In the short-stemmed group, no implants with extra-cortical plate osseointegration suffered loosening at a mean of 8.5 years (range 2 to 16 years). Three of ten (30%) without osseointegration suffered aseptic loosening at a mean of 7.7 years (range 2 to 11.5 years).

CONCLUSION

When extensive resections of bone are required in the surgical management of tumours, and in revision cases, the addition of extra-cortical plates to short medullary stems has shown non-inferiority to standard length medullary stems and minimises aseptic failure. Cite this article: Bone Joint J 2017;99-B:1689-95.

Rectal cancer in young adults: a series of 102 patients at a tertiary care centre in India

OBJECTIVE

Rectal cancer in young patients is uncommon. There is little information on rectal cancer in young adults in India. The aim of this study was to determine the relative incidence of rectal cancer in young patients in India and identify any differences in histological grade and pathological stage between younger and older cohorts.

METHOD

All adult patients presenting at a tertiary colorectal unit with primary rectal adenocarcinoma between September 2003 and August 2007 were included. Patients were divided into two groups: 40 years and younger, and older than 40 years. Details regarding patient demographics, preoperative assessment, management and tumour grade and stage were obtained from a prospectively maintained database.

RESULTS

One hundred and two of 287 patients (35.5%) were 40 or younger at presentation. Younger patients were more likely to present with less favourable histological features (52.0% vs 20.5% (P < 0.001)) and low rectal tumours (63.0% vs 50.0%) (P = 0.043), but were equally likely to undergo curative surgery compared to the older group (P = 0.629). Younger patients undergoing surgery had a higher pathological T stage (T0-2 18.9%, T3 62.3%, T4 19.7% vs 34.5%, 56.0%, 9.5%) (P = 0.027) and more advanced pathological N stage (N0 31.1%, N1 41.0%, N2 27.9% vs 53.4%, 26.7%, 17.2%) (P = 0.014).

CONCLUSION

The relative number of young patients with rectal cancer in this Indian series is higher than figures reported in western populations. The reasons for this are not clear. The histopathological features of rectal tumours in young patients in this study are consistent with similar studies in Western populations.

Chronically denervated rat Schwann cells respond to GGF in vitro

C-erbB receptor/neuregulin signalling plays a significant role in Schwann cell function. In vivo, Schwann cells up-regulate expression of c-erbB receptors in the first month after injury, but receptor expression is down-regulated with time to levels that are not detectable immunohistochemically. The inability of chronically denervated Schwann cells to respond adequately to signals derived from regenerating axons may be one reason why delayed repair of an injured peripheral nerve frequently fails. We have examined the effects of GGF on denervated Schwann cells in vitro. A modified delayed dissociation technique was used to obtain adult rat Schwann cells from the distal stumps of transected sciatic nerves which had been acutely (7 days) or chronically (2-6 month) denervated. We found that in vitro denervated Schwann cells invariably expressed p75NTR and c-erbB receptors. There was a progressive decrease in total cell yield and the percentage of cells with Schwann cell phenotype (p75NTR and/S-100 or/laminin or /GFAP or/c-erbB positive); proliferation rate; migratory potential; and expression of the cell adhesion molecules N-CAM and N-cadherin, with increasing time of denervation. Addition of GGF2 had a significant stimulatory effect upon Schwann cell proliferation and migration, and an increased proportion of Schwann cells expressed N-CAM and N-cadherin, suggesting that these responses were mediated via GGF/c-erbB signalling. Our results support the view that it may be possible to manipulate chronically denervated Schwann cells so that they become more responsive to signals derived from regrowing axons.

Different effects of a macrophage cytokine on proliferation in astrocytes and Schwann cells

The proliferative response in vitro to a novel macrophage inflammatory protein (MIP) 1 alpha has been investigated in astrocytes and Schwann cells. MIP 1 alpha is growth-inhibitory in all cell systems investigated so far and we show here that this cytokine also inhibits the proliferation of astrocytes. This response is seen most clearly when MIP 1 alpha reduces the proliferative response of astrocytes to a potent mitogen. Elevation of intracellular cyclic AMP with forskolin enhances the effects of MIP 1 alpha. In contrast, we show that the proliferation of cultured Schwann cells is stimulated by MIP 1 alpha, and that stimulation is enhanced by simultaneous exposure to forskolin. The possible consequences of these differing responses are discussed in the context of the acute response to injury and potential for regeneration of the peripheral and central nervous systems.