Peri-operative Monitoring of an Asystolic Cardiac Arrest Requiring Cardiopulmonary Resuscitation During Carotid Endarterectomy for Symptomatic Carotid Artery Stenosis.

INTRODUCTION: A carotid endarterectomy (CEA) has certain risks, of which peri-operative cardiovascular risk is one. Peri-operative neurological monitoring can be done with electroencephalography (EEG) and transcranial Doppler (TCD). No previous reports have been published demonstrating the actual changes in cerebral and cardiac activity during a peri-operative asystole. REPORT: The case of a 70 year old man with a symptomatic (bilateral) carotid stenosis is described. The patient complained of amaurosis fugax in both eyes. Duplex ultrasound showed a stenosis of >70% in both carotid arteries. The most severe symptoms were on the right side, so a staged approach was chosen, starting with a right sided eversion CEA (eCEA). Peri-operatively, the patient experienced an asystolic cardiac arrest after external carotid artery revascularisation, requiring brief cardiopulmonary resuscitation, which was recorded on the EEG. Post-operatively, the patient recovered fully, with no post-operative neurological or cardiac sequelae. The (symptomatic) contralateral stenosis was treated conservatively with best medical therapy (BMT; dual antiplatelets and statin). The patient is currently in good clinical condition, 1.5 years later. CONCLUSION: This case shows the unique EEG recording of a cardiological event during eCEA. The cause of asystole was most likely a vasovagal syncope as a result of the surgical procedure by iatrogenic damage to the carotid sinus fibres, causing impairment of the baroreflex and chemoreflex mechanisms, which is greater during eCEA. The unilateral eCEA and contralateral BMT in this symptomatic (bilateral) stenosis seemed appropriate when cardiological risk was increased but follow up ruled out any cardiological cause.

Optimal Treatment Strategy in Rectal Cancer Surgery: Should We Be Cowboys or Chickens?

BACKGROUND AND PURPOSE: Surgeons and hospitals are increasingly accountable for their postoperative complication rates, which may lead to risk adverse treatment strategies in rectal cancer surgery. It is not known whether a risk adverse strategy leads to providing better care. In this study, the association between the strategy of hospitals regarding defunctioning stoma construction and postoperative outcomes in rectal cancer treatment was evaluated. METHODS: Population-based data of the Dutch Surgical Colorectal Audit, including 3,104 patients undergoing rectal cancer resection between January 2009 and July 2012 in 92 hospitals, were used. Hospital variation in (case-mix-adjusted) defunctioning stoma rates was calculated. Anastomotic leakage and 30-day mortality rates were compared in hospitals with a high and low tendency towards stoma construction. RESULTS: Of all patients, 76 % received a defunctioning stoma; 9.6 % of all patients developed anastomotic leakage. Overall postoperative mortality rate was 1.8 %. The hospitals' adjusted proportion of defunctioning stomas varied from 0 to 100 %, and there was no significant correlation between the hospitals' adjusted stoma and anastomotic leakage rate. Severe anastomotic leakage was similar (7.0 vs. 7.1 %; p = 0.95) in hospitals with the lowest and highest stoma rates. Mild leakage and postoperative mortality rates were higher in hospitals with high stoma rates. CONCLUSIONS: A high tendency towards stoma construction in rectal cancer surgery did not result in lower overall anastomotic leakage or mortality rates. It seems that the ability to select patients for stoma construction is the key towards preferable outcomes, not a risk adverse strategy.

Treatment of types II-IV endoleaks by injecting biocompatible elastomer (PDMS) in the aneurysm sac: an in vitro study.

PURPOSE: To investigate if an elastomer [polydimethylsiloxane (PDMS)] can be used to effectively treat endoleaks after endovascular aneurysm repair. METHODS: A latex aneurysm (36-mm inner diameter sac, 15-mm inner diameter neck) was attached to an in vitro circulation model. The aneurysm was excluded from the circulation by placing an unstented polyester graft. Endoleak types II-IV were created using different setups. While the circulation setup running, the aneurysm was filled with contrast medium and then the biocompatible PDMS elastomer was injected to exclude the endoleaks and the perigraft area. The sac was considered full when all contrast was pushed out of the sac and the elastomer flowed into the proximal efferent lumbar artery. Treatment was successful when the aneurysm was free of endoleak after control angiography. RESULTS: The endoleaks were created successfully in the latex aneurysm models, with contrast present in the sac before "treatment." After elastomer sac filling, all endoleaks were successfully excluded on angiography; there was no leakage of contrast outside the graft lumen in any of the setups. With the type III endoleak, the disruption in the graft material was sealed by the elastomer, while the entire porous graft was encased in elastomer in the type IV endoleak setup. There was no elastomer within the graft lumen in either case. CONCLUSIONS: This concept of filling the aneurysm sac with PDMS may lead to a percutaneous treatment for endoleaks. While the results of this study show that PDMS may be used to treat endoleaks in vitro, further tests are required to determine if this approach is suitable in vivo.

The effect of injectable biocompatible elastomer (PDMS) on the strength of the proximal fixation of endovascular aneurysm repair grafts: an in vitro study.

PURPOSE: One of the major concerns in the long-term success of endovascular aneurysm repair (EVAR) is stent graft migration, which can cause type I endoleak and even aneurysm rupture. Fixation depends on the mechanical forces between the graft and both the aortic neck and the blood flow. Therefore, there are anatomical restrictions for EVAR, such as short and angulated necks. To improve the fixation of EVAR grafts, elastomer (PDMS) can be injected in the aneurysm sac. The support given by the elastomer might prevent dislocation and migration of the graft. The aim of this study was to measure the influence of an injectable biocompatible elastomer on the fixation strength of different EVAR grafts in an in vitro model. METHODS: The proximal part of three different stent grafts was inserted in a bovine artery with an attached latex aneurysm. The graft was connected to a tensile testing machine, applying force to the proximal fixation, while the artery with the aneurysm was fixated to the setup. The force to obtain graft dislodgement (DF) from the aorta was recorded in Newtons (N). Three different proximal seal lengths (5, 10, and 15 mm) were evaluated. The experiments were repeated after the space between the graft and the latex aneurysm was filled with the elastomer. Independent sample ttests were used for the comparison between the DF before and after elastomer treatment for each seal length. RESULTS: The mean DF (mean +/- SD) of all grafts without elastomer sac filling for a proximal seal length of 5, 10, and 15 mm were respectively, 4.4 +/- 3.1 N, 12.2 +/- 10.6 N, and 15.1 +/- 6.9 N. After elastomer sac filling, the dislodgement forces increased significantly (P < .001) to 20.9 +/- 3.8 N, 31.8 +/- 9.8 N, and 36.0 +/- 14.1 N, respectively. CONCLUSIONS: The present study shows that aneurysm sac filling may have a role as an adjuvant procedure to the present EVAR technique. The strength of the proximal fixation of three different stent grafts increases significantly in this in vitro setting. Further in vivo research must be done to see if this could facilitate the treatment of aneurysms with short infrarenal necks.

Aortic customize: a new alternative endovascular approach to aortic aneurysm repair using injectable biocompatible elastomer. An in vitro study.

PURPOSE: Aortic Customize is a new concept for endovascular aortic aneurysm repair in which a non polymerized elastomer is injected to fill the aneurysm sac around a balloon catheter. The aim of this in vitro study was to investigate the extent of aneurysm wall stress reduction by the presence of a noncompliant elastomer cuff. METHODS: A thin-walled latex aneurysm (inner radius sac 18 mm, inner radius neck 8 mm), equipped with 12 tantalum markers, was attached to an in vitro circulation model. Fluoroscopic roentgenographic stereo photogrammetric analysis (FRSA) was used to measure marker movement during six cardiac cycles. The radius of three circles drawn through the markers was measured before and after sac filling. Wall movement was measured at different systemic pressures. Wall stress was calculated from the measured radius (sigma = pr/2t). RESULTS: The calculated wall stress was 7.5-15.6 N/cm(2) before sac filling and was diminished to 0.43-1.1 N/cm(2) after sac filling. Before sac filling, there was a clear increase (P < .001) in radius of the proximal (range, 7.9%-33.5%), middle (range, 3.3%-25.2%), and distal (range, 10.5%-184.3%) rings with increasing systemic pressure. After sac filling with the elastomer, there remained a small, significant (P < .001) increase in the radius of the circles (ranges: 6.8%-8.8%; 0.7%-1.1%; 5.3%-6.7%). The sac filling reduced the extent of radius increase. The treated aneurysm withstood systemic pressures up to 220/140 mm Hg without noticeable wall movement. After the sac filling, there was no pulsation visible in the aneurysm wall. CONCLUSIONS: Filling the aneurysm sac of a simplified in vitro latex model with a biocompatible elastomer leads to successful exclusion of the aneurysm sac from the circulation. Wall movement and calculated wall stress are diminished noticeably by the injection of biocompatible elastomer.