The use of a porcine model to teach advanced abdominal wall dissection techniques.

BACKGROUND: In the era of minimally invasive surgery, it is clear that a robust simulation model is required for the training of surgeons in advanced abdominal wall reconstruction. The purpose of this experimentation was to evaluate whether a porcine model could be used to teach advanced minimally invasive abdominal wall dissection techniques to novice surgeons. Secondary objectives included: time to completion, identification of various anatomical landmarks, to note the difference in porcine and human models and finally, the ability to dock a Da Vinci Xi robotic platform on the porcine model. METHODOLOGY: Two post-fellowship surgeons were given the task of performing an extended total extraperitoneal dissection (ETEP) on one female Landrace pig under the supervision of a surgeon experienced in robotic-assisted ventral hernia repair. This included insertion of ports, developing a retro-rectus plane, crossover from left to right rectus, bilateral transverse abdominus release, and sub-diaphragmatic dissection. A 5-mm vessel sealer was used to facilitate the dissection. The steps of the surgery were given to the trainees, and an experienced hernia surgeon guided the steps of dissection. The emphasis of the tasks was to develop the planes of extraperitoneal dissection to demonstrate that the porcine model could be considered for a viable and realistic model for training. RESULTS: The candidates were able to successfully complete the task and dock a Da Vinci Xi with the porcine model providing a realistic platform for training. CONCLUSION: The porcine model can be a considerable tool in the education of surgeons embarking on learning the art of minimally invasive abdominal wall reconstruction techniques. The advantage of live tissue dissection, similarity in anatomy and the relatively inexpensive availability of porcine models, makes it an unparalleled form of simulation-based training. We believe that this will have transitional capabilities to robotic ETEP education for complex hernia repair.

Review of aspirin and clopidogrel resistance in peripheral arterial disease.

OBJECTIVE: Aspirin resistance (AR) and clopidogrel resistance (CR) are terms used to describe a reduction in the medication's efficacy in inhibiting platelet aggregation despite regular dosing. This review gives context to the clinical role and implications of antiplatelet resistance in peripheral arterial disease (PAD). METHODS: A review of English-language literature on AR and CR in PAD involving human subjects using PubMed and MEDLINE databases was performed in April 2017. A total of 2075 patients in 22 relevant studies were identified. To give this issue context, a review of the larger, more established literature on antiplatelet resistance in coronary disease was undertaken, identifying significant research associating resistance to major adverse cardiovascular events (MACEs). RESULTS: Studies in the coronary arterial disease literature have strongly associated antiplatelet resistance with increased MACE. Prevalence of AR or CR in coronary disease appears to be >55% for each in some studies. Meta-analyses of >50 studies revealed that AR and CR are significantly associated with MACE (relative risk of 2.09 and 2.8, respectively). This adds further weight to the literature reporting antiplatelet resistance as an independent predictor of and a threefold risk factor for major adverse cardiovascular events. The prevalence of resistance in PAD in this review was comparable to that in the coronary disease literature, with AR and CR prevalence up to 60% and 65%, respectively. There is evidence that the adverse effects of antiplatelet resistance are significant in PAD. In fact, research directly studying stent thrombosis populations with either coronary arterial disease or PAD revealed more significantly impaired platelet responsiveness to clopidogrel and aspirin in PAD compared with similar individuals with coronary disease. AR in PAD was found in studies to be a significant risk factor for iliofemoral stent reocclusion (P = .0093) and stroke in patients with symptomatic carotid disease (P = .018). CR was found to be a significant, independent risk factor in predicting ischemic outcomes in several recent PAD studies (P < .0001). Loss-of-function carriers of enzyme CYP2C19, important in clopidogrel metabolism, have a 30% greater risk of ischemic events (P < .001). Importantly, less antiplatelet drug resistance may be encountered with newer antiplatelet agents, including ticagrelor and prasugrel, because of reduced enzymatic polymorphisms. CONCLUSIONS: The limited research addressing AR and CR in PAD suggests that further research is required to clarify the role of platelet assays and potential for individualized antiplatelet therapy.

Hybrid repair of symptomatic aberrant right subclavian artery and Kommerell's diverticulum.

INTRODUCTION: An aberrant right subclavian artery (ARSA) with or without an associated Kommerell's diverticulum (KOD) is a rare vascular anomaly. Patients with an ARSA may present with a variety of symptoms, including rupture. Options for repair include open, endovascular, and a hybrid approach, with no clear consensus on which is best because of the rarity of the anomaly. We present 2 cases that underwent hybrid repair and a systematic review of the literature. METHODS: A systematic review of the literature was performed from 2000-2012 searching for patients with ARSA with or without KOD who underwent endovascular repair. Twenty-four articles were identified, including a few case reports and small case series, for a total of 31 patients. A chart review was also performed on 2 patients at our institution who underwent a hybrid repair for symptomatic ARSA. RESULTS: We report the presenting history, management, and follow-up of 2 symptomatic patients with ARSA with associated KOD. Both patients underwent a hybrid approach for repair, with no reported complications. After postoperative imaging and clinical follow-up, both patients remained in good general condition without signs of vascular complications. Our systematic literature review identified 31 reported cases of patients with ARSA who underwent endovascular repair (10 patients without an associated KOD and 21 patients with a KOD). The patients ranged in age from 21-82 years of age (average: 56 years). Of these patients, 17 (55%) were women. The presenting symptoms varied, and some patients had multiple symptoms noted on presentation, including dysphagia, dyspnea, or asymptomatic patients. In those patients with an associated KOD, the average size of the diverticulum was 3.3 cm (range: 2.3-7 cm). A number of operative strategies were used in the reported cases, depending on the presence of absence of an associated KOD. The average reported duration of hospital stay was 5.4 days (range: 1-60 days). Seven patients had postoperative complications (22%). There were 3 mortalities reported (10%). Only 1 of these could be directly related to the surgical procedure. Reported decrease in aneurysm size was between 25-50%, although this was not reported for most patients. Four of 31 patients (13%) had an endoleak (1 type I endoleak, 2 type II endoleaks, and 1 type IV endoleak). The range of reported follow-up varied between 6 weeks and 92 months, with 9 patients having no follow-up reported. CONCLUSION: Hybrid approach to repair of an ARSA with associated KOD appears to be feasible, safe, and effective. Despite the poor quality and heterogeneity of the evidence available in the literature for this rare condition, we believe that this could be the preferred treatment option for an ARSA either with or without KOD.

Pancreatic duct filling during cholecystectomy intraoperative cholangiogram and incidence of postoperative pancreatitis.

Background and Aim: Laparoscopic cholecystectomy (LC) with intraoperative cholangiography (IOC) is a commonly performed surgical procedure in most hospitals. Anecdotal evidence suggests that when the pancreatic duct (PD) inadvertently fills during IOC, there may be an increased risk of postoperative pancreatitis (POP). However, there is a paucity of information in the literature about both the incidence of pancreatitis post LC and the incidence of PD filling on IOC and any potential relationship between the two. Methods: A retrospective review was performed of all LC performed in our institution over a 10-year period. IOC images were reviewed and clinical data collated. Results: Of the 1243 procedures identified, 952 had IOC images available for review and were included in the study. The incidence of POP was 0.7%. The incidence of PD filling was 13.4%. Patient's age, sex, urgency of surgery, preoperative liver function tests (LFTs), history of pancreatitis, contrast leakage, and preoperative endoscopic retrograde cholangiopancreatography (ERCP) were not statistically related to the incidence of POP. Of those with PD filling, 2% had POP versus 0.5% who had no PD filling. This trended toward significance on univariate analysis (P = 0.05). However, on logistic regression, POP was the only significant independent risk factor (P = 0.02). Conclusion: The incidence of pancreatitis post LC and IOC is low. PD filling is associated with increased incidence of pancreatitis in this scenario and it is crucial for clinicians to be aware of this potential risk. This retrospective study was based on the review of saved images, and therefore PD filling might have been underestimated. Prospective studies would be useful to ascertain any definitive clinical association.

Management of an enormous inferior mesenteric vein aneurysm.

Venous aneurysms are rare entities, with mesenteric venous aneurysms among the rarest reported. We present a case of a 66-year-old man with abdominal pain secondary to an enormous 7.8-cm inferior mesenteric vein aneurysm. In addition, he had evidence of other venous abnormalities, including bilateral leg chronic venous insufficiency and a right varicocele. This appears to be the only reported case of an isolated inferior mesenteric vein aneurysm. Adding to its significance, this aneurysm is among the largest of any mesenteric vein aneurysm reported. Given the rupture risk, laparoscopic ligation above the aneurysm was performed.

Spontaneous Superior Mesenteric Artery Branch Pseudoaneurysm: A Rare Case Report.

BACKGROUND: Visceral arterial pseudoaneurysms (VAPAs) are rare vascular entities with serious consequences. Traditionally, they are associated with trauma, infection, and inflammatory disease, or they can arise as a post-operative complication. REPORT: An 87 year old man presented with abdominal pain and was found to have a spontaneous VAPA on a computed tomography angiogram. Serial imaging 4 months previously had demonstrated no aneurysm. Between scans, warfarin was changed to apixaban for aortic valve replacement, but he had no other changes to any other medications. He required urgent endovascular coiling of the pseudoaneurysm, with satisfactory recovery and outcome. DISCUSSION: VAPAs are extremely rare, with splenic artery VAPAs the most commonly reported. Regardless, fewer than 250 cases of splenic artery pseudoaneurysm have been reported. Superior mesenteric artery (SMA) pseudoaneurysms are the rarest type of VAPAs. Early identification and urgent treatment are warranted because of the associated high mortality risk, with a 50% risk of rupture in any given VAPA. Treatment options range from open operation to endoscopic and endovascular procedures. Apixaban has been proposed to contribute to pseudoaneurysm formation by slow and continuous bleeding that results in the formation of the pseudoaneurysm. CONCLUSIONS: Spontaneous VAPAs are extremely rare and this is the first time a VAPA has been associated with the novel oral anticoagulant "apixaban". Urgent management of any VAPAs is important because of the high risk of rupture and potential life threatening haemorrhage.

Blunt innominate artery trauma requiring repair and carotid ligation.

Traumatic dissection of the innominate artery is a rare clinical entity. Management of a patient with motorsensory compromise and dissection extending to the subclavian and right common carotid arteries is quite rare and can be quite involved. Here we present such a case and discuss the unique peri-operative decision-making in the context of what is reported in the literature. Restoration of motorsensory function is critical and in this case, requiring a multi-disciplinary team.

Influenza myocarditis and myositis: case presentation and review of the literature.

Myocarditis, a general inflammatory condition of the heart muscle, can result from a variety of etiologies, the most common being viral. Despite common pathogens, concomitant myocarditis and myositis remains a rare event. Although a common cause of respiratory illness, extrapulmonary infections with influenza are infrequent. We describe the case of a patient who presented to our centre with concomitant "seasonal" H1N1 influenza A myocarditis further complicated by pan-myositis. The patient's condition rapidly declined, eventually requiring biventricular mechanical support, in addition to multilimb fasciotomies. The cardiac support required was progressive, from a percutaneous left ventricular assist device, to extracorporeal membrane oxygenation, to eventual biventricular assist device support for bridge-to-transplantation. This case motivated a detailed review of the literature (a total of 29 cases were identified), in which we found that patients with influenza myocarditis/myositis were predominantly female (63%) and young (mean age 33.2 years) and continue to have a high incidence of morbidity and mortality (27%). As a result of its atypical pattern, the 2009 H1N1 pandemic strain has gained attention. From our review, we found 7 patients with of 2009 H1N1 pandemic influenza myocarditis. Serial serum cytokine analysis did not demonstrate a "cytokine storm," which has been associated with other virulent influenza strains. The PB1-F2 marker in particular has been associated with a vigorous cytokine response. The 2009 H1N1 and "seasonal" influenza strains lack this marker. In those patients with community-acquired influenza, interleukin-6 has been shown to correlate with symptoms. For patients with myocarditis resulting in shock, mechanical circulatory support has gained acceptance as a means to recovery or transplantation.

Minimally invasive left-heart decompression during venoarterial extracorporeal membrane oxygenation: an alternative to a percutaneous approach.

Decompression of the left-heart following initiation of extracorporeal membrane oxygenation, is at times required. In the setting of a closed chest this can present a challenge. We present a minimally invasive approach to left-heart decompression in an adult-sized patient, where a percutaneous option was not feasible.

Interprovincial spoke-to-hub transport using the Impella Recover LP 5.0 left ventricular assist device as a bridge to long-term circulatory support.

Current hospital administrative practices categorize health care centres in a network of  'spokes' (primary care centres) and 'hubs' (tertiary care centres). For the treatment of cardiogenic shock, long-term left ventricular assist devices (LVADs) and transplant therapies are only used at a few hub centres nationwide and are, thus, only available to patients living in close proximity to these centres. The relatively lower technical requirements of the Impella Recover LP 5.0 LVAD (ABIOMED Inc, USA) translate into greater use by spoke centres for the short-term treatment of cardiogenic shock, and facilitate appropriate stabilization and subsequent transportation to a suitable hub centre. Based on a review of the literature, the present report describes the first case demonstrating successful use of the Impella Recover LP 5.0 LVAD, implanted under local anesthetic, for the purposes of interprovincial spoke-to-hub transport in a bridge-to-bridge-to-transplant procedure. By providing an economical and technically straightforward alternative to traditional extracorporeal membrane oxygenation, the present case demonstrates that less invasive LVADs are valuable to the spoke-and-hub model for delivery of specialized cardiac care.