Brian J. Manning

Duplex ultrasound in aneurysm surveillance following endovascular aneurysm repair: a comparison with computed tomography aortography

OBJECTIVES Cumulative radiation dose, cost, and increased demand for computed tomography aortography (CTA) suggest that duplex ultrasonography (DU) may be an alternative to CTA-based surveillance. We compared CTA with DU during endovascular aneurysm repair (EVAR) follow-up. METHODS Patients undergoing EVAR had clinical and radiological follow-up data entered in a prospectively maintained database. For the purpose of this study, the gold standard test for endoleak detection was CTA, and an endoleak detected on DU alone was assumed to be a false positive result. DU interpretation was performed independently of CTA and vice versa. RESULTS One hundred thirty-two patients underwent EVAR, of whom 117 attended for follow-up ranging from six months to nine years (mean, 32 months). Adequate aneurysm sac visualisation on DU was not possible in 1.7% of patients, predominantly due to obesity. Twenty-eight endoleaks were detected in 28 patients during follow-up. Of these, 24 were initially identified on DU (four false negative DU examinations), and eight had at least one negative CTA with a positive DU prior to diagnosis. Twenty-three endoleaks were type II in nature and three of these patients had increased sac size. There was one type I and four type III endoleaks. Two of these (both type III) had an increased sac size. Of 12 patients with increased aneurysm size of 5 mm or more at follow-up, five had an endoleak visible on DU, yet negative CTA and a further five had endoleak visualisation on both DU and CTA. Of six endoleaks which underwent re-intervention, all were initially picked up on DU. One of these endoleaks was never demonstrated on CTA and a further two had at least one negative CTA prior to endoleak confirmation. Positive predictive value for DU was 45% and negative predictive value 94%. Specificity of DU for endoleak detection was 67% when compared with CTA, because of the large number of false positive DU results. Sensitivity for DU was 86%, with all clinically significant endoleaks demonstrated on CTA also detected on DU. CONCLUSION Despite its low positive predictive value, we found DU to be a sensitive test for the detection of clinically significant endoleaks. Given concerns about cumulative radiation exposure and cost, and the surprisingly low sensitivity of CTA for endoleak detection in this series, selective CTA based on DU surveillance may be a more appropriate long-term strategy.

The effect of aspirin on blood loss and transfusion requirements in patients with femoral neck fractures

Although it is widely accepted that aspirin will increase the risk of intra- and post-operative bleeding, clinical studies have not consistently supported this assumption. We aimed to assess the effect of pre-operative aspirin on blood loss and transfusion requirements in patients undergoing emergency fixation of femoral neck fractures. A prospective case-control study was undertaken in patients presenting with femoral neck fractures. Parameters recorded included intra-operative blood loss, post-operative blood loss, transfusion requirements and peri-operative reduction in haemoglobin concentration. Of 89 patients presenting with femoral neck fractures 32 were on long-term aspirin therapy. Pre-operative aspirin ingestion did not significantly affect peri-operative blood loss, or change in haemoglobin concentration or haematocrit. However those patients taking aspirin pre-operatively had a significantly lower haemoglobin concentration and haematocrit and were more likely to be anaemic at presentation than those who were not receiving aspirin. Patients taking aspirin were also more likely to receive blood transfusion post-operatively.

Subintimal angioplasty as a primary modality in the management of critical limb ischemia: comparison to bypass grafting for aortoiliac and femoropopliteal occlusive disease.

Purpose: To compare the 30-day morbidity, mortality, length of hospital stay, and patency rates in patients with critically ischemic limbs treated with subintimal angioplasty (SA) versus standard bypass surgery. Method: Between October 2001 and August 2003, 137 patients (74 women; mean age 70 years, range 43–92) with critical limb ischemia underwent subintimal angioplasty (n=88) or bypass surgery (n=49) for superficial femoral artery (SFA) or aortoiliac lesions. All patients had lesions classified as C or D according to the TransAtlantic Inter-Society Consensus. Data was retrieved from hospital inpatient inquiry and VascuBase. Parallel group comparison was used in performing a prospective observational study. Results: Primary technical success was 100% for both SA and bypass grafting. Thirty-day survival was 100% in the SFA-SA and aortoiliac bypass groups and 96% and 93%, respectively, in the SFA bypass and aortoiliac SA groups. Limb salvage was 97% and 82% in the SFA-SA and SFA bypass groups, respectively; at the aortoiliac levels, the rates were 100% and 86% for SA versus bypass. Subintimal angioplasty significantly reduced hospital stay (p<0.001). Primary patency was not statistically different in the SA versus bypass groups; however, secondary patency was higher in the SFA bypass group. Conclusions: Frequent clinical follow-up and a duplex surveillance program are necessary to maintain patency in this cohort. Subintimal angioplasty is increasingly replacing bypass surgery in the management of critical limb ischemia without compromising primary patency, limb salvage, patient survival, or subsequent vascular intervention.

Abdominal aortic aneurysm diameter: a comparison of ultrasound measurements with those from standard and three-dimensional computed tomography reconstruction.

OBJECTIVE Aortic aneurysm size is a critical determinant of the need for intervention, yet the maximal diameter will often vary depending on the modality and method of measurement. We aimed to define the relationship between commonly used computed tomography (CT) measurement techniques and those based on current reporting standards and to compare the values obtained with diameter measured using ultrasound (US). METHODS CT scans from patients with US-detected aneurysms were analyzed using three-dimensional reconstruction software. Maximal aortic diameter was recorded in the anteroposterior (CT-AP) plane, along the maximal ellipse (CT-ME), perpendicular to the maximal ellipse (CT-PME), or perpendicular to the centerline of flow (CT-PCLF). Diameter measurements were compared with each other and with maximal AP diameter according to US (US-AP). Analysis was performed according to the principles of Bland and Altman. Results are expressed as mean +/- standard deviation. RESULTS CT and US scans from 109 patients (92 men, 17 women), with a mean age of 72 +/- 8 years, were included. The mean of each series of readings on CT was significantly larger than the mean US-AP measurement (P < .001), and they also differed significantly from each other (P < .001). The CT-PCLF diameter was larger than CT-AP and CT-PME by mean values of 3.0 +/- 6.6 and 5.9 +/- 6.0 mm, respectively. The CT-ME diameter was larger than CT-PCLF by a mean of 2.4 +/- 5 mm. The US-AP diameter was smaller than CT-AP diameter by 4.2 +/- 4.9 mm, CT-ME by 9.6 +/- 8.0 mm, CT-PME by 1.3 +/- 5 mm, and smaller than CT-PCLF by 7.3 +/- 7.0 mm. Aneurysm size did not significantly affect these differences. Seventy-eight percent of 120 pairs of intraobserver CT measurements and 65% of interobserver CT measurements differed by <2 mm. CONCLUSIONS CT-based measurements of aneurysm size tend to be larger than the US-AP measurement. CT-PCLF diameters are consistently larger than CT-PME as well as CT-AP measurements. These differences should be considered when applying evidence from previous trials to clinical decisions.

In situ fenestration in the aortic arch

In situ fenestration of aortic stent grafts has the potential to allow for continued perfusion of supra-aortic trunks, without the need for extra-anatomic bypass, and without the need for custom-made devices. Angulation of the target vessel relative to the arch is an obstacle to success with this technique. In this report, we describe a case of successful in situ fenestration of the left subclavian artery (LSA) in a patient with an aortic arch aneurysm, treated with an endovascular stent graft. We outline a novel technique using through and through wire access and a pre-curved semi-rigid sheath, which allows successful access to the lumen of the aortic stent graft, despite an acute angle at the take-off of the LSA.

Early Outcome Following Endovascular Repair of Pararenal Aortic Aneurysms: Triple-Versus Double- or Single-Fenestrated Stent-Grafts

Purpose: To review the early outcome following endovascular repair of pararenal aortic aneurysm using fenestrated stent-grafts and to determine if the number of fenestrations required is predicative of outcome. Methods: A retrospective analysis was conducted of 20 consecutive patients (18 men; mean age of 75±7 years) treated with stent-grafts containing either ≥2 fenestrations (n = 10, group 1) or 3 fenestrations (n = 10, group 2). Target vessels also included those accommodated by a scallop (renal artery or superior mesenteric artery in group 1 and the celiac artery in group 2). Results: Comorbidities were similar in both groups. Aneurysm size [median 6.9 (IQR 6.7-8.3) versus 6.0 cm (IQR 5.8-6.6), p=0.03], procedure time (mean 6.6±2.1 versus 4.6±1.7 hours, p=0.04), and intensive care stay [median 4.5 (IQR 2-14) versus 2 (IQR 1-3) days, p=0.07] were greater in group 2. There were 2 postoperative deaths, both in group 2. Morbidity was significant and similar in both groups (4 patients in group 1 and 3 patients in group 2), including 1 patient requiring long-term hemodialysis. Target vessel preservation was similar in both groups (96% overall). There were 2 type II endoleaks (one in each group) and no type I or III endoleak. Conclusion: Triple-fenestrated stent-grafts allow patients with extensive pararenal aneurysms and significant comorbidity to be treated by endovascular means. Although the number of patients treated was small, which limited the validity of the comparison, longer procedures and greater early morbidity and mortality were seen in the triplefenestrated group. At present, the procedures are technically more demanding and associated with increased risk compared with double or single fenestrations, but the technology continues to evolve.

Endovascular treatment for chronic type B dissection: limitations of short stent-grafts revealed at midterm follow-up.

Purpose: To examine the incidence of and the indications for re-intervention, as well as the changes in aortic morphology, in patients with chronic type B aortic dissection who underwent endovascular intervention for false lumen aneurysms. Methods: A retrospective analysis was conducted of 10 patients (8 men; mean age 63 years, range 45–79) who underwent stent-graft repair of aneurysmal false lumen expansion related to chronic type B aortic dissection at a median 16 months (range 2–71) from the initial diagnosis. All grafts had been oversized by 10% relative to the normal non-dissected aorta and were implanted to cover the primary entry tear. Follow-up computed tomography scans were analyzed to define changes in aortic morphology. results: Mean radiological follow-up was 56 months (median 64.5; range 19–86.5). There was no perioperative mortality or stroke; no cases of aortic rupture were recorded during follow-up. One patient suffered a procedure-related stroke with postoperative hemiparesis following re-intervention for proximal erosion 15 months after the initial treatment. In 6 of the 7 re-interventions performed in 6 patients at a median 42 months after the index procedure, stent-graft extension was required to treat erosion of the dissection membrane that had resulted in endoleak with false lumen reperfusion. The extent of dissection, duration of follow-up, or length of aortic coverage was not predictive of the need for re-intervention during follow-up. At last follow-up, the mean false lumen diameter at the level of the stented aorta was significantly smaller than at baseline (11±15 versus 24±15 mm, p<0.01). This was associated with false lumen thrombosis at the level of the stent-graft in 9 of 10 cases, although 7 patients had persistent false lumen perfusion distal to the stent-graft. Conclusion: Endovascular stent-graft treatment is effective therapy for chronic type B dissection patients with false lumen aneurysms. Erosion of the dissection membrane, causing proximal or distal endoleak, is the most common reason for re-intervention during midterm follow-up.

Endovascular treatment of acute complicated type B dissection: morphological changes at midterm follow-up.

Purpose: To review midterm results and morphological changes following endovascular treatment of acute complicated type B dissection and to study the relation between extent of dissection and treatment outcome. Methods: Between February 2001 and March 2008, 52 patients (38 men; median age 67 years, range 40–82) received thoracic stent-grafts for acute complicated type B dissections. Outcome for those patients treated for intramural hematoma (IMH; group 1, n=7) or type IIIa dissection (group 2, n=17) were compared to those with type IIIb dissection (group 3, n=28). True lumen index (TLi), false lumen index (FLi; ratio of true or false lumen diameter, respectively, to the sum of both), and FL perfusion were calculated prior to treatment and at the last follow-up from computed tomographic angiography (CTA) scans. Results: Perioperative morbidity and mortality rates were 28.5% and 28.5% in group 1, 18% and 12%, respectively, for group 2, and 18% and 11% for group 3. No adjunctive treatment or re-intervention was required in groups 1 or 2, while the rates were 37% and 22%, respectively, for these events in group 3 (p=0.009 and p=0.034, respectively, versus groups 1 ² 2). Mean imaging surveillance was 31 months, and no patients were lost to follow-up. In group 2, there was 1 case of persistent FL perfusion at last CTA, whereas in group 3, 68% had persistent FL perfusion detected; the mean FLi ranged from 0.12 at the level of the carina to 0.33 at the level of the inferior mesenteric artery. Half of the patients in this group had an increase in FL diameter correlating significantly with FL perfusion, mostly distal to the stented aorta. Conclusion: Despite similar morbidity and perioperative mortality rates, outcomes following endovascular treatment of acute complicated type B dissection varied with the extent of the dissection. Persistent FL perfusion below the stent-graft, associated with aneurysm expansion and the need for re-intervention, was seen most often in type IIIb dissection. Patients with the more limited type IIIa dissection or IMH were likely to be cured by endovascular therapy.

Antiseptic wick: Does it reduce the incidence of wound infection following appendectomy?

The role of prophylactic antibiotics is well established for contaminated wounds, but the use of antiseptic wound wicks is controversial. The aim of this work was to study the potential use of wound wicks to reduce the rate of infection following appendectomy. This prospective randomized controlled clinical trial was conducted at a university hospital in the department of surgery. The subjects were patients undergoing appendectomy for definite acute appendicitis. They were randomized by computer to primary subcuticular wound closure or use of an antiseptic wound wick. For the latter, ribbon gauze soaked in povidone-iodine was placed between interrupted nylon skin sutures. Wicks were soaked daily and removed on the fourth postoperative day. All patients received antibiotic prophylaxis. They were reviewed while in hospital and 4 weeks following operation for evidence of wound infection. The main outcome measures were wound infection, wound discomfort, and cosmetic result. The overall wound infection rate was 8.6% (15/174). In patients with wound wicks it was 11.6% (10/86) compared to 5.6% (5/88) in those whose wounds were closed by subcuticular sutures (p=NS). We concluded that the use of wound wicks was not associated with decreased wound infection rates following appendectomy. Subcuticular closure is therefore appropriate in view of its greater convenience and safety.RésuméDans les plaies contaminées, le rôle de l’antibioprophylaxie est bien établi mais l’utilisation des pansements antiseptiques reste controversé. Le but de cette étude a été d’évaluer le potentiel d’utilisation de mèches antiseptiques dans la réduction du taux d’infection après appendicectomie. Cette étude, contrôlée par randomisation, provenant d’un service de chirurgie universitaire, comprend des patients opérés d’appendicectomie pour appendicite aiguë. Les patients ont été randomisés selon une méthode informatique pour recevoir soit une fermeture sous-cutanée primitive soit l’utilisation d’un pansement antiseptique. Dans ce dernier cas, la plaie a été traitée par un ruban de gaze trempé dans une solution de polividone iodé placé entre des sutures cutanées à points séparés. Les mèches ont été imbibées tous les jours et enlevées au quatrième jour. Tous les patients ont eu une antibioprophylaxie. Tous les patients ont été revus à l’hôpital et quatre semaines après leur sortie. Les critères de jugement ont été: l’infection de la plaie, une gène au niveau de la plaie et l’aspect esthétique. Le taux d’infection global a été de 8.6% (15/174). Chez les patients avec des pansements, ce taux a été de 11.6% (10/86) comparé à 5.6% (5/88) chez les patients dont la plaie a été fermée par sutures sous-cutanées (p=NS). L’utilisation de mèches ne diminue pas le taux d’infection de la plaie après apfrendfcectomie. La fermeture sous-cutanée est donc appropriée en vue de son applicabilité et sécurité.ResumenEn heridas contaminadas el papel de la antibioticoprofilaxis está bien definido, pero la introducción dentro de la herida de tiras antisépticas sigue estando controvertida. El objetivo de este estudio fue valorar la posible utilidad de la colocación de tiras asépticas en la reducción de las infecciones de las heridas operatorias tras apendicectomía. En un departamento quirúrgico de un Hospital Universitario se realizó este estudio prospectivo randomizado y controlado. En él se incluyeron todos aquellos pacientes apendicectomizados por padecer una apendicitis aguda verdadera. Los pacientes se randomizaron mediante ordenador para que en unos, se suturase primariamente el tejido celular subcutáneo y en otro, se empleasen tiras antisépticas. Las tiras de gasa empapadas en povidona yodada se introdujeron entre los puntos entrecortados de piel. Las tiras se empapaban diariamente con povidona yodada y se retiraron al 4° día del postoperatorio. Todos los pacientes recibieron antibioticoprofilaxis. Fueron curados y revisados durante su estancia hospitalaria y a las 4 semanas de la operación con objeto de valorar la existencia o no de infección de la herida operatoria. Se evaluaron: la infección de la herida, molestias a su nivel y resultados cosméticos. La incidencia global de infección de la herida operatoria fue del 8.6% (15/174). En pacientes tratados con tiras asépticas alcanzó el 11.6% (10/86) mientras que las heridas en las que se suturó el tejido celular subcutáneo el porcentaje de infección fue del 5.6% (15/88) p=NS. Tras apendicectomía, la infección de la herida operatoria no disminuyó con un tratamiento de tiras asépticas. La sutura del tejido celular subcutáneo parece ser más conveniente y segura.

A MultiCenter Pilot Randomized Controlled Trial of Remote Ischemic Preconditioning in Major Vascular Surgery.

A pilot randomized controlled trial that evaluated the effect of remote ischemic preconditioning (RIPC) on clinical outcomes following major vascular surgery was performed. Eligible patients were those scheduled to undergo open abdominal aortic aneurysm repair, endovascular aortic aneurysm repair, carotid endarterectomy, and lower limb revascularization procedures. Patients were randomized to RIPC or to control groups. The primary outcome was a composite clinical end point comprising any of cardiovascular death, myocardial infarction, new-onset arrhythmia, cardiac arrest, congestive cardiac failure, cerebrovascular accident, renal failure requiring renal replacement therapy, mesenteric ischemia, and urgent cardiac revascularization. Secondary outcomes were components of the primary outcome and myocardial injury as assessed by serum troponin values. The primary outcome occurred in 19 (19.2%) of 99 controls and 14 (14.1%) of 99 RIPC group patients (P = .446). There were no significant differences in secondary outcomes. Our trial generated data that will guide future trials. Further trials are urgently needed.