Total laparoscopically and robotically assisted aortic aneurysm surgery: a critical evaluation

BACKGROUND: Laparoscopically assisted aortic aneurysm resection requiring a minilaparotomy can be performed as a routine procedure. It was the purpose of our study to evaluate whether a total laparoscopic operation can be offered to aneurysm patients as a minimally invasive alternative. We also wanted to test whether a master-slave robot could facilitate the total laparoscopic procedure. METHODS: A prospective, consecutive number of 50 patients was evaluated. A transperitoneal left retrocolic access was used to expose the aorta. If possible, a tube graft repair was performed. The aortic anastomosis was sutured totally laparoscopically, with the surgeon standing on the right side of the operating table. In 10 consecutive patients, the anastomosis was sutured with the help of the Zeus robot. RESULTS: After excluding 3 cases that required suprarenal cross-clamping, 47 patients were operated using a total laparoscopic approach. A totally laparoscopic operation could be performed successfully in 39 patients with aneurysms. In 8 patients (17%), conversion to a laparoscopic hand-assisted operation with a 7-cm minilaparotomy was required. The robot was used to perform the aortic anastomosis in 10 patients. In 8 patients, a tube graft repair could successfully be performed totally laparoscopically. In the remaining patients, a bifurcated graft was implanted laparoscopically. The mean operating time was 227 minutes in the laparoscopy group and was 242 minutes in those patients in whom the anastomosis was sutured with the help of the Zeus Robot. Mean cross-clamping time, +/- SD, was 81.4 + 31 minutes. None of the patients died perioperatively. Major complications occurred in three patients (6.3%). The overall morbidity was 14.8%, including one patient who required temporary hemodialysis postoperatively. The time to suture the aortic anastomosis was significantly shorter in the robotic-assistance group (40.8 +/- 4 minutes), yet total operating time was longer in this group because of the technical complexity of the robotic device. Patients with a total laparoscopic procedure asked for significantly fewer analgesics and could regain full mobility earlier compared with those patients for whom a minilaparotomy after conversion to the laparoscopic hand-assist procedure was required. CONCLUSIONS: Total laparoscopic aneurysm resection can be offered to the majority of patients in our institution. The robot still requires further refinements to reduce operating times and the aortic cross-clamping period. We now have the technique and the instrumentation to offer laparoscopic aneurysm surgery as a minimally invasive alternative for patients whose conditions are unsuitable for endovascular aneurysm repair.     

Laparoscopic assisted aortic surgery. A review

We give an overview of different laparoscopic assisted techniques to perform aortic surgery. In a meta-analysis the paper describes the combined experience of two vascular surgical centers who together have performed more than 524 laparoscopic assisted aortic procedures. Basically the following techniques can be used to perform a laparoscopic assisted procedure: 1) transperitoneal approach (the Alimi procedure); 2) hand assisted laparoscopy (the Ferrari technique); 3) left retrocolic laparoscopic assisted; 4) combining laparoscopic assisted and total laparoscopy techniques. In all cases a transperitoneal approach was chosen to dissect the aorta. This was either accomplished directly or using a left retrocolic access originally described by Dion as the apron technique. In some cases a hand assist device was used, which permits the surgeon to introduce the non dominant hand while maintaining the pneumoperitoneum. The mortality in abdominal aortic aneurysm (AAA) patients in either center did not exceed 1.8%. ICU stay, postoperative ileus and length of stay were significantly shorter compared to patients with a full length incision. The Pisa group showed that there is still a significant reduction of operating time as well as aortic cross clamping time beyond the learning curve of the first 30 patients. The analysis of the pooled data shows that even in AAA patients the laparoscopic assisted procedure can be performed with operating times of less than 3 h and hospital stays up to 4 days, which we only know from endovascular aneurysm exclusion. This is the first publication of hand assisted laparoscopic endoaneurysm repair involving a large number of patients. The operations can be performed with expediency and safety. We can use these laparoscopic procedures to perform even complex aortic operations including suprarenal aneurysms with revascularization of the renal and visceral arteries. An outlook of future developments including stapling technology is given.     

Comparison of open transabdominal AAA repair with endovascular AAA repair in reduction of postoperative stress response

Operative intervention causes a necessary biologic response known as the hypermetabolic stress response. Less invasive operative procedures may cause fewer metabolic and endocrine derangements. To evaluate the metabolic and endocrine differences between endovascular and transperitoneal abdominal aortic aneurysm (AAA) repair, 10 patients underwent standard open repair (open group) and 10 patients underwent endovascular repair of AAA (endovascular group) with a modular bifurcated endograft. Blood samples were obtained prior to general anesthesia (baseline) and every 6 hr for a 24-hr period. Assays for hormones related to the postoperative stress response as well as retinol-binding protein were performed. Peak hormonal values are presented in relation to the baseline. Demographic analysis of the two groups showed that there were no significant differences in age or ASA classification. The open group had a 9.6-fold increase in epinephrine release, which was significantly higher than the 1.6-fold increase in the endovascular group (p < 0.05). Elevations in cortisol were also significantly higher in the open group. Early postoperative nutritional derangements, as reflected by the levels of retinol-binding protein, were far less in the endovascular group than in the open group. Endovascular AAA repair appears to be associated with a marked reduction in the hypermetabolic stress response and nutritional deterioration, compared to traditional open repair. This reduction in physiologic stress may have salutary effects on the incidence of postoperative medical morbidity.     

Open aneurysm repair at an endovascular center: value of a modified retroperitoneal approach in patients at high risk with difficult aneurysms

OBJECTIVE: This study was undertaken to evaluate elective open abdominal aortic aneurysm (AAA) repair and the role of a modified retroperitoneal approach in a high-volume endovascular center. METHODS: We reviewed prospectively collected data for 175 elective infrarenal open AAA repairs performed over 6 years. A transperitoneal approach was used in 118 procedures, and a modified retroperitoneal approach was used in 57 procedures. The incisional modification, which facilitated repair in patients with massive obesity, scarring, or ventral hernia, included a higher, more posterolateral location in the ninth intercostal space. Risk factors that added to the difficulty of the repair included aneurysms with a short (<1 cm) or no aortic neck in 45 patients; large, angled or flared aortic neck in 32 patients;, tortuous and calcified iliac arteries in 6 patients; morbid obesity in 10 patients; low ejection fraction (15%-30%) in 14 patients; chronic obstructive pulmonary disease, with forced expiratory volume at 1 second less than 55% in 4 patients; previous laparotomy in 18 patients; previous left-sided colectomy in 11 patients; large right iliac aneurysm in 8 patients; large ventral hernia in 8 patients; pelvic irradiation in 4 patients; failed endovascular repair in 5 patients; and previous failed open repair attempt in 2 patients. Many of these factors occurred with significantly greater frequency (P =.04-.001) in the retroperitoneal group. All factors were correlated with outcome. RESULTS: Despite these risk factors, overall 30-day mortality was 3.5% (retroperitoneal group, 3.8%), and mean length of hospital stay was 9 days (retroperitoneal group, 8 days). There was no significant correlation between mortality or length of stay and any of the mentioned risk factors (P >.2). CONCLUSION: In the era of endovascular aneurysm exclusion, open AAA repair is generally used to treat anatomically complex or difficult aneurysms, many of which are present in patients at high risk. Despite this combination of anatomic and systemic risk factors, the modified retroperitoneal approach facilitates treatment in difficult circumstances and enables open AAA repair to be performed with acceptable mortality and morbidity.     

Laparoscopy-assisted abdominal aortic aneurysm repair: early and middle-term results of a consecutive series of 122 cases

BACKGROUND: Endoaneurysmorrhaphy with intraluminal graft placement, described by Creech, is the gold standard for abdominal aortic aneurysm (AAA) repair. Endovascular aneurysm repair has gained popularity for its minimal invasiveness and satisfying short-term results, but there are still many concerns about the long-term success of the procedure. Since 1998, laparoscopic surgery has been proposed for AAA treatment. The potential benefits of a minimally invasive procedure reproducing the endoaneurysmorrhaphy results over time have been advocated. In our experience, hand-assisted laparoscopic surgery (HALS) has been routinely used for the open-surgery transperitoneal/retroperitoneal approach and for endovascular aneurysm repair. After 4 years, we are able to define the early and middle-term results of such laparoscopic-assisted treatment. METHODS: From October 2000 to March 2004, 604 consecutive nonurgent AAAs were treated at our institution. Of these, 122 (20.2%) were treated by HALS. Exclusion criteria for HALS were hostile abdomen (previous major abdominal or aortic surgery), bilateral diffuse common iliac and/or hypogastric aneurysms, massive aortoiliac calcifications, and severe cardiac (ejection fraction <35%) and respiratory (P(O2) <60 mm Hg or carbon dioxide >50 mm Hg) insufficiency. Juxtarenal and proximal iliac aneurysms were not a contraindication, nor was obesity. In all patients, we performed a minilaparotomy (7-8 cm) both for laparoscopic hand-assisted dissection and for endoaneurysmorrhaphy. All perioperative data were prospectively recorded. Follow-up consisted of ultrasonography and clinical evaluation after 6 and 12 months and then every year after surgery. RESULTS: The mean laparoscopic and total operative times were respectively 64 +/- 32 minutes and 257 +/- 70 minutes, the mean aortic cross-clamping time was 76 +/- 26 minutes, and the mean autotransfused blood volume was 1136 +/- 711 mL. The overall mortality and morbidity were respectively 0% and 12.2%. Morbidity was surgery related in only two cases (bleeding from an ipogastric artery lesion and a leg graft thrombosis). The mean intensive care unit stay was 14.3 +/- 13 hours. Oral food intake was resumed after 27.4 +/- 15 hours, and patients were discharged after a mean of 4.4 +/- 1.7 days. Operative times were not affected by obesity, suprarenal aortic cross-clamping, or aneurysm size. Both concomitant iliac aneurysms and bifurcated graft implantation (related to longer vascular reconstruction) involved significantly longer operative times. The learning curve of the procedure (comparing the first 30 patients with the last 92 patients) led to significantly shorter endoscopic, cross-clamping, and total operative times (P = .000). The mean follow-up was 28.6 +/- 16 months. Three incisional hernias and one case of bowel occlusion were detected. All these cases (3.4%) required laparoscopic treatment. CONCLUSIONS: The HALS technique is a safe and minimally invasive treatment for AAA; it is useful for limiting the need for conventional open surgery and reducing the length of hospital stay. Despite the lack of randomized studies, HALS seems to be associated with a better postoperative course than standard open surgery. HALS can also be considered as an equivalent of a well-established procedure and as a bridge between open and total laparoscopic surgery.     

Concomitant colorectal cancer and abdominal aortic aneurysm: evolution of treatment paradigm in the endovascular era

BACKGROUND: Although the incidence of patients presenting with concomitant colorectal cancer (CRC) and abdominal aortic aneurysm (AAA) is low, current treatment strategies in patients with both lesions remains controversial. Given recent advances in endovascular aortic aneurysm repair (EVAR), we sought to analyze the surgical outcomes of patients with concomitant CRC and AAA. STUDY DESIGN: A retrospective chart review was performed on all patients with CRC and AAA between December 1984 and July 2007. RESULTS: A total of 108 patients with concomitant CRC and AAA were identified. Forty-six patients presented with symptomatic or obstructing CRC, which was treated with colectomy followed by either open AAA repair (n=35, group A) or EVAR (n=11, group B). Thirty-eight patients underwent either open AAA (n=26, group C) or EVAR (n=12, group D) first, followed by staged CRC resection. Eight patients underwent combined CRC and open AAA repair (group E). The time delays after CRC resection to AAA repair in groups A and B were 42 and 35 days (NS), respectively. The time delays after open AAA or EVAR procedures before CRC resection in groups C and D were 115 days and 12 days (p < 0.0001), respectively. Two patients in group B developed sigmoid ischemia after EVAR and were treated with sigmoid resection. Increased perioperative morbidity and mortality rates were noted in group C (p < 0.002). CONCLUSIONS: In patients with concomitant colorectal cancer and AAA, the symptomatic lesion should be a treatment priority. Because EVAR results in early recovery and a shorter convalescence compared with open aneurysmorrhaphy, this modality offers potential treatment benefits in patients with suitable anatomy who have concomitant CRC. But EVAR treatment should be offered with caution because of the risk of sigmoid ischemia caused by inferior mesenteric artery occlusion.     

Endovascular repair of ruptured abdominal aortic aneurysm--a challenge to open repair? Results of a single centre experience in 20 patients.

INTRODUCTION: The mortality from ruptured abdominal aortic aneurysm (AAA) remains in the region of 50% despite advances in critical care. Endovascular repair of AAA has been shown to be associated with reduced physiological stress in the elective setting. It is hypothesised that the reduced physiological stress associated with EVAR may improve the outcome in patients with ruptured AAA. METHODS: A feasibility study of endovascular repair of ruptured AAA was undertaken at the University Hospital, Nottingham, U.K. between 1994 and 2000. Patients admitted with ruptured AAA were assessed by a team familiar with endovascular techniques for elective repair of AAA. After giving informed consent patients underwent spiral computed tomographic angiography (CTA) in the majority of cases. Patients were then transferred to the operating theatre for EVAR. RESULTS: Twenty patients underwent repair of ruptured AAA. Of these 20 patients, seven were referred from another hospital. Eight patients were considered unfit for open repair. The median duration of procedure was 180 min (range 120-480) and median blood loss was 1200 ml (range 750-2000 ml). The overall peri-operative mortality was 45%. A number of intra-operative and peri-operative procedures (both open and endovascular) were required to ensure aneurysm exclusion and to deal with the complications of endovascular surgery. CONCLUSIONS: Ruptured AAA remains a particularly hazardous condition to treat. There are a number of advantages of EVAR in this condition. A number of the problems early in the experience of EVAR have been addressed, but further experience is required to demonstrate its efficacy when compared with open repair.     

Hand-assisted laparoscopic abdominal aortic aneurysm repair.

Hand-assisted laparoscopic aneurysm resection enables the surgeon to use his tactile senses while performing a laparoscopic aneurysm repair. Even more complex procedures that involve suprarenal clamping of the aorta can be performed by using this laparoscopically assisted approach. Twenty-nine laparoscopic patients were compared with a control group of 19 patients who were operated on conventionally. Transperitoneal hand-assisted laparoscopic aneurysm resection with a tube graft or a bifurcated graft was performed. The anastomosis was sutured with conventional instruments using the mini-incision as an access. The time for laparoscopy did not exceed 40 minutes. The incidence of complications did not vary between groups. The mean operating time was 135 minutes in the conventional group versus 180 minutes in the minimal invasive group. Intensive care stay and postoperative hospital stay were significantly shorter after the laparoscopic procedure. An oral diet was resumed significantly earlier, and the time until complete recovery was shortened in the miniaccess group. Hand-assisted laparoscopic aneurysm resection can be performed safely with operating times almost as expeditiously as in open surgery. Because it can be offered to the majority of patients with aortic disease, the technique described has distinct advantages over a total laparoscopic approach and a less steep learning curve.     

腹腔镜肾上腺切除术（经腹腔途径）的早期经验

目的：介绍腹腔镜下经腹腔途径肾上腺切除术的早期经验,包括手术技术、影响因素及并发症。方法：回顾性分析2002年2月～2006年12月收治的47例腹腔镜肾上腺切除手术资料。结果：46例成功完成腹腔镜手术,1例转为开放手术。1例右肾上腺术中失血量达到1800ml,1例左肾上腺手术中造成胰尾损伤。肿瘤体积较大者手术时间及术中失血量有增加的趋势。肿瘤的病理类型、手术方式（全切／部分切除）、患者既往腹部手术史、体重指数与手术及术后相关指标无明显相关性。结论：虽然腹腔镜肾上腺切除手术是微创手术方式,但也是高技术含量手术,尤其在开展此项技术的早期,有一定并发症的比例。     

Trends in aortic aneurysm surgical training for general and vascular surgery residents in the era of endovascular abdominal aortic aneurysm repair

HYPOTHESIS: The emergence of endovascular abdominal aortic aneurysm (AAA) repair may negatively impact the open AAA experience of general surgery residents. METHODS: Prospectively collected data on general and vascular surgery resident training in AAA repair for a 5-year period (1997 to 2001) at a single institution were retrospectively reviewed. Five general surgery residents and one vascular resident completed training yearly. Institutional volume of open and endovascular repair of AAA was also assessed. RESULTS: The cumulative mean general surgical resident experience with open AAA repair fell significantly over a 5-year period; 9.5 +/- 2.5 cases were performed per general surgical resident finishing in 1997, 7.5 +/- 0.3 cases in 1998, 4.6 +/- 0.4 cases in 1999, 4.0 +/- 1.3 cases in 2000, and 4.2 +/- 1.0 cases in 2001 (P =.03). The vascular resident experience with open AAA repair did not change significantly over the 5-year period. However, the active development of an endovascular AAA program increased total AAA exposure of the vascular resident from 26 cases in 1997 to a mean of 70 cases in 2000 and 2001. The institution volume of open nonsuprarenal AAA repairs fell 38% during the 5-year period (P =.33) during a period when endovascular AAA repair increased from 9 (1996) to 55 (2000) cases (P <.001). The complexity of open AAA surgery also increased: 23.3% of open cases (7/30) in 2000 were juxta/pararenal versus 2.9% (1/35) in 1996 (P =.05). CONCLUSION: The introduction of endovascular AAA repair may have negatively impacted general surgical resident training in open AAA repair. The number of open AAA cases declined, and their complexity significantly increased. Many uncomplicated AAAs were managed with endovascular means. At programs with such a paradigm shift in AAA treatment, expectation that general surgery residents gain the proficiency necessary to safely perform AAA repair without additional training may be unrealistic.     

The inflammatory response and its consequence for the clinical outcome following aortic aneurysm repair.

OBJECTIVE: to review published studies on the outcome of the inflammatory response after abdominal aortic aneurysm (AAA) repair. METHODS: a literature search on PubMed was performed. All studies that determined the inflammatory response (cytokine release) after AAA repair were included. The results of the studies and differences between open and endoluminal repair were compared and evaluated. RESULTS: seventeen studies were identified. In most studies the investigated cytokines were TNF-alpha and IL-6. Determination of IL-1 beta, IL-8, TNFsr1 and TNFsr2 were less often performed. TNF-alpha may reflect, but not strictly predict, the clinical outcome in patients with ruptured AAA. IL-6 levels correlate well with the surgical trauma per se. Variations in recorded cytokine release during endovascular AAA repair may depend on the times of blood sampling. CONCLUSION: both open and endovascular AAA repair provoke a cytokine response. This response is greater during open repair than during endovascular aortic aneurysm exclusion.     

Minimal incision aortic surgery.

PURPOSE: In this study we evaluated the clinical and economic impact of minimal incision aortic surgery (MIAS) for treatment of patients with abdominal aortic aneurysms (AAAs) and aortoiliac occlusive disease (AIOD). METHOD: Fifty patients with either AAA (34) or AIOD (16), prospectively treated with the MIAS technique, were compared with 50 patients (40 AAA and 10 AIOD) treated in the same time period with long midline incision and extracavitary small bowel retraction. MIAS was also compared with a cohort of 32 patients with AAA treated by means of endoaortic stent-grafts. Outcomes and cost (based on metric mean length of stay) were compared for the open and endoaortic techniques. RESULTS: Patients who experienced no perioperative complications after the MIAS or endovascular repair technique had shorter hospital stays than patients with uncomplicated aortic repairs performed with a traditional long midline abdominal incision (3 days vs 3 days vs. 7.2 days). Hospital stay was also significantly shorter for the less invasive procedures when perioperative complications were included (4.8 days vs. 4.3 days vs 9.3 days). The MIAS and endovascular aortic repair groups had a shorter intensive care unit stay (< or = 1.0 day) and a quicker return to general dietary feeding (2.5 days) than patients treated with standard open repair (1.8 days, 4.7 days). The overall morbidity for the MIAS technique (14%) and endovascular technique (21%) was not significantly different from standard open repair (24%). The mortality rate for the different treatment groups was equivalent (MIAS, 2%; endovascular repair, 3%; standard repair, 2%). The MIAS was more cost-efficient than standard open repair ($12,585 vs $18,445) because of shorter intensive care unit and hospital stay and was more cost-efficient than endoaortic repair ($12,585 vs $32,040) because of reduced, direct intraoperative costs. CONCLUSIONS: MIAS is as safe as standard open or endovascular repair in the treatment of AAA and AIOD. MIAS is more cost-efficient than standard open or endoaortic repair.     

八十岁以上高龄腹主动脉瘤患者的外科治疗

目的探讨八十岁以上高龄腹主动脉瘤患者的传统手术及腔内治疗的疗效。方法回顾性分析20例年龄在80～90岁腹主动脉瘤患者的外科治疗经验,其中12例接受传统手术,8例行腔内治疗。结果20例患者围手术期有2例死亡,均为手术组患者。腔内组的手术及术后并发症情况均显著优于手术组。随访3～69个月,2例手术组患者失访,手术组和腔内组各有2例远期死亡。手术组和腔内组的累计生存率分别为6／10和6／8。结论对于八十岁以上高龄腹主动脉瘤患者的外科治疗可行,在合适病例首选腔内治疗。     

Broadening the applicability of endovascular aneurysm repair: the use of iliac conduits

OBJECTIVE: Suboptimal iliac anatomy has sometimes precluded endovascular repair of abdominal aortic aneurysm (AAA). In an effort to increase the applicability of endovascular repair, a limited retroperitoneal approach and iliac conduit was used in some patients with unsuitable iliac anatomy at high risk for open repair. METHODS: Charts and imaging studies of 312 patients who underwent endovascular (AAA) repair at the Cleveland Clinic Foundation between June 1999 and November 2000 were reviewed. Among these, 22 patients with complex iliac anatomy had an iliac conduit placed. Seventeen of these procedures were planned, but five were unplanned and placed after an iliac artery injury. A group of 17 patients who underwent a standard endovascular repair without conduits was selected and matched to the 17 patients in the planned conduit group by baseline comorbidities. The conduits were 8-mm or 10-mm polyester grafts sewn proximally to the common iliac artery and provided unobstructed access to the aneurysm. After insertion of the endograft device through the conduit, the distal end of the conduit was anastomosed to the external iliac or common femoral vessels. RESULTS: Operative time and estimated blood loss were higher among patients in whom conduits were performed, especially when performed urgently as an unplanned procedure. Although operative time and intensive care unit and hospital stays were longer for the group of patients with iliac conduits, the cardiac pulmonary and renal complication rates were similar for the conduit and the standard endovascular repair group. CONCLUSION: The use of a limited retroperitoneal approach and iliac conduit for patients with difficult iliac anatomy increases the applicability of the endovascular repair of AAA. This technique should be considered when an open surgical approach is inadvisable on the basis of medical comorbidities.     

Rupture of abdominal aortic aneurysm: concurrent comparison of outcome of those occurring after endovascular repair versus those occurring without previous treatment in an 11-year single-center experience

OBJECTIVE: The purpose of this single-center study was to compare findings at presentation and surgical outcome in patients in whom abdominal aortic aneurysms (AAAs) ruptured after endovascular repair and patients in whom AAAs ruptured before any treatment, over a defined period. METHODS: From May 1992 to September 2003, 1043 patients underwent elective repair of intact infrarenal AAAs. Endovascular repair was performed in 609 patients, and open repair in 434 patients. Eighteen of 609 patients (3%) who underwent endovascular AAA repair required treatment because of rupture of the aneurysm after a mean of 29 months (group 1). During the same 11-year period, another 91 patients without previous treatment required urgent repair of a ruptured AAA (group 2). Rupture was diagnosed at contrast material-enhanced computed tomography or by presence of extramural extravasation of blood at open repair. Except for a higher incidence of women in group 2, patients in both groups were similar with regard to demographics and clinical characteristics but differed in findings at presentation. Eight patients in group 1 had a known endoleak before AAA rupture, whereas contrast-enhanced computed tomography, performed in 15 patients at presentation, demonstrated an endoleak in all. Hypotension (systolic blood pressure <100 mm Hg) was noted at presentation in 4 of 18 patients (22%) in group 1 and 76 of 91 patients (84%) in group 2. All patients underwent open repair via a transperitoneal approach, except for 4 patients in group 1 and 3 patients in group 2 who underwent endovascular repair of ruptured AAAs. RESULTS: The proportion of patients with hypotension at presentation in group 1 (4 of 18) was significantly less than in group 2 (76 of 91; P < .01). The difference in perioperative (30 day) mortality rate in group 1 (3 of 18; 16.6%) compared with group 2 (49 of 91; 53.8%) was also significant (P < .01). The outcome in group 1 was therefore superior to that in group 2. CONCLUSIONS: This study confirms that endovascular AAA repair complicated by endoleak does not prevent rupture. The data suggest, however, that rupture, when it occurs in these circumstances, may not be accompanied by such major hemodynamic changes and high mortality as rupture of an untreated AAA. Further long-term follow-up and analysis in a larger group of patients are required to confirm the apparent intermediate level of protection afforded by failed endovascular repair, which does not prevent rupture but enhances survival after operation to treat rupture, possibly by ameliorating the hemodynamic changes associated with the rupture process.     

A prospective study of subclinical myocardial damage in endovascular versus open repair of infrarenal abdominal aortic aneurysms

BACKGROUND: Endovascular repair of abdominal aortic aneurysms (AAAs) is considered to be less invasive and better tolerated by the cardiovascular system than open repair. Our aim was to assess the true incidence of perioperative myocardial damage associated with endovascular vs open infrarenal AAA repair. METHODS: Between July 1999 and June 2001, preoperative and postoperative serum troponin T (TnT) levels were measured in all patients presenting for elective AAA repair at Royal Prince Alfred Hospital. The incidence of myocardial damage was recorded on the basis of standard clinical, biochemical, and electrocardiographic changes or a subclinical increase of 50% or more in serum TnT. Patients were excluded if the TnT increase was associated with a significant increase of serum creatinine (> or =50%) with no other evidence of myocardial ischemia. The differences between the two groups were analyzed with the chi 2 test and odds ratios. RESULTS: A total of 35 open and 112 endovascular AAA repairs were included in the study. There was no significant difference in age, sex, preoperative serum creatinine, or preoperative serum TnT between the two treatment groups. Seventeen patients had biochemical evidence of myocardial damage, which was clinically obvious in only one patient. Even though the incidence of previous myocardial infarction was significantly higher in patients undergoing endovascular repair (41%) than open repair (22%; P < .05), the overall incidence of myocardial damage (clinical or subclinical) was significantly higher in the open group compared with the endovascular group (8 [25%] of 32 vs 9 [8%] of 109, respectively; odds ratio, 3.7; 95% confidence interval, 1.28-10.49; P < .02). CONCLUSIONS: There is a previously underestimated incidence of subclinical myocardial damage associated with surgery for infrarenal AAA which is lower after endovascular than open repair.     

The incidence of hypomagnesaemia following abdominal aortic aneurysm surgery

IntroductionMagnesium is important for cardiac function. Hypomagnesaemia is associated with a higher incidence of arrhythmias and poorer outcomes in cardiac surgery. No studies have investigated the incidence or impact of postoperative hypomagnesaemia after abdominal aortic aneurysm (AAA) surgery. We aim to assess the incidence of hypomagnesaemia after AAA repair in our population.MethodsRetrospective analysis was performed of patients who underwent elective AAA surgery at a single vascular centre. The last 110 patients undergoing open or endovascular AAA repair were identified. The hospital pathology system was used to identify the immediate postoperative serum magnesium levels as well as patient demographics and admission details. Hypomagnesaemia was defined as serum magnesium of <0.7mmol/l.ResultsA total of 211 patients were studied and there were 3 deaths. Of the patients included, 101 underwent open elective AAA repair and 110 underwent endovascular repair. In the elective open repair group, 73 patients (73%) were hypomagnesaemic. In the endovascular repair group, 35 (32%) had hypomagnesaemia. A t-test showed a statistically significant difference in hypomagnesaemia between the open and endovascular groups (p<0.001).ConclusionsAAA surgery is associated with a high incidence of postoperative hypomagnesaemia, which is significantly greater among open repair patients. This is likely to have an effect on cardiac activity and lead to cardiac complications such as arrhythmias and poorer postoperative outcomes, especially in the open AAA repair subgroup. This stresses the importance of serum magnesium and cardiac monitoring in the postoperative phase. A prospective study is proposed to further investigate these findings, and their potential implications on perioperative morbidity and mortality.     

Zenith AAA endovascular graft: intermediate-term results of the US multicenter trial

PURPOSE: The intent of this study was to assess the safety and effectiveness of the Zenith AAA Endovascular Graft compared with conventional aneurysm repair. MATERIAL AND METHODS: The study was conducted in a prospective, multicenter, nonrandomized, concurrent control manner. Physiologically similar patients with infrarenal abdominal aortic aneurysms (AAAs) underwent either open surgery or repair with the Zenith AAA Endovascular Graft. Separate analyses of physiologically challenged patients were performed. Follow-up was conducted at hospital discharge and at 1, 6, and 12 months (endovascular repair group) or 1 and 12 months (open surgical repair group). Evaluation included computed tomography, abdominal radiography, laboratory tests, and physical examination. Mortality (AAA-related and overall), morbidity, in-hospital recovery, renal function, and secondary interventions were assessed. Patients in the endovascular repair group were evaluated for change in aneurysm size, endoleak, graft migration, conversion, rupture, and device integrity. Statistical analyses were performed with the Kaplan-Meier method, Blackwelder test, propensity score assessment, two-sample t test, Yates-corrected Pearson chi(2) test, and Fisher exact test. RESULTS: Conventional open surgery was used in 80 patients, and 200 patients underwent repair with the Zenith AAA Endovascular Graft. Technical success was accomplished in 98.8% of patients in the open repair group and 99.5% in the endovascular repair group. Patients in the endovascular repair group had fewer significant adverse events within 30 days (80% vs 57%; P <.001). All-cause mortality was similar (endovascular, 3.5%; open surgery, 3.8%). Aneurysm-related mortality was higher with conventional surgery at 12 months (3.8% vs 0.5%; P =.04). In-hospital recovery and procedural measures were better for endovascular repair in all categories (P <.001). The incidence of endoleak was 17% at 30 days, 7.4% at 12 months, and 5.4% at 24 months. Aneurysm shrinkage (>5 mm) was noted in more than two thirds of patients at 12 months and three fourths of patients at 24 months. Renal dysfunction rate did not differ between groups. Migration (>5 mm) was detected in four (2%) patients through 12 months; none was greater than 10 mm or associated with adverse events through 24 months. Three conversions were performed within 12 months, one because of aneurysm rupture. Secondary procedures were more common in the endovascular group (11% vs 2.5%; P =.03). In total, 351 patients had endografts implanted, and 6 patients were noted to have barb separations through 12-month follow-up. No stent fractures were noted. CONCLUSIONS: The Zenith AAA Endovascular Graft is safe and effective for treatment of infrarenal AAAs. The high likelihood of decrease in aneurysm size provides evidence that treatment of aneurysms with this device reverses the natural history of aneurysmal disease. The importance of long-term follow-up is underscored by the small but defined incidence of barb separation and the potential for unforeseen failure modes.     

Total laparoscopic infrarenal aortic aneurysm repair: preliminary results

OBJECTIVES: We describe our initial experience of total laparoscopic abdominal aortic aneurysm (AAA) repair. MATERIAL AND METHODS: Between February 2002 and September 2003, we performed 30 total laparoscopic AAA repairs in 27 men and 3 women. Median age was 71.5 years (range, 46-85 years). Median aneurysm size was 51.5 mm (range, 30-79 mm). American Society of Anesthesiologists class of patients was II, III and IV in 10, 19, and 1 cases, respectively. We performed total laparoscopic endoaneurysmorrhaphy and aneurysm exclusion in 27 and 3 patients, respectively. We used the laparoscopic transperitoneal left retrocolic approach in 27 patients. We operated on 2 patients via a tranperitoneal left retrorenal approach and 1 patient via a retroperitoneoscopic approach. RESULTS: We implanted tube grafts and bifurcated grafts in 11 and 19 patients, respectively. Two minilaparotomies were performed. In 1 case, exposure via a retroperitoneal approach was difficult and, in another case, distal aorta was extremely calcified. Median operative time was 290 minutes (range, 160-420 minutes). Median aortic clamping time was 78 minutes (range, 35-230 minutes). Median blood loss was 1680 cc (range, 300-6900 cc). In our early experience, 2 patients died of myocardial infarction. Ten major nonlethal postoperative complications were observed in 8 patients: 4 transcient renal insufficiencies, 2 cases of lung atelectasis, 1 bowel obstruction, 1 spleen rupture, 1 external iliac artery dissection, and 1 iliac hematoma. Others patients had an excellent recovery with rapid return to general diet and ambulation. Median hospital stay was 9 days (range, 8-37 days). With a median follow-up of 12 months (range, 0.5-20 months), patients had a complete recovery and all grafts were patent. CONCLUSION: These preliminary results show that total laparoscopic AAA repair is feasible and worthwhile for patients once the learning curve is overcome. However, prior training and experience in laparoscopic aortic surgery are needed to perform total laparoscopic AAA repair. Despite these encouraging results, a greater experience and further evaluation are required to ensure the real benefit of this technique compared with open AAA repair.     

Should endovascular surgery lower the threshold for repair of abdominal aortic aneurysms?

PURPOSE: Because endovascular repair of abdominal aortic aneurysms (AAAs) is less invasive, some investigators have suggested that this increasingly popular technique should broaden the indications for elective AAA repair. The purpose of this study was to calculate quality-adjusted life expectancy rates after endovascular and open AAA repair and to estimate the optimal diameter for elective AAA repair in hypothetical cohorts of patients at average risk and at high risk. METHODS: A Markov decision analysis model was used in this study. Assumptions were made on the basis of published reports and included the following: (1) the annual rupture rate is a continuous function of the AAA diameter (0% for <4 cm, 1% for 4.5 cm, 11% for 5.5 cm, and 26% for 6.5 cm); (2) the operative mortality rate is 1% for endovascular repair (excluding the risk of conversion to open repair) and 3.5% for open repair at age 70 years; and (3) immediate endovascular-to-open conversion risk is 5%, and late conversion rate is 1% per year. The main outcome measure in this study was the benefit of AAA repair in quality-adjusted life years (QALYs). The optimal threshold size (the AAA diameter at which elective repair maximizes benefit) was measured in centimeters. RESULTS: The benefit of endovascular repair is consistently greater than that of open repair, but the additional benefit is small-0.1 to 0.4 QALYs. For men in average health with gradually enlarging AAAs with initial diameters of 4 cm, endovascular surgery reduces the optimal threshold diameter by very little: from 4.6 to 4.6 cm (no change) at age 60 years, from 4.8 to 4.7 cm at age 70 years, and from 5.1 to 4.9 cm at age 80 years. For older men in poor health, endovascular surgery reduces the optimal threshold diameter substantially (8.1 to 5.7 cm at age 80 years), but the benefit of repair in this population is small (0.2 QALYs). CONCLUSION: For most patients, the indications for AAA repair are changed very little by the introduction of endovascular surgery. Only for older patients in poor health does endovascular surgery substantially lower the optimal threshold diameter for elective AAA repair.