Advances in the classification and treatment of isolated superior mesenteric artery dissection / 中华外科杂志

Isolated superior mesenteric artery dissection (ISMAD) has attracted more and more clinicians' attention in recent years. Patients onset of ISMAD often present with abdominal pain. The misdiagnosis or miss diagnosis is common because of the non-specific symptoms and signs, which even can endanger lives in serious cases. Imaging classification is of great significance for diagnosis and treatment of ISMAD. The Sakamoto classification and the Yun classification are two classical classified methods. However, with the further study of ISMAD, various new classifications emerge. Conservative treatment was once considered as the preferred. As the rapid development of endovascular therapy and the great progress of new devices, stenting therapy can significantly improve symptoms and achieve satisfactory long-term effects, and be even expected to become the preferred method for clinical therapy of ISMAD. However, the long-term effects of endovascular therapy still need a large number of follow-up data, and complications after stent implantation can't be ignored.

A novel pressure difference-induced perforation aortic stent-grafts system: an experimental study / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Most of endovascular stent-graft modifications to preserve side branch must be customized according to extensive pre-operative assessment, which may not be possible in many hospitals and emergency settings. The study was to develop a novel stent-grafts system that would allow in situ "fenestration", with less reliance on preoperative imaging.</p><p><b>METHODS</b>The magnitude of pressure difference (PD) between left subclavian artery (LSA) and aortic arch were measured in 12 experimental pigs. Changes of PD before and after LSA was covered were analyzed respectively. The novel stent graft was made by multi-dimensional and multiple textiles forming technology. According to the PD measurement in pigs, we evaluated the feasibility of the stent-graft in a mock circulation system.</p><p><b>RESULTS</b>In pigs, the blood pressure of aortic arch was significantly higher than that of LSA after it was covered (P < 0.001) and PD was (42.78 ± 5.17) mmHg. After target vessel was covered and when PD between the LSA and aorta reached the magnitude measured in pigs, contrast media oozed from the cranny of graft to the LSA, which was generated by sliding and deformation of yarns of novel stent-graft.</p><p><b>CONCLUSIONS</b>The study proposes the design of pressure difference-induced perforation aortic stent-grafts system and verifies that the PD between LSA and aortic arch is high enough to allow in situ "fenestration" by stent graft made by multi-dimensional and multiple textiles forming technology.</p>

Fibrin glue embolization treating intra-operative type I endoleak of endovascular repair of abdominal aortic aneurysm: long-term result / 中华外科杂志

<p><b>OBJECTIVES</b>To analyze the long-term results of fibrin glue embolization to eliminate type I endoleaks after endovascular aneurysm repair (EVAR), and to assess the feasibility and durability of this technique.</p><p><b>METHODS</b>From August 2002 to June 2010, among the 953 EVAR patients, 51 (5.4%) patients underwent intraoperative transcatheter fibrin glue sac embolization to resolve type I endoleak persisting after initial intraoperative maneuvers to close the leak or in necks too short or angulated for cuff placement. Computed tomographic angiography was performed to assess the outcome after 3, 6, and 12 months and annually thereafter. A retrospective study was conducted, and characteristics of the patients, intra-sac pressure, hospital course, and long-term outcomes were recorded.</p><p><b>RESULTS</b>Among the 51 patients, 19 (37.3%) patients had proximal necks long < 10 mm, and 6 (11.8%) patients had proximal neck angulation > 60°; 22 patients (3 additional iliac extension, 14 cuffs, and/or 8 stents) had been placed with additional devices. After fibrin glue injection, 50 (98.0%) of the 51 endoleaks were successfully resolved, and intra-sac pressure (including systolic, diastolic, mean pressures, pulse pressure, and the mean pressure indexes) decreased significantly in these cases. The patient who failed embolotherapy was converted to open surgery (2.0%); he died 2 months later from multiorgan failure. And other two (4.8%) patients died in the peri-operative period from myocardial infarction. The median of follow-up of 48 patients was 45 months (range 4 - 106 months). The mean maximal aneurysm diameter fell from the baseline (61.5 ± 15.2) mm to (48.8 ± 10.1) mm (P = 0.000). Three (6.2%) patients died in the follow-up duration (1 aneurysm-related, died of renal failure which was caused by the compromised renal artery). Cumulative survival was 97.9% at 1 year, 94.5% at 3 years, and 90.8% at 4 years. No recurrent type I endoleak or glue-related complications were observed in follow-up.</p><p><b>CONCLUSIONS</b>Fibrin glue embolization to eliminate type I endoleak after EVAR has yielded promising results in this study, and it can effectively and durable resolve the type I endoleaks. Balloon occlusion of the inflow of the endoleak must be done during glue injection, to enhance the safety and facilitate formation of a structured fibrin clot.</p>

Aortorenal bypass with autologous saphenous vein in Takayasu arteritis-induced renal artery stenosis: an analysis of 33 cases / 中华外科杂志

<p><b>OBJECTIVE</b>To clarify the outcome of surgical reconstruction for renal artery in Takayasu arteritis-induced renal artery stenosis (TARAS).</p><p><b>METHODS</b>A retrospective chart review was conducted on 33 consecutive patients with TARAS, who underwent aortorenal bypass (ARB) with autologous saphenous vein graft. There were 9 male and 24 female patients, with a mean age of (25 ± 11) years. The effects on blood pressure and renal function were analyzed. Primary, primary assisted, and secondary patency rates were determined. The effects of various factors on primary patency rate were analyzed. All patients showed hypertension. The mean blood pressure was (175 ± 26)/(100 ± 19) mmHg (1 mmHg = 0.133 kPa). The mean antihypertensive dosage was (2.1 ± 0.6) defined daily dose (DDD). Seventeen patients showed intractable hypertension. Mean estimated glomerular filtration rate was (78 ± 5) ml/min. One patient was dialysis-dependent, and 3 patients were combined with congestive heart failure.</p><p><b>RESULTS</b>ARB was performed for the 39 renal arteries, including 27 unilateral and 6 bilateral bypasses. Postoperative morbidity was 15.2%. All patients survived. During follow-up of mean (56 ± 18) months, two graft occlusions and four graft restenoses occurred. All graft restenoses were eliminated successfully with percutaneous angioplasty, but one patient experienced restenosis again six months later. At 1, 3, and 5 years of follow-up, primary patency was 92%, 89%, and 79%, respectively, primary assisted patency was 95%, 95%, and 91%, respectively, and secondary patency was 95%, 95%, and 91%, respectively. ARB resulted in a decrease in mean blood pressure to 139/85 mmHg (one month post-ARB, P = 0.000) and 136/80 mmHg (last follow-up, P = 0.000), and a reduction in mean antihypertensive dosage to 1.4 DDD (one month post-ARB, P = 0.084) and 0.6 DDD (last follow-up, P = 0.000). Mean estimated glomerular filtration rate increased to 82 ml/min (P = 0.458) one month post-ARB, and 91 ml/min (P = 0.044) at last follow-up, respectively. The dialysis-dependent patient no longer required hemodialysis, and left ventricular dysfunction resolved in all of the three patients.</p><p><b>CONCLUSION</b>ARB using the autologous saphenous vein graft is safe, effective and durable for treating TARAS.</p>

Effect of the size of abdominal aortic aneurysm on endovascular exclusion and its results / 中华外科杂志

<p><b>OBJECTIVE</b>To evaluate the effect of the diameter of abdominal aortic aneurysm (AAA) on endovascular exclusion (EVE) and its results.</p><p><b>METHODS</b>From March 1997 to June 2007, 429 AAA patients were treated with endovascular stent-graft exclusion. According to the maximal diameter of abdominal aortic aneurysm, the patients were divided into two groups: group A (diameter < 55 mm, n = 274) and group B (diameter > or = 55 mm, n = 155). The diameter of AAA, involvement of iliac artery, length, diameter and distortion of aneurismal neck in the two groups were recorded and compared retrospectively.</p><p><b>RESULTS</b>Patients in group B were significantly older than group A (73.7 vs 71.1 years, P < 0.05). More patients in group B was complicated with coronary artery disease than those in group A (P < 0.05). The mean diameter of AAA in group A was (46.6 +/- 6.8) mm, and (66.8 +/- 11.2) mm in group B (P < 0.05). Proximal aneurysmal necks were shorter, wider and more tortuous in group B than those in group A (P < 0.05). Extraperitoneal approach, embolism of inner iliac artery and reconstruction of another inner iliac artery and stretch technique were more applied in group B. There were more endoleak during operation in group B and more stent-grafts were used. There was significant difference in morbidity rate between the two groups, while no statistic difference in mortality. And in group B, there were a high rate of endoleak and secondary intervention post operation.</p><p><b>CONCLUSIONS</b>The diameter of AAA affects EVE and its results. In small aneurysms, EVE carries better outcome than in big aneurysms.</p>

Aneurysm repair in vitro and renal revascularization and renal autogenous transplantation for complex renal artery aneurysm in solitary kidney / 中华外科杂志

<p><b>OBJECTIVE</b>To discuss the safety and feasibility of aneurysm repair in vitro and renal revascularization and renal autogenous transplantation for complex renal artery aneurysm in solitary kidney.</p><p><b>METHODS</b>A complex hilar renal artery aneurysm involving the bifurcation of renal artery and its branches in a solitary left kidney was diagnosed by computed tomography angiography (CTA). After temporary nephrectomy, aneurysm repair in vitro and renal revascularization were done with the kidney protected by hypothermia and continuous perfusion with preservation solution, and then the kidney was replanted into the right iliac fossa.</p><p><b>RESULTS</b>The operation was done successfully and there were no significant perioperative complications. Although a serum creatinine level temporarily exceeded above 200 micromol/L after the surgery, it recovered gradually within half a month. CTA two weeks later demonstrated patent reconstructed renal arteries and its branches and patent renal vein in the right iliac fossa, and also a patent reconstructed ureter.</p><p><b>CONCLUSIONS</b>This technique is safe and feasible to manage complex renal artery aneurysm in solitary kidney and provide an alternative for similar complex renal diseases.</p>

Endovascular exclusion of juxtarenal abdominal aortic aneurysm with one-piece customized fenestrated endovascular stent-graft / 中华外科杂志

<p><b>OBJECTIVE</b>To evaluate the technical feasibility of juxtarenal abdominal aortic aneurysm (AAA) repair with fenestrated endovascular stent-graft</p><p><b>METHODS</b>A 64-year-old male was diagnosed with juxtarenal AAA with severe coronary artery stenosis, fenestrations was customized according to precise helical CT data to accommodate visceral and renal arteries. Under general anesthesia and dynamic supervision of digital subtraction angiography (DSA), juxtarenal AAA was excluded with the customized fenestrated stent-graft and balloon expandable mini stent-grafts were deployed into bilateral renal arteries respectively.</p><p><b>RESULTS</b>After operation, DSA showed the patency of the super mesenteric artery, bilateral renal arteries and left hypogastric artery, no endoleak was found. The serum creatinine decreased slightly after operation. CT angiography revealed favorable morphology of the stent-graft without tortuosity, migration, disjoint and endoleak 10 days after the operation and patency of super mesenteric artery, bilateral renal arteries and left hypogastric artery.</p><p><b>CONCLUSIONS</b>The placement of customized fenestrated endovascular stent-graft is a feasible option for juxtarenal AAA.</p>

Simultaneous multi-tear exclusion: an optimal strategy for type B thoracic aortic dissection initially proved by a single center's 8 years experience / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Endovascular stent-grafting is widely used to treat thoracic aortic dissection. However, little information is available regarding outcome following simultaneous exclusion of multiple tears. This report details eight years of experience using simultaneous multi-tear exclusion for treatment of Stanford type B thoracic aortic dissection resulting in successful aortic remodeling without adverse events.</p><p><b>METHODS</b>From September 1998 to January 2006, 29 type B thoracic aortic dissection patients (24 men, 5 women; 27 chronic, 2 acute; mean age 58 years, range 45 - 77 years) were treated by simultaneous multi-tear exclusion in our center. Magnetic resonance angiography was used as the preoperative evaluation method. Different kinds of stent-grafts were used. The patients were followed up with contrast-enhanced spiral computed tomography at 6 months postoperatively and yearly thereafter.</p><p><b>RESULTS</b>Twenty-nine surgeries were completed successfully using at least 2 stent-grafts per patient (range: 2 - 6, mean: 2.7). No major procedure-related complications, such as rupture, paraplegia, aortic branch ischemia or cerebral infarction, were observed. During follow-up, favorable remodeling of the aorta was observed.</p><p><b>CONCLUSIONS</b>The mid-term result of thoracic aortic dissection with simultaneous multi-tear exclusion was satisfactory. With the improvement of stent-grafts, simultaneous multi-tear exclusion should find wider application and become an optimal strategy for thoracic aortic dissection.</p>

Role of nitric oxide and inducible nitric oxide synthase in human abdominal aortic aneurysms: a preliminary study / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Nitric oxide (NO) is an important mediator in the pathophysiology of many vascular diseases. However, the definite role of NO in human abdominal aortic aneurysm (AAA) formation is unclear. The aim of this study was to investigate production of NO and expression of inducible nitric oxide synthase (iNOS), and their possible role in AAA.</p><p><b>METHODS</b>A total of 28 patients with AAA, 10 healthy controls, and 8 patients with arterial occlusive disease were enrolled into this study. Standard colorimetric assay was used to examine NO concentration in plasma from patients with AAA and normal controls, and in cultured smooth muscle cells (SMCs). Expression of iNOS in aortas and cultured SMCs were detected by immunochemistry. The correlation of iNOS expression with age of the patient, size of aneurysm, and degree of inflammation was also investigated by Cochran-Mantel-Haenszel chi2 test and Kendall' Tau correlation.</p><p><b>RESULTS</b>Expression of iNOS increased significantly in the wall of aneurism in the patients with AAA compared to the healthy controls (P < 0.05) and the patients with occlusive arteries (P < 0.05). iNOS protein and media NOx (nitrite + nitrate) also increased in cultured SMCs from human AAA (n = 4, P < 0.05), while plasma NOx decreased in patients with AAA (n = 25) compared to the healthy controls (n = 20). There was a positive correlation between iNOS protein and degree of inflammation in aneurismal wall (Kendall coefficient = 0.5032, P = 0.0029).</p><p><b>CONCLUSIONS</b>SMCs and inflammatory cells were main cellular sources of increased iNOS in AAA, and NO may play a part in pathogenesis in AAA through inflammation.</p>

To resolve the difficulties of entering into the aortic dissections' true lumen in endovascular graft exclusion / 中华外科杂志

<p><b>OBJECTIVE</b>To review the methods about resolving the difficulties of entering into the aortic dissections' true lumen in endovascular graft exclusion.</p><p><b>METHODS</b>The patients who had Stanford B type thoracic aortic dissection and been treated with endovascular graft exclusion from September 1998 to February 2004 were reviewed. The operations performed under DSA surveillance. In the operation, the wire was difficult to enter into the true lumen of the aortic dissection in 28 cases, and was wrong into the false lumen then into the true lumen in 4 cases. Five methods were used to resolve these problems, including catheter smoking technique, different position projection, left brachial artery puncture proximal guide-wire floating technique, arterial choice of entering into the true lumen and guide-wire transfixion between proximal and distal.</p><p><b>RESULTS</b>The method of catheter smoking technique was used in 32 cases, different position projection in 12 cases, left brachial artery puncture proximal guide-wire floating technique in 10 cases, arterial choice of entering into the true lumen in 28 cases, and guide-wire transfixion between proximal and distal in 2 cases. The wires were ultimately successful to enter the true lumen and the stent-grafts excluded successfully the tears of the aortic dissections in 32 cases.</p><p><b>CONCLUSION</b>The difficulty of entering into the true lumen and the wrong way into the false lumen could lead to losing the operation, even a disaster. The problem could be resolved by some methods of endovascular techniques.</p>

Endovascular stent-graft exclusion for Stanford B type aortic dissections: a report of 146 patients / 中华外科杂志

<p><b>OBJECTIVE</b>To assess the operation indications, preoperative evaluation, technique essentials and clinical prospect of endovascular stent-graft exclusion for aortic dissection.</p><p><b>METHODS</b>From September 1998 to April 2003, endovascular stent-graft exclusion for aortic dissection (Stanford B) was preformed in 146 patients. CTA or MRA were used as preoperative evaluation methods. Graft was constructed from self-expanding Z-stents covered with a woven Dacron polyester fabric graft (Talent). The stent-grafts were inserted from the femoral or iliac artery to exclude the tear of dissection, and all operations were performed under DSA guidance.</p><p><b>RESULTS</b>The grafts were installed successfully in 145 patients. In 119 patients only proximal tears were excluded, and 26 patients who had both the proximal and distal tears were excluded. The mean follow-up period was 16 months (1 - 54 months). Six patients died within the perioperative period, 2 patients died during the follow-up, 2 patients had recurrence of aortic dissection (Stanford A) and cured by Bentall operation. The others were in good state. No accidents related to the dissection and operation occurred.</p><p><b>CONCLUSIONS</b>Endovascular graft exclusion may be a safe and effective treatment for selected patients with thoracic aortic dissection. Endoleak may lead to aneurysmal expansion and rupture. Further follow-up is necessary to evaluate its long-term effect.</p>