Endoluminal isolation was performed in 121 cases of Stanford type B aortic coarctation and 6 cases of thoracic aortic aneurysm, of which 121 cases underwent endoluminal isolation alone, 24 cases had the left subclavian artery covered by an intraoperative overlapping stent, 2 cases of thoracic aortic aneurysm and 1 case of aortic coarctation were preceded by right common carotid artery-left common carotid artery-left subclavian artery artificial vessel diversion, left common carotid artery and left subclavian artery proximal ligation. Three cases failed.
The results showed that there was no death during hospitalization in this group, but two cases of aortic coarctation were found to have died 1 and 3 months after surgery due to ischemia of the superior mesenteric artery resulting in intestinal necrosis and type A coarctation respectively due to unsatisfactory blood pressure control, and one patient with aortic coarctation died 1 year after surgery due to paraplegia caused by coarctation of the abdominal aorta. one patient with thoracic aortic aneurysm breaking into the esophagus died 1 month after surgery due to infection of the aneurysm lumen.
Aortic coarctation and aortic aneurysm is a disease with an aggressive prognosis, and although open surgery has progressed in the past, the mortality rate is still high due to trauma. In the 1990s, endoluminal isolation techniques began to be applied to dilated thoracic aortic disease, and after nearly 20 years of development, they have become an important treatment for Stanford B-type aortic coarctation and aortic aneurysm. In this study, 127 patients with aortic coarctation and aortic aneurysm underwent endoluminal isolation. It is reported as follows.
1. Materials and methods
1.1 General data 127 patients admitted to our vascular surgery department from April 2005 to February 2013 were collected, including 105 males and 22 females. The age ranged from 31 to 81 years old, with an average of 55.74 years old. There were 121 cases of aortic coarctation and 6 cases of thoracic aortic aneurysm. Among the cases of thoracic aortic aneurysm, one case was found due to trauma resulting in aortic pseudoaneurysm, one case was found due to thoracic aortic aneurysm breaking into the esophagus with gastrointestinal hemorrhage, and the rest were found unintentionally during physical examination.
Among the 121 cases of aortic coarctation, 3 cases were chronic coarctation, which was found during physical examination with unclear history of chest pain, while the rest were admitted with acute chest and back pain and hypertension. 2 cases were accompanied by ischemia of one lower limb and 1 case had acute renal failure.
1.2 Examination results All patients underwent emergency computed tomographic angiography (CTA) of the thoracic and abdominal aorta on admission.
Among them, 2 cases of aortic aneurysm and 1 case of aortic coarctation involved the left common carotid artery. 79 of 121 cases of aortic coarctation were found to have multiple ruptures distal to the left subclavian artery, and 42 cases of aortic coarctation were found to have multiple ruptures distal to the left subclavian artery. The aortic coarctation was found to have multiple ruptures at the distal end in 79 of 121 cases. 42 patients had one or both renal arteries supplied by a false lumen, 6 patients had the superior mesenteric artery supplied by a false lumen, 69 cases had aortic coarctation that had torn into the common iliac artery on one side, and 1 case had aortic coarctation with abdominal aortic aneurysm.
1.3 Timing of surgery Patients were given antihypertensive and analgesic after admission. In all cases of acute aortic coarctation, except for one case in which acute renal failure occurred due to tearing of bilateral renal arteries at the time of admission and endoluminal isolation was performed urgently, endoluminal isolation was performed after 2 to 3 weeks of blood pressure control. The descending aortic aneurysm was performed with endoluminal isolation after perfect preoperative examination.
1.4 Surgical procedure All cases were performed with endotracheal anesthesia. An incision was made in the groin on one side, a section of the common femoral artery was isolated, a transverse incision was made, and a gold marker catheter was placed in the ascending aorta for imaging to clarify the location of the aortic dissection, the extent of the dissection and aneurysm involvement, whether the catheter was located in the true lumen, and the diameter of the aorta. After selecting the appropriate size of the overlapping stent and replacing the ultra-hard guidewire, the stent is fed into the overlapping stent delivery system along the guidewire and released after accurate positioning. Exit the delivery system and re-imaging to clarify whether there is endoleakage of the stent.
2.Results
2.1 Surgical results There were 124 cases in this group in which endoluminal isolation was successfully performed. In 2 cases of thoracic aorta and 1 case of aortic coarctation, because of the involvement of the left subclavian artery, the right common carotid artery-left common carotid artery-left subclavian artery artificial vessel diversion was performed first, and the proximal ligation of the left common carotid artery and left subclavian artery was performed, and then endoluminal isolation was performed 1 week after the operation, and the openings of the left common carotid artery and left subclavian artery were capped at the same time.
The systolic pressure of the left subclavian artery exceeded 7.98 KPa in 24 cases, and one case had an abdominal aortic aneurysm and underwent simultaneous endoluminal isolation of the abdominal aortic aneurysm. In 36 cases, type I endoleaks and 1 case of type II endoleaks were found on post-stent release angiography. In 8 cases with large type I endoleaks, compliant balloon dilation was performed in 6 cases, and in 2 cases, an extension graft (Cuff) was placed at the front of the stent. After treatment, the leak disappeared in 5 cases and was reduced in 3 cases.
Three cases of unsuccessful endoluminal isolation, two cases of chronic entrapment failed due to complete occlusion of the true lumen, and one patient was abandoned because the diameter of the aorta was less than 18 mm and no suitable stent was available.
2.2 Follow-up There was no death in this group during hospitalization. 2 cases were found to have died due to ischemia of the superior mesenteric artery leading to intestinal necrosis and secondary type A entrapment 1 and 3 months after surgery due to unsatisfactory blood pressure control, respectively, and 1 patient had paraplegia due to entrapment of the abdominal aorta with reverse tear 1 year after surgery. 1 patient with thoracic aortic aneurysm breaking into the esophagus died from infection of the aneurysmal cavity 1 month after surgery. Patients with blockage of the left subclavian artery had varying degrees of postoperative decreased skin temperature in the left upper extremity without functional impairment or ischemic pain in the upper extremity.
One case developed dizziness due to blood-stealing syndrome, and the dizziness improved after 3 months of reexamination.
3. Discussion
3.1 Selection and preparation of surgical timing for aortic coarctation:
Aortic coarctation has an acute onset, there is inflammatory edema in the aortic wall during the acute phase, the scope of the coarctation is still in a state of change, and the edematous and fragile vessel wall can hardly withstand the support of the stent-type artificial vessel, which can easily lead to the tearing of the coarctation or the appearance of a new rupture. However, some scholars both at home and abroad believe that treatment in the acute stage does not pose additional risks.
The author still adopts blood pressure control and analgesic treatment for patients with Stanford B type aortic coarctation in the acute stage, and then performs endoluminal isolation after 2 to 3 weeks. However, for patients with ischemia of important organ vessels or lower limb arteries, and patients with a precursor of rupture of the coarctation due to life-threatening conditions, emergency endoluminal isolation is performed. One patient in our group had acute renal failure at the time of admission, so emergency endoluminal isolation was performed, and renal function was restored after surgery, and the patient recovered well. For thoracic aortic aneurysm, if there is no contraindication to surgery, endoluminal isolation is feasible if the preoperative examination is complete.
However, for patients with ruptured thoracic aortic aneurysms resulting in esophageal fistula, prolonged fasting and anti-infection are important to ensure the success of the procedure.
At the time of admission of thoracic aortic coarctation and aneurysm, CTA or MRI has been performed to clarify the diagnosis, and careful preoperative film reading and measurement is essential for the selection of surgical cases. In the film reading, it is necessary not only to clarify the site of aortic coarctation and aneurysm, the extent of involvement, and the involvement of important internal vessels, but also to determine the diameter of the aorta and the access to the aorta.
Because CTA or MRI sometimes only examines the thoracoabdominal aorta, iliac artery stenosis is often overlooked by some physicians. In contrast, stenosis of the iliofemoral artery, if not detected preoperatively, can tear the intima of the iliac artery during intraoperative delivery or retraction of the stent delivery device resulting in lower extremity ischemia.
3.2 How to enlarge the anchorage zone
When endoluminal isolation techniques were applied to dilated thoracic aortic disease in the 1990s, Nienaber et al proposed that the distance between the proximal laceration or aortic aneurysm and the opening of the left subclavian artery should be greater than 1.0-1.5 cm. After more than a decade of development, various new methods and techniques such as closure of the left subclavian artery, hybridization procedures, and branching overlapping stents have been applied to endoluminal isolation, allowing the The scope of the anchoring zone has been expanded, increasing the application of endoluminal isolation.
In our group, 24 cases of aortic coarctation had the left subclavian artery closed, and the skin temperature of the left upper limb was reduced, and the symptoms were all relieved to different degrees after 3 months of follow-up. In the author’s opinion, if the left vertebral artery is clearly defined as the dominant artery before surgery and the systolic pressure of the left subclavian artery exceeds 7.98 KPa after closure, no serious ischemic symptoms will occur after surgery. The hybridization technique refers to the prior right common carotid artery-left common carotid artery-left subclavian artery bypass, proximal ligation of the left common carotid artery and left subclavian artery prior to intracavitary isolation.
This procedure allowed the anchorage area to be extended to the paramedian artery. The involvement of the lesion in the left common carotid artery was well resolved. In our group, two cases of thoracic aortic aneurysm and one case of aortic coarctation were treated with hybridization procedure with good results. Branched overlapping stents are just entering the clinic in China and are not yet technically mature, and only a few cases have been reported now.
3.3 Management of endoleaks
Because the overlapping stent is 10%-20% larger than the diameter of the aorta, plus some patients have severe aortic sclerosis. After the release of the overlapping stent, it does not fit the wall well, and type I and type II endoleaks often occur. For type I and type II endoleaks, the main clinical approach is to treat them with compliant balloon dilation or re-release Cuff at the endoleak.
Due to the high aortic pressure, the compliant balloon may cause stent displacement during dilation or the edematous and fragile vessel wall may not be able to accept the increased pressure and a new breach may occur. Moreover, in many cases the anchoring zone is already small and there may not be enough distance to release the Cuff again.
To prevent endoleaks the author believes that.
①, the diameter of the aorta should be carefully measured preoperatively and intraoperatively to select a good size stent for release;
②, patients with small endoleaks can be left untreated and reviewed regularly after surgery. Most of the endoleaks will disappear within 3 months after surgery;
(③, those with larger leaks must be treated with compliant balloon dilation or re-release Cuff. In this group, 36 cases of type I endoleaks and 1 case of type II endoleaks occurred, and only 6 cases were treated with compliant balloon dilation and 2 cases with Cuff placement at the front of the stent.
Although endoluminal isolation closes the primary rupture of aortic coarctation, secondary ruptures will be formed next to important visceral arteries during the tearing process of aortic coarctation, and how to deal with secondary ruptures has become a clinical problem. It is believed that with the development of endoluminal technology, these problems will also be well solved.