Zhihui Dong

Stent graft-induced new entry after endovascular repair for Stanford type B aortic dissection.

BACKGROUND Stent graft-induced new entry (SINE), defined as the new tear caused by the stent graft and excluding those arising from natural disease progression or iatrogenic injury from the endovascular manipulation, has been increasingly observed after thoracic endovascular aortic repair (TEVAR) for Stanford type B dissection in our center. SINE appears to be remarkably life threatening. We investigated the incidence, mortality, causes, and preventions of SINE after TEVAR for Stanford type B dissection. METHODS Data for 22 patients with SINE were retrospectively collected and analyzed from 650 patients undergoing TEVAR for type B dissection from August 2000 to June 2008. An additional patient was referred to our center 14 months after TEVAR was performed in another hospital. The potential associations of SINE with Marfan syndrome, location of SINE and endograft placement, and the oversizing rate were analyzed by Fisher exact probability test or t test. RESULTS We found 24 SINE tears in 23 patients, including SINE at the proximal end of the endograft in 15, at the distal end in 7, and at both ends in 1. Six patients died. SINE incidence and mortality reached 3.4% and 26.1%, respectively. Two SINE patients were diagnosed with Marfan syndrome, whereas there were only 6 Marfan patients among the 651 patients. The 16 proximal SINEs were evidenced at the greater curve of the arch and caused retrograde type A dissection. The eight distal SINEs occurred at the dissected flap, and five caused enlarging aneurysm whereas three remained stable. The endograft was placed across the distal aortic arch during the primary TEVAR in all 23 patients. The incidence of SINE was 33.33% among Marfan patients vs 3.26% among non-Marfan patients (P = .016). There was no significant difference in mortality between proximal and distal SINE (25% vs 28.6%, P > .99), incidence of SINE between endograft placement across the arch and at the straight portion of descending thoracic aorta (23 of 613 vs 0 of 38, P = .39), and the oversizing rate between SINE and non-SINE patients (13% ± 4.5% vs 16% ± 6.5%, P = .98). CONCLUSIONS SINE appears not to be rare after TEVAR for type B dissection and is associated with substantial mortality. The stress yielded by the endograft seems to play a predominant role in its occurrence. It is important to take this stress-induced injury into account during both design and placement of the endograft.

Treatment of symptomatic isolated dissection of superior mesenteric artery

OBJECTIVE To present the short- to midterm outcomes after management of 14 patients with symptomatic isolated dissection of superior mesenteric artery (SIDSMA) and propose a preliminary treatment algorithm. BACKGROUND SIDSMA is a rare but potentially fatal entity. However, most of these reports were isolated case reports, and a consensus treatment protocol remains lacking so far. It would be meaningful to propose a reasonable treatment algorithm for it. METHODS Patients with SIDSMA who were treated in our center between July 2007 and June 2011 were retrospectively collected and analyzed. Based upon the abdominal pain and signs, the clinical manifestations have been retrospectively classified into grade I (peritonitis absent) and grade II (peritonitis present). Medical treatment mainly included anticoagulation, antiplatelet, and bowel rest. Endovascular stent placement and surgical fenestration with exploratory laparotomy have been selected according to the grade classification. Computed tomographic angiography, magnetic resonance angiography, or duplex scans have been used for diagnosis and follow-up. RESULTS Fourteen consecutive patients with SIDSMA were collected; among them, 13 cases belonged to grade I and one to grade II. The mean duration from the onset to the admission was 12 ± 12 days (range, 0.5-45 days). The mean distance from the primary tear to the ostium of superior mesenteric artery (SMA) was 26 ± 4 mm (range, 15-32 mm). Medical treatment was given for 13 patients of grade I for the first 3 to 5 days after admission, and the abdominal pain remarkably or completely resolved in four patients who received continued medical treatment, whereas the other unresolved nine patients were converted to endovascular stent placement that succeeded in four and failed in five patients. Since these five cases were free from peritoneal signs, medical treatment was given again instead of an immediate surgical intervention, and ultimately achieved complete alleviation of abdominal pain within the following 1 week. The mean duration from the start of medical treatment to the alleviation of symptoms, including the continued medical treatment after the failed endovascular stent placement, was 8 ± 3 days (range, 4-12 days). The grade II patient underwent a successful emergency surgical SMA fenestration without bowel resection. Follow-up was accomplished in all 14 cases, ranging from 2 to 48 months (mean, 30 ± 15 months). No intestinal necrosis, morbidity, or mortality developed during hospitalization. During the follow-up, all patients were free from aneurysmal formation of SMA or chronic intestinal ischemia, and all stents remained patent. CONCLUSIONS For grade I SIDSMA, most cases might be successfully treated with medical therapy, and the endovascular stent placement appears to be an acceptable alternative if medical treatment fails. For grade II SIDSMA, the endovascular stenting combined with laparoscopic exploration and/or open surgery could be a reasonable option.

Transplantation of purified CD34+ cells in the treatment of critical limb ischemia.

BACKGROUND This study investigated the feasibility, safety, and efficacy of the intramuscular injection of CD34+ cells isolated from peripheral blood mononuclear cells (PB-MNCs) mobilized by granulocyte colony-stimulating factor (G-CSF) for the management of patients with critical limb ischemia (CLI) who were considered unlikely to have successful long-term revascularization with open bypass or endovascular methods. Cell therapy represents a new treatment modality for this subgroup of patients with CLI. To date, bone marrow or PB-MNCs have usually been used for transplantation. The current pilot study investigated whether the transplantation of purified CD34+ cells only would be competent in ischemia relief and limb salvage. METHODS From May 2009 to July 2011, 25 patients (mean age, 44 ± 12 years) were enrolled, and 25 lower extremities and three upper extremities were treated. After subcutaneous administration of G-CSF for 5 days at a dose of 5 to 10 μg/kg, apheresis and immunomagnetic separation were performed to acquire the isolated CD34+ cells, which were then intramuscularly injected into the ischemic sites. The patients were divided into three groups: low-dose, 10(5)/kg; medium-dose, 5 × 10(5)/kg; and high-dose, 10(6)/kg. The overall outcomes among all patients and the comparison among the groups were evaluated. RESULTS During the follow-up of 6 to 33 months, the overall outcomes showed that the Wong-Baker FACES pain rating scale score (WFPRSS) decreased from 7 ± 2 to 3 ± 3 (P < .001) and 1 ± 2 (P < .001) at 1 and 2 months, respectively; at 3 and 6 months, respectively, the peak pain-free walking time increased from 4 ± 3 to 13 ± 7 (P < .001) and 18 ± 6 minutes (P < .001), the ankle-brachial index increased from 0.46 ± 0.21 to 0.60 ± 0.17 (P = .003) and 0.67 ± 0.15 (P = .001), and the transcutaneous partial oxygen pressure increased from 27 ± 10 to 41 ± 11 (P < .001) and 55 ± 12 mm Hg (P < .001). Ulcers were healed in 10 of the 14 patients; four patients required above-knee or below-knee amputation ≤ 3 months. The Kaplan-Meier estimate of the rate of freedom from major amputation at 6 months was 84% (95% confidence interval, 63%-94%). The comparison among the three groups (low-dose, 5; medium-dose, 11; high-dose, 9) revealed no significant difference, except that the WFPRSS improvement at 1 month from baseline in the high-dose group (6.3 ± 1.7) was significantly superior to that in the low-dose (3.2 ± 3.3; P = .0487) and medium-dose (3.7 ± 2.8; P = .0352) groups. CONCLUSIONS Transplantation of CD34+ cells isolated from G-CSF-mobilized PB-MNCs appears to be feasible and safe, showing encouraging outcomes in the treatment of CLI patients who appear to have compromised options for long-term revascularization.

Mesenchymal stem cells attenuate acute ischemia-reperfusion injury in a rat model.

Ischemia-reperfusion injury (IRI) following lung transplantation is associated with increased pulmonary inflammatory responses during reperfusion. Mesenchymal stem cells (MSCs) may be able to modulate inflammatory responses in IRI. The aim of the present study was to evaluate the beneficial effects of an intravenous infusion of bone marrow-derived MSCs (BMSCs) in a rat model of pulmonary IRI. IRI was induced in male Lewis rats by 1-h ischemia followed by 2-h reperfusion. The rats received phosphate-buffered saline (PBS) or BMSC infusion at the onset of reperfusion. Pulmonary injury was determined based on the mean blood oxygenation, lung edema and vascular permeability, and performing histopathological examination. Pulmonary inflammation was also evaluated through the examination of the levels of inflammatory cytokines. Compared with the PBS infusion, the BMSC infusion significantly preserved lung function, reduced lung edema and pulmonary microvascular permeability, and decreased the total injury score in rats with IRI. The mRNA levels of the pro-inflammatory cytokines, tumor necrosis factor-α (TNF-α), interleukin (IL)-1β and IL-6, were significantly reduced, while the expression of anti-inflammatory cytokine IL-10 was increased in the rats receiving BMSC infusion. The levels of cytokine-induced neutrophil chemoattractant-1, IL-1β, and TNF-α in bronchoalveolar lavage fluid were also markedly reduced following BMCS infusion. In conclusion, the present results suggested that BMSC infusion exerts protective effects against pulmonary IRI by alleviating IRI-induced inflammation. These findings provide experimental evidence for the treatment of pulmonary IRI using BMSC cell therapy.

Strategies for endovascular treatment of complicated splenic artery aneurysms

Objective Endovascular treatment (ET) is being increasingly used for splenic artery aneurysms (SAAs), but systematic treatment strategies have not been defined. We set out to investigate the optimal strategies for ET of complicated SAAs (CSAAs). Methods CSAAs were classified into three types: type I, rupture or impending rupture; type II, at the origin of the splenic artery; and type III, having an aberrant splenic artery from the splenomesenteric trunk (type IIIA) or celiacomesenteric trunk (type IIIB). SAAs treated at our center during the last decade were reviewed, and CSAAs were selected for analysis. Patients’ demographics, clinical manifestations, aneurysm characteristics, ET strategies, and outcomes were analyzed. Results A total of 154 SAAs were identified, with 24 (15.6%) being CSAAs. Open surgery was employed in two patients, whereas 22 patients underwent ET. There were 3 patients with type I (type IIIA co‐occurred in one of them), 5 with type II, and 15 with type III CSAAs. Treatment strategies included the following: immediate and thorough exclusion with embolization of the collaterals for type I; and dense embolization of the sac and outflow artery, with or without embolization of the inflow artery, or covered stent placement in the splenomesenteric trunk or celiacomesenteric, for types II and III. Technical success was achieved in 21 patients (95.5%). Mean follow‐up was 33.7 ± 31.2 months (range, 1.5‐117.0 months). The aneurysms remained completely thrombosed and unenlarged in 21 patients (95.5%). Reintervention was needed in one patient (4.5%) for persistent sac enlargement. The covered stent was asymptomatically occluded in one patient (11.1%). No hepatic or intestinal ischemia or death developed perioperatively or during the follow‐up period. Conclusions With reasonable strategies toward the urgency and thoroughness needed for aneurysm exclusion as well as the anatomic challenges, ET appeared to be feasible, safe, and effective in the management of CSAAs. Graphical abstract Figure. No caption available.

Outcomes and aortic remodelling after proximal thoracic endovascular aortic repair of post type B aortic dissection thoracic aneurysm.

BACKGROUND The objective was to explore the outcomes and aortic remodelling after proximal thoracic endovascular aortic repair (TEVAR) in post type B aortic dissection thoracic aneurysm with a maximal diameter ≥ 5.5cm. PATIENTS AND METHODS 34 cases of type B aortic dissection thoracic aneurysm undergoing proximal TEVAR (coverage of the primary entry and the aneurysm extent) from 2008 to 2013 were retrospectively reviewed with follow-up for at least 2 years. The primary endpoints were 30-day mortality and survival at 2 years. The secondary endpoints were major complication and re-intervention. The aortic remodelling was investigated by comparison of the maximum diameter of the aneurysm and the diameter of true and false lumen at the same level between baseline and 2 years after TEVAR. Besides, we also analysed the possible relevant factors of aortic remodelling including the course of dissection, the involvement of dissection, and the length and shape of the stent graft. RESULTS The 30 day mortality was 2.9 % (1/34). The paraplegia rate post-TEVAR was 2.9 % (1/34). Overall, 32 out of the 34 cases were followed-up for 24 - 79 months. At 2 years, the overall and aortic specific survival were 87.5 % and 90.3 % respectively. The two year freedom from re-intervention rate was 87.5 %. Compared to the preoperative data, maximum diameter of descending aorta at 2 years demonstrated a slight increase (65.4±14.1mm Vs 63.9±9.1mm), but without significance (P>0.05). Meanwhile, we noticed a significant increase of true lumen (P < 0.01) and decrease of false lumen (P < 0.01) at the same level. Relevant analysis showed that positive aortic remodelling of the maximum diameter was associated with chronic phase (≥ 90 days of dissection onset) (P < 0.05) and the application of 150 - 170mm stent grafts (P < 0.05). CONCLUSIONS Proximal TEVAR of post type B dissection thoracic aneurysm had generally favourable short- and mid-term outcomes with low paraplegia rate. Besides, it can achieve a certain extent of aortic remodelling.

A Five‐Year Study of the Efficacy of Purified CD34+ Cell Therapy for Angiitis‐Induced No‐Option Critical Limb Ischemia

Angiitis‐induced critical limb ischemia (AICLI) patients constitute a remarkable proportion of no‐option critical limb ischemia (CLI) patients. Stem cell therapy has become an innovative and promising option for no‐option CLI patients. As one of these promising stem cell therapies, purified CD34+ cell transplantation (PuCeT) has shown favorable short‐term results. However, the long‐term efficacy of PuCeT has yet to be reported. This study evaluates the long‐term efficacy of PuCeT in AICLI patients. Twenty‐seven AICLI patients were enrolled from May 2009 to December 2011. Granulocyte colony‐stimulating factor (G‐CSF) and enoxaparin sodium were administered for 5 days. On day 5, CD34+ cell isolation was performed, and cells were transplanted by intramuscular injection. The primary endpoint, major‐amputation‐free survival rate (MAFS), as well as secondary endpoints, such as peak pain‐free walking time (PPFWT) and the Wong‐Baker FACES pain rating scale score (WFPRSS), were routinely evaluated during the 5‐year follow‐up period. The endpoints were as follows: the MAFS was 88.89%; PPFWT increased from 3 ± 3 to 17 ± 6 minutes; WFPRSS decreased from 7 ± 2 to 0.3 ± 1.7; the ulcer healing rate was 85.71%; the recurrence rate was 11.11%; and SF‐36v2 scores were significantly improved at 5 years after PuCeT. The rate of labor recovery 5 years after PuCeT was 65.38%, and no severe adverse effect was observed during the treatment. PuCeT demonstrated long‐term efficacy and durability as a treatment of AICLI not only in achieving limb salvage but also in recovering the labor competence and improving the quality of life of patients. Stem Cells Translational Medicine 2018;7:583–590

High Wall Stress May Predict the Formation of Stent-Graft–Induced New Entries After Thoracic Endovascular Aortic Repair

Purpose: To explore the potential role of morphological factors and wall stress in the formation of stent-graft–induced new entries (SINE) based on computed tomography (CT) images after thoracic endovascular aortic repair (TEVAR). Case Report: Two female patients aged 59 years (patient 1) and 44 years (patient 2) underwent TEVAR for type B dissection in the chronic (patient 1) or subacute (patient 2) phase. CT scans at 3-month follow-up showed varying degrees of false lumen thrombosis in both patients. At 14-month follow-up, a SINE was observed in patient 1 while the dissected aorta in the other patient remained stable. Morphological and finite element analyses were performed based on the first follow-up CT images. The computational results showed that the SINE patient had higher stent-graft tortuosity than the non-SINE patient and much higher wall stress in the region close to the distal SINE. Conclusion: This case study suggests that high stent-graft tortuosity can lead to high wall stress, which is potentially linked to the formation of SINE. Further large population-based studies are needed to confirm this preliminary finding.

Endovascular treatment for imminent rupture of a giant aberrant splenic aneurysm

A 64-year-old man was admitted to our hospital for a 1-day history of severe flank pain. On examination, a pulsatile mass with high tension and slight tenderness was palpated below the xiphoid. He underwent renal transplantation 17 years ago and has been taking immunosuppressant drugs since then. Renal function was normal. Computed tomography angiography showed a 10-cm aneurysm at the origin of the splenic artery (SA) arising from the superior mesenteric artery (SMA), and there was almost no proximal aneurysm neck (A). Given the invasion and higher potential risk for infection of open surgery and imminent rupture of the aneurysm, emergency endovascular treatment was selected. Through a right femoral approach, selective SMA angiography demonstrated a 10 10cm aneurysm of the SA originating from the proximal SMA (B). A 9 F sheath was placed into the SMA through the left brachial artery. A shaped 5F pigtail catheter (half of its tip curve was cut) was advanced into the distal outlet of the SA aneurysm; a microcatheter was then introduced into the distal SA. Two control embolization coils (Interlock, 10 mm 30 cm; Boston Scientific, Marlborough, Mass) and four microcoils were placed into the SA distal to the aneurysm. Angiography showed much slower flow into the distal SA. After that, a covered stent (Viabahn, 9 50 mm; W. L. Gore & Associates, Flagstaff, Ariz) was deployed from the origin of the SMA to its first large branch, excluding the orifice of the SA. Completion angiography evidenced satisfactory exclusion of the aneurysm and patency of the SMA (C). The pulsatility of the aneurysm was decreased and flank pain was significantly relieved the day after the operation. The patient’s postoperative course was uneventful, and he was prescribed oral warfarin. Computed tomography angiography at 3 months showed complete aneurysmal thrombosis and patency of the SMA (D). Informed consent was obtained from the patient for publication.

Endovascular treatment of acute and chronic isolated abdominal aortic dissection

Objective To discuss the strategies and clinical outcomes of endovascular aortic repair (EVAR) for acute and chronic isolated abdominal aortic dissection (IAAD). Methods From January 2012 to June 2017, 33 patients with IAAD were retrospectively reviewed. Patients were classified into acute and chronic groups based on the time to EVAR from IAAD onset (acute: ≤90 days; chronic: >90 days). Patient demographics, clinical parameters, procedural factors, and clinical outcomes were evaluated and compared between the two groups. Results Among 33 patients, 21 were diagnosed with acute IAAD and 12 were diagnosed with chronic IAAD. All patients underwent EVAR, and no significant difference in EVAR-related procedural factors was observed between the two groups. The primary technical success rate in all patients was 100%. The overall survival rate in the chronic group was lower than that in the acute group, but the difference was not statistically significant (P = 0.186). However, the reintervention-free survival rate in the chronic group was significantly lower than that in the acute group (P = 0.039). Significant enlargement of the true lumen (TL) and regression of the false lumen (FL) and maximal aortic diameter were observed in all patients after EVAR (P < 0.05). The mean diameter of the TL in the acute group increased significantly more than that in the chronic group (14 ± 3 mm vs. 11 ± 3 mm, P = 0.040). A significant difference was not observed in the regression of the FL (P = 0.628) or maximal aortic diameter (P = 0.319) between the two groups. Conclusion EVAR continues to be a safe therapeutic approach with a high technical success rate and favorable clinical outcomes. The clinical outcomes and aortic remodeling in the chronic group seem to be poorer than those in the acute group.