Bengt Lindblad

Endovascular repair of descending thoracic aortic aneurysms: an early experience with intermediate-term follow-up

PURPOSE The purpose of this study was to report an initial experience with the endovascular repair of descending thoracic aortic aneurysm. Complications and intermediate-term morphologic changes were identified with the intent of altering patient selection and device design. METHODS Endografts were placed into 25 patients at high-risk for conventional surgical repair over a 3(1/2)-year period. Devices were customized on the basis of preoperative imaging information. Follow-up computed tomography scans were obtained at 1, 3, 6, and 12 months and yearly thereafter. Additional interventions occurred in the setting of endoleaks, migration, and aneurysm growth. RESULTS The overall 30-day mortality rate was 20% (12.5% for elective cases; 33% for emergent cases). There were 3 conversions to open repair. Neurologic deficits developed in 3 patients; 1 insult resulted in permanent paraplegia. Neurologic deficits were associated with longer endografts (P =.019). Three endoleaks required treatment, and 1 fatal rupture of the thoracic aneurysm treated occurred 6 months after the initial repair. Migrations were detected in 4 patients. The maximal aneurysm size decreased yearly by 9.15% (P =.01) or by 13.5% (P =.0005) if patients with endoleaks (n = 3 patients) were excluded. Both the proximal and distal neck dilated slightly over the course of follow-up (P =.019 and P =.001, respectively). The length of the proximal neck was a significant predictor of the risk for endoleakage (P =.02). CONCLUSION The treatment of descending thoracic aortic aneurysms with an endovascular approach is feasible and may, in some patients, offer the best means of therapy. Early complications were primarily related to device design and patient selection. All aneurysms without endoleaks decreased in size after treatment. Late complications were associated with changing aneurysm morphologic features and device migration. The morphologic changes remain somewhat unpredictable; however, alterations in device design may result in improved fixation and more durable aneurysm exclusion.

Femoropopliteal-crural graft patency is improved by an intensive surveillance program: A prospective randomized study

PURPOSE The purpose of this study was to evaluate whether intensive surveillance compared with routine follow-up examinations improves femoropopliteal/crural graft patency. METHODS After operation the patients were randomized to intensive (n = 79) or routine surveillance (n = 77). The groups were matched with regard to sex, diabetes, indication for surgical procedure, surgical procedure, and graft material. Intensive surveillance was clinical examination, ankle/brachial index measurements, and duplex scans 1, 3, 6, 9, 12, 15, 18, 21, 24, and 36 months after operation. Routine surveillance was clinical examination and ankle/brachial index measurements without duplex scanning 1, 12, 24, and 36 months after operation. Grafts with a decrease in ankle/brachial index of more than 0.15 compared with the initial postoperative ankle/brachial index or a duplex scan showing a graft or anastomotic stenosis of more than 50% underwent angiography and if necessary, a revision or repeat procedure. Occluded grafts were reopened with thrombectomy or thrombolysis or were replaced with a new graft. RESULTS Assisted primary cumulative vein graft patency in the intensive group (n = 56) compared with that in the routine surveillance group (n = 50) after 3 years was 78% versus 53% (chi square analysis, 4.51; one degree of freedom; p < 0.05). Secondary patency was 82% versus 56% (chi square analysis, 5.62; one degree of freedom; p < 0.05). Assisted primary cumulative e-polytetrafluoroethylene and composite graft patency after 1 year in the intensive group (n = 23) compared with that of the routine surveillance group (n = 20) was 57% vs 50% (chi square analysis, 2.17; one degree of freedom; p > 0.1). Secondary patency was 67% vs 54% (chi square analysis, 1.85; one degree of freedom; p > 0.1). Revisions were made on 14 patent and 10 thrombosed grafts in the intensive group and on four patent and 15 thrombosed grafts in the routine surveillance group. All except eight were made during the first postoperative year. CONCLUSIONS Intensive surveillance identified failing vein grafts leading to a significantly higher cumulative assisted primary and secondary patency compared with cumulative assisted primary and secondary patency after routine follow-up examination. The patency of e-polytetrafluoroethylene and composite grafts was not influenced by intensive surveillance.

Endovascular AAA Exclusion: Will Stents with Hooks and Barbs Prevent Stent-Graft Migration?

PURPOSE To investigate if stents with hooks and barbs will improve stent-graft fixation in the abdominal aorta. METHODS Sixteen- to 24-mm-diameter Dacron grafts were deployed inside cadaveric aortas. The grafts were anchored by stents as in endovascular abdominal aortic aneurysm repair. One hundred thirty-seven stent-graft deployments were carried out with modified self-expanding Z-stents with (A) no hooks and barbs (n = 75), (B) 4 5-mm-long hooks and barbs (n = 39), (C) 8 10-mm-long, strengthened hooks and barbs (n = 19), or (D) hooks only (n = 4). Increasing longitudinal traction was applied to determine the displacement force needed to extract the stent-grafts. The radial force of the stents was measured and correlated to the displacement force. RESULTS The median (interquartile range) displacement force needed to extract grafts anchored by stent A was 2.5 N (2.0 to 3.4), stent B 7.8 N (7.4 to 10.8), and stent C 22.5 N (17.1 to 27.9), p < 0.001. Both hooks and barbs added anchoring strength. During traction, the weaker barbs were distorted or caused intimal tears. The stronger barbs engaged the entire aortic wall. The radial force of the stents had no impact on fixation, while aortic calcification and graft oversizing had marginal effects. CONCLUSIONS Stent barbs and hooks increased the fixation of stent-grafts tenfold, while the radial force of stents had no impact. These data may prove important in future endograft development to prevent stent-graft migration after aneurysm exclusion.

Distal Migration of Stent-Grafts after Endovascular Repair of Abdominal Aortic Aneurysms

PURPOSE To analyze patients after endovascular repair of abdominal aortic aneurysm (AAA) with respect to distal migration of stent-grafts and its underlying causes. MATERIALS AND METHODS Sixty-five patients underwent endovascular repair between January 1994 and February 1997. There were seven women and 58 men, with a mean age of 71 years (range, 51-84 years). Three patients died in the perioperative period (one of myocardial infarction and two of multiorgan failure) and two patients died within 4 months of the procedure of non-procedure-related causes. In addition, two patients were followed at another hospital. The remaining 58 patients were followed up with spiral computed tomography scans at 1, 3, and 6 months, and biannually thereafter. Angiography was performed at 1 month and 1 year after the procedure and additionally when deemed clinically necessary. Mean follow-up was 29 months (range, 1-49). Migration more than 5 mm was considered significant. RESULTS Twenty-six patients (45%) showed distal migration of stent-grafts during follow-up. Mean follow-up time at detection of migration was 13 months (range, 1-36 months). Thirteen cases of migration were ascribed to dilatation of the proximal aneurysmal neck during follow-up. Ten cases of migration were ascribed to causes other than neck dilatation or poor patient selection. In three cases, no obvious cause for the migration was found. The migration was complete in eight cases, leading to late conversion to open surgical repair. On two of these occasions, complete migration lead to aneurysm rupture. In addition, four patients received additional stent-grafts as proximal extensions. CONCLUSIONS Distal migration of stent-grafts after endovascular AAA repair occurred frequently in this series. Dilatation of the proximal aneurysmal neck is a major cause of distal migration of stent-grafts. Improved proximal fixation is needed to secure long-term durability.

Persistent collateral perfusion of abdominal aortic aneurysm after endovascular repair does not lead to progressive change in aneurysm diameter

PURPOSE To differentiate between the phenomenon of collateral perfusion from a side branch versus graft-related endoleaks after endovascular repair of abdominal aortic aneurysms (AAA), with respect to aneurysm size and prognosis. METHODS We successfully treated 64 AAA patients with endovascular grafting. We followed all the patients postoperatively with spiral computed tomography at one, three, six and 12 months, and biannually thereafter. We measured aneurysm diameters preoperatively and postoperatively. We calculated preoperatively the relation of maximum aortic diameter (D) to the thrombus-free lumen diameter (L) expressed as an L/D ratio. Median follow-up was 15 months. RESULTS Sixteen patients had collateral perfusion during follow-up. We successfully treated two patients with embolization. One patient showed resolution of collateral perfusion after we stopped warfarin treatment. Two patients died of unrelated causes during follow-up. One patient was converted to surgical treatment, and two patients showed spontaneous resolution of their collateral perfusion. The group of patients with perfusion showed no statistically significant change of their aortic diameter on follow-up. The group of patients without perfusion showed a median decrease in aortic diameter of 8mm (p < 0.0001) at 18 months postoperatively. The group of patients with perfusion had significantly less thrombus in their aneurysm sac preoperatively than the group without perfusion, as expressed by the L/D ratio (mean L/D 0,61 versus 0,78, respectively; p=0.0021.) CONCLUSION There was no significant increase in aortic diameter on an average 18 months postoperatively despite persistent collateral perfusion. This may indicate a halted disease progression in the short term. Embolization of collateral vessels is associated with risk of paraplegia. We recommend a conservative approach with close observation if aneurysm diameter is stable.

Reduced pulsatile wall motion of abdominal aortic aneurysms after endovascular repair

PURPOSE The reduced size of abdominal aortic aneurysms (AAAs) after endovascular repair suggests lowered intraaneurysmal pressure. In the presence of endoleaks, the size is not decreased. Although postoperative intraaneurysmal pressure is difficult to record, the pulsatile wall motion (PWM) of aneurysms can be measured noninvasively. The aim of this study was to assess the PWM of AAAs before and after endovascular repair and to relate the change in the PWM to aneurysmal size and presence of endoleaks. METHODS Forty-seven patients underwent endovascular repair of an AAA. The aneurysm diameter and PWM were measured with the use of ultrasonic echo-tracking scans preoperatively; at 1, 3, and 6 months; and thereafter biannually. Fifteen aneurysms developed endoleaks, whereas 32 were completely excluded. The leaks were characterized with the use of computed tomographic scanning and angiography. Median follow-up was 12 months (interquartile range, 5 to 24 months). RESULTS The preoperative PWM of the aneurysms was 1.0 mm (range, 0.8 to 1.3 mm). After complete endovascular exclusion, the PWM was 25% (range, 16% to 37%) of the preoperative value (p < 0.001), and aneurysm diameter decreased by 8 mm (range, 6 to 14 mm) (p < 0.001). After 18 months, no further diameter reduction occurred. In three patients without endoleaks but with enlarging aneurysms, the postoperative PWM showed less reduction (p < 0.05). Aneurysms with endoleaks showed no diameter decrease, and the postoperative PWM was 50% higher than that in the totally excluded cases (p < 0.01). In five patients with transient endoleaks, the PWM was reduced after leakage ceased (p < 0.05). Leaks of various sources displayed similar PWM. CONCLUSION The size and PWM of aneurysms are reduced after endovascular repair. The diameter reduction may cease after 1.5 years. Endoleaks are associated with higher PWM than expected. Pressure may be transmitted without evidence of leaks.

A1C in children and adolescents with diabetes in relation to certain clinical parameters. The Swedish Childhood Diabetes Registry, SWEDIABKIDS

OBJECTIVE—We explored the relationship between A1C and insulin regimen, duration of diabetes, age, sex, and BMI as well as the differences between clinical mean A1C levels at pediatric diabetes clinics in Sweden. RESEARCH DESIGN AND METHODS—Data from 18,651 clinical outpatient visits (1,033 girls and 1,147 boys) at 20 pediatric clinics during 2001 and 2002 registered in the Swedish Childhood Diabetes Registry SWEDIABKIDS, a national quality registry, were analyzed. RESULTS—A1C was <7.0% (target value ∼8% per Diabetes Control and Complications Trial/National Glycohemoglobin Standardization Program standards) at 35% of the visits. Girls had significantly higher mean A1C than boys during adolescence. High mean A1C was correlated with high mean insulin dose, long duration of diabetes, and older age. Mean A1C varied between clinics (6.8–8.2%). Differences between centers could not be explained by differences in diabetes duration, age, BMI, or insulin dose. CONCLUSIONS—Adolescents with a high insulin dose and a long duration of diabetes, especially girls, need to be focused on. Differences in mean values between centers remained inexplicable and require further investigation.

Abdominal aortic aneurysm with perianeurysmal fibrosis: Experience from 11 Swedish vascular centers ☆ ☆☆

Case records of 2026 patients operated on because of abdominal aortic aneurysms from 11 Swedish Vascular Centers were reviewed and revealed 98 cases (4.8%) of inflammatory abdominal aortic aneurysm. Also included in this case-control study was an analysis of a randomized group of 82 patients from the same centers who had noninflammatory abdominal aortic aneurysms. Four inflammatory aneurysms were ruptured, compared with 16 in the noninflammatory group (p less than 0.01). A higher proportion of patients with inflammatory abdominal aortic aneurysms had symptoms that led to radiographic investigations. The median erythrocyte sedimentation rate was 39 mm versus 19 mm (26% of patients with inflammatory abdominal aortic aneurysms had erythrocyte sedimentation rates greater than 50 mm; p less than 0.001), and the serum creatinine level was increased in 27 and 8 patients (p less than 0.01) in the inflammatory and noninflammatory groups, respectively. Preoperative investigations revealed ureteral obstruction in 19 patients with inflammatory abdominal aortic aneurysms, of whom 12 had preoperative nephrostomy or ureteral catheter placement. At operation, 20 additional patients exhibited fibrosis around one or both ureters. Although ureterolysis was performed in 19 patients, preoperative and postoperative creatinine levels did not differ between these patients and the conservatively treated ones. Duration of surgery (215 vs 218 minutes), intraoperative blood loss (2085 vs 2400 ml) and complications did not differ significantly between the groups. Overall operative (30-day) mortality was equal (11% vs 12%) but was increased for patients undergoing elective surgery for inflammatory abdominal aortic aneurysms (9% vs 0%; p = 0.03).(ABSTRACT TRUNCATED AT 250 WORDS)

A 2-yr national population study of pediatric ketoacidosis in Sweden: predisposing conditions and insulin pump use

Abstract:  The aim was to investigate triggering factors and insulin pump usage (continuous subcutaneous insulin infusion, CSII) at diabetic ketoacidosis (DKA). Data from 1999 and 2000 were collected retrospectively from Sweden. In 1999 and 2000, 7.4 and 11.0%, respectively, of children with diabetes used CSII. One hundred and forty‐two episodes of DKA (pH < 7.30) were identified in 115 children (DKA at onset not included). Their hemoglobin A1c (HbA1c) was 10.1 ± 2.0%, age 14.6 ± 3.1 yr (range 1.5–19.9 yr), and diabetes duration 6.6 ± 3.5 yr (range 0.4–17.7 yr). Fourteen persons (seven girls) had more than one episode of DKA. Reported causes of DKA were missed insulin doses (48.6%), gastroenteritis (14.1%), technical pump problems (12.7%), infection (13.4%), social problems (1.4%), unknown (5.6%), and not stated (4.2%). Alcohol was involved in eight episodes and drugs in one. Thirty of 115 patients (19 girls) used insulin pumps. The overall DKA incidence was 1.4/100 patient years in 1999 and 1.7/100 patient years in 2000. For insulin pump users, the DKA incidence was 3.2/100 patient years in 1999 and 3.6/100 patient years in 2000. HbA1c at DKA admission was lower for CSII users than patients who used injections (9.1 ± 1.5 vs. 10.8 ± 2.2%, p < 0.01), but pH and age did not differ. CSII had been used for 6 months (median) before the DKA episode. In conclusion, the DKA frequency in CSII users was approximately twice that of patients who used injections. Seventy‐seven percent of the episodes occurred within 1 yr after CSII start. The high number of events reported to be caused by gastroenteritis is alarming because this may reflect a misinterpretation of DKA symptoms.

Reduced Prevalence of Diabetic Ketoacidosis at Diagnosis of Type 1 Diabetes in Young Children Participating in Longitudinal Follow-Up

OBJECTIVE Young children have an unacceptably high prevalence of diabetic ketoacidosis (DKA) at the clinical diagnosis of type 1 diabetes. The aim of this study was to determine whether knowledge of genetic risk and close follow-up for development of islet autoantibodies through participation in The Environmental Determinants of Diabetes in the Young (TEDDY) study results in lower prevalence of DKA at diabetes onset in children aged <2 and <5 years compared with population-based incidence studies and registries. RESEARCH DESIGN AND METHODS Symptoms and laboratory data collected on TEDDY participants diagnosed with type 1 diabetes between 2004 and 2010 were compared with data collected during the similar periods from studies and registries in all TEDDY-participating countries (U.S., SEARCH for Diabetes in Youth Study; Sweden, Swediabkids; Finland, Finnish Pediatric Diabetes Register; and Germany, Diabetes Patienten Verlaufsdokumenation [DPV] Register). RESULTS A total of 40 children younger than age 2 years and 79 children younger than age 5 years were diagnosed with type 1 diabetes in TEDDY as of December 2010. In children <2 years of age at onset, DKA prevalence in TEDDY participants was significantly lower than in all comparative registries (German DPV Register, P < 0.0001; Swediabkids, P = 0.02; SEARCH, P < 0.0001; Finnish Register, P < 0.0001). The prevalence of DKA in TEDDY children diagnosed at <5 years of age (13.1%) was significantly lower compared with SEARCH (36.4%) (P < 0.0001) and the German DPV Register (32.2%) (P < 0.0001) but not compared with Swediabkids or the Finnish Register. CONCLUSIONS Participation in the TEDDY study is associated with reduced risk of DKA at diagnosis of type 1 diabetes in young children.