Percutaneous endovascular delivery of calcium chloride to the intact porcine carotid artery: A novel animal model of arterial calcification

OBJECTIVE

The present study evaluated the effect of endovascular administration of calcium chloride to the carotid artery of swines, to create a model of arterial calcification.

METHODS

Fifteen Large White pigs were used for the study. Via endovascular treatment, carotid arteries were exposed during 9 min to either calcium chloride (experimental artery) or saline (control artery) with the use of the TAPAS catheter. Intravascular ultrasound (IVUS) imaging was obtained at baseline, postprocedure and at 30 days. Optical coherence tomography (OCT) imaging was obtained in vitro after carotids were harvested. Longitudinally cut parallel arterial segments were placed in a system of delicate clamps and underwent uniaxial strain test. All arteries underwent histopathological examination.

RESULTS

Calcium chloride treated segments showed extensive circumferential parietal calcification evident on both IVUS and OCT. Reduction in minimal lumen area on IVUS was evident in experimental arteries both at 24 hr and 30 days postprocedure. Histopathologic assessment (Von Kossa stain) confirmed medial calcification with mild intimal thickening. Biomechanical testing showed treated segments to have smaller breaking strength and less elastic deformation than controls.

CONCLUSION

We developed a nonexpensive, reproducible model of early carotid medial calcification in pigs. Our model has the potential to help the development of research to unravel mechanisms underlying arterial calcification, the use of current or new devices to treat calcified lesions as well as to serve as an option for training interventionalists on the use of such devices.

Inner tubing technique used for the treatment of anastomotic aneurism

The authors report the case of a 66-year-old male patient diagnosed with a pseudoaneurysm of the distal aorto-aortic anastomosis treated with the inner tubing technique. The patient had been operated on 1 year before when he had an aortic prosthesis implanted as treatment for a ruptured abdominal aortic aneurysm. The inner tubing technique was developed to facilitate the treatment in bifurcated vascular lesions, where endovascular conventional prosthesis is not available.

Feeding tube replacement: not always that simple!

Although surgical gastrostomy is not a technically troublesome surgery, the procedure may be accompanied by unfavorable outcomes. Most complications occur early in the post-operative period and include feeding tube dislodgment, stomal infection, peritonitis, and pneumonia. The authors report the case of an 83-year-old man who underwent a surgical gastrostomy because of a swallowing disorder after an ischemic stroke. Nine months after the procedure, the feeding tube dislodged and a new tube was inserted with a certain delay and with some difficulty, causing a false path and consequently an intrabdominal abscess after diet infusion. The outcome was fatal. The authors call attention for meticulous care with the insertion of feeding tubes and advise the performance of imaging control to assure its precise positioning.

Endovascular model of abdominal aortic aneurysm induction in swine

Abdominal aortic aneurysms are among the main causes of death. The high morbidity and mortality associated with aneurysm rupture and repair represents a challenge for surgeons and high risk for patients. Although experimental models are useful to understand, train, and develop new treatment and diagnostic methods for this pathology, animal models developed to date are far from ideal. Animals are either too small and do not represent the pathology of humans, or the procedures employ laparotomy, or the aortic behavior does not resemble that of a true aneurysm. We developed a novel, less invasive and effective method to induce true aortic aneurysms in Large White pigs. Animals were submitted to an endovascular chemical induction using either calcium chloride (25%) or swine pancreatic elastase. Controls were exposed to saline solution. All animals were operated on using the same surgical technique under general anesthesia. They were followed weekly with ultrasound examinations and at 4 weeks the aorta was harvested. Although elastase induced only arterial dilation, imaging, histological, and biomechanical studies of the aorta revealed the formation of true aneurysms in animals exposed to calcium chloride. Aneurysms in the latter group had biomechanical failure properties similar to those of human aneurysms. These findings indicate that the endovascular approach is viable and does not cause retroperitoneal fibrosis.

Endovascular management of massive pulmonary embolism with clot fragmentation and suction

Massive pulmonary embolism with right ventricular dysfunction may be treated with thrombolysis, embolectomy, or percutaneous mechanical thrombectomy. This study describes our experience with two patients that had massive pulmonary embolism and were treated with percutaneous mechanical thrombectomy and reports on the mid-term results of this procedure. A 28-year-old man and a 70-year-old woman were diagnosed with deep venous thrombosis and massive pulmonary embolism. They first had lower limb edema followed by sudden onset of dyspnea. Their physical examination revealed edema, tachypnea, chest discomfort and jugular turgescence. Both needed to receive oxygen using a nasal cannula. Doppler ultrasound, echocardiography, and computed tomography angiography were used to establish the diagnoses. Patients underwent percutaneous mechanical thrombectomy using the Aspirex® system (Straub Medical), and their clinical condition and imaging study findings improved substantially. At mid-term follow-up, patient conditions were improving satisfactorily.

Inner tubing endograft: a new technique for bifurcation preservation

Treating narrow arteries and their bifurcations is a major challenge to the endovascular surgeon. We describe a new endovascular technique that was used to treat a narrow aorta and that may also be used to preserve other bifurcations. Using three straight stents may enable the endovascular surgeon to treat bifurcation while maintaining flow to both distal arteries.

Attempted establishment of proficiency levels for laparoscopic performance on a national scale using simulation: the results from the 2004 SAGES Minimally Invasive Surgical Trainer—Virtual Reality (MIST-VR) learning center study

BACKGROUND

The Minimally Invasive Surgical Trainer-Virtual Reality (MIST-VR) has been well validated as a training device for laparoscopic skills. It has been demonstrated that training to a level of proficiency on the simulator significantly improves operating room performance of laparoscopic cholecystectomy. The purpose of this project was to obtain a national standard of proficiency using the MIST-VR based on the performance of experienced laparoscopic surgeons.

METHODS

Surgeons attending the Society of American Gastrointestinal Endoscopic Surgeons (SAGES) 2004 Annual Scientific Meeting who had performed more than 100 laparoscopic procedures volunteered to participate. All the subjects completed a demographic questionnaire assessing laparoscopic and MIST-VR experience in the learning center of the SAGES 2004 meeting. Each subject performed two consecutive trials of the MIST-VR Core Skills 1 program at the medium setting. Each trial involved six basic tasks of increasing difficulty: acquire place (AP), transfer place (TP), traversal (TV), withdrawal insert (WI), diathermy task (DT), and manipulate diathermy (MD). Trial 1 was considered a "warm-up," and trial 2 functioned as the test trial proper. Subject performance was scored for time, errors, and economy of instrument movement for each task, and a cumulative total score was calculated.

RESULTS

Trial 2 data are expressed as mean time in seconds in Table 2.

CONCLUSION

Proficiency levels for laparoscopic skills have now been established on a national scale by experienced laparoscopic surgeons using the MIST-VR simulator. Residency programs, training centers, and practicing surgeons can now use these data as guidelines for performance criterion during MIST-VR skills training.

Tratamento endoluminal de aneurismas anastomóticos na aorta abdominal: relato de dois casos

Os aneurismas anastomóticos que envolvem a anastomose proximal de reconstruções do território aorto-ilíaco são graves, e as operações convencionais para sua correção são complexas e passíveis de graves complicações. Apresentamos dois casos de aneurismas de anastomoses proximais de enxerto aorto-bifemoral que ocorreram após 15 e 18 anos, respectivamente, de evolução dos enxertos e que foram corrigidos pela técnica endoluminal. Ambos os pacientes evoluíram bem e foram submetidos a controle pela tomografia computadorizada com 12 e 6 meses de evolução, respectivamente, com exclusão do aneurisma.

Cirurgia Endoscópica Subfascial de veias Perfurantes Insuficientes (CESPI): experiência inicial

OBJETIVO: Estudar os resultados imediatos e a médio prazo da cirurgia endoscópica subfascial de perfurantes. MÉTODO: Estudo clínico, prospectivo e descritivo. Critérios de inclusão: insuficiência venosa crônica primária ou secundária, sistema venoso profundo pérvio e índice tornozelo/braço maior que 0,8. Critérios de exclusão: ocorrência da trombose venosa profunda, ou trauma ou cirurgia ortopédica e cirurgia sobre o sistema venoso profundo durante o período de seguimento pós-operatório. Todos doentes foram examinados pelo ecodoppler colorido antes da operação. RESULTADOS: Foram operados 43 membros a partir de junho/1997. Eram 27 doentes com média de idade 56,5 anos. A insuficiência venosa crônica era secundária à trombose venosa em dois membros. Três membros foram classificados como C3, 15 como C4, 11 como C5 e 14 como C6. A retirada das veias safena interna, safena externa e tributárias foi associada em 35 membros. Foram ligadas três a cinco perfurantes por membro; não houve óbitos no pós-operatório imediato; houve três infecções e as úlceras cicatrizaram em períodos variáveis de duas a 15 semanas. Dezenove doentes obtiveram alta hospitalar no primeiro dia de pós-operatório, seis no segundo e dois no terceiro. Houve uma recidiva de úlcera (4,0%) durante o período de seguimento de 25 meses (média) por causa de perfurante não-ligada. CONCLUSÕES: A cirurgia endoscópica subfascial de veias perfurantes insuficientes associada à cirurgia radical de varizes é segura, acompanha-se de baixo índice de complicações, pode ser adaptada aos instrumentos comuns da cirurgia laparoscópica, indicada para doentes classificados como C4, C5 e C6 e se acompanha de bons resultados imediatos e a médio prazo.

Ring-stripping retrograde common carotid endarterectomy: case report

CONTEXT

Total occlusion of the common carotid is rare and the indications and techniques for surgical treatment are still a matter of controversy.

OBJECTIVE

To demonstrate the feasibility of retrograde common carotid endarterectomy.

DESIGN

Retrospective case report study.

SETTING

Tertiary care private hospital.

PARTICIPANTS

Three patients underwent ring-stripping retrograde common carotid endarterectomy. Their ages were 81, 68 and 65 years. All were hypertensive with generalized atherosclerosis, two had diabetes mellitus, and one had undergone coronary artery bypass some years earlier and had non-dialytic chronic renal insufficiency. Symptoms of brain ischemia were present in two patients. All patients had total occlusion of the common carotid, extending from the origin to the bifurcation and localized in the right common carotid in two cases. In two cases the internal carotid artery was also occluded.

MAIN MEASUREMENTS

Postoperative early mortality and stroke rate, and the medium and long-term endarterectomy patency.

RESULTS

There were no deaths. One patient had a transient ischemic attack. All endarterectomies were patent after eight months, four years and seven years of follow-up.

CONCLUSION

There is low mortality, and the procedure can be done through only one cervical incision. Tandem lesions of the carotid arteries can be treated together. It is suitable for long total occlusions of the common carotid, and long-term patency.

Aortofemoral thromboendarterectomy

PURPOSE: To study whether endarterectomy is feasible in all patients with aortofemoral atherosclerotic obstruction, considering early and late results. METHODS: A clinical, prospective, and descriptive study carried out in a university hospital. Inclusion criteria were atherosclerotic aortofemoral obstructive disease, clinical status compatible with major surgery, and absence of prior restorative procedure. Exclusion criteria were aneurysm, inflammatory arterial disease, and prior restorative procedure found during surgery. Eighty patients entered the protocol, but 9 were excluded (11.2%). Seventy-one patients, mean age of 57.3 years, underwent endarterectomy. Operative indications were intermittent claudication and critical ischemia. A ring-stripper endarterectomy technique was employed in all patients. Results were related to age, gender, symptoms, presence of diabetes mellitus, extension of endarterectomy, and extent of obstructive disease. Chi square or Fisher exact tests were used when appropriate, and the Wilkoxon (Gehan) test was used to compare survival curves. RESULTS: Sixty-eight (100%) endarterectomies were patent at discharge. The mortality rate was 4.2%. The amputation rate (4.3%) was higher in diabetic patients and when there was associated femoropopliteal obstruction. The 5-year survival rate was 83.3%, and late deaths were mostly cardiovascular. Diabetes mellitus, age above 65 years, and associated femoropopliteal obstruction lowered the survival rate. The 5-year patency rate was 87.0%. Critical ischemia and less extensive endarterectomies were associated with a lower patency rate. There were no anastomotic aneurysms or deep infections. CONCLUSIONS: Aortofemoral thromboendarterectomy is feasible in 90% of patients, early mortality rate is low, diabetic patients and those with associated femoropopliteal obstructive disease have a higher mortality rate, amputation rate is low, late deaths are mostly cardiovascular, and late patency rate is high, and even higher in the intermittent claudication group.

Early and late results of carotid endarterectomy: retrospective study of 70 operations

CONTEXT

Indications and results of carotid endarterectomy have been defined from clinical multicentric trials like the European Carotid Surgery Trialists, North-American Symptomatic Carotid Endarterectomy Trial and Asymptomatic Carotid Atherosclerosis Study. The patients included in these trials were highly selected, as were the surgeons performing the operations. Clinical practice is different but the same results should be achieved.

OBJECTIVE

To study indications, technique, early and late results, and whether carotid endarterectomy has been performed in accordance with standards defined by multicentric trials.

DESIGN

Retrospective case report study.

SETTING

A tertiary care private hospital.

PARTICIPANTS

57 patients, on whom 70 carotid endarterectomies were performed over a 10-year period. The median age was 66.4 +/- 7.8 years; 43 (75.4%) were male, 41 (71.9%) hypertensive, 36 (63.1%) current smokers and 24 (21.0%) had diabetes. Bilateral carotid stenosis was present in 31 (54.3%) patients, peripheral arterial occlusions in 32 (56.1%) and ischemic cardiopathy in 25 (43.1%). All patients had had angiography and 41 (71.9%) had also had a duplex-scan of neck arteries. Cerebral imaging via computerized tomography scan or magnetic resonance imaging was obtained for 36 patients. Patients were followed up over a period of one to 122 months.

MAIN MEASUREMENTS

early and late post-operative death, early and late post-operative stroke, and recurrence of atheroma plaque and symptoms relative to carotid stenosis.

RESULTS

There was one post-operative death (1.4%) caused by myocardial infarction and two early strokes (2.8%): a total complication rate of 4.2%. After 3 and 5 years, 95.4% and 81.3% of patients respectively were stroke-free and 72.8% and 67.3% were alive. There were four recurrences and two of them related to stroke. Forty-nine (70%) stenoses operated on were symptomatic. Brain infarction was detected in 59.2% of patients who underwent computerized tomography scan or magnetic resonance imaging.

CONCLUSIONS

Carotid endarterectomy was done in accordance with international standards. The most frequent cause of late death was myocardial infarction, and recurrences were related to stroke. Patients should be followed up closely.