Biomedical subjects

Michael D Addis

Publications and source records attributed to Michael D Addis.

7 recordsLinked to original sources

PubMed2006

Successful endovascular treatment of bleeding aortoenteric fistula: a case report.

Aortoenteric fistula (AEF) is an infrequent but disastrous complication of open abdominal aortic repair. Left untreated, it has a 100% fatality rate. The traditional approaches to the repair of secondary AEF (SAEF) are associated with average mortality rates of 21-59% and numerous major complications. Here, we report a case of acute gastrointestinal bleeding due to SAEF, successfully treated with endovascular stent graft repair. At 1-year follow-up, the patient was doing well without any signs of recurrent fistula. Endovascular treatment of AEF provides another treatment option that may be particularly valuable in patients whose comorbidities would preclude open repair.

Aged, 80 and over↗

PubMed2006

Endovascular thoracic aortic repair and previous or concomitant abdominal aortic repair: is the increased risk of spinal cord ischemia real?

Spinal cord ischemia after endovascular thoracic aortic repair remains a significant risk. Previous or concomitant abdominal aortic repair may increase this risk. This investigation reviews the occurrence of spinal cord ischemia after endovascular repair of the descending thoracic aorta in patients with previous or concomitant abdominal aortic repair. Over an 8-year period, 125 patients underwent endovascular exclusion of the thoracic aorta at the Mount Sinai Medical Center. Twenty-eight of these patients had previous or concomitant abdominal aortic repair. The 27 patients who underwent staged repairs all had cerebrospinal fluid (CSF) drainage during and following repair. This population was analyzed for the complication of spinal cord ischemia and factors related to its occurrence. Mean follow-up was 19.3 months (range 1-61). Spinal cord ischemia developed in four of the 28 patients (14.3%) who underwent endovascular thoracic aortic repair with previous or concomitant abdominal aortic repair, while one of 97 patients (1.0%) developed ischemia among the remaining thoracic endograft population. One patient with concomitant abdominal aortic repair developed cord ischemia that manifested 12 hr following the procedure. The remaining three patients with previous abdominal aortic repair developed more delayed-onset paralysis ranging from the third postoperative day to 7 weeks following repair. Irreversible cord ischemia occurred in three patients, with full recovery in one patient. Major complications from CSF drainage occurred in one patient (3.7%). Spinal cord ischemia occurred at a markedly higher rate in patients with previous or concomitant abdominal aortic repair. This risk continued beyond the immediate postoperative period. The benefit of perioperative and salvage CSF drainage remains to be determined.

Angioplasty↗

PubMed2006

Abdominal aortic aneurysm sac shrinkage after endovascular aneurysm repair: correlation with chronic sac pressure measurement.

OBJECTIVES: Abdominal aortic aneurysm (AAA) sac shrinkage after endovascular aneurysm repair (EVAR) is considered to be evidence of clinical success. Exclusion of the sac from systemic pressure is the likely cause of shrinkage. We report our continuing clinical experience with the use of a permanently implantable, ultrasound-activated remote pressure transducer to measure intrasac pressure and its correlation with changes in sac diameter over time. METHODS: Over a 22-month period, 21 patients underwent EVAR of an infrarenal AAA with implantation of an ultrasound-activated remote pressure transducer fixed to the outside of the stent-graft and exposed to the excluded aortic sac. Intrasac pressures were measured directly with an intravascular catheter and by the remote sensor at the time of stent-graft deployment. Follow-up sac pressures were measured by remote sensor and compared with systemic arterial pressure at every follow-up visit. Mean follow-up was 11.4 +/- 5.0 months (range, 1 to 26 months). Twenty patients had follow-up of > or =6 months. Mean pressure index (MPI) was calculated as the ratio of mean sac pressure to mean systemic pressure. RESULTS: Pressures could be obtained at all visits in 15 of the 21 patients. Fourteen of these 15 patients had follow-up of at least 6 months. Aneurysm sac shrinkage of >5 mm was seen in seven (50%) of these 14 patients. No aneurysm enlargement was observed in any patient. The MPI was significantly lower in patients with sac shrinkage at 6 months and at final follow-up. CONCLUSIONS: Endovascular aneurysm repair results in marked reduction of sac pressure in most patients. Patients with aneurysm shrinkage after EVAR have significantly lower MPI; however, the absence of sac shrinkage does not imply persistent pressurization of the sac. Further clinical follow-up will delineate the role of long-term sac pressure monitoring in surveillance after EVAR.

Aortic Aneurysm, Abdominal↗

PubMed2004

First experience in human beings with a permanently implantable intrasac pressure transducer for monitoring endovascular repair of abdominal aortic aneurysms.

OBJECTIVES: Endovascular stent graft repair of abdominal aortic aneurysms (AAAs) prevents rupture by excluding the aneurysm sac from systemic arterial pressure. Current surveillance protocols after endovascular aneurysm repair (EVAR) follow secondary markers of sac pressurization, namely, endoleak and sac enlargement. We report the first clinical experience with the use of a permanently implantable, ultrasound-activated remote pressure transducer to measure intrasac pressure after EVAR. METHODS: Over 7 months, 14 patients underwent EVAR of an infrarenal abdominal aortic aneurysm with implantation of an ultrasound-activated remote pressure transducer fixed to the outside of the stent graft and exposed to the excluded aortic sac. Twelve patients received modular bifurcated stent grafts, and 2 patients received aortouniiliac devices. Intrasac pressures were measured directly with an intravascular catheter and by the remote sensor at stent-graft deployment. Follow-up sac pressures were measured with a remote sensor and correlated with systemic arterial pressure at every follow-up visit. Mean follow-up was 2.6 +/-1.9 months. RESULTS: Excellent concordance was found between catheter-derived and transducer-derived intrasac pressssure intraoperatively. Pulsatile waveforms were seen in all functioning transducers at each evaluation interval. One implant ceased to function at 2 months of follow-up. In 1 patient a type I endoleak was diagnosed on 1-month computed tomography (CT) scans; 3 type II endoleaks were observed. Those patients with complete exclusion of the aneurysm on CT scans had a significant difference in systemic and sac systolic pressures initially (P <.001) and at 1 month (P <.001). Initial sac diastolic pressures were higher than systemic diastolic pressures (P <.001). The ratio of systemic to sac systolic pressure increased over time in those patients with complete aneurysm exclusion ( P <.001). Four of 6 patients with no endoleak and greater than 1-month follow-up had diminution of sac systolic pressure to 40 mm Hg or less by 3 months. CONCLUSION: This is the first report of a totally implantable chronic pressure transducer to monitor the results of EVAR in human beings. Aneurysm exclusion leads to gradual diminution of sac pressure over several months. Additional clinical follow-up will be necessary to determine whether aneurysm sac pressure monitoring can replace CT in the long-term surveillance of patients after EVAR.

Angioplasty↗

PubMed2004

Endovascular therapy for aortic disease.

Minimally invasive repair of thoracic and abdominal aortic aneurysms (AAAs) is rapidly becoming a vital tool in the arsenal of the vascular specialist. Historically, surgical replacement of the aorta has been the "gold standard" for treatment of aortic aneurysms. However, transfemoral placement of an endovascular stent graft, first described by Dr. Parodi and colleagues in 1991, marked the beginning of a new era in treatment of aortic aneurysms. This approach has evolved, allowing success with significantly less morbidity. Over time, if the long-term results continue to prove favorable, endovascular stent graft repair of aortic aneurysms may become the most effective means to treat this life-threatening disease.

Angiography↗

PubMed2003

Minimally invasive endocrine surgery.

BACKGROUND: Minimally invasive endocrine surgery has experienced multiple new developments. METHODS: Comprehensive review of the literature. CONCLUSIONS: Minimally invasive techniques can be efficaciously and safely applied to most endocrine disorders. Endocrine surgeons should be skilled in these techniques in order to individualize the operative approach.

Adrenalectomy↗

PubMed2002

Abdominal aortic aneurysmorrhaphy and cholelithiasis in the era of endovascular surgery.

The incidence of acute cholecystitis complicating standard abdominal aortic aneurysm (AAA) repair has been reported between 0.3 and 18 per cent. This has prompted considerable debate regarding the management of cholelithiasis discovered incidentally during open aortic reconstruction. This study seeks to determine the incidence of cholelithiasis and acute cholecystitis after endovascular AAA repair and evaluate options for management. Between February 1996 and October 2001 492 patients underwent endovascular AAA repair. All the procedures were performed in the operating room under fluoroscopic guidance. Epidural (98.9%), local (0.5%), or general (1.7%) anesthesia was used during these cases. The incidence of cholelithiasis and acute cholecystitis was evaluated by CT scan and abdominal ultrasound. Serum measurements of alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, total and direct bilirubin, and amylase were performed and clinical assessment was conducted at 1, 6, and 12 months postoperatively and annually thereafter. The mean age of these patients was 76.6 years; 84% were male. Comorbid medical conditions were present in all patients (average 3.5 conditions/patient). Follow-up ranged from 2 to 35 months (mean 12.8 months). Endovascular stent graft deployment was successful in 486 of the 492 patients (98.8%). Six patients were converted to standard open repair because of inability to achieve successful endovascular aneurysm repair. The perioperative major morbidity rate was 14.9 per cent. Minor morbidity rate was 8.5 per cent. The perioperative mortality rate was 1.9 per cent. No deaths were related to biliary disease. Cholelithiasis was identified in 64 (13%) patients preoperatively. One of 64 patients with a prior Billroth II reconstruction for peptic ulcer disease developed jaundice 8 days after AAA repair as a result of choledocholithiasis that required surgical repair. One patient without gallstones developed acute acalculous cholecystitis on postoperative day 16 as determined on pathologic analysis of the gallbladder. A third patient who had gallstones identified on preoperative CT scan developed calculous cholecystitis 16 months after endovascular AAA repair. These two patients underwent uncomplicated laparoscopic cholecystectomy and recovered uneventfully. The incidence of postoperative symptomatic cholelithiasis is 1.6 per cent (one of 64). The incidence of postoperative acute cholecystitis was 0.2 per cent (one of 486) and was unrelated to the presence of gallstones. The incidence of delayed symptomatic cholelithiasis was 1.6 per cent (one of 64). Endovascular repair of AAA does not appear to predispose the patient to the development of symptomatic cholelithiasis during the perioperative period. Therefore a preoperative or intraoperative diagnosis of cholelithiasis does not necessitate cholecystectomy in the setting of planned endovascular AAA repair. Patients who develop cholecystitis after endovascular AAA repair may be effectively treated by standard laparoscopic techniques.

Acute Disease↗