Localization of pulmonary nodules using suture-ligated microcoils.

Percutaneous localization of pulmonary nodules in five patients was performed utilizing suture-ligated embolization microcoils and CT guidance. Each localization was performed prior to video-assisted thoracoscopic wedge resection of the targeted nodules. Each suture-ligated microcoil was placed within 1.0 cm of the targeted pulmonary nodule. The attached suture served as a guide to direct accurate resection of the nodules. This technique is easily performed and provides a reliable alternative to nodule localization prior to thoracoscopic resection.

Bioabsorption qualities of chitosan-absorbable vascular templates(1).

PURPOSE:The scope of endovascular surgical techniques has expanded to include the treatment of diseases considered at one time to be amenable only to surgical treatment. The development of the biodegradable template follows as an extension of current permanent stent technology. The goal of our project is to develop and test chitosan as an absorbable template for the vascular system.Ultrapure chitosan, heparin sodium salt and lysozyme, and contrast agents MD-76R and Oxilan-350 were used to give radioopaque quality. Prototype chitosan vascular templates were obtained by a dip coating method in which alternate layers of chitosan were coagulated with nonsolvents or heparin. The amount of loaded and released heparin was determined using Azure II colorimetric assay. In vitro enzymatic degradation of templates was evaluated using lysozyme solutions in phosphate buffered saline. Mechanical properties were analyzed using the Dynamic Mechanical Analyzer, DMA-7 (Perkin Elmer, Foster City, Calif.). The microstructure of freeze-dried templates was investigated by field emission scanning electron microscopy (FE SEM) using an LEO 982 electron microscope (Zeiss, Thornwood, NY).In vivo deployment of the templates was undertaken in 10 full-sized pigs (Sus scrofa). After open expose and control of the iliac artery, a closed balloon catheter technique was used to advance and place the balloon catheter and template. The balloon was then expanded, deploying a Palmaz stent with a chitosan template anchored distally. Patency and deployment of the stent-template complex was confirmed by an arteriogram. The animals were sacrificed at 1, 2, 3, 4, and 5 weeks poststent placement, and arterial sections were taken for microscopic analysis. The amount of chitosan remaining was estimated to determine an in vivo rate of absorption.On hematoxilyn and eosin staining of the section arterial samples, a marked inflammatory response was noted and progressed with duration of in vivo contact. A giant cell foreign body reaction coupled with intense intimal hyperplasia and organized thrombus was also noted and progressed with duration of time in vivo. Also noted was the degradation of the template material with only small remnants of material noted within the giant cell by week 4. Clinically, none of the pigs developed limb ischemia or evidence of thromboembolic events.In this in vivo study, the chitosan template proved to be biodegradable but elicited an intense thrombotic and foreign body reaction despite heparin bonding. Further investigation is ongoing as to decreasing the thrombogenic and antigenic qualities of the template materials by either alteration of the base material or addition of bioactive side chains.

Early rethrombosis of clotted hemodialysis grafts: graft salvage achieved with an aggressive approach.

OBJECTIVE: The purpose of this study was to assess the efficacy of repeated pulsed spray pharmacomechanical thrombolysis for salvage of early rethrombosis of hemodialysis grafts and to identify factors that predict successful outcome. MATERIALS AND METHODS: Thirty-four patients with initial successful thrombolysis were referred for repeated thrombolysis because of early rethrombosis. Repeated thrombolysis occurred within 1 month of initial thrombolysis. Technical success and patency rates were calculated. Causes of graft thrombosis and procedural modifications were analyzed. RESULTS: The 39 rethrombosed grafts were successfully treated using pharmacomechanical thrombolysis, and patients underwent subsequent hemodialysis. The underlying flow-limiting stenoses were treated with balloon angioplasty using a larger balloon (41%), a same-size angioplasty balloon (18%), stent placement (15%), or increased anticoagulation (5%). A new stenosis location was discovered in 18%. Mean primary patency was 80.9 days (2.6 months) and secondary patency was 235.4 days (7.8 months). With life table analysis, 1-, 3-, 6-, and 12-month primary patency rates were 72%, 31%, 23%, and 15%, and secondary patency rates were 77%, 62%, 51%, and 31%, respectively. Graft patency rates in our study were compared with our institutional historic graft patency rates, with no significant difference noted (p = 0.76). No major procedural complications occurred. CONCLUSION: Adequate technical success and patency rates for pharmacomechanical thrombolysis occur even for hemodialysis grafts that rethrombose within 1 month. After thrombolysis, aggressive search for and treatment of additional stenoses are warranted.

Combined aortorenal reconstruction: is there an optimum method of exposure?

OBJECTIVE: To determine the advantages and disadvantages of two different transabdominal approaches to expose the pararenal aorta; infacolic (IC) and medical visceral rotation (MVR). DESIGN: Retrospective study. METHODS: We reviewed a consecutive series of concurrently treated patients undergoing combined aortorenal reconstruction using one of these two approaches (IC n = 45; MVR n = 30). RESULTS: The two groups were identical with respect to demographics, risk factors and associated illnesses. Aortic aneurysmal disease predominated among MVR patients, and occlusive disease among IC patients (p = 0.001). The most common aortic reconstruction was aortofemoral bypass grafting. Renal revascularisation was most often performed for symptoms; only in the MVR group it was the result of involvement by aortic aneurysmal disease (p = 0.000). Thromboendarterectomy was the most common renal reconstruction, though performed only 10 times in the MVR group (p = 0.01). Except for supraceliac aortic cross-clamping, which was required more often in the MVR group (p = 0.004), operative details did not differ between the groups. Although the overall perioperative mortality and complication rate were equal, intraoperative splenic injury occurred solely in the MVR group (p = 0.001), and these patients experienced more pulmonary complications (p = 0.004) and they were hospitalised longer than the IC group (29.7 +/- 35.8 vs. 17.2 +/- 15.4 days; p = 0.04). CONCLUSIONS: MVR has increased morbidity, but its unrestricted continuous exposure is optimum for combined aortorenal reconstruction involving pararenal aneurysmal disease. Pararenal occlusive disease is adequately exposed in most cases by the IC approach.

Surgical methods for renal revascularization.

The availability of newer treatment alternatives for patients with renovascular disease has resulted in many patients being referred for surgical intervention in a delayed fashion. As a result of these changes in the type of patients being referred to surgery with more advanced renovascular hypertension and renal excretory dysfunction, vascular surgeons need to be well versed in the variety of surgical renal revascularization techniques. Each of the procedures has its own advocates, but many of these techniques are not applicable in all patients. Familiarity with the various techniques allows the surgeon to have a choice in the method of renal revascularization appropriate for a given clinical situation. Ultimately, the efficacy of any interventional procedure must be considered along with its associated morbidity, mortality, and long-term clinical outcome. All become important factors when considering the optimal primary surgical procedure to treat the patient with renovascular hypertension or renal excretory dysfunction.

Assessment of carotid artery stenosis by ultrasonography, conventional angiography, and magnetic resonance angiography: correlation with ex vivo measurement of plaque stenosis.

PURPOSE: Several studies have investigated the correlation between Doppler ultrasonography (DUS), angiography (CA), and magnetic resonance angiography (MRA) in the evaluation of stenosis of the carotid bifurcation. However, these studies suffer from the lack of a true control-the lesion itself-and therefore conclusions about the diagnostic accuracy of each method remain relative. To determine the absolute accuracy of these modalities, we have prospectively studied lesion size with DUS, MRA, and CA in 28 patients undergoing 31 elective carotid endarterectomies and compared the percent of carotid stenosis determined by each technique to the carotid atheroma resected en bloc. METHODS: All patients were evaluated by each modality within 1 month before the thromboendarterectomy. With DUS, stenosis size was determined by standard flow criteria. For angiography and MRA, stenosis was defined as residual lumenal diameter/estimated normal arterial diameter (European Carotid Surgery Trial criteria). At surgery the carotid atheroma was removed en bloc in all patients. Patients in whom the lesion could not be removed successfully without damage were excluded from the study. Stenosis of the atheroma was determined ex vivo with high-resolution (0.03 mm3) magnetic resonance and confirmed by acrylic injection of the specimen under pressure and measurement of the atheroma wall and lumen. RESULTS: The measurements of the ex vivo stenosis by high-resolution magnetic resonance imaging correlated closely with the size of stenosis determined by the acrylic specimen casts (r = 0.92). By ex vivo measurement, the lesions were placed in the following size categories: 40% to 59% stenosis (n = 2), 60% to 79% stenosis (n = 6), 80% to 89% stenosis (n = 7), and 90% to 99% stenosis (n = 16). CONCLUSIONS: In general, the correlation of measurements of ex vivo stenosis with all modalities was good in these severely diseased arteries, although it was better for DUS (r = 0.80; p < 0.001) and MRA (r = 0.76; p < 0.001) than for CA (r = 0.56; p < 0.05).

Complex branch renovascular disease: management options and late results.

PURPOSE: The purpose of this report is to review management options and late results of complex renovascular disease managed over the last 22 years. METHODS: Complex branch renal artery disease in 84 kidneys was repaired during 75 operations performed in 68 consecutive patients. There were 61 females (90%) and 7 males (10%) whose predominant pathologic diagnosis was fibromuscular dysplasia manifesting as either renovascular hypertension or aneurysmal degeneration. These patients underwent 15 in situ, 52 ex vivo, and 8 combined reconstructions. In situ repair primarily with use of the bifurcated internal iliac artery autograft was used for primary lesions of the proximal renal artery bifurcation (two branches). Ex vivo repairs, primarily with use of the multibranch internal iliac autograft and hypothermic perfusion preservation, were used for all other patterns of distal renal artery branch disease and reoperative problems. RESULTS: Renovascular reconstruction was successful in salvaging 83 of 84 kidneys (98.8%) in 67 of 68 patients. There were no operative deaths. Two reconstructions thrombosed in the early postoperative period. One was due to severe aortic disease, the other to branch artery dissection after a failed balloon angioplasty. Both patients continued to have hypertension. Before hospital discharge 65 patients had 81 renal revascularizations proven patent by arteriography. Their renal function was assessed and blood pressure was determined in a follow-up extending to 20 years (mean 7.5 years, median 7.9 years). Late arteriograms were obtained in 30 patients (46%) an average of 52 months after operation (range 6 months to 18 years). They demonstrate stable renal artery repair with no evidence of late graft failure in each. Hypertension was cured or improved in 51 of 53 patients (96%) with a proven patent reconstruction. Aneurysms were successfully repaired in 11 patients. Renal function was improved in four patients with ex vivo repairs, unchanged in 59 patients (15 in situ, 44 ex vivo), and persistently worse in only three patients, all of whom had in situ repairs. CONCLUSION: The branched arterial autograft allows the restoration of normal renal arterial anatomy and function when inserted to replace complex distal renovascular disease. This provides a durable repair, essential for younger patients affected by this pattern of disease who anticipate a normal life span after renovascular repair. Successful long-term correction of diastolic hypertension and aneurysmal disease was accomplished without significant morbidity.

Laryngocele associated with squamous carcinoma in a 20-year-old nonsmoker.

A laryngocele associated with squamous cell carcinoma of the larynx is reported in a 20-year-old man without a history of smoking. This is the youngest reported case of carcinoma associated with laryngocele in the literature. This association is supported by the patient's young age and his nonsmoking status. However, this case does not appear to support the conclusion that laryngoceles predispose to the development of squamous cell carcinoma. The clinical history supports the tumor obstruction theory, whereby a laryngocele developed from an obstructing carcinoma of the ventricle.

Chronic visceral ischemia.

The clinical syndrome of chronic intestinal ischemia has been examined through its evolution over the past century. Particular attention has been paid to the past 40 years and the contributions made by Dr Charles Rob. Although various diagnostic strategies have been introduced, the cornerstone of diagnosis remains the biplanar aortogram. Improvement in non-invasive imaging may allow us to understand the natural history of the disease via surveillance screening programs. Modern treatment, resulting in successful and durable reconstruction, consists of either anterograde bypass or transaortic endarterectomy. The future holds promise for the young investigator interested in solving the questions that persist concerning this unique vascular bed.

Optimal exposure of the proximal abdominal aorta: a critical appraisal of transabdominal medial visceral rotation.

PURPOSE: Adequate exposure of the upper abdominal aorta and its branches is a necessary prelude to safe and durable reconstruction of this aortic segment. Although a variety of approaches to this exposure have been described, few outcome data are available to assess the benefits and limitations of the different exposure options. In this series we report the results of the transabdominal medial visceral rotation (MVR) approach to exposure of the paramesenteric and pararenal aorta. METHODS: One hundred eight operations were performed in 104 patients, representing 19.5% of all aortic reconstructions during a 5.5 year interval. Most patients had hypertension (n = 77, 71.3%) or a history of smoking (n = 83, 76.9%). Heart disease was present in one third of patients (n = 33) and a similar proportion had abnormal renal function (elevated creatinine level) before operation (n = 40, 37.0%). One third of patients (n = 34) had undergone previous aortic or aortic branch reconstruction. Eighty percent of procedures were elective (n = 87). Seventy-one patients (65.7%) required renal revascularization, usually for hypertension or elevated creatinine levels, whereas 37 patients (34.3%) underwent visceral reconstruction, most often for symptoms of chronic mesenteric ischemia. Only 22 patients required isolated infrarenal aortic repair. Most of the aortic lesions were aneurysmal (n = 42). Eighty percent of procedures (n = 88) required suprarenal or more proximal aortic clamping. The most frequently used reconstruction techniques were bypass (n = 39, 36.1%), endarterectomy (n = 18, 16.7%), or both (n = 23, 21.3%). RESULTS: There were four intraoperative deaths (3.7%) and 15 postoperative deaths (13.9%). All intraoperative deaths and four postoperative deaths were related to hemorrhage and its complications. Visceral infarction was the most frequent cause of postoperative death. The intraoperative complications that were determined to be related to the medial visceral rotation approach included splenic injury (n = 23, 21.3%), one aortic injury, and one adrenal injury. The aortic injury was associated with substantial intraoperative bleeding and subsequent death. The postoperative complications resulting from MVR included pancreatitis (n = 5), which contributed to death in two patients, and possibly some of the cases of visceral infarction not associated with visceral reconstruction. The other common postoperative complications, cardiac (n = 25, 24.0%), pulmonary (n = 32, 30.8%), renal (n = 20, 19.2%), and infectious (n = 17, 16.3%), were attributed to the procedures performed. CONCLUSIONS: Transabdominal MVR exposure of the upper abdominal aorta provides unrestricted access to the visceral branch-bearing segment of the aorta and places no limitations on the choice of arterial reconstruction technique. The associated morbidity and mortality rates are typical of patients undergoing these complex vascular repairs, but the frequency of splenic injury and postoperative pancreatitis is increased.