Geniculate Artery Endovascular Embolization Post-Total Knee Arthroplasty for Hemarthrosis Treatment: A Systematic Review of the Literature.

PURPOSE: To provide an updated systematic review on the use of geniculate artery embolization (GAE) in the management of recurrent hemarthrosis post-total knee arthroplasty (TKA). MATERIALS AND METHODS: A systematic literature review was conducted, and all clinical reports in the English language from inception to July 2022 were identified. References were manually reviewed to identify additional studies. Demographics, procedural techniques, post-procedural complications, and follow-up data were extracted and analyzed using STATA 14.1. RESULTS: A total of 20 studies (9 case reports, 11 case series; n= 214) were included for review. In all cases, patients underwent coil embolization of one or more geniculate arteries. Procedure success was reported in 94.8% (n=203/214) of cases without perioperative adverse events. Improvement of symptoms was seen in 72.6% (n=119/164) of cases, with 30.7% (n=58/189) of cases requiring repeat embolization. Recurrent hemarthrosis occurred in 22.2% (n=22/99) of cases over a mean follow-up of 48 months. CONCLUSION: GAE appears to be a safe and effective treatment for recurrent hemarthrosis following TKA. Future studies in the form of randomized controlled trials should be conducted to further evaluate such embolization techniques and compare outcomes between GAE and standard techniques. CLINICAL IMPACT: Conservative management of post total knee arthroplasty (TKA) hemarthrosis is successful in only one third of cases. Geniculate artery embolization (GAE) has recently gained attention due to its minimally invasive nature compared to open or arthroscopic synovectomy promising faster rehabilitation, decreased infection rates and less additional surgeries. The purpose of this article was to summarize current literature, provide an updated review on the use of GAE in the management of recurrent hemarthrosis post-TKA and describe immediate and long-term outcomes in an effort to help optimize current treatment algorithms.

Endovascular Repair of Popliteal Artery Injury Post-total Knee Arthroplasty is Safe and Effective: A Case Report and Systematic Review of the Literature.

BACKGROUND: Popliteal artery pseudoaneurysms are a rare but serious complication following total knee arthroplasty that have been traditionally managed with open surgical repair. Endovascular stenting, while relatively new, offers a promising alternative that is less invasive and may reduce the risk of perioperative complications. METHODS: A systematic literature review was conducted, and all clinical reports in the English language from inception to July 2022 were identified. References were manually reviewed to identify additional studies. Demographics, procedural techniques, postprocedural complications, and followup data were extracted and analyzed using STATA 14.1. Additionally, we present a case of a patient with a popliteal pseudoaneurysm treated with a covered endovascular stent. RESULTS: A total of 14 studies (12 case reports, 2 case series; n = 17) were included for review. In all cases, a stent-graft was placed across the popliteal artery lesion. In 5 out of 11 cases, popliteal artery thrombus was present and treated with adjacent modalities (i.e., mechanical thrombectomy, balloon angioplasty, etc.). Procedure success was reported in all cases without perioperative adverse events. Stents remained patent over a median followup of 32 weeks (interquartile range: 36). In all but one case, the patients experienced immediate symptom relief and had an uneventful recovery. For our case, at the 12-month followup the patient was asymptomatic, and ultrasound demonstrated vessel patency. CONCLUSIONS: Endovascular stenting is a safe and effective treatment for popliteal pseudoaneurysms. Future studies should be aimed at evaluating the long-term outcomes of such minimally invasive techniques.

A Prospective Noninterventional Study of Type I Collagen Matrix Plus Polyhexamethylene Biguanide Antimicrobial for the Treatment of Venous Leg Ulcers: A Secondary Analysis.

BACKGROUND: The RESPOND registry study was the first prospective noninterventional study evaluating the real-world effectiveness of a native type 1 collagen matrix plus polyhexamethylene biguanide antimicrobial (PCMP) barrier in nonhealing wounds. PURPOSE: The objective of this secondary analysis was to describe the effects of PCMP in the subgroup of patients with venous leg ulcers (VLUs) in the RESPOND registry. METHODS: RESPOND was a 28-site, prospective, noninterventional study for up to 32 weeks. All patients (N = 307) in RESPOND received PCMP. Eligibility criteria included patients being 18 years of age and older and having cutaneous wounds, not including third-degree burns. Kaplan-Meier methods analyzed the frequency and median time to wound closure. RESULTS: For the cohort of PCMP-treated VLUs (n = 67), the mean baseline wound area was 20.07 cm2 and mean wound duration was 89 days. Wound closure frequencies were 33%, 42%, 45%, 53%, and 73% at weeks 8, 12, 16, 24, and 32, respectively. The median time to closure was 22 weeks. Incidences of achieving >60% reduction in baseline area and depth were 78% and 70%, respectively, with 87% showing a reduction of >75% in volume. CONCLUSION: PCMP appears to be a valuable adjunct for treating venous leg ulcers.

Efficacy of the Application of a Purified Native Collagen With Embedded Antimicrobial Barrier Followed by a Placental Allograft on a Diverse Group of Nonhealing Wounds of Various Etiologies.

INTRODUCTION: Invoked by the presence of biofilm, upregulation of tissue-destroying proteases is the hallmark of continuous inflammation in nonhealing wounds. Preventing biofilm re-formation and quenching protease activity in the wound bed, followed by providing regenerative factors to the area may aid in triggering a wound healing trajectory. OBJECTIVE: In this case series, the author evaluated a multimodal approach in patients with wounds that did not respond to conventional therapy. These patients were initially treated with purified native cross-linked extracellular matrix (ECM) with polyhexamethylene biguanide (PHMB) antimicrobial barrier (PCMP) followed by placental allografts MATERIALS AND METHODS: Wounds underwent once-weekly debridements, followed by application of PCMP and subsequent applications of hypothermically stored amniotic membrane (HSAM) and/or dehydrated amnion/chorion membrane (dACM) placental allografts. RESULTS: Sixteen wounds were included in the study, but 1 patient died before healing rates were calculated. Of the remaining 15 wounds, 13 (86.67%) closed at or before week 12, with the remaining 2 wounds achieving complete wound closure by week 17. A subgroup analysis of larger wounds (> 25 cm2) also was conducted. Of the 16 wounds, 6 (37.5%) were present for 8.5 weeks; these wounds ranged in size from 31 cm2 to 78 cm2, with mean baseline area (standard deviation) of 43.5 cm2 (15.99) and median baseline area of 42 cm2. Of the 5 larger wounds, 3 (60%) closed before 12 weeks. All wounds achieved complete wound closure by week 17 following application of PCMP and subsequent application of HSAM or dACM. CONCLUSIONS: Applications of PCMP to nonhealing wounds, followed by application of dACM or HSAM placental allograft, in conjunction with the standard of care provided at the author's institution, resulted in satisfactory wound closure rates in a diverse group of wounds in a patient group with multiple comorbidities.

Synchronous versus staged carotid artery stenting and coronary artery bypass graft for patients with concomitant severe coronary and carotid artery stenosis: A systematic review and meta-analysis.

BACKGROUND: Coronary artery disease requiring coronary artery bypass graft (CABG) frequently coexists with critical carotid stenosis. The most optimized strategy for treating concomitant carotid and coronary artery disease remains debatable. OBJECTIVE: The aim of this meta-analysis was to compare synchronous CAS and CABG versus staged CAS and CABG for patients with concomitant coronary artery disease and carotid artery stenosis in terms of peri-operative (30-day) and long-term clinical outcomes. METHODS: This study was performed according to the PRISMA guidelines. Eligible studies were identified through a search of PubMed, Scopus and Cochrane database until December 2019. A meta-analysis was conducted with the use of a random effects model. The I-square statistic was used to assess heterogeneity. RESULTS: Four studies comprising 357 patients were included in this meta-analysis. Patients who were treated with the synchronous approach had a statistically significant higher risk for peri-operative stoke (OR: 3.71; 95% CI: 1.00-13.69; I2 = 0%) compared tο the staged group. Peri-operative mortality (OR: 4.50; 95% CI: 0.88-23.01; I2 = 0%), myocardial infarction (MI) (OR: 1.54; 95% CI: 0.18- 13.09; I2 = 0%), postoperative bleeding (OR: 0.27;95% CI: 0.02-3.12; I2 = 0%), transient ischemic attacks (TIA) (OR: 0.60; 95% CI: 0.04- 9.20; I2 = 0.0%), acute kidney injury (AKI) (OR: 0.34; 95% CI: 0.03-4.03; I2 = 0.0%) and atrial fibrillation rates (OR:0.27; 95% CI: 0.02-3.12; I2 = 0.0%) were similar between the two groups. Synchronous CAS-CABG and staged CAS followed by CABG were associated with similar rates of late mortality (OR: 3.75; 95% CI: 0.50-27.94; I2 = 0.0%), MI (OR: 0.33; 95% CI: 0.01-12.03; I2 = 0.0%) and stroke (OR:3.58; 95% CI:0.84-15.20; I2 = 0.0%) after a mean follow-up of 47 months. CONCLUSION: The simultaneous approach was associated with an increased risk of 30-day stroke compared to staged CAS and CABG. However, no statistically significant difference was found in long-term results of mortality, MI and stroke between the two approaches. Future studies are warranted to validate our results.

Type I collagen matrix plus polyhexamethylene biguanide antimicrobial for the treatment of cutaneous wounds.

Aim: Determine the effectiveness of purified native type I collagen matrix plus polyhexamethylene biguanide antimicrobial (PCMP) on cutaneous wounds. Materials & methods: A prospective cohort study of 307 patients (67 venous leg ulcers, 62 diabetic foot ulcers, 45 pressure ulcers, 54 post-surgical wounds and 79 other wounds) was conducted. Results: Cox wound closure for PCMP was 73% at week 32. The median time to wound closure was 17 weeks (Kaplan-Meier). The incidence of PCMP-treated wounds showing >60% reductions in areas, depths and volumes were 81, 71 and 85%, respectively. Conclusion: PCMP demonstrated clinically meaningful benefits to patients with various types of cutaneous wounds. Clinical Trial registration number: NCT03286452.

Synchronous Carotid Endarterectomy and Coronary Artery Bypass Graft versus Staged Carotid Artery Stenting and Coronary Artery Bypass Graft for Patients with Concomitant Severe Coronary and Carotid Stenosis: A Systematic Review and Meta-analysis.

BACKGROUND: Owing to the systemic nature of atherosclerosis, medium and large arteries at different sites are commonly simultaneously affected. As a result, severe coronary artery disease (CAD) requiring coronary artery bypass graft (CABG) frequently coexists with significant carotid stenosis that warrants revascularization. The aim of this study was to compare synchronous carotid endarterectomy (CEA) and CABG vs. staged carotid artery stenting (CAS) and CABG for patients with concomitant CAD and carotid artery stenosis in terms of perioperative (30-day) outcomes. METHODS: This study was performed according to the Preferred Reporting Items for Systematic reviews and Meta-Analyses guidelines. Eligible studies were identified through a search of PubMed, Scopus, and Cochrane until July 2018. A meta-analysis was conducted with the use of a random-effects model. The I-square statistic was used to assess heterogeneity. RESULTS: Five studies comprising 16,712 patients were included in this meta-analysis. Perioperative stroke (odds ratio [OR]: 0.84; 95% confidence interval [CI]: 0.43-1.64; I2 = 39.1%), transient ischemic attack (TIA; OR: 0.32; 95% CI: 0.04-2.67; I2 = 27.6%), and myocardial infarction (MI) rates (OR: 0.56; 95% CI: 0.08-3.85; I2 = 68.9%) were similar between the two groups. However, patients who underwent simultaneous CEA and CABG were at a statistically significant higher risk for perioperative mortality (OR: 1.80; 95% CI: 1.05-3.06; I2 = 0.0%). CONCLUSIONS: The current meta-analysis did not detect statistically significant differences in the rates of perioperative stroke, TIA, and MI between the groups. However, patients in the simultaneous CEA and CABG group had a significantly higher risk of 30-day mortality. Future randomized trials or prospective cohorts are needed to validate our results.

Synchronous versus Staged Carotid Endarterectomy and Coronary Artery Bypass Graft for Patients with Concomitant Severe Coronary and Carotid Artery Stenosis: A Systematic Review and Meta-analysis.

BACKGROUND: Due to the systemic nature of atherosclerosis, arteries at different sites are commonly simultaneously affected. As a result, severe coronary artery disease (CAD) requiring coronary artery bypass grafting (CABG) frequently coexists with significant carotid stenosis that warrants revascularization. To compare simultaneous carotid endarterectomy (CEA) and CABG versus staged CEA and CABG for patients with concomitant CAD and carotid artery stenosis in terms of perioperative outcomes. METHODS: This study was performed according to the Preferred Reporting Items for Systematic reviews and Meta-Analyses guidelines. A meta-analysis was conducted with the use of a random effects model. The I2 statistic was used to assess for heterogeneity. RESULTS: Eleven studies comprising 44,895 patients were included in this meta-analysis (21,710 in the synchronous group and 23,185 patients in the staged group). The synchronous CEA and CABG group had a statistically significant lower risk for myocardial infarction (MI) (odds ratio [OR] 0.15, 95% CI 0.04-0.61, I2 = 0%) and higher risk for stroke (OR 1.51, 95% CI 1.34-1.71, I2 = 0%) and death (OR 1.33, 95% CI 1.01-1.75, I2 = 47.8%). Transient ischemic attacks (TIAs) (OR 1.27, 95% CI 1.00-1.61, I2 = 0.0%), postoperative bleeding (OR 0.82, 95% CI 0.22-3.05, I2 = 0.0%), and pulmonary complications (OR 1.52, 95% CI 0.24-9.60, I2 = 67.5%) were similar between the 2 groups. CONCLUSIONS: Patients in the simultaneous CEA and CABG group had a significantly higher risk of 30-day mortality and stroke and lower risk for MI as compared to staged CEA and CABG group. The rates of TIA, postoperative bleeding, and pulmonary complications were similar between the 2 groups. Future randomized trials or prospective cohorts are needed to validate our results.

Ascending aortic aneurysms: asymmetrical differences in aortic cross-sectional wall motion detected by epiaortic echocardiography.

OBJECTIVE: To evaluate in vivo cross-sectional conformational changes of ascending aortic wall excursion in patients undergoing resection for aortic aneurysm with those undergoing elective coronary artery bypass grafting (CABG) using epi-aortic echocardiography. DESIGN: A prospective observational investigation. SETTING: A single tertiary care university hospital. PARTICIPANTS: Thirty-four patients undergoing elective ascending aorta resection and 23 elective CABG patients. INTERVENTION: In an open-chest model and with use of an epi-aortic echocardiographic probe, measurements of aortic wall excursion were made on the ascending aortic aneurysms. Control measurements were made on the transitional neck portions of the aneurysmal aortas (internal control) and CABG aortas (external control). MEASUREMENTS AND MAIN RESULTS: The aortic aneurysm measurements exhibited no difference (2.8%, p < 0.62) between the excursion of the anterior and posterior walls. In contrast, under similar hemodynamic conditions, the anterior wall of the aneurysm neck moved 48.2% (p < 0.0004) more than the posterior wall. Similarly, in the CABG control group, the anterior wall moved 24% (p < 0.027) more than the posterior wall. CONCLUSION: This in vivo study documented a lack of asymmetric aortic wall motion in ascending aortic aneurysms. In contrast, both the internal and external control groups (aneurysm neck and CABG) demonstrated asymmetric wall motion. The lack of asymmetric wall motion may be an important aspect of aneurysm pathophysiology and key to the development of management strategies for timing of surgical intervention.

State-of-the-art of hybrid procedures for the aortic arch: a meta-analysis.

Questions have risen regarding procedural indications, techniques, and outcomes for hybrid arch procedures. We performed a meta-analysis to benchmark this innovative approach. Studies and case reports involving hybrid aortic arch procedures listed through May 2008 were reviewed (n = 718). End points were 30-day mortality, stroke, paraplegia, and endoleak rates. A total of 15 studies with 463 patients were included in the meta-analysis. Overall 30-day mortality was 8.3%. Endoleak rate was 9.2%, stroke was 4.4%, and paraplegia was 3.9%. Treated on-pump or off-pump did not affect any of the endpoints. Results compare favorably with standard operative repair. Long-term follow-up is needed.

Is endovascular repair the new gold standard for primary adult coarctation?

OBJECTIVE: Primary adult aortic coarctation (PAAC) is an unusual cause of hypertension. The standard of care includes surgical repair, which can be associated with considerable morbidity and operative risk. Although balloon angioplasty has been successfully used in paediatric and adolescent patients with coarctation, little information exists regarding the endovascular repair of PAAC. This study examines the procedural safety and efficacy of endovascular repair of PAAC along with midterm outcomes. METHODS: Between January 2000 and July 2008, 16 patients underwent endovascular repair of PAAC. All patients were hypertensive with 13 patients (81.3%) receiving medical therapy. Symptoms included chest pain (n=11, 69%), progressive fatigue (n=5, 31%), exercise intolerance (n=4, 25%) and shortness of breath (n=3, 19%). Associated cardiac concerns included depressed ejection fraction (n=6, 38%), pulmonary hypertension (n=5, 31%), ascending aortic dilatation (n=5, 31%) and bicuspid aortic valve (n=4, 25%). Endovascular repair was achieved using a percutaneous femoral approach. Balloon angioplasty of the coarctation was performed prior to treatment using a balloon-expandable uncovered stent. Aortic diameters were assessed using intravascular ultrasound. Pre- and post-procedure pressure gradients were measured and success was determined as a residual pressure gradient across the treated aorta of less than 20 mmHg. RESULTS: The male:female (M:F) ratio was 9:7 with a mean age of 39.7 years. Procedural success was 100%. Mean pre-procedural aortic diameter was 8.4mm (3-14 mm) and mean post-procedural aortic diameter was 16.3mm (10-20mm) (p=0.04). The mean pre-procedural pressure gradient was 48.3 mmHg (25-100 mmHg) and the mean post-procedural pressure gradient was 0.5 mmHg (0-15 mmHg) (p=0.05). Twelve patients received one stent, two patients received two stents, one patient received three stents and one other patient received a thoracic stent graft. The rate of paraplegia was 0% with no blood transfusions, strokes or deaths. Follow-up ranged from 12 to 72 months (mean=22.8 months). One patient required re-intervention with an additional stent 14 months following the initial procedure and all the patients remain symptom-free. CONCLUSION: Endovascular repair of PAAC is safe and effective and compares favourably with open surgical repair. Midterm follow-up suggests that the treatment is durable and may be an alternative to surgical repair. Although this is the largest endovascular treatment series for PAAC reported to date, additional study and follow-up are needed.

Inferior mesenteric artery stenting: a solution for chronic mesenteric ischemia.

Chronic mesenteric ischemia (CMI) is a rare entity with potentially tragic consequences. Meanwhile, there is still no consensus regarding the most adequate treatment approach. The authors herein report a case of a 65-year-old woman with severe CMI as a result of an occlusion of both the celiac artery (CA) and superior mesenteric artery (SMA) and a significant stenosis of the inferior mesenteric artery (IMA) ostium. The patient was successfully treated by angioplasty and stenting of the IMA. Even though the usual approach for CMI is revascularization of the CA and the SMA, the present case demonstrates that IMA can have a central role in visceral circulation, and its endovascular revascularization can be the first treatment option in selected cases.

Role of exertion or emotion as inciting events for acute aortic dissection.

It is well known that hypertension, aortic dilatation, and collagen disorders predispose to acute aortic dissection (AAD). The inciting events that precede the instant of AAD are incompletely understood. One hundred seventy-five consecutive patients having AAD, treated at our institution during a 10-year period, were reviewed; 65 were women and 110 were men (mean age 61 years). The ascending aorta was affected in 110 patients, and the descending in 65. Information was collected using patients' charts supplemented with direct telephone interviews. Ninety patients were contacted; 65 (24 women, 41 men, mean age 61 years, average aortic size 5.56 cm) could recall specific inciting events for their dissection. In 34 patients, the ascending aorta was involved and in 31 the descending. Eighteen patients (28%) had a positive family history of aortic disease, defined as having > or =1 first-degree relative with aortic disease (aneurysm or dissection). In 24 of the 90 patients contacted (27%), strenuous activity was identified as a clear precipitating factor before the acute onset of thoracic pain; in 36 of 90 (40%) severe emotional stress preceded the onset of dissection pain. Three dissections were iatrogenic. Two additional patients reported a severe exacerbation of chronic obstructive pulmonary disease before their acute onset of chest pain. In conclusion, severe physical and emotional stress may precipitate AAD, presumably on the basis of a transient, severe hypertensive reaction.

The Nicks-Nunez posterior enlargement in the small aortic annulus: immediate-intermediate results.

OBJECTIVES: To avoid prosthesis-patient mismatch, posterior enlargement of the small aortic annulus using the Nicks-Nunez surgical approach was performed in fifteen patients and the immediate-intermediate results are reported retrospectively. METHODS: During the period November 1995 to June 2005, 220 patients underwent aortic valve replacement (AVR) for primary aortic stenosis (AS). Fifteen patients (15/220 - 6%), all women, 40-76 years old (mean age 65.8 years) with AS, underwent AVR applying the Nicks-Nunez posterior enlargement of the small aortic annulus with an effective aortic valve area 0.7+/-0.2 cm(2). In addition, mitral valve replacement (MVR) was performed in two patients and coronary artery bypass grafting (CABG) in three (2 grafts/pt). Endarterectomy of the ascending aorta was performed in one patient. With the exception of one patient, mechanical valves were used. In all cases, transesophageal echo (TEE), normothermic cardiopulmonary bypass (CPB), left ventricular venting, antegrade crystalloid cardioplegic arrest and local myocardial cooling, was used. The defect after the enlargement was closed with autologous pericardium in four and synthetic graft in eleven patients. The follow-up period was 5-120 months (mean 61.5 months). RESULTS: There was no operative or hospital mortality. The length of CPB and aortic crossclamping was increased as well as the duration of mechanical ventilation. In one, out of two patients, in whom the decision for enlargement was delayed, intraaortic balloon pump was used. However, there was no other morbidity and the final length of stay was 7-10 days (same as for routine AVR). One patient died five years later from lung cancer. Serial follow-up transthoracic echoes have shown statistically significant improvements in left ventricular-intraventricular septum thickness (LVIVS) (16.5+/-1.3 mm vs. 14.3+/-1.7 mm, P<0.01), left ventricular posterior wall thickness (LVPWT) (16.7+/-1.4 mm vs. 14.5+/-1.8 mm, P<0.01), left ventricular (LV) mass/g (415+/-33 vs. 388+/-41, P<0.01), peak gradient (98+/-10 mmHg vs. 48+/-7 mmHg, P<0.001) and in mean gradient (58+/-10 mmHg vs. 22+/-8 mmHg, P<0.001). The functional aortic valve orifice postoperatively was 1.4+/-0.5 cm(2). The ejection fraction (EF) and the left ventricular end-diastolic pressure (LVEDP) were unchanged. CONCLUSIONS: Immediate and intermediate results reveal the safety of the procedure and the significant functional and anatomical improvement of the left ventricle. Although the number of patients is small, female patients, small or large, seem to be the usual candidates for this procedure.

Tissue microarray detection of matrix metalloproteinases, in diseased tricuspid and bicuspid aortic valves with or without pathology of the ascending aorta.

OBJECTIVE: The degeneration of bicuspid aortic valve and its frequent association with ascending aortic pathology, point to a still unidentified genetic tissue defect with unknown mediators. Metalloproteinases (MMPs) are lytic enzymes that have been strongly implicated in aneurysm formation. The purpose of this study was to detect the presence of these enzymes in aortic valvular tissue in healthy and diseased aortic valves with or without the presence of synchronous ascending aortic pathology. METHODS: Aortic valve specimens from 26 aortic valve replacement patients as well as 4 healthy control tricuspid aortic valves were included. 10 patients had bicuspid aortic valves, and 16 had tricuspid aortic valves. Half of our patient population had a concomitant aortic procedure for aortic pathology. The study detected MMPs 1,2 and 9 as well as their Tissue inhibitors (TIMPs) 1 and 2. MMP and TIMP detection was accomplished with the construction of a tissue micro array and immunohistochemistry. CONCLUSIONS: MMP-9 expression was significantly higher in bicuspid aortic valves compared to normal valves (P<0.05). When compared to the tricuspid valve group, MMP-9 mean value was significantly higher in bicuspid valves (P<0.05). When the entire rest of the valve group (n=4+16, i.e. control and tricuspid valve groups) was compared to the bicuspid valve group, bicuspid valves had significantly higher MMP-2, and MMP-9 (P<0.01) expression. TIMP expression also changed in diseased valves, among different patient groups. This increased proteolytic presence in bicuspid aortic valves may attribute to the observed decreased elastin and collagen content, and their resultant functional failure.

Increased tissue microarray matrix metalloproteinase expression favors proteolysis in thoracic aortic aneurysms and dissections.

BACKGROUND: Little information is available regarding the role of matrix metalloproteinases (MMPs) in thoracic aortic aneurysms and dissections. We applied tissue microarray analysis to determine MMP profiles in a large group of surgically resected thoracic aneurysms and dissections. METHODS: Specimens from 47 patients undergoing a variety of surgical procedures for thoracic aneurysm (n = 30) and dissection (n = 17) were included. Expression of MMP-1, MMP-2, and MMP-9 and tissue inhibitors of metalloproteinases (TIMP-1 and TIMP-2) were assessed by aortic tissue microarray immunostaining. Matrix metalloproteinase and TIMP expression in aortic tissue was compared with seven control aortic specimens, free of any vascular disease. RESULTS: Expression of MMP-1 and MMP-9 was significantly increased in aneurysm and aortic dissection patients compared with control specimens (p < 0.05). Expression of TIMP-2 was significantly increased in the entire patient group, compared with control specimens (p < 0.05). Aortic dissection patients had higher MMP-2 and MMP-9 expression than aortic aneurysm patients in areas of disease. Compared with control patients, the MMP-9 to TIMP-1 ratio (a relative index of proteolytic state) was increased in both the aortic aneurysm and dissection groups (p < 0.05). CONCLUSIONS: The increased MMP expression in aortic aneurysms and dissections indicates a metamorphosis in the aneurysm wall toward increased proteolysis compared with the normal aorta. Furthermore, we find even higher MMP-2 and MMP-9 presence in aortic dissection. In both aneurysms and dissections, this transformation to a proteolytic state likely plays an important pathophysiologic role in the development and progression of the aortic disease. The recognition of this pathophysiologic mechanism raises the potential for drug therapy to interrupt the cascade of events.

Current assessment and management of spontaneous pneumomediastinum: experience in 24 adult patients.

OBJECTIVES: Spontaneous pneumomediastinum (SPM) is an uncommon, benign, self-limited disorder that usually occurs in young adults without any apparent precipitating factor or disease. The purpose of this study was to review our experience in dealing with this entity and detail a reasonable course of assessment and management. METHODS: A retrospective case series was conducted to identify adult patients with SPM who were diagnosed and treated in a single institution between 1993 and 2000. RESULTS: Twenty-four patients were identified who included 18 men and 6 women with a mean age of 17.5 years. Acute onset chest pain was the predominant symptom at presentation. Only half of the patients developed clinically evident subcutaneous emphysema. The most frequent precipitating factor was a history of illegal drug abuse seen in 25% of patients. Other factors included asthmatic bronchospasm, physical activity and violent coughing or vomiting. Chest radiography and computerized tomography (CT) were diagnostic in all cases with CT scan revealing six cases with associated pulmonary abnormalities. Esophagogram and flexible bronchoscopy were selectively used. Twelve patients (50%) were admitted to the hospital. Their mean hospital stay was 2 days. All patients were conservatively treated. In a follow-up of 3-10 years no complications or recurrences were observed. CONCLUSIONS: SPM follows alveolar rupture in the pulmonary interstitium. It shows a rising incidence in young drug users. It has a wide range of clinical features necessitating a high index of suspicion. Chest X-ray and CT scan should be always performed. Hospitalization and aggressive approach should be limited. SPM responds well to conservative treatment and follows a benign natural course.