HGF and SDF-1-mediated mobilization of CD133+ BMSC for hepatic regeneration following extensive liver resection.

BACKGROUND: The molecular mechanisms of haematopoietic stem cells (HSC) mobilization and homing to the liver after partial hepatectomy (PH) remain largely unexplored. METHODS: Functional liver volume loss and regain was determined by computerized tomography (CT) volumetry in 30 patients following PH. Peripheral HSC mobilization was investigated by fluorescence-activated cell sorting (FACS) analyses and cytokine enzyme-linked immunosorbent assay assays. Migration of purified HSC towards hepatic growth factor (HGF) and stroma-derived factor-1 (SDF-1) gradients was tested in vitro. Mice after 70% PH were examined for HSC mobilization by FACS and cytokine mRNA expression in the liver. FACS-sorted HSC were administered after PH and hepatocyte proliferation was evaluated by immunohistochemical staining for Ki67. RESULTS: Impaired liver function was noted after extended hepatic resection when compared to smaller resections. Patients with large liver resections were characterized by significantly higher levels of peripheral HSC which were positively correlated with the extent of resected liver volume and its regain after 3 weeks. Increased plasma levels of HGF, SDF-1 and insulin like growth factor (IGF-1) were evident within the first 6 hours post resection. Migration assays of human HSC in vitro showed a specific target-demonstrated migration towards recombinant HGF and SDF-1 gradients in a concentration and specific receptor (c-Met and CXCR4) dependent manner. The evaluation of peripheral human alpha foetoprotein expression demonstrated pronounced stemness following increased CD133(+) HSC in the course of liver regeneration following PH. Our human data were further validated in a murine model of PH and furthermore demonstrated increased hepatocyte proliferation subsequent to CD133(+) HSC treatment. CONCLUSION: HGF and SDF-1 are required for effective HSC mobilization and homing to the liver after hepatic resection. These findings have significant implications for potential therapeutic strategies targeting chemotactant modulation and stem cell mobilization for liver protection and regeneration.

CD39 modulates hematopoietic stem cell recruitment and promotes liver regeneration in mice and humans after partial hepatectomy.

OBJECTIVE: To study molecular mechanisms involved in hematopoietic stem cell (HSC) mobilization after liver resection and determine impacts on liver regeneration. BACKGROUND: Extracellular nucleotide-mediated cell signaling has been shown to boost liver regeneration. Ectonucleotidases of the CD39 family are expressed by bone marrow-derived cells, and purinergic mechanisms might also impact mobilization and functions of HSC after liver injury. METHODS: Partial hepatectomy was performed in C57BL/6 wild-type, Cd39 ectonucleotidase-null mice and in chimeric mice after transplantation of wild-type or Cd39-null bone marrow. Bone marrow-derived HSCs were purified by fluorescence-activated cell sorting and administered after hepatectomy. Chemotactic studies were performed to examine effects of purinergic receptor agonists and antagonists in vitro. Mobilization of human HSCs and expression of CD39 were examined and linked to the extent of resection and liver tests. RESULTS: Subsets of HSCs expressing Cd39 are preferentially mobilized after partial hepatectomy. Chemotactic responses of HSCs are increased by CD39-dependent adenosine triphosphate hydrolysis and adenosine signaling via A2A receptors in vitro. Mobilized Cd39 HSCs boost liver regeneration, potentially limiting interleukin 1ß signaling. In clinical studies, mobilized human HSCs also express CD39 at high levels. Mobilization of HSCs correlates directly with the restoration of liver volume and function after partial hepatectomy. CONCLUSIONS: We demonstrate CD39 to be a novel HSC marker that defines a functionally distinct stem cell subset in mice and humans. HSCs are mobilized after liver resection, limit inflammation, and boost regeneration in a CD39-dependent manner. These observations have implications for monitoring and indicate future therapeutic avenues.

How acute renal failure led to the diagnosis of aortic coarctation.

The present case report focuses on a rare presentation of aortic coarctation. A 38-year-old man with well-controlled arterial hypertension, minimal change glomerulonephritis and colitis ulcerosa was suffering from recurrent acute renal failure episodes during viral gastroenteritis. No other symptoms at rest or during physical activity were present. The workup included renal duplex sonography, which unmasked tardus parvus profile in both kidneys without any acceleration of blood flow in the renal arteries. Further examination included CT angiography, which confirmed the diagnosis of aortic coarctation. The observed narrowing of the aorta measured 4 mm and was treated with percutaneous transluminal angioplasty and stent implantation (final diameter 12 mm). After the procedure, the patient had normal blood pressure values without the need of any medication; duplex sonography showed improved renal perfusion. The present case confirms the importance of evaluation for secondary hypertension and thorough workup of acute renal failure in young patients.

Minimally invasive application of thrombin in the treatment of pseudoaneurysms following open aortic surgery.

BACKGROUND: Anastomotic leaks are uncommon complications following aortic surgery. To avoid the morbidity associated with a second surgical procedure, minimally invasive techniques have become increasingly popular. PURPOSE: To evaluate the feasibility and safety of thrombin in interventional treatment of postoperative pseudoaneurysms. MATERIAL AND METHODS: CT-guided percutaneous injection was chosen in four cases. Endovascular access using an occlusion balloon catheter placed in the orifice of the pseudoaneurysm was utilized in one case. RESULTS: The average volume of all pseudoaneurysms was 178 ± 190 mL with a volume of the patent lumen of 25 ± 28 mL. All aneurysms thrombosed after injection of 600 ± 237 IU of thrombin. During the follow-up period of an average of 10 months all pseudoaneurysms remained occluded. CONCLUSION: Our series demonstrates the feasibility of thrombin in the treatment of aortic anastomotic pseudoaneurysms. In combination with occlusion balloon catheters, even wide-necked pseudoaneurysms may be treated successfully. However, further investigations are warranted.

Update: Selective adrenal venous sampling (AVS) - Indication, technique, and significance. / Update: Selektive Nebennierenvenenblutentnahme (NNVBE) ­ Indikation, Technik und Stellenwert.

BACKGROUND: Primary aldosteronism (PA) is the most common detectable cause of secondary hypertension. The majority of patients have either an adrenal aldosterone-producing adenoma (APA) or bilateral adrenal hyperplasia (BAH) demanding different therapeutic approaches. Screening tests and imaging cannot reliably distinguish between a unilateral or bilateral PA. METHODS: This review article gives an overview concerning etiology, diagnostics, and therapeutic options of PA, and reviews the indication, the technique, and relevance of selective adrenal venous sampling (AVS) in the context of the current literature and the authors' experience. RESULTS: AVS can verify or exclude a unilaterally dominated secretion with a high success rate. Patients with PA and a unilateral APA can be treated curatively by adrenalectomy. CONCLUSIONS: AVS is an established diagnostic examination for differentiation of unilateral from bilateral adrenal disease in patients with PA. KEY POINTS: · Selective adrenal venous sampling (AVS) is a safe, reliable, and minimally invasive method to detect a unilateral or bilateral adrenal adrenal gland disease.. · Verification of lateralization by AVS has direct therapeutic relevance for patients with primary aldosteronism (PA).. · AVS can be performed with low radiation exposure, without contrast medium, and with a high success rate when performed by an experienced interventional radiologist.. CITATION FORMAT: · Loberg C, Antoch G, Stegbauer J et al. Update: Selective adrenal venous sampling (AVS) - Indication, technique, and significance. Fortschr Röntgenstr 2021; 193: 658 - 666.

Minimally invasive catheter procedures to assist complicated pacemaker lead extraction and implantation in the operating room.

We report on percutaneous catheter procedures in the operating room (OR) to assist complicated manual extraction or insertion of pacemaker (PM) and implantable cardioverter defibrillator leads. We retrospectively reviewed complicated PM revisions and implantations performed between 2004 and 2009 that required percutaneous catheter procedures performed in the OR. The type of interventional procedure, catheter and retrieval system used, venous access, success rates, and procedural complications were analyzed. In 41 (12 female and 29 male [mean age 62 ± 17 years]) of 3021 (1.4%) patients, standard manual retrieval of old leads or insertion of new leads was not achievable and thus required percutaneous catheter intervention for retrieval of misplaced leads and/or recanalisation of occluded central veins. Thirteen of 18 (72.2%) catheter-guided retrieval procedures for misplaced (right atrium [RA] or ventricle [RV; n = 3], superior vena cava [n = 2], brachiocephalic vein [n = 5], and subclavian vein [n = 3]) lead fragments in 16 patients were successful. Percutaneous catheter retrieval failed in five patients because there were extremely fixed or adhered lead fragments. Percutaneous transluminal angiography (PTA) of central veins for occlusion or high-grade stenosis was performed in 25 patients. In 22 of 25 patients (88%), recanalization of central veins was successful, thus enabling subsequent lead replacement. Major periprocedural complications were not observed. In the case of complicated manual PM lead implantation or revision, percutaneous catheter-guided extraction of misplaced lead fragments or recanalisation of central veins can be performed safely in the OR, thus enabling subsequent implantation or revision of PM systems in the majority of patients.

Where does it lead? Imaging features of cardiovascular implantable electronic devices on chest radiograph and CT.

Pacemakers and implantable cardioverter defibrillators (ICDs) are being increasingly employed in patients suffering from cardiac rhythm disturbances. The principal objective of this article is to familiarize radiologists with pacemakers and ICDs on chest radiographs and CT scans. Therefore, the preferred lead positions according to pacemaker types and anatomic variants are introduced in this study. Additionally, the imaging features of incorrect lead positions and defects, as well as complications subsequent to pacemaker implantation are demonstrated herein.

Infrarenal transposition of the superior mesenteric artery: a new approach in the surgical therapy for Wilkie syndrome.

The superior mesenteric artery syndrome, also known as Wilkie syndrome or as arteriomesenteric obstruction of the duodenum, is a rare condition of upper intestinal obstruction in which the third part of the duodenum is compressed by the overlying, narrow-angled superior mesenteric artery against the posterior structures. It is characterized by early satiety, recurrent vomiting, abdominal distention, weight loss, and postprandial distress. When nonsurgical management is not possible or the problem is refractory, surgical intervention is necessary. Usually a laterolateral duodenojejunostomy or Roux-en-Y reconstruction for reconstruction of the intestinal passage is performed. We report the first successful transposition, to our knowledge, of the superior mesenteric artery into the infrarenal aorta in the therapy of Wilkie syndrome.

Surgical access to jejunal veins for local thrombolysis and stent placement in portal vein thrombosis.

Portal vein thrombosis is an infrequent entity, which may cause high morbidity and mortality. We report a case of portal vein thrombosis due to benign stenosis following partial pancreatoduodenectomy with segmental replacement of the portal vein by a Gore-tex graft. Using a surgical access to jenunal veins, local thrombolysis, mechanical fragmentation of thrombus, and stent placement were successfully performed.

Minimally invasive therapy of pseudoaneurysms of the trunk: application of thrombin.

Thrombin injection has been proven to be successful in postcatheterization pseudoaneurysms. However, there are only a few reports on the treatment of pseudoaneurysms of the trunk. We report our first experiences using a percutaneous as well as an endovascular access. Eight iatrogenic pseudoaneurysms of the trunk (aorta, n = 4; pulmonary artery, n = 1; gastroduodenal artery, n = 1; left gastric artery, n = 1, renal artery, n = 1) were treated either percutaneously using CT guidance (n = 3) or via an endovascular access (n = 5). Noninvasive control angiograms were performed at day 1 and weeks 1 and 3 by either CT or MR angiography. The total volume of the pseudoaneurysms was 31.2 +/- 23.1 ml on average, with a mean volume of the perfused aneurysmal lumen of 12.9 +/- 7.2 ml. The maximum diameter was 4.1 +/- 1.39 cm on average. In each case, the aneurysmal neck was not wider than 2 mm. One pseudoaneurysm occluded spontaneously following selective catheterization. The remaining pseudoaneurysms were successfully treated by injection of 765 +/- 438.1 IU thrombin. In one individual, a nontarget embolization occurred, as well as an intervention-associated rupture of a pseudoaneurysm. High-grade stenoses of the donor artery were found in a different case. Only once was the endoluminal access converted to a percutaneous one. Thrombin injection might be a future first-line treatment of vascular lesions such as pseudoaneurysms of the trunk. In our experience both percutanous and endoluminal access are technically feasible and safe. However, further experiences are mandatory, especially concerning the question of dosage and long-term results.

Portal vein embolization and autologous CD133+ bone marrow stem cells for liver regeneration: initial experience.

PURPOSE: To prospectively evaluate the effectiveness of portal vein embolization (PVE) and CD133(+) bone marrow stem cell (BMSC) administration to the liver, compared with PVE alone, to augment hepatic regeneration in patients with large hepatic malignancies. MATERIALS AND METHODS: The study was approved by the institutional ethics committee; informed consent was obtained. Thirteen patients underwent PVE of liver segments I and IV-VIII to stimulate hepatic regeneration prior to extended right hepatectomy. In six patients (three men, three women; mean age, 61 years; range, 46-72 years) with a future liver remnant volume (FLRV) below 25% and/or limited quality of hepatic parenchyma, PVE alone did not promise adequate proliferation. These patients underwent BMSC administration to segments II and III (group I). In seven patients (three men, four women; mean age, 69 years; range, 63-75 years) with an FLRV below 25%, PVE alone was performed (group II). Two radiologists blinded to patients' identity and each other's results measured liver and tumor volumes with helical computed tomography. Absolute, relative, and daily FLRV gains were compared by using the t test or the Wilcoxon test. RESULTS: The increase of the mean absolute FLRV in group I from 239.3 mL +/- 103.5 (standard deviation) to 417.1 mL +/- 150.4 was significantly higher than that from 286.3 mL +/- 77.1 to 395.9 mL +/- 94.1 in group II (P = .049). The relative gain of FLRV after PVE in group I (77.3% +/- 38.2) was significantly higher than that in group II (39.1% +/- 20.4) (P = .039). The daily hepatic growth rate in group I (9.5 mL/d +/- 4.3) was significantly superior to that in group II (4.1 mL/d +/- 1.9) (P = .03). Time to surgery was 27 days +/- 11 in group I and 45 days +/- 21 in group II (P = .057). CONCLUSION: In patients with malignant liver lesions, the combination of PVE with CD133(+) BMSC administration substantially increased hepatic regeneration compared with PVE alone.

Reconstruction for renal artery aneurysm: operative techniques and long-term results.

BACKGROUND: Ninety-four patients (37 male, 57 female; mean age, 51.0 years) underwent reconstruction for renal artery aneurysm (RAA) between 1980 and 2001. RAAs were present in 52 patients in the right kidney, in 29 patients in the left kidney, and in 13 patients in both kidneys. Eighty-three aneurysms were located in the mainstem, 49 in a branch artery, and four in an accessory artery. Additional ipsilateral renal artery stenoses (RAS) occurred in 26 patients, bilateral RAS in 18, and contralateral RAS in six. The causes of RAA were fibromuscular dysplasia (n = 48), atherosclerosis (n = 28), dissection (n = 7), aortic coarctation (n = 5), arteritis (n = 3), giant cell arteritis (n = 1), Marfan's syndrome (n = 1), and trauma (n = 1). Seventy-five patients had hypertension, 14 were asymptomatic, and five had rupture. Indications for RAA repair concerned aneurysms with 1 cm or more diameter in combination with risk factors of hypertension, ipsilateral and contralateral stenosis, and childbearing age in women. Without risk factors, aneurysm size eligible for reconstruction was limited to 2 cm or more. METHODS: Methods applied for reconstruction in 107 kidneys and 136 aneurysms included aneurysm resection with tailoring (n = 37), saphenous vein graft interposition (n = 40), tailoring and saphenous vein graft interposition (n = 7), resection and reanastomosis (n = 14), saphenous vein graft interposition and resection and reanastomosis (n = 3), polytetrafluoroethylene bypass (n = 5), and homologous vein graft interposition (n = 1). Four reconstructions had to be performed ex situ because of multiple branch involvement in three patients and rupture in one. In all patients, the concerned kidney was protected with hypothermic flush perfusion with addition of heparin and prostaglandin E1. RESULTS: The overall morbidity rate was 17%, including one early graft occlusion, one partial thrombosis of the renal artery that necessitated fibrinolytic therapy, and a branch artery stenosis after tailoring managed with aortorenal bypass. The mortality in elective cases was null; one patient died of myocardial infarction 2 days after an emergency operation for ruptured RAA. The technical primary success rate was 96.8%; the secondary success rate was 98.9%. After a follow-up period from 1 to 143 months (mean, 46 months) in 83 patients (88%), 67 (81%) had patent renal arteries free of stenoses. Among six patients with RAS, four underwent successful reoperation, five had mainstem occlusions, three had segmental artery occlusions, and two underwent nephrectomy. Concerning the patients who underwent reoperation, percutaneous transluminal angioplasty was considered seriously but assessed as inappropriate because of long extension of stenosis or involvement of branch arteries. Hypertension was cured in 19 patients (25%) and improved in 17 (22%). CONCLUSION: Surgical reconstruction of RAA is a safe procedure that provides good long-term results, prevents aneurysm rupture, cures or improves hypertension in about half of the cases, and can be achieved with autogenous reconstruction in 96%.

Prophylactic nasal continuous positive airway pressure after major vascular surgery: results of a prospective randomized trial.

BACKGROUND: The efficacy of nasal continuous positive airway pressure (nCPAP) as a prophylactic method for preventing cardiopulmonary complications after major vascular surgery has not been investigated. PATIENTS/METHODS: In a prospective randomized trial, 204 patients undergoing elective midline laparotomy for vascular surgery were randomized to receive standard therapy ( n=105) or additional prophylactic nCPAP ( n=99) for the first postoperative night. Postoperative oxygenation, incidence of severe cardiac, and pulmonary complications, length of intensive care surveillance and length of total postoperative hospital stay (LOS) were compared. RESULTS: Prophylactic nCPAP significantly reduced the number of patients with severe oxygenation disturbances defined as paO(2) < 70 mmHg with FiO(2) > or = 0.7 (5 versus 17, P=.01). There were no differences with respect to death, cardiac and pulmonary complications, length of intensive care surveillance or LOS. CONCLUSION: Prophylactic 12 h nCPAP significantly reduces the occurrence of postoperative oxygenation disturbances but has no effect on cardiac or pulmonary complications, need for intensive care, LOS or mortality after major vascular surgery.