Scuba diving after a heart transplant: excessive daring or calculable risk?

Over the past 50 years, outcomes after heart transplantation (HTX) have continuously and significantly improved. In the meantime, many heart transplant recipients live almost normal lives with only a few limitations. In some cases, even activities that actually seemed unreasonable for these patients turn out to be feasible. This article describes the encouraging example of a patient returning to recreational scuba diving after HTX. So far, there were no scientific experiences documented in this area. We worked out the special hemodynamic features and the corresponding risks of this sport for heart transplant recipients in an interdisciplinary manner and evaluated them using the patient as an example. The results show that today, with the appropriate physical condition and compliance with safety measures, a wide range of activities, including scuba diving, are possible again after HTX. They illustrate again the significant development and the enormous potential of this therapy option, which is unfortunately only available to a limited extent.NEW & NOTEWORTHY Example for shared decision-making process for tricky questions: First scientific publication about heart transplantation (HTX)-recipient restarting scuba diving. As exercise physiology after HTX combined with specific diving medicine aspects is challenging, we formed a multidisciplinary team to identify, evaluate, and mitigate the risks involved. The results show that today, with the appropriate physical condition and compliance with safety measures, a wide range of activities are possible again after HTX.

Treatment of the aortic root in acute aortic dissection type A: insights from the German Registry for Acute Aortic Dissection Type A

OBJECTIVES

Surgery of the aortic root in acute aortic dissection type A (AADA) remains a topic of vague evidence since the extend of dissection and surgeons' capability and interpretation of the disease vary remarkably. We aimed to interpret root operation strategies in the German Registry for Acute Aortic Dissection cohort.

METHODS

German Registry for Acute Aortic Dissection collected the data of 56 centres between July 2006 and June 2015. A total of 3382 patients undergoing operations for AADA were included and divided into 3 groups according to aortic root procedure types: supracommissural replacement (SCR), conduit replacement (CR) and valve sparing root replacement (VSRR).

RESULTS

Patients in SCR (2425, 71.7%) were significantly older than CR (681, 20.1%) and VSRR (276, 8.2%) (63.4 vs 57.5 vs 54.2 years; P < 0.001), more female (38.9% vs 32.0% vs 26.1%; P < 0.001) and presented with less aortic regurgitation (26.3% vs 57.1% vs 56.5%; P < 0.001). VSRR presented with slightly less multiple organ malperfusion (11.6% vs 12.0% vs 10.9%; P = 0.045) and were more often diagnosed for Marfan syndrome (2.4% vs 5.1% vs 9.1%; P < 0.001). Thirty-day mortality was lower for VSRR (11.6%) compared to SCR (16.1%) and CR (19.8%; P = 0.010). Despite longer procedural times, multivariable regression showed no influence of total arch replacement for VSRR on mortality compared to CR (odds ratio 0.264; 95% confidence interval, 0.033-2.117; P = 0.21).

CONCLUSIONS

SCR remains the procedure of choice in elderly and compromised patients. Extended root preservation techniques may be applied even in combination with extended aortic arch surgery for selected patients for AADA with promising early outcomes.

Identification of a Blood-Based Protein Biomarker Panel for Lung Cancer Detection

Lung cancer is the deadliest cancer worldwide, mainly due to its advanced stage at the time of diagnosis. A non-invasive method for its early detection remains mandatory to improve patients’ survival. Plasma levels of 351 proteins were quantified by Liquid Chromatography-Parallel Reaction Monitoring (LC-PRM)-based mass spectrometry in 128 lung cancer patients and 93 healthy donors. Bootstrap sampling and least absolute shrinkage and selection operator (LASSO) penalization were used to find the best protein combination for outcome prediction. The PanelomiX platform was used to select the optimal biomarker thresholds. The panel was validated in 48 patients and 49 healthy volunteers. A 6-protein panel clearly distinguished lung cancer from healthy individuals. The panel displayed excellent performance: area under the receiver operating characteristic curve (AUC) = 0.999, positive predictive value (PPV) = 0.992, negative predictive value (NPV) = 0.989, specificity = 0.989 and sensitivity = 0.992. The panel detected lung cancer independently of the disease stage. The 6-protein panel and other sub-combinations displayed excellent results in the validation dataset. In conclusion, we identified a blood-based 6-protein panel as a diagnostic tool in lung cancer. Used as a routine test for high- and average-risk individuals, it may complement currently adopted techniques in lung cancer screening.

Magnetic resonance-guided placement of aortic stents grafts: feasibility with real-time magnetic resonance fluoroscopy

PURPOSE

The artifact behavior of different aortic stent-grafts was evaluated with real-time magnetic resonance (MR) imaging, and the feasibility of real-time MR-guided stent-graft placement in the abdominal aorta was tested.

MATERIALS AND METHODS

Seven different stent-grafts and their deployment systems were analyzed in an in vitro setting regarding their artifacts on different real-time MR images with cartesian, spiral, and radial k-space filling. The device and the real-time sequence with the fewest artifacts were used for an in vivo study in a swine model. In four animals, a straight aortic stent-graft was placed in the infrarenal abdominal aorta under real-time MR guidance. Results were controlled with MR angiography, multislice spiral computed tomography, and digital subtraction angiography.

RESULTS

The in vitro study proved only one of the seven stent grafts (including deployment systems) to be suitable for real-time MR-guided intervention. MR-guided placement of the stent-grafts was possible in all animals. In one animal, the stent-graft dislocated during withdrawal of the deployment system as a result of a mismatch between stent-graft diameter and size of the infrarenal aorta.

CONCLUSION

Real-time MR-guided placement of stent-grafts in the abdominal aorta with use of commercially available standard instruments is feasible. However, for clinical use, dedicated devices and deployment systems producing less artifacts are required.

Polysegmental spondylodiscitis and concomitant aortic aneurysm rupture: case report with 3-year follow-up period

STUDY DESIGN

A case report describing a patient with spondylodiscitis of the thoracic and lumbar spine complicated by rupture of an abdominal aortic aneurysm and aggravation of neurologic symptoms is presented.

OBJECTIVE

To present a cardiovascular complication worsening the clinical condition during conservative spondylodiscitis therapy, and to describe a minimally invasive treatment regimen for both spondylodiscitis and aortic aneurysm rupture in multimorbid patients at high risk for complications or refusal of surgery.

SUMMARY OF BACKGROUND DATA

Few articles describe minimally invasive treatment of spondylodiscitis. Some available reports describe neurologic symptoms resulting from spinal cord ischemia in aortic aneurysm rupture. No data were found describing simultaneous therapy for spondylodiscitis and rupture of aortic aneurysm.

METHODS

Therapy consisted of CT-guided percutaneous drainage of the spondylodiscitis and parenteral antibiotic treatment combined with immobilization and minimally invasive endoluminal exclusion of the aortic aneurysm with a bifurcated stent graft.

RESULTS

Effective therapy for polysegmental spondylodiscitis on the one hand and contained rupture of aortic aneurysm on the other are presented. The successful clinical outcome after conservative orthopedic therapy and vascular intervention has been followed for 3 years.

CONCLUSIONS

In older patients, spondylodiscitis may be complicated by other underlying diseases. Pain and neurologic symptoms may occur secondarily to concomitant illnesses instead of being caused by the inflammation itself. Minimally invasive therapy is shown to be an effective alternative to surgery in older and multimorbid patients with spondylodiscitis and contained aortic aneurysm rupture.

[Weakly malignant leiomyosarcoma of the inferior vena cava. A case report]

Primary vascular leiomyosarcomas of the great vessels are rare and the most common localization is the inferior vena cava. Due to nonspecific clinical signs, diagnosis is often made during operation or autopsy. At present, a radical tumor resection is the first choice of treatment. This is a case report of a 49-year-old woman who suffered from abdominal pain for 10 years because of a weakly malignant leiomyosarcoma of the inferior vena cava. A radical tumor resection and reconstruction with a prosthetic vascular graft were performed. Diagnosis, therapy, and prognosis are discussed.

Long-term results 10 years after iliac arterial stent placement

PURPOSE

To retrospectively evaluate results in 110 patients who had iliac arterial occlusive disease and were treated with stents before 1991.

MATERIALS AND METHODS

From 1987 to 1990, 110 patients (mean age, 57 years) with iliac arterial occlusive disease (Fontaine stage IIa, seven patients; IIb, 95 patients; III, four patients; IV, four patients) underwent implantation of a self-expanding metal stent. Stenoses (n = 66) were treated after failed angioplasty, and occlusions (n = 60) were treated with primary stent placement. Follow-up included angiography and/or color duplex ultrasonography and clinical examination with ankle-brachial index measurement. Patients lost to follow-up were interviewed by using dedicated questionnaires administered by telephone and/or mail. If a patient was deceased, relatives and attending doctors were interviewed.

RESULTS

The fate of 109 of the 110 patients was determined. Overall, 46 patients died: 18 within 5 years, 39 within 10 years, and seven after more than 10 years. The 5- and 10-year survival rates were 83% and 64%, respectively. Cardiovascular disease caused 23 deaths; malignant tumor caused 15. The cause of death remained unknown in five patients. Primary stent patency rates were 66% +/- 4.8 (standard error) after 5 years and 46% +/- 5.9 after 10 years; secondary patency rates were 79% +/- 4.2 after 5 years and 55% +/- 6.3 after 10 years (Kaplan-Meier test). Seventeen (16%) patients underwent surgical bypass of the aortoiliac arteries that involved the segment with the stent, 14 because of stent restenosis and three because of stenosis in other iliac arterial segments.

CONCLUSION

The main cause of death in patients with intermittent claudication was cardiac disease. Long-term patency of iliac arterial stents was moderate.

Tissue engineering: complete autologous valve conduit--a new moulding technique

OBJECTIVE

The use of fibrin gel, which can be produced from patients' blood, was investigated as an autologous, biodegradable scaffold. A new moulding technique was developed to create a complete aortic root.

METHODS

A new moulding technique was generated for the creation of complete valve conduit. On the basis of biomechanical valve design studies, a tricuspid "ventricular" and "aortic" stamp were developed. A silicone-coated aluminum cylinder was used to circumferentially limit the mould. The cell/gel suspension was filled into the mould and polymerization was started.

RESULTS

The creation of complex structures such as complete valve conduits is possible with the moulding technique described. With a layer thickness of up to 2 mm, histological investigations showed excellent tissue development with viable fibroblasts surrounded by collagen bundles.

CONCLUSION

Fibrin gel unifies many properties of an ideal scaffold: The formation of complex structures is possible, the degradation and polymerization is controllable and the formation of the extracellular matrix is excellent.

The St. Jude "Silzone" valve: midterm results in treatment of active endocarditis

BACKGROUND

The Silzone-coated St. Jude Medical valve (SJM "Silzone" valve), developed to reduce prosthetic valve endocarditis (PVE), was recalled by SJM due to a higher rate of paravalvular leaks. The aim of this study was to determine the efficacy of the SJM "Silzone" valve in avoiding PVE and to evaluate the frequency of paravalvular leaks, when the valve was used exclusively for active bacterial endocarditis.

METHODS

From January 1998 to December 1999, the SJM "Silzone" valve was implanted in 40 consecutive patients with active endocarditis (20 aortic, 14 mitral, and 6 both valves). Late transesophageal echocardiography was performed in 87% of survivors, and transthoracic echocardiography in the remaining 13%. Follow-up was 100%.

RESULTS

Hospital mortality was 17.5%. Early PVE occurred in 2 of 40 patients (5%). There were two late deaths without signs of recurrent PVE. A hemodynamic relevant paravalvular leak necessitating reoperation was seen in 2 patients within 6 months after operation. The rate of a minor paravalvular leak was 13% (4 of 31 patients).

CONCLUSIONS

The SJM "Silzone" valve when implanted for active bacterial endocarditis does not give better results than other mechanical prostheses with regard to early recurrence of endocarditis. The rate of a hemodynamic relevant paravalvular leak requiring reoperation seems rather high during the early postoperative period, whereas the occurrence of minor paravalvular leaks is comparable with that of other mechanical prostheses. Routine observation, recommended for all patients with mechanical heart valves, is also sufficient for patients with the SJM "Silzone" valve.

Fibrin gel -- advantages of a new scaffold in cardiovascular tissue engineering

OBJECTIVE

The field of tissue engineering deals with the creation of tissue structures based on patient cells. The scaffold plays a central role in the creation of 3-D structures in cardiovascular tissue engineering like small vessels or heart valve prosthesis. An ideal scaffold should have tissue-like mechanical properties and a complete immunologic integrity. As an alternative scaffold the use of fibrin gel was investigated.

METHODS

Preliminary, the degradation of the fibrin gel was controlled by the supplementation of aprotinin to the culture medium. To prevent tissue from shrinking a mechanical fixation of the gel with 3-D microstructure culture plates and a chemical fixation with poly-L-lysine in different fixation techniques were studied. The thickness of the gel layer was changed from 1 to 3 mm. The tissue development was analysed by light, transmission and scanning electron microscopy. Collagen production was detected by the measurement of hydroxyproline. Injection molding techniques were designed for the formation of complex 3-D tissue structures.

RESULTS

The best tissue development was observed at an aprotinin concentration of 20 microg per cc culture medium. The chemical border fixation of the gel by poly-L-lysine showed the best tissue development. Up to a thickness of 3 mm no nutrition problems were observed in the light and transmission electron microscopy. The molding of a simplified valve conduit was possible by the newly developed molding technique.

CONCLUSION

Fibrin gel combines a number of important properties of an ideal scaffold. It can be produced as a complete autologous scaffold. It is moldable and degradation is controllable by the use of aprotinin.

[Changes in the region and the proximal aneurysm neck after endovascular repair of infrarenal aortic aneurysms]

PURPOSE

To analyze short and mid-term changes of the proximal aneurysm neck and to evaluate renal function after endovascular repair of infrarenal abdominal aortic aneurysms.

MATERIALS AND METHODS

24 of 29 patients, who were treated endoluminally with the bifurcated Vanguard Stent graft between 1997 and 1999 underwent spiral CT follow-up after 1, 3, 6 and every 12 months. Mean follow-up period was 10.5 months (3-32 months). Follow-up included spiral CT scanning. The aortic diameter as well as cross-sectional area were measured. Stent graft position and renal perfusion were checked by spiral CT. Serum creatinine levels were determined preoperatively and during follow-up.

RESULTS

Supra- and infrarenal aortic sizes remained stable. No correlation to the distance between the stent-graft and the renal arteries was observed. Caudal migration of the stent-graft with an average of 6.5 (3-15) mm occurred in 13 patients. Cranial migration was observed in 3 patients. Uncovered stent wires partially overlapped at least one renal artery in 18 patients. No renal infarction occurred. No significant increase of the serum creatinine level was found.

CONCLUSION

The risk of proximal endoleakage due to post-interventional dilatation of the aorta abdominalis seems to be low. Insufficient stent graft fixation requires a wide distance between the proximal end of the stent graft and the aneurysm. In the mid-term uncovered stent wires overlapping the renal arteries had no relevant influence on renal function.

[Hepatic ischaemia during Whipple resection: case report of a rarely required revascularisation]

With the performance of a partial duodenopancreatectomy, the collateral vascular bed between the coeliac trunk and the superior mesenteric artery is reduced. Normally, this does not lead to ischaemia of the upper abdominal organs. However, we present the rare case of a patient in whom a Whipple resection in combination with a hyploplastic coeliac trunk led to hepatic and splenal ischaemia and aorto-hepatic bypass grafting. The indication for preoperative arteriography is in discussion, since variations or alteration of the upper abdominal vessels are known to be common but manifest organ ischaemia during resection is a rare complication. Patients with signs of general arteriosclerosis or those in whom upper abdominal resection has been performed previously may benefit from angiography. In other cases a test occlusion before vessel ligation is considered to be suitable in assessing the need for vascular surgical intervention.

Septic endarteritis and fatal iliac wall rupture after endovascular stenting of the common iliac artery

A 52-year-old female with arterial occlusive disease underwent an uneventful percutaneous transluminal angioplasty and placement of a vascular metallic stent in the left common iliac artery. Ten days later she presented with clinical symptoms of septic endarteritis. Shortly after re-admittance, an emergency laparotomy had to be performed because of an acute retroperitoneal bleeding. Rupture of the common iliac artery directly overlaying the penetrating stent was found but control of haemorrhage was of no avail. In this report of a case, septic endarteritis following placement of a vascular metallic stent preceded fatal rupture of the common iliac artery. This up to now unknown constellation requires surgical intervention without undue delay.

Percutaneous retrieval of a central venous catheter sutured to the wall of the right atrium

A transjugular central venous catheter was inadvertently sutured to the wall of the right atrium in a 63-year-old female during coronary bypass surgery. Using two nitinol Goose Neck snares via a transfemoral and a transjugular approach the catheter was severed into two pieces and retrieved percutaneously.

[Novel endoluminal stents for the treatment of arterial fistulas and perforations]

PURPOSE

To evaluate the use of polycarbonate-polyurethane (Corethane) stented grafts for the treatment of arteriovenous fistulas and arterial perforations.

MATERIALS AND METHODS

4 patients at the age of 34 to 81 underwent percutaneous insertion of corethane endoluminal grafts. Two patients had an arterial fistula--one iliaco-iliac, one brachio-brachial. Two patients underwent treatment to seal arterial perforations that occurred in the external iliac artery in one and in a femoral venous bypass in another.

RESULTS

In all cases the communication or leakage was sealed by the endograft in place but had to be combined with a detachable balloon in om case. In three patients, a longer follow-up became available, one patient died three weeks after treatment from unrelated causes. While two stent grafts remained open for 15 and 24 months, one patient experienced stent graft occlusion three months after treatment.

CONCLUSIONS

Corethane stent grafts are helpful to seal short-neck arteriovenous fistulas and arterial perforations even under emergency conditions.

Alterations of glucose levels in the blood and the anterior eye segment of rabbits exposed to ketamine-xylazine anaesthesia

In rabbits the blood glucose and consequently the aqueous humour glucose levels were increased under general anaesthesia by Ketanest-xylazine. Between 60 and 90 min of the general anaesthesia the average blood glucose levels were found to be three times and those of the aqueous humour twice the normal values. After more than 75 min of anaesthesia the glucose levels tended to be further elevated.