Case Reports

Case 1: Less invasive mitral valve repair with remote smart canulation

Less invasive mitral valve surgery with small access is increasingly popular. Remote canulation for CPB is an additional step for further reduction of the access aperture in the chest. In this setting, we usually perform first a small anterior mini-thoracotomy in the fifth intercostal space, just at the level of the atria. In females, the skin incision is placed in the sub-mammary grove, which is marked in the up-right position in the evening before surgery. A flexible video-endoscope with a tip-mounted camera and lens rinsing capability is then introduced either through the mini-thoracotomy or an additional port, which is later used for drainage. After positioning of a pediatric rib-spreader, the pericardium is opened and its borders are lifted sequentially with disposable elastic hooks which are attached to an extra-thoracic ring. This technique allows for optimization of the exposure because the heart can be pulled up to some degree towards the access aperture in the chest. Femoral arterial and venous smart canulation is our preferred approach in this setting after systemic heparinization. On the venous side, this patient required a 63 cm long, 36F Venous smartcanula (ordering nr V 3/8 36 630 S; for smaller patients, the somewhat shorter 53 cm version with the ordering nr V 3/8 36 530 S may be preferable). The previously exposed femoral vein was punctured with a hollow needle, a guide wire was inserted, and moved up to the right atrium and the superior vena cava respectively, where it was identified by TEE. After small transverse phlebotomy, the Venous smartcanula, stretched on the corresponding mandrel was inserted over the guide wire up to the level of the superior vena cava. The guide wire was removed first to avoid canula tip dislocation, and the mandrel second. The smartcanula was secured with a snare tied to its body. At this stage, care has to be taken, not to occlude the vessel lumen with the smartcanula inside. After canulation of the femoral artery, the perfusion set was connected and CPB was initiated. A vent was inserted into the aortic root, the aorta cross clamped, and the heart arrested with ante-grade blood cardioplegia. The left atrium was entered through a cranio-caudal incision in the Waterstone groove. The mitral valve was exposed and repaired in standard fashion with a quadrangular resection of P2 and consolidated with a ring. Testing with saline showed a tight valve, a finding that was later confirmed by TEE, which demonstrated a nice coaptation surface. The recovery of the patient was uneventful.

Case 2: Mini-invasive mitral valve repair for acute endocarditis during CPB with femoral smart canulation

Acute mitral endocarditis with recurrent peripheral embolization was the indication for mini-invasive mitral valve repair in a 20 years old female patient. A short sub-mammary incision was selected for exposing the left atrium through a retro-mammary anterolateral mini-thoractomy in the sixth intercostal space. The pericardium was opened in cranio-caudal fashion anterior to the phrenic nerve. A series of elastic hooks were placed under progressive tension on the border of the pericardium providing an improved approach to the left atrium. A semi-open approach was selected for remote canulation. A short segment of the common femoral vessels was exposed just below the inguinal ligament. After systemic heparinization, the femoral vein was punctured with a hollow needle, a J-type guide wire was inserted and brought forward up to the superior vena cava as visualized by TEE. The venous access aperture was dilated and a 53 cm long venous smartcanula (ordering nr 3/8 36 530 S) was stretched with the corresponding mandrel and inserted in collapsed configuration over the guide wire. Once the smartcanula tip appeared on the echo screen within the superior vena cava, the guide wire was removed first and the mandrel second. The expanded smartcanula was connected to the venous line and after femoral arterial canulation, CPB was started. The full flow was achieved with gravity drainage alone. An aortic vent was installed and after induction of ventricular fibrillation with an external stimulator, the left atrium was opened and the mitral valve inspected with video-endoscopic assistance. Multiple vegetations were removed from the sub-mitral apparatus and more of them were identified behind the posterior mitral leaflet. Para-annular mobilization of the posterior leaflet allowed for detailed inspection, thorough debridement/disinfection, and patch augmentation with briefly tanned autologous pericardium for mitral repair. Left atrial closure, de-airing, defibrillation, and weaning from CPB were realized in standard fashion with an excellent clinical outcome after appropriate antibiotic treatment.

Case 3: Less-invasive redo-mitral replacement relying on CPB with femoral smart canulation

Redo less-invasive mitral valve replacement was realized in a female patient 10 years after mitral valve repair through a median sternotomy. A short sub-mammary incision was selected for exposing the left atrium through a retro-mammary anterolateral mini-thoractomy in the sixth intercostals space. The pericardium was opened in cranio-caudal fashion anterior to the phrenic nerve and the inter-atrial groove was dissected free. Progressive traction was put on the borders of the pericardial opening providing an improved approach to the left atrium. A semi-open approach was selected for remote canulation. A short segment of the common femoral vessels was exposed just below the inguinal ligament. After systemic heparinization, the femoral vein was punctured with a hollow needle, a J-type guide wire was inserted and brought forward up to the superior vena cava as visualized by TEE. The venous access aperture was dilated and a 53 cm long venous smartcanula (ordering nr 3/8 36 530 S) was stretched with the corresponding mandrel and inserted in collapsed configuration over the guide wire. Once the smartcanula tip appeared on the echo screen within the superior vena cava, the guide wire was removed first and the mandrel second. The expanded smartcanula was connected to the venous line and after femoral arterial canulation, CPB was started. The full flow was achieved with gravity drainage alone. An aortic vent was installed and after induction of ventricular fibrillation with an external stimulator, the left atrium was opened and the mitral valve was replaced with video-endoscopic assistance. Left atrial closure, de-airing, defibrillation, and weaning from CPB were realized in standard fashion. The patient’s recovery was uneventful.

Case 4: Redo tricuspid valve replacement with remote smart canulation

Inadequate anticoagulation resulted in thrombosis of a bi-leaflet mechanical valve in the tricuspid position in a female patient with long-standing atrial fibrillation. The indication for re-operation with a new mechanical valve was based on the reduced physical performance since the period of inadequate anticoagulation and in the presence of a second mechanical valve in the mitral position. This fourth open-heart procedure was started with the exposure of the femoral vessels, and arterial and venous smart canulation after systemic heparinization. For the latter, a 43 cm long, 36F Venous smartcanula (ordering nr V 3/8 36 430 S) and a percutaneous arterial canula were selected. The femoral vein was opened with a small tranverse incision, a guide wire was inserted, and moved up to the right atrium and the superior vena cava respectively, where it was identified by TEE. The Venous smartcanula stretched over the corresponding mandrel was inserted over the guide wire up to the level of the hepatic veins. The guide wire was removed first to avoid canula tip dislocation and the mandrel second. After canulation of the femoral artery in standard fashion, the canulae were connected to the perfusion circuit and normo-thermic CPB was initiated. Full flow (4.1 l/min) was achieved with gravity drainage alone. The chest was entered, and the right atrium was exposed. The superior vena cava was canulated separately and snared. After positioning a vent onto the aortic root, the right atrium was entered, and the diagnosis of tricuspid mechanical valve thrombosis was confirmed. The valve with both leaflets fixed in an open position was excised and a new mechanical bi-leaflet valve was implanted with interrupted sutures. The right atrium was closed and de-aired. Weaning from CPB was uneventful and the patient recovered rapidly.

Case 5: Mini-invasive ASD closure with remote smartcanula canulation for a girl (13 kg)

Although a small antero-lateral thoracotomy through a sub-mammary incision is an elegant approach to the cardiac cavities in young women (see also case nr 2), this is not feasible in little girls because of the potential disturbance of breast development. Hence, a posterior-lateral mini-thoracotomy is preferred for the less invasive repair of congenital heart defects, and this can by now also be realized with remote canulation. A large secundum type ASD without the necessary borders for device closure was repaired in this 13 kg girl with mini-invsive technique relying on remote smart arterial and smart venous canulation. After exposure of the common femoral vessels in the right groin, a postero-lateral mini-thoracotomy was realized in the fourth intercostal space. The ribs were gently spread with a pediatric retractor. The pericardium was opened and its borders were suspended with small elastic hooks sequentially. This approach brings the heart closer to the mini-thoracotomy. After systemic heparinization, the common femoral vein was punctured with a hollow needle and a guide wire was fed into the inferior vena cava, the right atrium, and the superior vena cava under control by TEE. Small transverse phlebotomy was realized and a 26cm long 20F smartcanula (ordering Nr: smart canula mini ® V ¼ 20 260 S) was introduced over the guide wire up to the level of the supra-hepatic veins. Similarly, a guide wire was introduced into the common femoral artery, and identified in the aorta with TEE. A 20F arterial smartcanula (ordering Nr: smart canula mini ® A ¼ 20 220 S) stretched with the corresponding mandrel, was inserted over the guide wire and expanded. For this purpose, the guide wire has to be removed first and the mandrel second. Before connection to the respective lines of the perfusion set, the canulas were tied at the level of the canula body to the corresponding snare. CPB was initiated and a second venous canula was inserted into the superior vena cava. In addition, a vent was placed onto the aortic root. A pump flow of 1.5 l/min was reached for a target flow of 1.4 l/min by gravity drainage alone. After induction of ventricular fibrillation with an electrical stimulator, the superior vena cava was snared, and the right atrium was opened. The borders of the ASD were identified, and patch closure was realized with autologous pericardium. The right atrium was closed and carefully de-aired. Weaning from CPB was straightforward forward and recovery was uneventful.

Case 6: Cavo-atrial anastomosis for Budd-Chiari syndrome with direct visualization of the supra-hepatic veins

Recurrent stenosis despite stenting of the inferior vena cava due to recurrence of echinococcosis in a female patient with a liver transplant was the indication for a cavo-atrial anastomosis (the other Senning operation). A median sternotomy was selected for accessing the right atrium and the dome of the liver after exposure to the femoral vein for smart venous canulation. Heparin was given systemically. A 34cm 45F Venous smartcanula (ordering Nr V 3/8 45 340 S) was selected for remote canulation of the inferior vena cava. For this purpose, a guide wire was advanced through a transverse incision at the level of the common femoral vein, up to the level of the renal veins. The collapsed smartcanula stretched over the corresponding mandrel was inserted over the guide wire. Once in position, the guide wire was removed first, to avoid canula tip dislocation, and the mandrel second. On the arterial side, the ascending aorta was canulated, the perfusion set was connected, and CPB was initiated. A second venous canula was positioned in the superior vena cava and was snared, whereas the inferior vena cava remained uncontrollable because of the huge inflammatory tumor. Pump flow stabilized at the target level in normo-thermia and augmentation of venous return with a centrifugal pump was not necessary. The right atrium was opened by a hockey stick incision. The inflammatory tumor originating from the liver was excised in a funnel-like fashion reaching deep into the liver. Several supra-hepatic veins were sectioned allowing for free drainage, the inferior vena cava was identified by the tip of the smartcanula, and hepato-atrial anastomosis was realized. The latter had to be completed with a pericardial patch on the lateral side because of the resection of the infiltrated right atrial wall. Weaning from CPB was uneventful and the patient recovered rapidly without residual venous stasis.

Case 7: Completion Fontan with open caval anastomosis femoro-femoral smart canulation

Completion Fontan (Total cavo-pulmonary connection) was realized in a 20 kg patient with a univentricular heart, who had previously received a bidirectional Glenn. After exposure to the common femoral vessels, the chest was re-entered through a median sternotomy. Heparin was given systemically, and the femoral vein was punctured with a hollow needle. A guide wire was fed through the inferior vena cava and identified in the right atrium with TEE. A 34 cm long 24 F Venous smartcanula (ordering Nr: V 3/8 24 360 S) was stretched with the corresponding mandrel and inserted over the guide wire after a transverse incision. Once in position at the level of the hepatic veins, the guide wire was removed first, and the mandrel second for expansion of the smart canula mini ®, which was secured together with a snare at the level of its body by a tie. After arterial canulation and connection to the respective lines, CPB was initiated. A second venous canula was inserted into the anonymous vein. Full pump flow (1.8 l/min) was reached under normothermia by gravity drainage alone. The inferior vena cava was clamped and trans-sected. The right atrium was closed with a running suture. An end-to-end anastomosis between the un-snared inferior vena cava and a 19mm PTFE graft was realized with a running suture (5/0 PTFE). The distal anastomosis was made in retro-aortic fashion onto the right pulmonary artery after trans-section of the disbanded pulmonary artery and direct suture of its proximal part. After completion of the total-cavo-pulmonary-connection (TCPC), a weaning attempt was made and pressure above 17 mmHg was measured in the extra-cardiac conduit. Hence, a fenestration was realized during partial CPB, and weaning was completed thereafter. The patient recovered rapidly and a re-evaluation is scheduled for transcatheter closure of the fenestration.

Case 8: Redo aortic root replacement with remote smart canulation for ventriculo-aortic disconnection and acute endocarditis

Femoral canulation as been recommended in the past prior to sternal re-entry, and helps for management of major hemorrhage during the sometimes necessary sharp dissection of the heart. More recently, preference has been given to axillary or subclavian arterial canulation, which allow for continuous cerebral perfusion during arch replacement. In this case, the right subclavian vessels were exposed through an infra-clavicular skin incision, and heparin was given. The subclavian vein was punctured with a hollow needle, a soft guide wire (0.035 inch) was inserted, and brought into the superior vena cava as checked by TEE. An exchange catheter was necessary to bring a stiffer guide wire (Amplatz type) into the superior vena cava, the right atrium and the inferior vena cava. After a small phlebotomy, a 34cm long 36F Venous smartcanula (ordering nr V 3/8 36 340 S) was stretched with the corresponding mandrel and inserted over the guide wire into the right atrium. The smartcanula was secured with a snare and a tie at the level of the wire armed canula body. Care was taken not to constrict the flexible part of the smartcanula. The guide wire was withdrawn first and the mandrel second in order to prevent canula tip dislocation. After standard canulation of the subclavian artery, the perfusion set was connected and CPB initiated. Full flow was achieved with gravity drainage alone (there was no need for augmentation with vacuum or a centrifugal pump) and the chest was re-entered after decompression of the heart. A vent was positioned on the aortic root and a catheter was placed in the coronary sinus for retrograde cardioplegia. The aorta was cross-clamped and the heart was arrested first with ante-grade and then with continuous retro-grade blood cardioplegia. The ascending aorta was opened and the old composit-gaft was explanted and sent for bacteriological assessment. After careful debridement, a new, Rifampicin ®impregnated composit-graft was implanted with interrupted sutures and the coronary buttons were re-attached to their respective neo-ostia. The distal anastomosis was realized with a running suture, the cross-clamp was removed, the heart de-aired, and re-perfused. The patient was weaned from CPB on high dose vaso-pressors and stabilized. He recovered after 6 weeks of intra-venous antibiotic therapy and is under long term per-oral antibiotics since.

Case 9: Thoraco-abdominal aortic aneurysm repair with femoral smart canulation

Proximal unloading and distal protection with partial CPB have proven helpful for thoracic and thoraco-abdominal aortic aneurysm repair where additional oxygenation and shed blood recovery are helpful too. Our standard protocol for these procedures includes after thoraco-phreno-laparotomy, mobilization of the diaphragm in a para-costal fashion, proximal and distal control of the aneurysm, as well as low systemic heparinization, femoral or external iliac canulation relying on a long Venous smartcanula for right atrial drainage (ordering nr V 3/8 36 530 S or V 3/8 36 630 S in accordance to body size). In this case, the femoral vein was punctured with a hollow needle and a soft J-type guide wire (typical radius 7.5mm) was inserted. The guide wire should advance without resistance into the inferior vena cava, the right atrium, and the superior vena cava as visualized by TEE. It is important to position the guide wire into the superior vena cava. This may require removing the guide wire completely, to make it steerable with a 5o angle a few cm from its J-type tip or to use a curved catheter. Once the guide wire is positioned in the superior vena cava, insertion of the stretched Venous smartcanula over the wire is usually straightforward. However, there are a few cases, where some resistance is felt, and it is preferable not to insist, to exchange the soft guide wire with a stiffer guide wire (Amplatz type) by the means of a catheter. Once the Venous smartcanula is in position (in this case a 63 cm long 36 F Venous smartcanula was used: ordering nr V 3/8 36 630 S), care has to be taken, that the guide wire is removed before the mandrel to prevent canula tip dislocation. After canulation on the arterial side, the perfusion set was connected, CPB initiated, and full flow was achieved by gravity drainage alone and there was no need augmentation by a centrifugal pump. For additional spinal chord protection, we cooled the patient to a core temperature of 28oC. Although the target flow is only 50% of the theoretical flow during partial CPB for distal protection, it is important to be able to achieve full flow in case of ventricular fibrillation, a situation requiring trans-apical canulation of the aortic root or another type of proximal return. The thoracic aortic aneurysm was repaired during segmental cross-clamping using the island technique and additional grafts for reconnection of the main intercostal and visceral arteries. Rewarming was started as soon as all significant branches were reconnected. At 35oC the patient was weaned from CPB straight forward. The access vessels were repaired in standard fashion and the thoraco-phreno-laparotomy was closed with running sutures after reinsertion of the diaphragm. Recovery was uneventful and the patient is free from neurological deficits.

Case 10: Ascending aorta and root replacement with subclavian arterial and venous smart canulation

Trans-subclavian smart venous canulation of the right atrium in combination with arterial canulation of the right subclavian artery was selected for aneurysm repair of the ascending aorta and the aortic root. An infra-clavicular skin incision allowed for the exposure of both, the subclavian vein and the subclavian artery. After entering the chest and systemic heparinization, the subclavian vein was punctured with a hollow needle and a soft guide wire (0.035 inches) was inserted. A curved catheter was necessary to bring the guide wire into the superior vena cava, the right atrium, and the inferior vena cava. After small phlebotomy, a 34 cm long 36F Venous smartcanula (ordering nr V 3/8 36 340 S) was stretched with the corresponding mandrel and inserted over the guide wire. However, some resistance was felt after partial insertion, and therefore, the collapsed Venous smart canula® was removed, and the well-positioned soft guide wire was exchanged with the help of a catheter against a more stiff guide wire (Amplatz type). This maneuver allowed for easy positioning of the Venous smartcanula in the right atrium, and withdrawal of the stiff guide wire (first) and the mandrel (second) to prevent canula tip dislocation. After canulation of the subclavian artery with a 21 F percutaneous canula, the perfusion set was connected and CPB was initiated. A pump flow of 4.8 l/min was achieved with subclavian smart canulation and gravity drainage alone and the heart was perfectly emptied. Aortic root replacement was realized with the arrested heart under continuous retrograde blood cardioplegia in standard fashion with re-implantation of the coronary ostia, and the distal anastomosis was constructed at the level of the brachio-cephalic trunk. Weaning from CPB was straightforward, the patient was transferred to the ICU in stable condition and recovered well.

Case 11: Remote smart canulation for biventricular VAD implantation in terminal heart failure as a bridge to transplantation

Right and left ventricular assist devices (Thoratec IVAD) were implanted in a 20 year old patient with terminal heart failure. Considering the critical hemodynamic condition of the patient, the femoral vessels were exposed prior to entering the chest, and, after systemic heparinization, canulated. For this young adult with a body surface area of 1.6 m2, a 63 cm long, 36F Venous smartcanula (ordering nr V 3/8 36 630 S) and a percutaneous arterial canula were selected. The femoral vein was punctured with a hollow needle, a guide wire was inserted, and moved up-to the right atrium and the superior vena cava respectively, where it was identified by TEE. After a small transverse phlebotomy, the Venous smartcanula, stretched on the corresponding mandrel was inserted over the guide wire up to the level of the superior vena cava. The guide wire was removed first in order to avoid canula tip dislocation, and the mandrel second. After arterial canulation in standard fashion, the canulas were connected to the perfusion circuit and CPB was initiated. Full flow was achieved with gravity drainage alone (target flow 4.0 l/min, achieved flow 5.0 l/min = 125%: there was no need for augmentation of venous drainage with a centrifugal pump nor other means). The two VADS were positioned in a pre-peritoneal pocket and connected from the left ventricular apex to the aorta and from the right atrium to the pulmonary artery respectively in standard fashion. After thorough hemostasis, the chest was closed, the patient weaned from CPB, and transferred to the ICU in stable condition. He was later discharged with a portable VAD driver.

Case 12: Mini-invasive ASD closure with remote smart canulation in a young woman

Larger ASDs without borders are not suitable for device closure and surgery remains indicated. A small infra-mammary skin incision (to be marked in the upright position on the evening before surgery) was selected for a right anterior thoracotomy in the 5th intercostal space. A pediatric spreader was used for gentle rib retraction and the pericardium was opened. A video-endoscope was introduced through a separate port, which was later used for drainage. We use elastic hooks for progressive suspension of the pericardium. Femoral arterial and venous smart canulation is our preferred approach in this setting after systemic heparinization. On the venous side, this patient required a 43cm long, 36F Venous smartcanula (ordering nr V 3/8 36 430 S; for smaller patients, the somewhat shorter 34cm version with the ordering nr V 3/8 36 340 S may be preferable). The previously exposed femoral vein was punctured with a hollow needle, a guide wire was inserted, and moved up-to the right atrium and the superior vena cava respectively, where it was identified by TEE. After small transverse phlebotomy, the Venous smartcanula, stretched on the corresponding mandrel was inserted over the guide wire up to the level of the hepatic veins. The guide wire was removed first in order to avoid canula tip dislocation and the mandrel second. The smartcanula was secured with a snare tied to its body. At this stage, care has to be taken, not to occlude the vessel lumen with the smartcanula inside. After canulation of the femoral artery, the perfusion set was connected and CPB was initiated. A vent was inserted into the aortic root, and the superior vena cava was canulated and snared. For a theoretical pump flow of 4.0 l/min (body surface area = 1.68m2), smart canulation of the inferior vena cava allowed to reach 3.8 l/min, and the second venous canula brought the flow to 4.2 l/min (105%) without augmentation by vacuum nor a centrifugal pump. The heart was arrested by stimulation with an external fibrillator. The right atrium was opened and the limits of the ASD were inspected. Patch closure (PTFE) was realized with running sutures. Once completed, and after careful de-airing of the left atrium, the right atrium was closed, and the heart defibrillated. Weaning was uneventful, and the young lady recovered rapidly.

Case 13: Remote smart canulation for implantation of an apico-aortic valved conduit for re-re-redo valve surgery

Re-redo procedures remain a major challenge, because of the increasing severity of (epi-)cardial adhesions on one side and the growing risks linked to procedures with higher complexity. Apico-aortic valved conduits allow for an elegant approach to circumvent some of the issues raised. A small lateral left thoracotomy in the 7th intercostal space was selected for approaching the apex of the left ventricle as well as the descending thoracic aorta in this patient. The apical pericardium was opened and dissected free at the planned position for an angled apical connector. Then the left femoral vessels of the patient were canulated in semi-open fashion through a small infrainguinal incision. After systemic heparinization, the femoral vein was punctured with a hollow needle, a J-type guide wire was inserted and brought forward up to the superior vena cava as visualized by TEE. The venous access aperture was dilated and a 63 cm long venous smartcanula (ordering nr 3/8 36 630 S) was stretched with the corresponding mandrel and inserted in collapsed configuration over the guide wire. Once the smartcanula tip was visualized within the superior vena cava with TEE, the guide wire was removed first and the mandrel second. The expanded smartcanula was connected to the venous line and after femoral arterial canulation, CPB was started. The full flow was achieved with gravity drainage alone. However, during the next phase, pump flow was reduced to 50% of the target flow and the heart was kept ejecting. The descending thoracic aorta was identified just above the diaphragm, partially excluded, and connected end-to-side to a valved tube graft with a running suture. The system was de-aired and unclamped. CPB was brought back to full flow for the cardiac stage. Temporary ventricular fibrillation was induced by an external stimulator, a left apical orifice was created with a scalpel, eight braided polyester U-stitches with pledgets were placed, and the angled apical connector was inserted and attached. After an end-to-end suture between the apical connector and the valved conduit, the heart was de-aired, defibrillated, and weaned from CPB without a problem.

Case 14: Trans-subclavian venous smart canulation for full CPB in redo ascending aorta and arch replacement

Progression of chronic type-A dissection is an indication for re-operation despite the initial replacement of the ascending aorta in the acute setting and decompression of the heart with CPB before re-sternotomy can be helpful for lesion-free re-exposure of the diseased aorta. Trans-subclavian smart venous canulation of the right atrium and the inferior vena cava can be used in combination with arterial subclavian canulation to establish CPB with full flow before re-sternotomy. For this purpose, the right sublavian vessels were exposed through a small infra-clavicular incision. The patient was heparinized, the subclavian vein was punctured with a hollow needle, and a J-type guide wire was inserted and brought forward through the superior vena cava, the right atrium, and into the inferior vena cava as visualized by TEE. In some cases, positioning of the guide wire may require angled catheters and stiffer guide wires. Then, the venous access aperture was dilated and a 43 cm long venous smartcanula (ordering nr 3/8 36 430 S) was stretched with the corresponding mandrel and inserted in collapsed configuration over the guide wire. Once the smartcanula tip was visualized within the inferior vena cava (TEE), the guide wire was removed first and the mandrel second. The expanded smartcanula was connected to the venous line and after subclavian arterial canulation, CPB was started. Full flow (4.5 l/min) was achieved with gravity drainage alone before resternotomy. After minimal dissection, a balloon catheter was inserted into the coronary sinus for retro-grade cardioplegia application. Once ventricular fibrillation occurred, systemic flow was reduced, the ascending aorta and proximal arch were opened, balloons were inserted into the supra-aortic vessel in trans-aortic fashion, and continuous retrograde cardioplegia was started. The distal oblique anastomosis for a typical hemi-arch repair was realized using a woven graft and a running suture. The balloons were removed before completion of the suture, the arch was de-aired, the graft was cross-clamped, and re-rewarming was started at full flow after 10 min, whereas the proximal anastomosis was realized in standard fashion. The heart restarted spontaneously in sinus rhythm, weaning from CPB was uneventful, and the patient’s recovery was straightforward.

Case 15: Ross procedure with single right atrial smart venous canulation

Congenital aortic valve stenosis is nowadays primarily treated by balloon dilatation. However, this procedure is frequently combined with some degree of post-procedural aortic valve regurgitation. Hence, the invasive cardiology approach usually buys some time. Once the child has grown, residual aortic stenosis increases, and is often combined with aortic regurgitation. Under such circumstances, like in this case, the Ross operation (aortic valve replacement with a pulmonary homograft) is the procedure of choice, if an aortic valve replacement with adult-size prostheses is not feasible yet. After median sternotomy, „high“ aortic canulation was associated with a single 26 cm long 24 F smartcanula (ordering Nr: smart canula mini ® V 3/8 24 260 S) for right atrial canulation and connected to the respective lines of the pump oxygenator. CPB was initiated and a pump flow of 4.3 l/min was achieved for a target flow of 3.6 l/min (119%) in normothermia, and the pulmonary autograft was harvested on the assisted beating heart. Care is taken to position the smartcanula in such a fashion that the heart is well drained, but no air is aspirated. After positioning of an aortic root vent and a coronary sinus canula, the aorta was cross clamped and the heart arrested with antegrade and retrograde blood cardioplegia. The aortic valve was excised, and the coronary buttons were prepared. The autograft was implanted in inversed fashion with running sutures, reversed, and tested with saline. An epicardial suture line was placed at its base, and the coronary Ostia were reimplanted in standard fashion before anastomosing the neo-aortic root with the recalibrated ascending aorta. Reconstruction of the right ventricular outflow tract was realized with an unclamped aorta and an empty beating heart, using a bovine valved venous conduit. Weaning from CPB was uneventful and the patient was extubated on the same day.

Case 16: Mini-invasive cor triatriatrum repair with femoro-femoral smart canulation for CPB

A small right submammary incision was used for entering the right chest in the sixth intercostal space. The pericardium was incised in craniocaudal fashion and the Waterstone groove was prepared. Following systemic heparinization, the right femoral vein was canulated with a long Venous smartcanula for right atrial drainage (ordering nr V 3/8 36 530 S or V 3/8 36 630 S in accordance with body size). In this case, the femoral vein was punctured with a hollow needle and a soft J-type guide wire (typical tip radius 7.5 mm) was inserted. The guide wire was advanced without resistance into the inferior vena cava, the right atrium, and the superior vena cava as visualized by TEE. With the guide wire positioned in the superior vena cava, insertion of the stretched Venous smartcanula over the wire was straightforward (in this case a 63 cm long 36 F Venous smartcanula was used: ordering nr V 3/8 36 630 S), and the guide wire was removed before the mandrel to prevent canula tip dislocation. After canulation on the arterial side, the perfusion set was connected, CPB initiated, and full flow was achieved (5.3 l/min or 113% of the target flow of 4.7 l/min) by gravity drainage alone and there was no need for augmentation by a centrifugal pump. A vent was inserted into the ascending aorta before the initiation of ventricular fibrillation with an external fibrillator. The left atrium was entered with a cranio-caudal incision and explored with an endoscope carrying a tip-mounted camera. The orifice of the septum separating the left atrium in two cavities was identified and split before complete excision. The left atrium was closed in standard fashion, the heart was de-aired and defibrillated. At 35°C the patient was weaned from CPB and decanulated. A Blake drain was inserted before the closure of the chest. Extubation was straightforward.

Case 17: Mini-invasive aortic valve replacement with percutaneous smart venous canulation

A J-type upper mini-sternotomy was realized in a patient with severe aortic stenosis, the pericardium was entered, and the ascending aorta was exposed. After systemic heparinization, the left femoral vein was punctured with a hollow needle. A 0.035″ guide wire was brought up through the inferior vena cava, the right atrium, and positioned in the superior vena cava as checked with TEE. Following one-step dilatation, a 63 cm long 36F Venous smartcanula (ordering nr V 3/8 36 630 S) was stretched with the corresponding mandrel and inserted over the guide wire up, into the superior vena cava. The guide wire was removed first and the mandrel second to prevent canula tip dislocation. After canulation of the aortic arch with a 21 F percutaneous canula, the perfusion set was connected and CPB was initiated. A pump flow of 5.5 l/min (equivalent to 112% of the 4.9 l/min target flow) was achieved with percutaneous smart venous canulation and gravity drainage alone and the heart was perfectly emptied. Aortic valve replacement was realized with the arrested heart and intermittent antegrade cardioplegia in standard fashion. Weaning from CPB was straightforward forward and the patient was decanulated. Simple compression was applied for hemostasis at the femoral venous canulation site. Transfer to the ICU and recovery was uneventful.

Case 18: HeartMate II implantation with smart central canulation for assisted beating heart surgery

A left ventricular assist device (Thoratec HeartMate II) was implanted in a 50 year old patient with terminal heart failure and mixed venous oxygen saturation of 45% despite intravenous positive inotropic support. Under general anesthesia, the chest was entered through a median sternal splitting incision for central canulation after systemic heparinization. A 43 cm long, 36F Venous smartcanula (ordering nr V 3/8 36 430 S) and a 19 F percutaneous arterial canula were selected for this patient with a body surface area of 2.3 m2. The aortic arch was punctured on its anteroinferior circumference with a hollow needle, a guide wire was inserted, and moved into the descending aorta, where it was identified by TEE. After two-step dilatation, the tip of the arterial canula was positioned in the descending thoracic aorta. The right atrium was canulated with the same technique using a hollow needle and a guide wire which was placed into the iinferior vena cava and its position checked with TEE. Following one step dilatation, the Venous smartcanula, stretched on the corresponding mandrel was inserted over the guide wire down into the inferior vena cava. The guide wire was removed first to avoid canula tip dislocation and the mandrel second. The full flow was achieved with gravity drainage alone (target flow 5.6 l/min, achieved flow 5.9 l/min = 105%: there was no need for augmentation of venous drainage with a centrifugal pump nor other means). Gravity drainage allowed for collapsing the right atrium, emptying the right ventricle, and zero ejection by the left ventricle as demonstrated by a flat arterial line and absence of aortic valve opening (TEE). The apex of the left ventricle was entered with a coring device and the inflow canula for the HeartMate II axial flow pump was attached in standard fashion with braided, pledged, full-thickness sutures. The blood pump was connected and positioned in a pre-peritoneal pocket just below the diaphragm. After connection of the outflow canula, and proper de-airing of the ventricular assist system, weaning from CPB was realized under NO therapy. The assist device flows stabilized between 4.8 and 5.0 l/min. Hemostasis was completed, the chest was closed, and the patient was transferred to the ICU in stable condition.