1. Potts Shunt for Children With Severe Pulmonary Hypertension
Pirooz Eghtesady, MD, PhD 
Operative Techniques in Thoracic and Cardiovascular Surgery 
Volume 20, Issue 3, Pages (September 2015)
DOI: /j.optechstcvs
Copyright © 2016 Elsevier Inc. Terms and Conditions

2. Figure 1
Patient is positioned in the right lateral decubitus position to allow a posterior lateral thoracotomy. If the patient has been previously cannulated for ECMO support via the right cervical approach, then those cannulas need to be adequately secured in the right neck prior to positioning. Single lung ventilation may be considered if ECMO support is utilized; however, in most other patients that would not be feasible. It is important to have pulse oximetry on an upper and lower extremity as well as a blood pressure cuff above and below. These would allow assessment of the effect of the shunt on patient׳s circulatory status. We have typically placed a TEE to monitor RV function during the procedure as well as both cerebral and somatic NIRS for general assessment of cardiac output. ECMO = extracorporeal membrane oxygenation; NIRS = near-infrared spectroscopy, TEE = Transesophageal echocardiography probe.
Operative Techniques in Thoracic and Cardiovascular Surgery  , DOI: ( /j.optechstcvs )
Copyright © 2016 Elsevier Inc. Terms and Conditions

3. Figure 2
The left chest is entered through a posterolateral incision at the fourth intercostal space, depending on whether or not the patient has had a prior history of thoracotomy. Although the size of the incision can vary, adequate visualization is important as in any surgical procedure. Though the incision is called posterolateral, it is more posterior than lateral similar to one that would be created for performance of a coarctation. The lung is retracted anteriorly, and the pleura is opened widely over the descending aorta, which also allows dissection of the left pulmonary artery. Silk sutures can be placed at the edge of the reflected pleura to help with the retraction of the lung. Standard malleable retractors may be challenging to use in this setting because of the prominence of the left pulmonary artery; caution is warranted to avoid potential bruising or hematoma in the wall of the pulmonary artery that easily lead to a dissection due to high pressure within the vessel. Ao = aorta; LPA = left pulmonary artery.
Operative Techniques in Thoracic and Cardiovascular Surgery  , DOI: ( /j.optechstcvs )
Copyright © 2016 Elsevier Inc. Terms and Conditions

4. Figure 3
The posterior part of the fissure between the left upper lobe and left lower lobe is opened up partially providing better exposure to arterial branches of both lower and upper lobes. There are generally 2 branches to the upper lobe segment that need to be controlled as the location of Potts shunt is close to the proximity of these vessels. Potts ligatures or vessel loop skin can be used once access is obtained to control these vessels. Often, the main pulmonary artery segment is quite large and would be rather treacherous to try to go around the structure completely especially in older patients. If so, great care must be taken due to the presence of the pulmonary vein near the back side of the artery. Similarly, during the dissection of the pleura, it is important to recognize or appreciate the close proximity of the recurrent nerve coming off the vagus at this junction. The dissection of the apical dorsal branch should be performed with great caution because it usually has a very short length, and it is often surrounded by nodes. If it cannot be safely mobilized, then it is advisable to have enough of a segment that one could place a side-biting clamp. Furthermore, although these vessels have been exposed to very high pressures and generally the wall thickness is quite significant, they are still quite fragile and can easily be torn as appreciated once the vessels are opened.
Operative Techniques in Thoracic and Cardiovascular Surgery  , DOI: ( /j.optechstcvs )
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5. Figure 4
The dissection of the aorta extends from the level of the subclavian artery to the mid-descending aorta. Enough of a segment of the aorta needs to be exposed to allow placement of a side-biting clamp. Generally, no dissection of the arch and other arch vessels is necessary unless patients had prior surgeries. The latter would be the instance wherein placement of an interposition graft is most suitable. Many of these patients have prominent collaterals for reasons unclear to me. Posterior dissection of the descending aorta, therefore, needs to proceed with caution; often there are 1 or 2 small branches just after the take-off the left subclavian artery, right at or after the isthmus segment.
Operative Techniques in Thoracic and Cardiovascular Surgery  , DOI: ( /j.optechstcvs )
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6. Figure 5
After administration of heparin (100units/kg), a side-biting clamp is applied to the left pulmonary artery and an arteriotomy is performed. Before application of the clamp, I routinely inspect the teeth to make sure there are no distortions or other damage to the clamp that could lead to problems subsequently. Furthermore, it is valuable to assess the potential juxtaposition and positioning of the clamps in the chest simultaneously. The assistant is critical in maintaining the position of the clamps and the required tension to approximate them during the anastomosis; a separate individual would need to follow the suture line, especially during the posterior aspect because that area cannot be visualized subsequently. Generally, the dimension of this should correspond to a diameter that is slightly smaller than the diameter of the descending aorta. Some clamps have markings that can help gauge the extent of the incision (these were clamps originally designed to help with sizing the Waterston shunts). It is advisable to start the incision smaller because the opening tends to stretch. When the procedure is performed with graft, this part of the procedure can be completed and the clamp can be removed to confirm hemostasis. With a conduct of a primary anastomosis, however, the clamp has to stay on while the aorta is open and a side-to-side connection is made. LPA = left pulmonary artery.
Operative Techniques in Thoracic and Cardiovascular Surgery  , DOI: ( /j.optechstcvs )
Copyright © 2016 Elsevier Inc. Terms and Conditions

7. Figure 6
(A) A PTFE graft of appropriate dimension is attached in an end-to-side fashion to the opening in the pulmonary artery with a running 5-0 Prolene suture, leaving the marking of the graft (blue line, not shown in figure) allows proper orientation to avoid potential distortion. It is important that the arteriotomy is done directly on the segment of the artery opposite to the descending aorta. Generally, this corresponds to the segment of the left pulmonary artery coming off essentially directly away from the apical posterior branch. We prefer to use the vascular stretch graft as it gives some flexibility with potential subsequent lie of the graft. PTFE = polytetrafluoroethylene.
Operative Techniques in Thoracic and Cardiovascular Surgery  , DOI: ( /j.optechstcvs )
Copyright © 2016 Elsevier Inc. Terms and Conditions

8. Figure 6
(A) A PTFE graft of appropriate dimension is attached in an end-to-side fashion to the opening in the pulmonary artery with a running 5-0 Prolene suture, leaving the marking of the graft (blue line, not shown in figure) allows proper orientation to avoid potential distortion. It is important that the arteriotomy is done directly on the segment of the artery opposite to the descending aorta. Generally, this corresponds to the segment of the left pulmonary artery coming off essentially directly away from the apical posterior branch. We prefer to use the vascular stretch graft as it gives some flexibility with potential subsequent lie of the graft. PTFE = polytetrafluoroethylene.
Operative Techniques in Thoracic and Cardiovascular Surgery  , DOI: ( /j.optechstcvs )
Copyright © 2016 Elsevier Inc. Terms and Conditions

9. Figure 6
(Continued) (B) The graft is trimmed, usually not more than a cm long, the cut is slightly beveled to account for the subsequent rotation of lung on its hilum and to prevent kinking of graft.
Operative Techniques in Thoracic and Cardiovascular Surgery  , DOI: ( /j.optechstcvs )
Copyright © 2016 Elsevier Inc. Terms and Conditions

10. Figure 7
(A) A side-biting clamp is applied to the descending aorta, and the 2 clamps are then brought in proximity by the assistant. In general, it is safer and easier to move the descending aorta, and it is for that reason the more generous mobilization and dissection of descending aorta has previously been completed. It is for the same reason that this part of the procedure is simpler in younger patients with greater mobility of their descending aorta, allowing direct anastomosis more frequently. The interposition graft, therefore, is more frequently used in older patients or those with difficult dissections. The connection is carried out in a side-to-side fashion with a running 5-0 Prolene suture for either the direct anastomosis or for the graft to vessel connection. Before removing the clamp, deairing maneuvers are performed and then the descending aorta clamp is removed first followed by removing the clamp from the left pulmonary artery. (B) The length of the aortotomy should be kept to less than the diameter of the graft since the vessel will stretch with high flow.
Operative Techniques in Thoracic and Cardiovascular Surgery  , DOI: ( /j.optechstcvs )
Copyright © 2016 Elsevier Inc. Terms and Conditions

11. Figure 8
(A) With interposition graft variant, the length of the graft is measured. Generally, this does not need to be more than a centimeter. Indeed, if the graft is made too long, it can lead to kinking. The clamp can then be removed from the left pulmonary artery and repositioned on the graft to allow blood flow within the left pulmonary artery to left lung. The aortic end of the PTFE graft is then carried out after the application of side-biting clamp to the descending aorta. This anastomosis is carried out with a running 5-0 Prolene suture. (B) Deairing maneuver is carried out with heparinized saline. It is important to ensure no clot material is present or accidentally left behind to avoid systemic embolization post shunt creation. PTFE = polytetrafluoroethylene.
Operative Techniques in Thoracic and Cardiovascular Surgery  , DOI: ( /j.optechstcvs )
Copyright © 2016 Elsevier Inc. Terms and Conditions

12. Figure 8
(A) With interposition graft variant, the length of the graft is measured. Generally, this does not need to be more than a centimeter. Indeed, if the graft is made too long, it can lead to kinking. The clamp can then be removed from the left pulmonary artery and repositioned on the graft to allow blood flow within the left pulmonary artery to left lung. The aortic end of the PTFE graft is then carried out after the application of side-biting clamp to the descending aorta. This anastomosis is carried out with a running 5-0 Prolene suture. (B) Deairing maneuver is carried out with heparinized saline. It is important to ensure no clot material is present or accidentally left behind to avoid systemic embolization post shunt creation. PTFE = polytetrafluoroethylene.
Operative Techniques in Thoracic and Cardiovascular Surgery  , DOI: ( /j.optechstcvs )
Copyright © 2016 Elsevier Inc. Terms and Conditions

13. Figure 8
(Continued) (C) The PTFE interposition between the left pulmonary artery and the descending aorta. A silk ligature suture is placed around the PTFE graft and passed through a tourniquet or snare. The snare is then secured to this ligature (to prevent accidental tightening) with a couple of hemoclips. The ends of the sutures are brought out from the lumen of the tourniquet and folded back onto the tourniquet; the hemoclip then secures the sutures to the body of the tourniquet. This snare or tourniquet is then brought over the apex of the lung to the anterior mediastinum and attached to the medial aspect of the chest wall with a couple of sutures. (D) This ligature allows easy control of the shunt during transplantation to avoid substantial runoff with initiation of cardiopulmonary bypass. We believe that this simple maneuver reduces the hazards of taking down the shunt directly during transplantation. PTFE = polytetrafluoroethylene.
Operative Techniques in Thoracic and Cardiovascular Surgery  , DOI: ( /j.optechstcvs )
Copyright © 2016 Elsevier Inc. Terms and Conditions