J THoRAc CARDIOVASC SURG 1987;93:523-32 Anomalous systemic and pulmonary venous connections in conjunction with atriopulmonary anastomosis (Fontan-Kreutzer) Technical considerations Anomalom systemic or pulmonary venous connections can coexist with certain forms of complex cyanotic heart diseases that are reparable only by atriopulmonary anastomotic procedures, thus compticating the intraatrial separation of systemic and pulmonaryvenous pathways. Anomalous systemic or pulmonary venom connections were encountered isolated or in combination in 17 patients (10%) among a series of 170 modified Fontan-Kreutzer procedures. Fourteen of these 17 patients (82.3%) survived their operations, which utilized different techniques to deal with the various forms of anomalous systemic and pulmonaryvenous connections. There was one late death (5.8%). Extracardiac exclusionof a left superior vena cava with an end-to-side left cavopulmonary shunt proved to be a more successful alternative than the use of complicated intratrial baflles. Because of the complexity of the anatomic variables, repair of anomalous systemic or pulmonary venous connectionsin conjunction with a modified Fontan-Kreutzerprocedure requires a detailed preoperativeanatomical and physiologic diagnosis,and an individualized plan for each patient must be formulated to provide unobstructed venous pathways. Florentino J. Vargas, M.D.,* John E. Mayer, Jr., M.D., Richard A. Jonas, M.D., and AIdo R. Castaneda, M.D., Boston, Mass. Although the Fontan-Kreutzer operation was originally conceived for physiologic correction of tricuspid atresia.I, 2 the procedure has since been modified and extended to other more complex lesions.':" Included among these are anomalies in which rerouting of the pulmonary and systemic venous pathways is necessary." 7,12,13 The coexistence of anomalies of systemic venous and pulmonary venous connection poses both technicaldifficulties at repair and an increased operative mortality." 12, 13 The purpose of this article is to outline several technical aspects of the surgical management of patients in whom rerouting of systemic and/or pulmonary venous return was required in combination with a modified Fontan-Kreutzer operation. From the Department of Cardiovascular Surgery, the Children's Hospital; and the Department of Surgery, Harvard Medical School, Boston, Mass, Received for publication March 17, 1986, Accepted for publication April 8, 1986, Address for reprints: Aldo R, Castaneda, M,D" Department of Cardiovascular Surgery, Children's Hospital, 300 Longwood Ave" Boston, Mass, 02115, Patients Between August 1981 and October 1985, 17 patients with various types of anomalous systemic and pulmonary venous connection had a modified Fontan-Kreutzer procedure. Twelve were male and five were female (2.4:1). Ages ranged from 16 months to 27 years (mean, 9.6 years). Nine patients were aged 7 years or younger. Segmental cardiac anatomy" was diagnosed as {S,D,D} in seven patients, {A,L,L} in four, {A,D,D} in four, and {S,L,L} in two. Ten patients had a common atrium. Eleven had a common atrioventricular (AV) valve. Two had double-inlet AV valves, two had a straddling right AV valve, and two had either stenosis or atresia of the left AV valve. Dextro-loop of the ventricles occurred in 11 patients (64.7%). Ventricular anatomy included a single ventricle in 14 patients, hypoplastic left ventricle in two, and hypoplasticright ventricle in one. Pulmonary stenosisor atresia was present in all but one patient. This patient had had pulmonary artery banding as part of a complex palliative procedure. The details of the systemic and pulmonary venous anomalies for each patient are found in Table I. The systemic venous anomalies included persistent left superior vena cava (SVC) drain523 The Journal of Thoracic and Cardiovascular Surgery 524 Vargas et af. Table I. Surgical management of systemic anti/or pulmonary anomalous venous drainage in patients who had a modified Fontan procedure (N = 17 patients) Patient Previous operation Age 5 yr Diagnosis Anomalous venous drainage Central shunt Polysplema {A,L,L} common atrium, CA VV, SV, DORV, PS Asplenia, {A,D,D}, common atrium, CA VV, 2 22 Mo RBTS 3 27 yr LBTS Waterston 4 6 yr RBTS 5 16 mo None {A,D,D}, common atrium, double inlet--<iouble outlet SV, PS SV, D-TGA, PS Asplenia {S,D,D} common atrium, CA VV, SV, D-TGA, PS {A,D,D}, common atrium, CA VV, SV, D-TGA, PS; dextrocardia 6 9 RBTS Asplenia {A,L,L} common atrium, CA VV, SV, L-TGA, PS 7 5 yr LBTS {S,D,D}, common atrium, CA VV, SV, D-TGA, PA, JLAA 8 10 yr RBTS {S,D,D}, common atrium, CAVY, SV, D-TGA, PS, LJAA Bilateral SVC (LSVC to LA side), interrupted IVC (az. cont. to RSVC) hepatic veins-left side common atrium; CS absent Bilateral SVC (LSVC to LA side); IVC-LA side; CS absent Bilateral SVC (LSVC to LA side); CS absent Total APVR to right side of common atrium; bilateral SVC, (LSVC to LA side) IVC-LA side; CS absent Bilateral SVC (LSVC to LA side); interrupted IVC (az. cont. to RSVC) hepatic veins to right side common atrium; CS absent Total APVR to LSVC-LA side; absent RSVC, IVC-LA side; CS absent Bilateral SVC (LSVC to LA side); interrupted IVC (az. cont. to LSVC) hepatic veins-left side common atrium; CS absent Bilateral SVC (LSVC to CS) Legend: APVR, Anomalous pulmonary venous return. az. cont, Azygos vein continuation. CAVY, Common atrioventricular valve. CPV, Common pulmonary vein. CS, Coronary sinus. D-TGA/L-TGA, Dextro/levo transposition of the great arteries. DORV, Double-outlet right ventricle. FC, Functional class. HLV, Hypoplastic left ventricle. IVC, Inferior vena cava. JLAA, Juxtaposed left atrial appendages. LA side, Left atrial side. LAVV, Left atrioventricular valve. LBTS, Left Blalcok-Taussig shunt. LCO, Low cardiac output. LlVC, Left inferior vena cava. L/RSVC, Left/right superior vena cava. NYHA, New York Heart Association. PA, Pulmonary atresia. PAB, Pulmonary artery banding. PS, Pulmonary stenosis. PVR, Pulmonary venous return. RA, Right atrium. RAVV, Right atrioventricular valve. RBTS, Right Blalock-Taussig shunt. RPA, Right pulmonary artery. sp ADKSR, Previous Alvarez-Damus-Kaye-Stanscl repair (restrictive bulboventricular foramen) followed by RBTS. sp APWR, Previous aortopulmonary window repair. sp. CoAR, Previous coarctation repair. sp IAAR, Previous interrupted aortic arch (type B) repair (10 mm conduit). SV, Single ventricle. SVC, Superior vena cava. SVR, Systemic venous return. ing into the left atrium (seven patients) or draining to the coronary sinus (seven patients), 'left-sided entrance of the inferior vena cava (lVC) (four patients), and IVC interruption with azygos continuation (three patients, two of them with hepatic veins connecting to the left side of a common atrium). Pulmonary veins connected anomalously to a left vertical vein, which drained to the innominate vein (one patient), to the right side of the atrium (two patients), and to a left SVC (one patient). Surgical techniques A pressure line was routinely placed in the left jugular vein when the diagnosis of bilateral SVC was made preoperatively. All patients were placed on cardiopulmo- nary bypass; deep hypothermia «20 C) and circulatory arrest were utilized with 10 patients, and in the remaining seven patients, cardiopulmonary bypass with hypothermia to 25 0 C was used. Cold crystalloid cardioplegia was added during aortic cross-clamping and repeated every 30 minutes. The persistent left SVC was cannulated (either directly or through the coronary sinus) in only two instances. The atrium was opened through an incision 1 em away from and parallel to the AV groove; it extended from the base of the right atrial appendage to the right atrium-IVC junction in most cases (Fig. 1, A). In all but one patient, in whom an intraatrial tube graft was used, an intraatrial baffle was placed to direct pulmonary venous return to either a common AV valve or to the 0 Volume 93 Number 4 April 1987 Fontan-Kreutzer operation 525 Results Procedure Patch diversion PVR-CAVV (LSVC, RSVC, and hepatic veins to the right); modified Fontan (atriopulmonary conduit interposed) Patch diversion PVR-CAVV (LSVC, RSVC, and IVC to the right); modified Fontan Patch diversion PVR-CAVV, (LSVC, RSVC, and IVC to the right); modified Fontan. Intramural tract opened (unroofed) displacing the APVR entrance to the left. Patch diversion APVR orifice to CA VV (LSVC, RSVC, and IVC to the right); modified Fontan. LSVC exclusion (modified Glenn); patch diversion PVR-RAVV (RSVC and hepatic veins to the right); modified Fontan Divided LSVC distal to APVR; proximal end closure (APVR connected to LA side); distal end anastomosed to LPA (modified Glenn); patch diversion of LSVC-APVR entrance to CA VV (lVC to the right); modified Fontan (atriopulmonary conduit interposed) LSVC and azygous anastomosed to LPA (modified Glenn); patch diversion of pulmonary veins to coronary (RSVC and hepatic veins to right) Patch diversion PVR-CAVV, CS (and LSVC) to the right by suturing the patch to the anterior inner aspect of the CS; modified Fontan. Reoperation 24 yr (PVR obstruction); baffle replaced (isolating RSVC and IVC); LSVC excluded (modified Glenn) Early Late Death; SVR obstruction; conduit compressed by the sternum Death; SVR obstruction Well (2 yr); FC (NYHA) Well (5 mol; FC I (NYHA) Well (2 yr) FC I(NYHA) Well (4 mol Recatheterized r /0 right/left sided ob. Well (45 days) peath (LCO) Continued. right AV valve (Fig. 1, B). Systemic venous return was kept on the functional right side of the baffle for direct connection to the pulmonary artery. Placement of the atrial baffle varied, according to the various types of anomalous systemic or pulmonary venous connection. Anomalous systemic venous connection Three anomalies of the systemic venous return were encountered, which necessitated alteration of our standard technique of atriopulmonary anastomotic procedure. In the first group (Cases 1 to 7), the left SVC drained directly into the left side of the atrium. Two different operative approaches have been utilized. In our initial cases (Nos. 1 to 4), an intraatrial baffle was constructed to divert all systemic venous return to the right side of the atrial baffle and to direct all pulmonary venous return to the AV valve or valves. In three of them, additional systemic venous drainage from the lower half of the body (hepatic veins in Case 1 and IVC in Cases 2 and 4) also entered the left side of the atrium. As a consequence of the venous connections, the patches necessary to separate pulmonary from systemic venous return had a complex configuration. Two of the four patients in this subgroup died (Cases I and 2), both with low cardiac output caused by obstruction of systemic venous return. The remaining two patients did well. The last three patients operated on for left SVC connection to the left atrium (Cases 5 to 7) have been managed by division of the left SVC and construction of an endto-side anastomosis between the left SVC and left pulmonary artery (bidirectional modified Glenn shunt) (Fig. 2). One of these patients also had total anomalous pulmonary venous connection to a left SVC, draining into the left atrium (Case 6). The proximal left SVC was simply oversewn. All three patients survived. In the second group, the anomalous left SVC drained to the coronary sinus. In four patients (Cases 8 to 11), the atrial baffle separating systemic and pulmonary venous blood was sewn to the anterior lip of the coronary sinus to avoid the area of the AV node and to leave the coronary sinus orifice on the right atrial side of the patch The Journal of Thoracic and Cardiovascular Surgery 526 Vargas et af. Table I. Cont'd Patient Age Previous operation Anomalous venous drainage Diagnosis 9 22 yr RBTS {S,D,D}, straddling RAVV, hypoplastic RV, D-TGA, PS BIlateral SVC (LSVC to CS) 10 19 yr BTS {S,L,L}, double-inlet SV, LTGA, PS Bilateral SVC (LSVC to CS) II 8 yr PAB {S,D,D}, CAVY, SV, D-TGA, JLAA Bilateral SVC (LSVC to CS) 12 16 mo sp APWR; sp 1AAR {S,D,D}, LA VV stenosis, HL V, PS Bilateral SVC (LSVC to CS) 13 7 yr Septectomy Asplenia {S,D,D} straddling RA YY, SY, D-TGA, PS Bilateral SVC (LSVC to CS) 14 5 yr sp CoAR; sp ADKSR {S,L,L}, LA VV atresia, hypoplastic outlet chamber Bilateral SVC (LSVC to CS) 15 5 yr None Heterotaxy-{A,D,D}, CAVY, DORV; PS RSVC, IYC-LA side 16 19 yr Land RBTS Asplenia {A,L,L}, common atrium, CAVY, SV, L-TGA, PS Total APVR to LSVC to innominate veins; retrocardiac CPV 17 12 yr LBTS Asplenia {A,L,L}, common atrium, CAVY, SV, L-TGA, PS Total APVR to RA; no LSYC; CS absent (Fig, 3). Three patients survived. A fourth patient (Case 8) died with pulmonary venous obstruction. The atrial septal patch was redundant and could have potentially limited the pulmonary venous-common AV valve pathway. In the three remaining patients with left SVCcoronary sinus connections (Cases 12 to 14), the potential for a patch passing between the coronary sinus and the right AV valve anulus to bow to the left (since right atrial pressure would exceed left atrial pressure), obstruct the valve orifice, and cause pulmonary venous obstruction was recognized. In these cases an end-to-side left SVC-left pulmonary artery anastomosis was done, and the intraatrial patch was placed well away from the level of the right AV valve. The coronary sinus orifice remained on the left (pulmonary venous) side of the patch. All three patients survived this operation. One final patient with anomalous systemic venous connection had an IVC draining to the left side of the common atrium and a right-sided SVC (Case 15). The complete atrial baffie required to divert the pulmonary veins to the common AV valve had to separate both the right-sided SVC and the left-sided IVC would have obstructed the pulmonary venous pathway. This patient was successfully managed by placing an intraatrial tube graft between the left IVC and right SVC and then connecting the upper end and the side of the graft to the right pulmonary artery. The pulmonary veins drained to the common AV valve around the tube graft (Fig. 4). Anomalous pulmonary venous connection Four different types of anomalous pulmonary venous return were encountered, In the first, total anomalous pulmonary venous connection drained to a persistent left vertical vein, which connected to the innominate vein (Case 16). In this patient, a side-to-side anastomosis was created between the common pulmonary vein and the posterior left atrial wall, followed by atrial baffiing of the newly created pulmonary venous connection to the common AV valve (Fig. 5). The IVC and right SVC flows were collected within the right-sided systemic venous chamber and connected to the right pulmonary artery by direct anastomosis. In the second case (Case Volume 93 Number 4 April 1987 Fontan-Kreutzer operation 5 27 Results Procedure Patch diversion PVR to RA VV, CS (and LSVC) to the right by suturing the patch to the anterior inner aspect of the CS; modified Fontan Patch diversion PVR to RA VV, CS (and LSVC) to the right by suturing the patch to the anterior inner aspect of the CS; modified Fontan Patch diversion PVR-RA VV, CS (and LSVC) to the right by suturing the patch to the anterior inner aspect of the CS; modified Fontan LSVe exclusion (modified Glenn); patch diversion PVR to RAVV (RSVC and Ive to the right); es to the left; modified Fontan LSVe exclusion (modified Glenn); patch diversion PVR to RAVV (RSVe and IVC to the right); es to the left; modified Fontan LSVe exclusion (modified Glenn); patch diversion PVR to RAVV (RSVe and Ive to the right); es to the left; Modified Fontan Intracardiac tube graft to connect LIVe to RSVC; RSVC + RA anastomosis to RPA. CPV-posterior atrial wall anastomosis; LSVC ligated; patch diversion of anastomotic orifice to CA VV (RS and CV IVC to the right); modified Fontan Patch diversion of total APVR to CAVY (RSVC and Ive to the right); modified Fontan 17), all of the pulmonary venous return entered the heart at the right atrium-right SVC junction. An intraatrial baffle was placed, rerouting the pulmonary venous return to the common AV valve. (IVC and right SVC were excluded to the right.) The area of potential obstruction to right SVC flow was subsequently enlarged during creation of the atriopulmonary anastomosis(Fig. 6). In a third case with associated anomalous systemic venous connection (Case 4), the pulmonary veins entered the heart on the right side of a common atrium at the midatrial level. The pulmonary veins joined to form a posterior common vein that was incorporated into the posterior wall of the atrium (distal to the atrial orifice of the vein). This intramural channel of the common pulmonary vein was unroofed, which widely opened the entrance of the anomalous pulmonary venous connection toward the left side of the atrium. The pulmonary venous flow was then directed to the common AV valve by an intraatrial baffle sutured within the original orifice of the pulmonary veins and then to the anterior border of the atriotomy. The Early Late Well (18 mol FC I (NYHA) Late drainage (pleural eff.) Well (18 mol FC I (NYHA) Well (4 mol FC I (NYHA) Well (2 yr 7 mol Fe I (NYHA) Well (I yr) Normal hemodynamics (recatheterization) Well (40 days) Well (2 yr) FC I Death (third month); iliac vein; thrombosis; pulmonary embolus, 2-D echo, rio R/L-sided obs. Well (18 mol CF I (NYHA) bilateral SVC and IVC flows were thus channeled into the systemic venous compartment. In a fourth case also with anomalous systemic venous connection (Case 6), the pulmonary veins drained to a persistent left SVC, which entered the left atrium. There was no right SVC. The left SVC was divided distal to the entrance site of the pulmonary veins. The atrial end was closed, leaving the total anomalous pulmonary venous connection draining to the left side of the atrium (via the proximal left SVC). The distal left SVC was anastomosed end to side to the left pulmonary artery (bidirectional cavopulmonary shunt). The stoma of the left SVC into the atrium (now draining all the pulmonary veins) was then diverted by an atrial septal patch to the common AV valve, which isolated the IVC into a systemic venous chamber (Fig. 7) connected to the left side of the main pulmonary artery by a conduit. The above-outlined baffle procedures were followed by a direct "right" atriopulmonary anastomosis in 15 patients. In the remaining two patients, a systemic venous atrium-left pulmonary artery conduit had to be The Journal of Thoracic and Cardiovascular Surgery 528 Vargas et al. Incision Fig. 1. Surgical technique for intraatrial septation in modified Fontan procedure. A, Incision runs parallel to the interatrial groove. B, Atrial septal patch diverts the pulmonary venous flow to the common or right atrioventricular (AV) valve, separating the systemic venous return into an anterior chamber. Because the anterior border of the patch is attached to the anterior lip of the atriotomy (coronary sinus to the left), the suture lines are placed away from the conduction tissue. interposed because of {I,L,L} and {A,L,L} configurations. In these two patients, the main pulmonary artery was divided, its proximal end oversewn, and the distal stoma was used as a part of the anastomosis between the atrium and conduit. Early results There were three patients who died during hospitalization (17.6%). The first death (Case 1) occurred in a patient with complex intraatrial anatomy (bilateral SVC, hepatic veins draining to the left side of the atrium). The autopsy revealed obstruction of the systemic venous pathways and also external compression of the nonvalved conduit used to connect the systemic venous chamber with the left pulmonary artery. The second hospital death occurred in a patient in whom the systemic venous return (bilateral SVC, IVC into the left atrial side) had been excluded with a complex intraatrial patch. He remained in severe low cardiac output after the operation, with signs of obstruction to the systemic venous return. He died 48 hours later (Case 2). The third hospital death (Case 8) occurred in a patient with a left SVC connected directly to the coronary sinus. This patient required reoperation within the first 24 hours because of obstruction to the pulmonary venous return. The redundant atrial patch was obstructing the pulmo- Fig. 2. Surgical technique (Cases 5 to 7). A, Left superior vena cava (LSVC) draining into the left atrial side. B, The LSVC was divided, its proximal end suture ligated (arrow), and the distal end anastomosed end-to-side (arrow) to the left pulmonary artery (bidirectional cavopulmonary shunt). The main pulmonary artery was divided, its proximal end suture ligated, and the distal orifice enlarged toward the right pulmonary artery. The pulmonary veins were diverted toward the common or right AV valve by an intraatrial septal patch attached to the anterior lip of the atriotomy. C, A modified Fontan procedure was completed. nary venous return at the coronary sinus entrance site. The left SVC was divided, and an end-to-side bidirectional cavopulmonary shunt was performed. The original baffle was also replaced by a geometrically simpler patch, since the left SVC had been diverted to the left pulmonary artery. However, the patient continued to have a low cardiac output despite normal right and left atrial pressures. He died within 24 hours after the second operation. The remaining patients did well. In the operating room right atrial pressures ranged from 12 to 18 em H 20 (mean, 16 em H 20) and left atrial pressures were less than 7 em H 20 in all cases. All patients remained in sinus rhythm postoperatively. Late results The mean follow-up period of the 14 survivmg patients was 21 months, ranging from 40 days to 2 years and 7 months. There was one late death (5.8%) attributed to massive pulmonary embolism in a 19year-old patient (Case 16), who was receivingoutpatient anticoagulant treatment 3 months after the operation Volume 93 Fontan-Kreutzer operation 529 Number 4 April 1987 RSve 4 Fig. 3. Surgical technique (Cases 8 to II). A, Left superior vena cava (LSVCj to the coronary sinus (eS). B, An intraatrial septal patch, which diverts the pulmonary venous flow to the common or right AV valve, is sutured to the inner aspect of the anterior wall of the CS and then to the anterior lip of the atriotomy. Injury to the conduction tissue has been avoided in this way. The CS-LSVC flow has been directed into a right-sided systemic venous chamber. C, A modified Fontan procedure was completed. because of late postoperative iliac vein thrombosis. No postmortem examination was obtained. However, a two-dimensional echocardiogram obtained shortly before death ruled out obstruction to systemic or pulmonary venous pathways. Two patients with persistent pericardial and pleural effusions were recatheterized. Normal "right atrial" pressures without atriopulmonary gradients were demonstrated in both. They were successfully managed by fashioning of a pericardial pleural window in one patient and a pleural drainage in the other patient. All 13 patients are currently in New York Heart Association Class I. Discussion At the beginning of Choussat's and Fontan's" experience with atriopulmonary anastomosis for tricuspid atresia, patients with abnormal systemic and pulmonary venous return were excluded. With increasing experi- Fig. 4. Surgical technique (Case 15). A, Inferior vena cava (IVCj draining to the left side of the common atrium in a close relationship with the pulmonary veins. Tailoring of complex intraatrial septal baffle could result in obstruction to either systemic or pulmonary pathways. B, An intraatrial circular graft is sutured inferiorly around the orifice of the left IVC and superiorly around the entrance of the right superior vena cava (RSVCj and to the adjacent atrial roof. C, A modified Fontan procedure was completed. ence, the indications for a Fontan-Kreutzer operation have been expanded 16-21 to include younger and older patients, non-tricuspid atresia anatomy, and patients with anomalous systemic and pulmonary venous connections." The latter associated anomalies represented 10% (17 patients) of the total number (170 patients) of modified Fontan-Kreutzer procedures done at our institution. The coexistence of the anomalous systemic and/or pulmonary venous connections initially had been recognized as increasing both operative morbidity and mortality/- 7.12.13 This was also true in our experience. However, after an initial disappointing learning curve, results have been improved. We have learned that intraatrial baffles constructed to divert a left SVC-Ieft atrium connection to the right side of the atrium have a significant potential (two of four cases) to cause either systemic or pulmonary venous obstruction with consequent mortality. When the left SVC drains to the coronary sinus, the baffle can be carried along the inner and anterior aspect of the coronary sinus, to exclude the coronary sinus-left SVC, right SVC, and IVC into a right-sided venous chamber. There was only one death among the four 5 3 0 Vargas et al. The Journal of Thoracic and Cardiovascular Surgery Fig. 5. Surgical technique (Case 16). A, Total anomalous pulmonary venous return to right superior vena cava (via left vertical innominate vein). B, The common pulmonary vein was anastomosed with the posterior left atrial wall (A), and the pulmonary venous return was thus directed to the common AV valve by an intra atrial septal patch (arrow). The systemic venous return was therefore excluded into an anterior atrial chamber to be connected with the pulmonary artery (modified Fontan). The left vertical vein was ligated. Fig. 6. Surgical technique (Case 17). A, Total anomalous pulmonary venous return (PVR) to the superior (RSVC) cavoatrial junction. B, The orifice of the entrance was channeled to the common AV valve (arrow). C, Right atrium-pulmonary artery (PA) (arrow) anastomosis was completed (modified Fontan). patients with this anatomy treated in this manner, and this death was caused by pulmonary venous obstruction. In patients in whom the right AV valve or common AV valve is a critical component of the pulmonary venous pathway, this baffle placement is potentially dangerous. An extracardiac exclusion of the left SVC by a bidirectional end-to-side left cavopulmonary anastomosis seems safer in this situation. This modified Glenn shunt can be performed regardless of the site of drainage of the left SVC, and it avoids manipulations around the AV node area. The left SVC-Ieft pulmonary artery anastomosis can be accomplished without cannulating the distal left SVC by lowering the body temperature to 25° C, reducing bypass flow, and occluding the left SVC for 10 to 15 minutes. This modified Glenn anastomosis is done to facilitate separation of systemic and pulmonary venous return in these situations of complex venous anatomy; it is not proposed as a necessary or desirable adjunct to the routine Fontan-Kreutzer operation. The presence of an IVC draining into the left atrial side poses a different problem. The use of an intraatrialtube graft to connect both IVC with the right SVC, followed by an anastomosis of the upper part of the graft to the right pulmonary artery (modified Fontan), as done in Case 15, is an attractive alternative. This procedure, previously reported at the Mayo Clinic," has the advantage of being technically simpler than a complex septation. It also minimizes the risk for venous pathway obstruction, since the higher-pressure systemic venous pathway is contained within the tube graft. (The risk for baffle obstruction of the pulmonary venous drainage is eliminated in this way.) However, the long-term outcome of such a prosthetic intraatrial tubular graft in terms of patency remains to be eluci- dated." Anomalous pulmonary venous drainage also can be satisfactorily managed. The repair of total anomalous pulmonary venous connection to the left SVC by the use Volume 93 Number 4 April 1987 of a modified Glenn shunt to exclude the distal left SVC, as accomplished in Case 6, simplifies the procedure and avoids pulmonary venous obstruction. It can also be applied for anomalous pulmonary venous connections (partial or total) to the right SVc. A similar rerouting of anomalous pulmonary venous connections through the proximal end of a previously transected right SVC was recently reported for total anomalous pulmonary venous connections into the upper right SVC,23 In the other cases, appropriate baffle placement allowed separation of systemic and pulmonary venous drainage. Whatever the technique used for rerouting the anomalous pulmonary venous connection or anomalous systemic venous connections the patches should be geometrically simple and without redundancy to avoid the possibilityof obstructing one or both pathways." To minimize this possibility, a left atrial retroaortic extension of the atriotomy for the atriopulmonary anastomosis has been reported. 5. 25 We prefer instead to attach the anterior portion of the patch to the anterior lip of the atriotomy, which allows for a smaller and straighter patch. (Fig. 1). In hearts with abnormal AV connections (AV discordance, straddling, and double-inlet AV valve), the course of the conduction tissue is usually abnormal.v" Nevertheless, the AV node always remains on the atrial side and closely related to the valve anulus. Consequently, anchoring the atrial baffle to the atrial incision rather than around the AV valve prevents injury to the AV node and bundle. With the use of this technique, we have not observed any AV rhythm disturbances in these patients. Preoperative echocardiographic and angiographic studies are critically important to outline in detail the pulmonary and systemic venous drainage pattern. Unrecognized anomalous pulmonary venous connection has been reported as causing serious hemodynamic deterioration from pulmonary thrombosis or infarction during the postoperative period in patients who had an otherwise uncomplicated Fontan- Kreutzer procedure." During the past decade, the use of the FontanKreutzer principle has been extended to include more complex malformations than tricuspid atresia. Patients with single ventricle and associated anomalous systemic and/or pulmonary venous connection can now also have a modified Fontan-Kreutzer procedure at a substantially reduced surgical risk. In cases of persistent left SVC with or without associated anomalous pulmonary venous connection, an end-to-side anastomosis between the left SVC and the left pulmonary artery (modified Glenn) greatly facilitates the intraatrial rerouting of both systemic and pulmonary venous pathways. Because of the Fontan-Kreutzer operation 531 Fig. 7. Surgical technique (Case 6). A, Total anomalous pulmonary venous connection (arrows) to the left superior vena cava (LSVC). There is no right superior vena cava ({A,L,L} configuration). B, The LSVC was divided distal to the entrance of the pulmonary veins, and the proximal end was closed with a suture (arrow). The anomalous pulmonary venous return was directed (via the proximal LSVC) to the common atrial chamber in this way. An intraatrial septal patch directs the pulmonary venous flow through a common AV valve into the single ventricle (SV). The inferior vena cava was excluded into a systemic venous chamber. C, The distal end of the LSVC was end-to-side anastomosed (white arrow) to the left pulmonary artery (bidirectional cavopulmonary shunt). Repair was completed by interposing a conduit (black arrow) between the systemic venous chamber (containing the inferior vena caval drainage) and the left pulmonary artery (modified Fontan). complexity of the anatomic variables in anomalous systemic and pulmonary venous connections, each patient must be carefully studied and the operative technique planned according to each anatomic variant. REFERENCES I. Fontan F, Baudet E. Surgical repair of tricuspid atresia. Thorax 1971;26:240-8. 2. Kreutzer G, Galindez E, Bono H. An operation for the correction of tricuspid atresia. J THORAC CARDIOVASC SURG 1973;66:105-11. 3. Gale AW, Danielson GK, McGoon DC, Wallace RB, Mair DD. Results of Fontan operation for tricuspid atresia. Circulation 1979;59,60(pt. 2):IIl71. 5 3 2 Vargas et al. 4. Kreutzer GO, Vargas FJ, Schlichter AJ, Laura JP, Suarez JC. Atriopulmonary anastomosis. J THORAC CARDlOVASC SURG 1982;83:427-36. 5. Doty DB, Marvin WJ, Lauer RM. 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