Biomedical subjects

C R Hung

Publications and source records attributed to C R Hung.

At least 73 records · Page 4Linked to original sources

PubMed1991

[Treatment with new surgical method for chronic atrial fibrillation in 5 cases with mitral valve disease].

Chronic atrial fibrillation is the most common arrhythmia in patients with mitral valve disease, it not only deteriorates cardiac output, but also promotes a 5.6 times higher incidence of thromboembolic events. Nevertheless, the exact mechanism of atrial fibrillation is still poorly understood. Moreover, the long-term results of treatment, either by drugs or cardioversion, are almost always disappointing. Recent investigations suggest that atrial fibrillation is probably due to intraatrial multiple reentrant waves. It is also well-known from animal experiments that for sustenance of the fibrillation a critical mass of atrium is necessary. Based on these data, a new surgical method has been carefully designed to reduce atrial mass and to prevent sustenance of fibrillation. Between July and December 1988, five patients, one male and four females, with mitral valve disease and chronic atrial fibrillation were selected for this new surgical method. The age distribution ranged from 25 to 57 years, with a mean of 36 +/- 13 years. All of them had chronic atrial fibrillation which had been documented for more than one year. The operation was performed using the cardiopulmonary bypass and cardioplegia myocardial protection techniques. The left atrium was opened via the interatrial sulcus. After the mitral valve was repaired, cryosurgery (-60 degrees C for 120 sec) was applied along the borders of the left atrial free-wall. The left atrium was separated by these cryolesions into two sections, each about half the mass of the original and both sections were connected with a few atrial fibers located behind the coronary sinus. No surgical mortality or complications were encountered.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1991

Left atrial isomerism in the adolescence: report of two cases.

Atrial isomerism is very rare in adolescence. Two cases of left atrial isomerism are reported here in 2 females, aged 21 and 19 years. They had presented with cyanosis and dyspnea since childhood. High kilovoltage filter films showed a bilateral morphologically left bronchus. Cardiac catheterization in Case 1 revealed normal pulmonary artery pressure, severe subvalvular pulmonic stenosis, a double outlet right ventricle, a significant oxygen step-up at the atrial level and moderate systemic oxygen desaturation; while Case 2 disclosed pulmonary hypertension and mild systemic oxygen desaturation. Both cases had the following anatomical features: ipsilateral connection of pulmonary veins to the bilateral morphological left atrium; interrupted inferior vena cave with azygos or hemiazygos continuation; total anomalous hepatic venous return to the right-sided atrium; complete atrioventricular canal. The diagnoses were confirmed in both cases at surgical correction.

Adult↗

PubMed1991

Surgical treatment of tricuspid atresia.

From April 1984 to July 1989, 6 consecutive patients underwent an orthoterminal repair for classical tricuspid atresia (TA). Their ages ranged from 6 to 14 years with a mean of 8.3 years. Four patients had ventriculoarterial concordance (VA-con) and 2 had ventriculoarterial discordance (VA-dis). One patient with VA-dis underwent a total cavopulmonary connection. The other five patients had modified Fontan operation. All 6 patients survived the operation. At a mean follow-up of 28 months, all patients were in the New York Heart Association Functional Class I. A follow-up color Doppler echocardiogram showed that the forward pulmonary flow was mainly during the ventricular diastolic phase except in one case. In this case, a tripartite right ventricle (RV) could be identified by angiocardiogram 4.5 years after the atrioventricular (A-V) connection without obliteration of the trabecular portion. A big "V" wave was demonstrated in the RV and pulmonary trunk. The pulmonary valve was closed in the ventricular diastolic phase. In the other case with an A-V connection and obliteration of the trabecular portion, revealed a fixed-open pulmonary valve with a forward flow more in the atrial systolic phase than in the ventricular systolic phase. The graded exercise test in these 2 patients with an A-V connection revealed a normal functional capacity. The mean maximal oxygen uptake was 8.4 +/- 0.1 METS. In the other 3 children without an A-V connection the mean maximal oxygen uptake was 6.6 +/- 0.5 METS. We concluded that the Fontan-like repair was the procedure of choice for TA, and that excellent surgical results could be obtained.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed1991

Surgical treatment of thoracoabdominal aortic aneurysm with graft inclusion technique.

Two male patients with huge thoracoabdominal aortic aneurysms were treated surgically at the National Taiwan University Hospital (NTUH) during the last 6 years. Case 1 was 70 years old with a case of malignant lymphoma. A huge thoracoabdominal aortic aneurysm was found which ruptured suddenly during the course of chemotherapy for malignant lymphoma. An emergency operation was performed because the patient suffered from profound shock. Case 2 was 34 years old and was referred to our hospital with a huge pulsating mass over his abdomen and progressive dysphagia. Both had atherosclerosis, thought to be the underlying etiology. The surgical technique we employed was the graft inclusion technique with major branch vessel reattachment to the side holes of the graft. Postoperative surgical results were excellent. Neither spinal cord complications nor visceral organ failure was found in either case. Case 1 unfortunately died 3 months after surgery because of advanced lymphoma with many organs being involved and upper GI bleeding. Case 2 is doing well and being followed up at our OPD at present.

Adult↗

PubMed1991

Aneurysm arising from the branch of the superior mesenteric artery.

Superior mesenteric branch aneurysms are rare and usually become symptomatic at the time of rupture. Pain, gastrointestinal blood loss and intra-abdominal hemorrhage draw attention to the presence of aneurysms in 70% of the reported cases. We report on a 64-year-old male patient who had an emergent laparotomy for acute abdominal pain at a local hospital in Changhua in March of 1988. The operative finding was an unresectable mesentric mass, and the pathologic finding of the biopsy was a chronic abscess. Because of two episodes of tarry stools after the operation, the patient was referred to the National Taiwan University Hospital for further evaluation of the intra-abdominal mass. After admission in April of 1990, abdominal sonogram and CT examinations demonstrated the presence of a multilobulated mass which was suspected to be an aneurysm. Selective superior mesenteric arteriography confirmed this diagnosis and showed that the aneurysm arose from the origin of the ileocolic branch. At surgery, the aneurysm was found to have a fistula tract communicating with the terminal ileum. The aneurysm and the associated segment of the terminal ileum were successfully removed. We herein report this unusual case.

Aneurysm↗

PubMed1990

Reappraisals of atrioventricular node reentrant tachycardia: lessons learned from surgical treatment.

The exact site of reentrant circuit involved in the atrioventricular node reentrant tachycardia was questioned. Seven patients (6 females and 1 male), aged 21 to 64 years (mean = 40 +/- 17 years), with refractory nodal reentry, underwent surgical treatment. The associated cardiac diseases included rheumatic valvar disease in two and an atrial septal defect. Electrophysiologic studies before surgery showed dual nodal pathways in 4 patients. Right atrial endocardial mapping was performed and the earliest retrograde atrial activation during tachycardia was mapped to the apex of the triangle of Koch in 6 patients and near the orifice of coronary sinus in one. Perinodal dissection was performed according to the location of earliest retrograde atrial activity. Care was taken to preserve as much of the atrioventricular node and its arterial supply as was possible. Immediately after surgery, conduction in an antegrade direction recovered and the tachycardia could no longer be reproduced. There was no surgical mortality or morbidity. At 10 to 26 months of follow-up, all patients remain free of tachycardia without antiarrhythmic drugs. Four patients underwent repeated electrophysiologic studies at 2 weeks to 6 months after surgery. Dual nodal pathways were no longer demonstrated. It is concluded that the perinodal atrial tissue plays a part in the atrioventricular nodal reentry, and that surgical dissection is a simple and effective treatment for patients with refractory atrioventricular node reentrant tachycardia.

Adult↗

PubMed1990

The use of TDMAC-heparin-impregnated shunt for managing aneurysm of the descending thoracic aorta.

From April 1981 to December 1988, a total of 23 patients were operated upon for the repair of an aneurysm of the descending thoracic aorta with a tridodecylmethylammonium chloride (TDMAC)-heparin-impregnated shunt. There were 20 men and 3 women. The ages ranged from 29 to 72 years with a mean of 52.3 years. The major pathological change of the aortic wall was medial cystic necrosis in 19 patients and atherosclerosis in 4. Among them, only 6 patients underwent elective surgery, while 17 patients underwent emergency operations with the surgical indication being shock in 4, oliguria in 3, persistence of chest pain in 2, massive hemoptysis in 1, rapid size progression of the aneurysm in 3, and impending rupture of the aneurysm in 4. During surgery, the aortic cross-clamping time ranged from 40 to 76 minutes with a mean of 54 minutes. Hospital death was limited to 2 patients with a mortality rate of 8.7%. Postoperative complications were noted in 5 patients, cerebrovascular accidents in 4 and transient paraparesis in 1. However, the clinical conditions recovered before those patients were discharged. The follow-up period ranged from 4 to 84 months with a mean of 32.3 months. Except for 1 patient who died of anaphylactic shock due to drug allergy, the other 20 survivors had an apparent improvement of their clinical status and life quality.

Adult↗

PubMed1990

Aortico--left ventricular communication: report of a case.

An 11-month-old male infant whose condition had been followed since birth was referred to the National Taiwan University Hospital for management of a congenital heart disease. On admission, this infant was noted to have a systolic and diastolic precordial thrill and a grade 4/6 systolic and diastolic murmur. Echocardiography, cardiac catheterization and cineangiogram revealed aortic stenosis, aortic regurgitation and dilatation of the aortic root. Surgical repair was performed to correct this congenital anomaly due to the progressive congestive heart failure. Intraoperatively, a breach between the aortic valve and the edge of the sinus of Valsalva along the aortic annulus was found. This congenital defect was repaired with a Teflon patch successfully. Postoperatively, this patient convalesced steadily and was discharged. We report this unique case with aortico-left ventricular communication which we believe to be the ninth case in the English-language literature and the first in the Republic of China.

Aortic Aneurysm↗

PubMed1990

Emergency surgery of patients with ruptured great vessels and profound shock.

From October 1986 to March 1989, a total of 7 patients who had preoperative profound shock underwent surgical treatment at the National Taiwan University Hospital for a ruptured aorta or vena cava. All 7 patients were men. Their age ranged from 21 to 70 years with a mean of 45 years. Emergency operations were performed due to a ruptured abdominal aortic aneurysm in 2, a ruptured dissecting thoracic aneurysm in 1, a penetrating injury which transected the intrahepatic vena cava in 2, and blunt chest injury which resulted in acute traumatic aortic transection in 2. One of these 7 patients died of acute tubular necrosis, anoxic encephalopathy and secondary sepsis, in spite of successful restoration of circulation. Two patients had postoperative complications. One had a transient paraparesis after an aortic cross-clamp, and the other had a transient impairment of the hepatic function due to the penetrating hepatic injury and the hypoxic hepatic damage. All 6 survivors were restored to an excellent state of health and had minimal post-resuscitation sequelae. We emphasize the importance of aggressive surgical treatment for those patients with the threat of impending death due to massive hemorrhage from a ruptured great vessel.

Adult↗

PubMed1990

Chronic intravascular hemolysis after valvular surgery.

The Phenomenon of intravascular hemolysis following cardiac valvular surgery was studied among 156 randomly selected patients. There were 76 men and 80 women, varying in ages between 15 and 71 years, with a mean age of 48.3 years. The time interval between the study and the operations ranged from 2 to 163 months with a mean of 41.1 months. The prosthetic valve was used in 129 patients; the xenograft tissue valve in 26 and the mechanical valve in 103. Subclinical hemolysis occurred in 68.9% of the 129 patients who had one or more prosthetic valve implants and in 14.8% of the 27 patients who underwent plastic repair of the mitral valve. Compared among the groups with different valve prosthesis, hemolysis could be detected in 81.6% of the patients with a mechanical prosthetic valve and in 23.1% of those with a bioprosthetic tissue valve (p less than 0.05). Twelve patients who had a valve prosthesis were documented to have symptomatic gallstones with an incidence of 9.3%. Among them, only 2 patients had biliary colic and required cholecystectomy to relieve the associated symptom. Anemia, secondary to the hemolysis, occurred in 3.8% of those with a xenograft tissue valve and 8.8% of those with a mechanical valve (p less than 0.05). None of them needed a blood transfusion. None had related renal impairment. In conclusion, the mechanical valve prosthesis has a higher incidence of hemolysis than the xenograft valve. Though the mechanical valve prosthesis has its own merits, the xenograft tissue prosthesis is superior in this respect.

Adolescent↗

PubMed1990

Hemolysis following correction of ventricular septal defect.

Hemolysis following repair of a ventricular septal defect (VSD) is an unusual complication. Three cases of patients who had simple VSD are described here. After repair of the VSD, the postoperative course was complicated by the intravascular hemolysis induced by the interaction between the red blood cells and the double velour Dacron patch. Thus the patients' hemodynamic status deteriorated. The first 2 patients had a course of hemoglobinuria, hyperamylasemia, hyperglycemia, malignant hypertension, hepatospenomegaly, acute renal failure and hypertensive encephalopathy. One patient, who did not undergo reoperation, died due to multiple organ failure; the other one, who underwent operation revision in order to arrest the hemolysis, died of sepsis. Early reoperation was performed in the remaining patient to replace the double velour Dacron patch with a pericardium-covered knitted Dacron patch, and he survived. Hemolysis ceased in both patients who had the double velour Dacron patch replaced with a pericardium-covered patch. A review of the literature failed to show previous reports concerned with hemolysis associated with repair of a simple VSD. We now report what we believe to be the first cases in the literature with this unique clinical course following hemolysis.

Blood Vessel Prosthesis↗

PubMed1990

The atrioventricular conduction axis of hearts with isolated ventricular septal defects.

We studied the surgical anatomy of 14 hearts with isolated ventricular septal defects and the precise relationship of the atrioventricular conduction axis to their rims. Ten of these hearts were investigated by serial sectioning of their atrioventricular conduction systems. All defects were divided into perimembranous or muscular types as previously suggested by Soto et al. The distinguishing feature of the perimembranous defect was that the central fibrous body formed part of its rim, this fact indicated that the conduction tissue was always to the right of the surgeon's hand when the defect was approached through the right atrium. The precise relationship of the ventricular conduction tissues varied depending upon whether the perimembranous defect extended into the inlet, trabecular or outlet components of the muscular septum. The nonbranching bundle was closest to the septal rim in the inlet and trabecular defects, frequently being buried in a remnant of the interventricular membranous septum. However, in these defects the nonbranching and branching bundles were also found in other specimens remote from the septal crest, yet were carried on the left ventricular aspect of the septum. In perimembranous inlet defects, the penetrating bundle detoured deep into the central fibrous body. In perimembranous outlet defects, the conduction tissues were remote from the septal crest. In contrast to these findings, the conduction tissues were away from the edges of the defects in trabecular and outlet muscular defects. In conclusion, in the perimembranous inlet defect, the placement of the sutures on the annulus of tricuspid valve should be avoided in view of its abnormal long penetrating bundle.

Atrioventricular Node↗

PubMed1990

Ruptured aneurysms of the sinus of Valsalva in Oriental patients.

Between 1964 and 1987, a total of 57 cases of ruptured aneurysm of the sinus of Valsalva underwent surgical correction at the National Taiwan University Hospital. This represents 0.96% of all cardiac operations. The origin of ruptured aneurysm of the sinus of Valsalva was the right coronary sinus in 46, the noncoronary sinus in nine, and the left coronary sinus in two. The aneurysms ruptured into the right ventricle in 44, into the right atrium in 11, into the left ventricle in one, and into both the right ventricle and right atrium in one. Associated congenital cardiac anomalies included ventricular septal defect in 30 patients, aortic regurgitation in 20, and infundibular pulmonic stenosis and coarctation of the aorta in one each. Operative death occurred in two patients (3.5%) and one patient had a successful reoperation. The remainder did well following surgery. To compare the differences between Oriental and Western countries in ruptured aneurysm of the sinus of Valsalva, 361 cases (195 Oriental patients versus 166 Western) were collected from the literature. Analyses of these cases revealed that ruptured aneurysm of the sinus of Valsalva in Oriental patients compared with Western series is characterized by a higher incidence (5 times), more aneurysms originating from the right coronary sinus (87.9% versus 63.6%), more aneurysm rupturing into the right ventricle (84.2% versus 56.6%), a higher incidence of association with ventricular septal defect (mainly supracristal) (59.0% versus 34.6%), less incidence of association with other congenital cardiac abnormalities (4.1% versus 21.5%), very few instances of rupturing into cardiac chambers other than the right ventricle and right atrium, and less incidence of occurrence in the extremities of ages (the youngest was 7 years in Oriental patients versus 11 months in the Western series). In other words, ruptured aneurysm of the sinus of Valsalva in Oriental patients is more or less a simple and uniform disease entity in contrast to the more diverse and protean pathologic profiles encountered in Western series. However, both Oriental patient and Western patient series have similar incidences of combination with aortic regurgitation (24.6% versus 20.0%), with 40.4% of Oriental patients and 60.6% of Western patients presenting with intact ventricular septum. Therefore the pathogenetic mechanisms of ruptured aneurysm of the sinus of Valsalva may at the same time contribute to the development of aortic regurgitation.

Adolescent↗

PubMed1989

Is the sinus node visible grossly? A histological study of normal hearts.

The sinus node is said to be occasionally visible in the human heart, while some have denied this visibility. This histological study of the normal sinus node was made on 11 adults and 10 infants. The node was always located subepicardially along the terminal groove at the junction of the superior caval vein and the right atrium. When no fatty infiltration (all infants and 2 adults) or minimal fatty tissue (2 adults) was found over the epicardial side of the node, it was not visible grossly. When fatty infiltration was obvious, then the node could be identified grossly as a yellowish spindle-shaped structure along the terminal groove. This arrangement was observed in 7 adults. The majority of nodes were in lateral position, but the so-called horseshoe arrangement was seen in 2 infants and 2 adults. The artery to the sinus artery was located centrally or eccentrically in the majority of cases, but the artery ramified through the nodal substance in 1 infant and 4 adults. We conclude that the node is not visible grossly in either the infant hearts or in those adult hearts without fatty infiltration. The whole cephalic part of the terminal groove should be carefully avoided to be sure of preventing the injury to the node during cardiac surgery.

Adult↗

PubMed1989

Surgical treatment of prosthetic valve endocarditis.

From January 1980 to June 1987, a total of 16 consecutive patients underwent surgical therapy in addition to an antimicrobial regimen for prosthetic valve endocarditis at the National Taiwan University Hospital. The ages ranged from 26 to 55 years, with a mean of 40. Nine of these 16 patients (56%) were men and 7 (44%) women. The infected valve prostheses were located at the aortic position in 5 patients, at the mitral position in 6 patients and at both mitral and aortic position in 5 patients. Among the total of 21 infected valve prostheses, 19 were bioprosthetic tissue valves and only 2 were mechanical valve prostheses. Hospital death occurred in 5 patients with an early mortality rate of 31%. Among them, 1 had fungal infection, 2 had streptococcal infection, and 2 had enterococcal infection. Four patients died of low cardiac output due to extensive myocardial involvement and one patient died of uncontrollable upper gastrointestinal bleeding. Late mortality occurred in 1 patient with fungal endocarditis and the cause of death was clinical deterioration due to multiple organ failure. The follow-up period ranged from 7 to 93 months. Except for one who was lost to follow-up, all of the patients survived in good condition without any complication.

Adult↗

PubMed1989

Color flow mapping in perimembranous ventricular septal defect with left ventricular-to-right atrial shunts.

The natural history of ventricular septal defect (VSD) varies with the exact location of the defect and also with the tissue changes surrounding it. Seven cases of perimembranous trabecular VSD were noted during color Doppler echocardiographic examination to have left ventricular-to-right atrial (LV-to-RA) shunts in association with aneurysmal transformation of VSD. Repeated cardiac catheterization documented the role of aneurysmal transformation in the increase of LV-to-RA shunts. A VSD located near the antero-septal commissure was diagnosed in all cases by echocardiography from the apical 5-chamber and parasternal inflow views. Echocardiographic signs of LV-to-RA shunts are high velocity backward turbulence in the RA without the presence of an elevated right ventricular systolic pressure and a two-directional turbulence through the "transformed" VSD. Corrective surgery confirmed the diagnosis in one case. Another case was complicated by an episode of viridans streptococcal endocarditis. The significance of LV-to-RA shunts in perimembranous trabecular VSD remains unknown.

Child↗

PubMed1989

A case of acute superior mesenteric embolism successfully treated by embolectomy.

Superior mesenteric artery embolism is undoubtedly fatal unless operative intervention is promptly performed. The first case successfully managed by embolectomy in Taiwan is reported in this communication. The key to successful management lies in the early suspicion in patients with atrial fibrillation or recent myocardial infarction, presenting with sudden abdominal pain and an unremarkable physical examination. Abdominal angiography is strongly recommended; however, immediate laparatomy should not be postponed if angiography is not available. Early embolectomy is the only useful means of treatment to restore mesenteric circulation, preserve the bowel and rescue the patient. A 56-year-old woman was admitted with a 5-year history of rheumatic heart disease and atrial fibrillation. She had a sudden attack of severe abdominal pain 8 hours after cardiac catheterization. Abdominal examination was not remarkable and plain abdominal X-ray was negative, while bloody stools and leukocytosis developed 7 hours later. Superior mesenteric embolism was highly suspected and emergency laparotomy was performed. Successful embolectomy was carried out through the distal approach and the patient recovered completely without requiring small bowel resection. All branches of the superior mesenteric artery were demonstrated patent upon postoperative angiography.

Embolism↗

PubMed1989

Mitral valve reconstruction with Carpentier ring for mitral regurgitation: experience with Chinese patients.

Between December 1985 and June 1987, 38 consecutive patients with mitral regurgitation underwent mitral valve reconstruction (MVP) with Carpentier rings. There were 16 men and 22 women, ranging in age from 16 to 63 years (mean 36.4 +/- 14.4). The underlying causes were rheumatic heart disease (55%), degenerative valvular disease (42%), and congenital heart disease (3%). Thirty patients were categorized in the New York Heart Association's functional classification III or IV preoperatively. The concomitant procedures included aortic valve replacement (AVR) in 6 patients, tricuspid valve repair (TVP) in 9, and closure of atrial septal defect in one. Hospital death happened to one patient (3%). All but one patient were followed up at 31 months postoperatively (rate 98.6%). There was one late death due to myocardial failure not related to the valves. The actuarial survival rate at 31 months was 96.8%. The thromboembolic rate was 1.44% per patient-year. No reoperation or endocarditis was encountered. All 36 survivors were in functional classes I and II. Twenty-one patients underwent Doppler echocardiography 3 to 12 months after surgery and 17 (81%) showed no or mild mitral regurgitation and 4 (19%) had moderate regurgitation. We conclude that MVP with Carpentier rings is a satisfactory method with low mortality and complication rates in Chinese patients.

Adolescent↗