The maze III procedure for atrial fibrillation: should the indications be expanded?

BACKGROUND: We favor the maze III procedure over nonsurgical treatments for atrial fibrillation and have advocated addition of the maze in symptomatic patients with other compelling indications for cardiac surgery. METHODS: Characteristics and perioperative outcomes of our 76 cumulative maze recipients between 1993 to 1998 were reviewed. The original maze III technique was employed without modification. RESULTS: Isolated maze III was performed in 19 patients (25%) and combined with other procedures in 57 patients (75%), 49 of these involving one or more valves. Patients having combined procedures were taking fewer antiarrhythmics (p < 0.0001), but were older (p < 0.01), more often female (p < 0.05), and more often had chronic atrial fibrillation (p < 0.01) compared with isolated maze III recipients. The mean duration of aortic clamping and cardiopulmonary bypass for isolated maze was 69 +/- 11 and 145 +/- 22 minutes, and for combined valve procedures it was 122 +/- 38 and 205 +/- 47 minutes. There was no operative mortality. Complications occurred in 15 patients (19.7%). At 3 months atrial fibrillation was cured in 73 of 75 patients (97.3%). Sick sinus syndrome required pacemaker implantation in 3 patients (4.0%). CONCLUSIONS: The maze III can be performed alone or as a combined procedure with equivalent success, and technical modifications may be unnecessary. A lower threshold for its expanded use in symptomatic patients with atrial fibrillation who require isolated or combined operations is appropriate.

The Maze procedure: the LDS Hospital experience.

At our center we have encouraged consideration of the Maze procedure over noncurative therapies for atrial fibrillation, particularly in patients who have other indications for cardiac surgical intervention. As a result, 78 of the 99 Maze procedures we have performed since 1993 have involved combined procedures. These combined operations included procedures on 1 or more valves in 69 of 78 patients (88%). The unmodified "cut-and-sew" Maze-III technique was used in all patients. There has been no operative mortality, and the median postoperative stay has been 7 days. Cure of atrial fibrillation has been observed in 97% of patients, and pacemaker implantation was required for sick sinus syndrome in 6%. Our results favor broader use of the Maze procedure for symptomatic atrial fibrillation and support use of the original Maze-III technique as the procedure of choice.

Methods for graft size selection in aortic valve-sparing operations.

Simple and reproducible methods for accurate restoration of aortic root dimensions during aortic valve-sparing operations are described. The methods are based on choice of an appropriate size vascular graft based on the measured or desired diameter of the aortic annulus.

Evolution of the maze III procedure: are modifications necessary?

The maze III procedure has been the culmination of multiple surgical approaches for supraventricular arrhythmias. Its success in curing atrial fibrillation has generated multiple modifications which constitute attempts to simplify the operation, particularly with associated mitral or multiple valvular pathology. Our preference in these patients, however, has been to employ the original maze III procedure without modification. This review tracks the development of the maze III procedure and its modifications and compares the early outcomes in patients requiring the maze procedure combined with mitral and additional valvular procedures.

Refractory post-transplant airway strictures: successful management with wire stents.

OBJECTIVE: Bronchial stenosis, malacia and dehiscence are major airway complications of lung transplantation. Our success in managing this problem evolved from the use of semi-rigid dilators, to balloon dilation and placement of a stent, which were initially silicone, thereafter wire balloon-expandable and finally wire self-expandable. METHODS: From May, 1994 until July 1997, we performed a total of 49 single and 58 bilateral lung transplants. Symptoms of shortness of breath, verified by a drop in the forced expiratory volume in one second (FEV1), led to bronchoscopic inspection of the airway in lung transplant patients. Eighteen patients (16%) suffered a severe form of airway complication (dehiscence or stenosis) in 24 of 151 airways at risk (15.9%). These anastomotic strictures were recalcitrant to conventional therapy. Intervention consisted of rigid bronchoscopy, dilation of the stricture and placement of a stent. Flexible bronchoscopy and fluoroscopy were used for precise placement of the stent. As the initial stent, the Hood silicone stent was placed five times in four patients and the Dumont studded stent five times in four patients. The Palmaz wire stent was used as the initial stent 10 times in seven patients and the Wallstent used eight times in seven patients. Four patients had multiple stents. Balloon inflation moulded the wire stent to the airway. RESULTS: There was no mortality resulting from the airway complication or any intervention. The most serious complication was a perforation of the airway using the semi-rigid dilator that necessitated immediate thoracotomy and re-anastomosis of the bronchus. Other complications necessitated repeat interventions due to restenosis or failure of the stents. The success of the stent placement was measured subjectively by the immediate ease of breathing enjoyed by each patient and objectively by the significant increase of the FEV1 from a pre-operative mean of 1.19 l (SD 0.64 l) to a post-operative mean of 2.06 l (SD 0.70 l) (P < 0001). The mean number of interventions according to the type of wire stent first used was significantly fewer with Wallstent insertion (1.28 (SD 0.48)) than in those patients in whom a Palmaz stent was inserted (5.22 (SD 2.38)) (P < 0008). CONCLUSION: The airway complication of stricture, broncho-malacia or dehiscence following lung transplantation can be managed effectively and easily with the use of balloon catheter dilation followed by precise placement of a self-expandable wire stent. The Wallstent is the superior stent for this application.

Effect of lung volume reduction surgery on neuromechanical coupling of the diaphragm.

The mechanisms for symptomatic improvement following lung volume reduction surgery for emphysema are poorly understood. We hypothesized that enhanced neuromechanical coupling of the diaphragm is an important factor in this improvement. We studied seven patients with diffuse emphysema before and 3 mo after surgery. Patients showed improvements in 6-min walking distance (p = 0.002) and dyspnea (p = 0.04). The pressure output of the respiratory muscles, quantified as pressure-time product per minute (PTP/min), decreased after surgery (p = 0.03), as did PaCO2 (p = 0.02). Maximal transdiaphragmatic pressures (Pdi(max)) increased from 80.3 +/- 9.5 (SE) to 110.8 +/- 9.3 cm H2O after surgery (p = 0.03), and the twitch transdiaphragmatic pressure response to phrenic nerve stimulation (Pdi(tw)) increased from 17.2 +/- 2.4 to 25.9 +/- 3.0 cm H2O (p = 0.02); these increases were greater than could be accounted for by a decrease in lung volume. The contribution of the diaphragm to tidal breathing, assessed by relative changes in gastric and transdiaphragmatic pressures, increased after surgery (p = 0.008). Net diaphragmatic neuromechanical coupling, quantified as the quotient of tidal volume (normalized to total lung capacity) to tidal change in Pdi (normalized to Pdi(max)), improved after surgery (p = 0.03) and was related to the increase in 6-min walking distance (r = 0.86, p = 0.03) and decrease in dyspnea (r = 0.76, p = 0.08). In conclusion, lung volume reduction surgery effects an improvement in diaphragmatic function, greater than can be accounted for by a decrease in operating lung volume, and enhances diaphragmatic neuromechanical coupling.

Bronchial dehiscence after lung transplantation: correlation of CT findings with clinical outcome.

PURPOSE: To determine whether computed tomography (CT) can help predict which patients will require surgical or bronchoscopic intervention during healing of bronchial anastomotic dehiscence after lung transplantation. MATERIALS AND METHODS: The authors followed up 25 bronchoscopically proved dehiscent anastomoses through healing in 19 patients who underwent lung transplantation. CT findings were correlated with bronchoscopic results and clinical outcome. RESULTS: A bronchial defect and extraluminal air were initially present at CT in all 25 dehiscent anastomoses. Of 12 bronchial defects less than or equal to 4 mm, only one required intervention during healing (P < .05). Of 12 bronchial defects greater than 4 mm, six required intervention during healing. Eight of nine dehiscences with a tiny or small amount of extraluminal air healed with conservative treatment. Of 16 dehiscences associated with a moderate to large amount of extraluminal air, nine were treated conservatively and six required therapeutic intervention. Three healing anastomoses required bronchial stent placement. One patient died in the perioperative period. CONCLUSION: In patients with small dehiscences ( < 4mm) and patients with a tiny or small amount of extraluminal air, the anastomosis tends to heal without sequela. When patients have larger amounts of extraluminal air or larger ( > 4mm) dehiscences at presentation, CT cannot help predict which patients will require intervention.

Improved airway healing after lung transplantation. An analysis of 348 bronchial anastomoses.

We evaluated various clinical factors to identify predictors of airway complication after lung transplantation. Two hundred twenty-nine consecutive single (n = 110) and bilateral (n = 119) lung transplants were done between September 1988 and August 1994. These 348 bronchial anastomoses were retrospectively analyzed. Airway complication that necessitated clinical intervention affected 33 anastomoses (9.5%) in 29 patients (12.8%). Satisfactory healing was achieved in 22 of these patients by conservative therapy such as one or a combination of dilation, stent, and laser. There were five deaths (2.2%) attributable to airway complications. One patient had an early postoperative death unrelated to airway complication and one patient has a recalcitrant bronchus intermedius stricture. Complication occurred more often in single-lung than in bilateral lung transplants (16/110, 14.4%, versus 17/238, 7.1%; p < 0.05). The use of a mattress suture (21/153, 13.7%) was associated with more frequent complications than was simple interrupted suture (8/122, 6.6%) or figure-of-eight suture (4/73, 5.5%) (p < 0.05). For patients in whom airway complications subsequently developed, the duration of postoperative mechanical ventilation was greater than that for those in whom an airway complication did not develop. The prevalence of airway complications as our program evolved was evaluated by separating the 229 transplants into three groups: phase I, the first 77 transplants; phase II, the next 76 transplants; and phase III, the most recent 76 transplants. The airway complication rate per anastomosis was significantly lower in phase III (5/126, 4.0%) than in phase I (12/110, 10.9%; p < 0.05) and phase II (16/112, 14.3%; p < 0.01). The majority of airway complications are successfully treated and rarely fatal. The recent reduction in prevalence of airway complications is likely a result of better maintenance immunosuppression and rejection surveillance.

Initial experience with the Cosgrove-Edwards Annuloplasty System.

BACKGROUND: The mitral valve has a nonplanar shape and a sphincter action. Pathologic dilatation occurs along the posterior annulus. To preserve the physiologic function and correct annular dilatation, we developed an annuloplasty system that is universally flexible and produces a measured plication of the posterior annulus (Cosgrove-Edwards Annuloplasty System). METHODS: The results of 150 consecutive mitral valve repairs using this system were analyzed. Mean age was 58 +/- 13 years; 59% were men. The cause of the valve disease was degenerative in 75% of the patients, rheumatic in 13%, ischemic in 8%, and infectious in 4%. Associated procedures were performed in 61 patients (41%). RESULTS: Echocardiographic mitral regurgitation decreased from 3.7 +/- 0.6 before repair to 0.2 +/- 0.4 after repair (p < 0.0001). There were no hospital deaths and no cases of hemodynamically significant systolic anterior motion or other annuloplasty-related complications. Follow-up was 100% complete at a mean of 3.1 +/- 3.6 months. There were three late deaths, three transient ischemic attacks, and one episode of endocarditis. Five patients (3.3%) have undergone reoperation for recurrent mitral insufficiency; no reoperations were related to the annuloplasty system. At a mean of 9 months, three-dimensional reconstruction of the mitral annulus from multiple echocardiographic images confirmed the nonplanar shape and sphincter mechanism of the annulus. Annular orifice area decreased 19% during the cardiac cycle from a mean of 10.3 cm2 in diastole to 8.6 cm2 in systole. CONCLUSIONS: This annuloplasty system is effective for repair of insufficiency secondary to all causes, preserves physiologic annulus function, and is associated with a low incidence of valve-related complication.

Bronchial dehiscence in lung transplantation: CT evaluation.

PURPOSE: To determine the signs of bronchial dehiscence on computed tomographic (CT) scans in a select subset of lung transplant recipients. MATERIALS AND METHODS: In 23 patients who underwent single or bilateral sequential lung transplantations, CT scans were obtained for suspected or known diagnosis of bronchial dehiscence. Dehiscence was identified at bronchoscopy in 17 of the 23 patients. In four patients, the dehiscence was bilateral, resulting in 21 anastomotic dehiscences. RESULTS: CT allowed identification of a bronchial defect in 100% of the bronchoscopically proved dehiscences but only one (5%) of the 18 bronchoscopically proved intact anastomoses. CT also demonstrated extraluminal air in 100% of the bronchoscopically proved dehiscences. Only a very small amount of extraluminal air (without associated bronchial defect) was identified on CT scans in the early postoperative period in four additional patients with bronchoscopically proved intact anastomoses. CONCLUSION: CT is an easily performed and well-tolerated technique that has a high degree of sensitivity and specificity for depicting bronchial dehiscence.

Reperfusion of infarcting myocardium: benefit of surgical reperfusion in a chronic model.

Surgical reperfusion of experimental infarction leads to improved recovery of regional function compared with medical reperfusion, but sustained myocardial salvage has not been demonstrated. Twenty-two dogs were subjected to two hours of anterior descending occlusion and divided into three groups: group P (n = 7), no reperfusion; group M (n = 8), medical reperfusion; and group S (n = 7), controlled surgical reperfusion. Ischemia caused systolic bulging (-36% of control systolic shortening, p less than 0.01) and decreased regional work (9% of control pressure-length loop area, p less than 0.05). Thirty minutes after reperfusion group M had persistent systolic bulging (-9% of control systolic shortening) and decreased regional work (9% of control pressure-length loop area), whereas group S had +17% of control systolic shortening and 33% of control pressure-length loop area. After 1 week, regional function improved in all three groups (percent of control systolic shortening: group P, 26%; group M, 19%; group S, 52%), but systolic shortening was significantly better in group S (p less than 0.05 versus group M). Surgical reperfusion also resulted in one half of the eventual myocardial necrosis found in the other groups (group P, 45% of area at risk; group M, 38%; group S, 19%; p less than 0.05, group S versus group P or M). In this model, medical reperfusion offered no demonstrable benefit, whereas controlled surgical reperfusion led to a sustained (1 week) improvement in regional function and significant myocardial salvage.

Intracavitary right heart cooling during coronary bypass surgery. A prospective randomized trial.

Augmented right heart cooling (RHC) with bicaval cannulation, pulmonary artery venting, and intracavitary cooling has been advocated for prevention of right ventricular failure and supraventricular tachyarrhythmias after open heart surgery. To evaluate RHC, 78 patients undergoing coronary bypass surgery were prospectively randomized to receive added RHC (n = 38) or standard protection with single atrial cannulation (SC) (n = 40). RHC and SC patients were similar regarding right coronary artery occlusion (n = 10 and 12, respectively), number of grafts performed (3.7 +/- 1.0 and 3.4 +/- 0.9), and cross-clamp time per graft (10.2 +/- 1.8 and 9.8 +/- 2.3 minutes). RHC led to significantly lower right atrial (11.6 degrees +/- 1.0 degree vs. 19.5 degrees +/- 3.3 degrees C) and right ventricular (7.2 degrees +/- 1.9 degrees vs. 12.2 degrees +/- 1.9 degrees C) temperatures. There was no detectable deterioration in right heart function or left heart function in either group after cardiopulmonary bypass. Bypass time was longer in RHC patients (86.7 +/- 17.9 vs. 76.0 +/- 18.2 minutes, p less than 0.05). Technical problems related to multiple cannulation occurred in four RHC patients. After cross-clamp removal, creatine kinase-MB levels were significantly higher with RHC at 2 hours (14.2 +/- 7.6 vs. 6.4 +/- 4.6 IU/l, p less than 0.001), 12 hours (19.1 +/- 19.5 vs. 8.6 +/- 10.3 IU/l, p less than 0.005), and 24 hours (14.1 +/- 19.6 vs. 7.1 +/- 9.2 IU/l, p less than 0.05). Mortality and morbidity were similar in the two groups. In particular, supraventricular tachyarrythmias occurred in 11 (28.9%) RHC and 10 (25%) SC patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Treatment of moderate mitral regurgitation and coronary disease by coronary bypass alone.

We have favored treatment of moderate mitral regurgitation and coronary disease with coronary bypass alone because of the high operative mortality of combined mitral valve replacement and coronary bypass. Between 1977 and 1983, coronary bypass alone was performed on 58 patients (mean age 63 +/- 8 years). Preoperatively, 90% had Canadian Cardiovascular Society class III or IV angina, and 10% had class III or IV congestive heart failure. In 72% mitral regurgitation had been caused by coronary disease. Hospital mortality was 3.4% (2/58). At follow-up (100% complete, mean 4.3 years) 66% of survivors were functional classes I and II (compared with 7% preoperatively, p less than 0.0001). Of those patients who worked preoperatively, 84% returned to work. There were no reoperations. The 5-year survival was 77%. In the same period combined mitral valve replacement and coronary bypass was required in 20 unmatched patients with moderate mitral regurgitation and coronary disease. Indications for valve replacement included congestive heart failure (10 cases), high left atrial pressure (three cases), and mitral stenosis (four cases). In these patients with more advanced symptoms the hospital mortality was 25%, and the 5-year survival was 31%. Treatment of moderate mitral regurgitation and coronary disease by coronary bypass alone achieved excellent hospital survival and long-term functional stability without a subsequent valve operation.

Trends in invasive treatment of single-vessel and double-vessel coronary disease.

We examined our practice of invasive therapy for one- and two-vessel coronary disease to assess the impact of the randomized trials of coronary surgery and the current use of angioplasty. We first reviewed our results with coronary artery bypass graft in equivalent patients in the Coronary Artery Surgery Study with one- and two-vessel disease between 1976 and 1981. Among 1376 patients, hospital mortality was 0.07%, and 5-year survival was 95.2% +/- 0.8%. To define trends in invasive therapy, which have since occurred, we compared 100 patients with one- and two-vessel disease in each of three groups: 1979 coronary artery bypass graft, 1984 coronary artery bypass graft, and 1984 percutaneous transluminal coronary angioplasty. Preoperative characteristics in the average 1979 and 1984 patients were similar; however, in 1984, patients who had a coronary artery bypass graft were older than patients who had percutaneous transluminal coronary angioplasty (61.5 versus 56.7 years, p less than 0.01), they required more heart medications (2.1 versus 1.5, p less than 0.01), had more previous infarctions (0.8 versus 0.5, p less than 0.01), and more patients had an ejection fraction of less than 50% (34% versus 7%, p less than 0.01). Patients who had angioplasty had a shorter postoperative stay (median number of days 7, 7, 2, p less than 0.01). Freedom from major complications was similar among the groups (91%, 87%, 85%). Unstable symptoms were the most frequent indication for invasive therapy (approximately 80%), whereas long-term symptoms, those considered in the randomized trials, occurred in relatively few patients. The number of patients without at least one definite indication for invasive therapy was 13%, 3%, and 11%, p less than 0.05, suggesting that the indications for the 1984 coronary artery bypass graft group have become more restrictive since the 1979 coronary artery bypass graft group. Indications for the 1984 percutaneous transluminal coronary angioplasty group remained less restrictive, being similar to those for the 1979 coronary artery bypass graft group. A continuing trend toward the use of percutaneous transluminal coronary angioplasty was evident, as 56% of the 1979 coronary artery bypass graft group of patients and 32% of the 1984 coronary bypass group of patients would be offered percutaneous transluminal coronary angioplasty rather than coronary artery bypass graft on the basis of 1986 percutaneous transluminal coronary angioplasty criteria. The p values were obtained with analysis of variance or chi 2 test.

Emergency coronary bypass for cardiogenic shock.

Emergency coronary bypass for cardiogenic shock has been associated with a high operative mortality. From January 1983 through March 1986, 69 patients at Crawford W. Long Hospital underwent emergency coronary artery bypass. Seventeen of 69 were in shock, 15 with hypotension requiring treatment (intra-aortic balloon pump in 10; catecholamines in six). The other two patients had a low cardiac index and a pulmonary capillary wedge pressure greater than 25 mm Hg. Of these patients, nine presented with acute infarction, four with failed angioplasty, and four with uncontrollable angina. Four patients required cardiopulmonary resuscitation. After operation, 94% of the patients required catecholamine support and 71% were treated with an intra-aortic balloon pump. There were two hospital deaths (12%). The median postoperative stay for survivors was 9 days. Major complications occurred in 47%. Follow-up (100%, mean 20.5 months) revealed no late deaths, a 3 year survival of 88 +/- 8%, and a functional class of I in six patients, II in seven patients, and III in two patients. The nine patients who were working before operation all returned to work. Of the 52 emergency coronary bypass patients without shock, one patient died in the hospital (2%), 52% required catecholamines (p less than .05 vs shock group by chi-square analysis), and 12% required an intra-aortic balloon pump after operation (p less than .05 vs shock group by chi-square analysis). Median stay was 8 days. Complications occurred in 13% (p less than .05 vs shock group by chi-square analysis). Three year survival was 91 +/- 4%.(ABSTRACT TRUNCATED AT 250 WORDS)

A valveless counterpulsation left ventricular assist pump in the descending aorta: hemodynamic benefit with a reduced risk of cerebral emboli.

Because of valve malfunction and cerebral embolism reported with use of the total artificial heart, the descending aorta was reexamined as a site for a valveless counterpulsation left ventricular assist pump. The pump was introduced into the thoracic aorta at the level of the eight thoracic vertebra in 11 canine right-heart bypass preparations. Heart rate (110 beats per minute), stroke volume (20 ml), and mean arterial pressure (80 or 100 mm Hg) were precisely controlled. The pump ejection volume was adjusted to equal 1 time or 2 times the stroke volume of the dog. A 20-ml ejection led to an 11% reduction in left atrial pressure, an 11% reduction in peak left ventricular pressure, and a 20% reduction in tension time index (all, p less than .05 at a mean arterial pressure of 80 mm Hg). Systolic shortening (ultrasonic crystals) increased by 5% (p less than .05 at a mean arterial pressure of 80 mm Hg). A 40-ml pump ejection led to an 11% reduction in mean left atrial pressure, a 17% reduction in peak left ventricular pressure, and a 21% reduction in tension time index (all, p less than .05 at a mean arterial pressure of 80 mm Hg). The systolic shortening increased by 15% (p less than .05). To assess the relative risk of cerebral embolism, albumin spheres (40 to 60 micrograms) labeled with technetium-99 were injected into the pump chamber in 5 dogs (40-ml ejection, 2.1 +/- 0.1 times the dog's stroke volume).(ABSTRACT TRUNCATED AT 250 WORDS)

Vasoactive drug effects on blood flow in internal mammary artery and saphenous vein grafts.

The internal mammary artery is a dynamic coronary graft, whereas the saphenous vein graft is passive. Therefore, potential exists not only for beneficial vasodilation but also for catastrophic spasm of the artery. The purpose of this study was to examine blood flow in the internal mammary and saphenous vein grafts during infusion of drugs that are commonly used after cardiac operations. A canine right heart bypass preparation allowed precise control of cardiac output, blood pressure, and heart rate, which were maintained constant during drug infusion. Both the internal mammary and saphenous vein grafts were constructed so that they perfused the same coronary bed: They were anastomosed in a Y fashion to a ligated anterior descending coronary artery. Electromagnetic flow probes measured graft flow (with the other graft occluded) before and after 15 minutes of drug infusion. The order of drug infusion was randomized and changes were compared by tests for paired differences. Phenylephrine (2 micrograms/kg/min) decreased flow in both the internal mammary and saphenous vein grafts, whereas norepinephrine (0.1 microgram/kg/min) increased flow in both grafts. Epinephrine (0.05 microgram/kg/min) increased mammary artery flow 16% +/- 6% but decreased saphenous vein graft flow 9% +/- 7%. Nitroglycerin (1 microgram/kg/min) significantly increased internal mammary flow (36% +/- 13%), from 47 +/- 7 to 59 +/- 7 ml/min (p less than 0.01), whereas flow decreased significantly in the saphenous vein graft 14% +/- 3%, from 64 +/- 9 to 59 +/- 8 ml/min (p less than 0.01). Nitroprusside (1 microgram/kg/min) decreased mammary artery flow 12% +/- 2%, from 50 +/- 7 to 44 +/- 7 ml/min (p less than 0.01), but increased saphenous vein graft flow 25% +/- 8%, from 64 +/- 9 to 77 +/- 7 ml/min (p less than 0.01). All hemodynamic variables were unchanged, except for norepinephrine, which significantly increased the first derivative of left ventricular pressure. The results suggest that flow through the canine internal mammary artery is changed by the drugs commonly used in perioperative management. Epinephrine and nitroglycerin increased internal mammary artery flow and decreased saphenous vein graft flow, whereas nitroprusside had the opposite effect. The vascular reactivity of the internal mammary artery must be considered when these drugs are used after coronary revascularization.

Midzonal necrosis as a pattern of hepatocellular injury after shock.

Midzonal necrosis is rarely observed in human liver, except in patients with yellow fever. In a retrospective analysis of livers from 1000 consecutively autopsied adult patients, we observed midzonal necrosis in 1.8% of the cases, and in 8% of patients with centrilobular necrosis. All of the affected patients had a history of one or more episodes of hypotension several days before death, and most patients (72%) had a history of congestive heart failure. Although the midzonal pattern of necrosis was always accompanied by centrilobular necrosis, the two patterns were not uniformly observed in the same microscopic fields. In 11 of 18 cases (61%), the midzonal pattern of necrosis appeared to be partially a consequence of centrilobular regeneration of hepatocytes. In 28% of the cases, however, the midzonal pattern of necrosis was primary and associated with selective survival of centrilobular and periportal hepatocytes. We conclude that midzonal hepatocellular necrosis may be observed after hypotension, and toxin- or drug-induced injury need not be implicated in the pathogenesis. This information may be useful in the interpretation of needle biopsy specimens of the liver.

Hepatic morphology in cardiac dysfunction: a clinicopathologic study of 1000 subjects at autopsy.

Chronic passive congestion (CPC) and centrilobular necrosis (CLN) are well recognized pathologic changes, but their exact relationship to different forms of cardiac dysfunction is uncertain. We reviewed clinical data and hepatic, renal, and adrenal morphology related to cardiac dysfunction in 1000 autopsy subjects at The Johns Hopkins Hospital whose hearts had been studied after postmortem arteriography and fixation in distention. Fourteen pathologic variables, including body and organ size, and microscopic changes graded on a semiquantitative scale, and 18 clinical variables including congestive heart failure, shock, and cardiovascular disease, were analyzed statistically. Distinct patterns of cardiac dysfunction emerged for the two spectra of hepatic morphologic change. Among patients with variable CPC, but slight or absent CLN, the amount of CPC was predicted in a multivariate analysis by severity of right-sided congestive heart failure. CPC severity correlated with cardiac weight and chamber enlargement (P less than 0.001). Among patients with variable CLN, but slight or absent CPC, CLN was predicted by profound hypotension and by renal failure. In addition, CLN, but not CPC, was significantly correlated with renal acute tubular necrosis (P less than 0.001) and adrenal cortical medullary junction necrosis (P less than 0.05), two lesions associated with shock. Among all 1000 patients CPC and CLN were highly significantly correlated (P less than 0.001). The results show that hepatic CPC arises from conditions producing elevated systemic venous pressure but that CLN arises from reduced systemic arterial pressure; and the presence of one potentiates the development of the other.