Compositional and surface changes of retrieved stainless-steel hardware and its effects on surrounding soft tissues: A prospective study

Purpose

To evaluate the surface, compositional, and histological changes in the overlying soft tissues of retrieved stainless-steel mini-plates and screws used for rigid internal fixation in the maxillofacial skeleton.

Materials and Method

A prospective study was conducted comprising 60 patients who sustained maxillofacial trauma and underwent ORIF in our unit previously and who required hardware retrieval in the post-operative phase. The retrieved hardware was evaluated for surface and compositional changes with the help of a scanning electron microscope for surface roughness and corrosion changes. Energy-dispersive X-ray study was done to know the composition and metal release from the hardware. The data obtained from these results were compared with a control unused and a sterile stainless-steel mini-plate and screw. The effects of the corrosion changes of this hardware on the adjacent soft tissues were evaluated histologically to assess the cellular changes of the soft tissue cover overlying the stainless-steel mini-plates and screws.

Results

A total of 96 stainless-steel mini-plates and 380 stainless-steel screws were retrieved from 60 patients. The control plate was smooth without any surface and corrosion defects, while the retrieved mini-plates irrespective of the reason for removal have shown surface roughness. Fe and Ni ions were found to be significantly reduced in the retrieved mini-plates. The presence of CrC in the retrieved plates indicates corrosion, which was seen only in hardware retrieved from symptomatic patients. The histological study revealed chronic inflammatory cell infiltrate with hyalinized connective tissue in all the samples irrespective of the reason for the removal of the plate.

Conclusion

Stainless-steel mini-plates and screws act as a potent foreign body material and initiate a localized inflammatory reaction due to its corrosive products with longer duration of stay. Hence, the authors advocate the overall shift in the use of stainless-steel hardware to titanium hardware for ORIF.

Can "Aseptic" Looking TIBIA Non-union be Result of an Unrecognized Subclinical Infection?

Introduction

The usual cause of a distal tibial fracture is a high-energy trauma. Although multiple options are available for their treatment such as intramedullary nailing, open plating, and external fixator, each of these options might result in a non-union. Knowing the type of non-union not only allows us to guess the cause but also directs us toward the best possible treatment. Despite this, we might still get surprises on the operating table due to pre-operative misdiagnosis.

Case Report

Reporting a case of a 42-year-old male with a 15-month-old left distal tibia non-union. The index injury was a grade 1 distal third tibia fibula fracture which was fixed with a plate and screws 15 months back. All the clinical and biochemical signs hinted toward the diagnosis of an aseptic non-union and the treatment was planned accordingly. However, intraoperative findings were much different due to which the surgeons had to improvise and change the intervention to an antibiotic-coated nail.

Conclusion

Although each variety of non-union has its set of signs and symptoms, they can be misleading. Different etiologies can coexist making it difficult to give a perfect pre-operative diagnosis and management. Non-unions, especially in the tibia, thus need meticulous understanding of the underlying disease process and extensive treatment strategies.

Evolution of TNM Classification for Clinical Staging of Oral Cancer: The Past, Present and the Future

Purpose

The AJCC (American Joint Committee on Cancer) Cancer Staging Manual, 1st Edition, was published in 1977 which focused on the TNM classification and staging of cancer to allow easy communication, formulation of a treatment plan and predict the prognosis, among the medical fraternity.

Methods

Ever since the beginning, various modifications of the classification were introduced and released by the joint collaboration of AJCC and UICC (International Union Against Cancer) in various editions of cancer staging manuals.

Results

The present review article was kept focused onto the changes introduced in the clinical staging of cancers of oral cavity. These changes came a long way since 1st edition 1944, to the eighth edition which was published in 2017.

Conclusions

This article is a critical review on the past and present perspectives of the TNM classification of the oral cavity that were addressed and changed, adding a light on the future trends or necessary inclusions that would formulate a much easily acceptable and useful classification system.

Pulmonary vagal innervation is required to establish adequate alveolar ventilation in the newborn lamb

To investigate the effects of bilateral intrathoracic vagotomy on the establishment of continuous breathing and effective gas exchange at birth, we studied 8 chronically instrumented, unanesthetized, sham-operated and 14 vagotomized newborn lambs after a spontaneous, unassisted vaginal delivery. Fetal lambs were instrumented in utero to record sleep states, diaphragmatic electromyogram, blood pressure, arterial pH, and blood-gas tensions. Six of eight sham-operated lambs established effective gas exchange within 10 min of birth, whereas 12 of 14 vagotomized animals developed respiratory acidosis and hypoxemia (P = 0.008). Breathing frequency in vagotomized newborns was significantly lower during the entire postnatal period compared with sham-operated newborns. Vagotomized subjects also remained hypothermic during the entire postnatal period (P < 0.05). Bronchoalveolar lavage indicated an increased minimum surface tension, whereas lung histology showed perivascular edema and partial atelectasis in the vagotomized group. We conclude that stimulation of breathing and effective gas exchange are critically dependent on intact vagal nerves during the transition from fetal to neonatal life.

Somatosensory evoked potential monitoring during cardiac surgery: an examination of brachial plexus dysfunction

OBJECTIVE

To observe the effects of the Favoloro and sternal retractors on the ulnar and median nerve somatosensory evoked potentials (SSEPs) and to identify any relationship with postoperative brachial plexus injury.

DESIGN

Prospective study.

SETTING

University hospital.

PARTICIPANTS

Twenty cardiac patients.

INTERVENTIONS

SSEPs were studied in patients undergoing cardiac surgery using normothermic cardiopulmonary bypass. Evoked potentials were obtained from bilateral median and ulnar nerves.

MEASUREMENTS

The incidence of nerve-specific SSEP changes and their temporal relationship to retractor usage were determined. The overall incidence of SSEP changes was 75%. There were no differences (p > 0.05) between the group showing changes (n = 15) and the group with no changes (n = 5) with respect to age, body surface area, weight, cross-clamp or cardiopulmonary bypass times. There also were no differences (p > 0.05) between the frequencies of left- and right-sided changes, or in nerve-specific SSEP changes. Seventy-four percent of SSEP changes correlated with retractor usage. No SSEP changes were associated with the Favoloro retractor. Significant SSEP depression, assessed by either percentage reduction in amplitude or persistent amplitude reduction, occurred in the absence of postoperative neurological deficits. There were no detected postoperative brachial plexus injuries.

CONCLUSIONS

SSEP changes correlate with the use of the sternal retractor but not the Favoloro retractor. It was not possible to replicate the results of previous investigators in predicting postoperative neurological deficits based on the SSEP changes, and therefore the routine application of SSEP as a monitor cannot be recommended on the basis on these data.

Superoxide dismutase and catalase in protection of cardiopulmonary bypass-induced cardiac dysfunction and cellular injury

BACKGROUND

Cardiac dysfunction following cardiopulmonary bypass (CPB) is well known. Various possible sources for increased levels of oxygen free radicals (OFRs) exist during CPB and OFRs depress cardiac function. Postpump (following CPB) cardiac dysfunction may be due to increased levels of OFRs.

METHODS

This study investigated the effects of cold crystalloid cardioplegia with and without superoxide dismutase (SOD) and catalase (CAT) on cardiac function (cardiac index [CI], left ventricular work index [LVWI]), cardiac contractility (+dp/dt, +dp/dt/PAW [pulmonary arterial wedge pressure], +dp/dt/LVEDP [left ventricular end-diastolic pressure]), diastolic compliance (-dp/dt), OFR-producing activity of polymorphonuclear leukocytes (PMNL-CL); creatine kinase (CK) and MB isoenzyme of CK (MBCK), malondialdehyde (MDA), and white blood cells (WBC) and PMNLs from coronary sinus blood; and lactate levels in arterial blood in anesthetized dogs at various times (up to 90 mins) of reperfusion following 90 mins of hypothermic ischemic cardiac arrest. The dogs were divided into three groups: group I, sham bypass; group II, cold crystalloid cardioplegic cardiac arrest; group III, similar to group II but received SOD and catalase treatment.

RESULTS

Postpump decreases in cardiac function, contractility and diastolic compliance were associated with increases in PMNL-CL activity, blood MDA, plasma CK and MBCK, and plasma lactate, and decreases in WBC and PMNLs. Prevention of postpump cardiac dysfunction (function and contractility) by SOD and CAT was associated with restoration in PMNL-CL activity, plasma CK and MBCK activity, and blood MDA towards control values although not complete. The levels of plasma lactate, total WBC and PMNLs were similar in group II and group III.

CONCLUSIONS

These results suggest that postpump depression of cardiac function and contractility could be due to increased levels of OFRs and that SOD and CAT scavengers of superoxide anion and hydrogen peroxide respectively may be effective in preventing postpump cardiac dysfunction.

The effect of a synthetic analogue of prostaglandin E2 on wound healing in rats

This was a prospective, randomized, double-blind experimental study to assess the effect of a long-acting prostaglandin (PG) analogue on wound healing in rats. Eight-cm long, dorsal midline skin incisions were made on rats (n = 44) and immediately resutured. The treatment group (n = 22) received daily intraperitoneal injections of 16,16-dimethyl prostaglandin E2-methyl ester (di-MPGE2) for 7 days, whereas the controls (n = 22) received normal saline. The rats were sacrificed in groups of 11 at 7 and 14 days, respectively. The wounds were excised and analyzed. Histology showed that there was increased fibrosis (p < 0.03) and a decreased number of macrophages (p < 0.02) in the PG group at 7 days. Tensile strength and hydroxyproline content also increased but did not attain significant levels. The differences between the PG and control groups at 14 days similarly did not attain statistical significance. The results suggest that in wound healing, the administration of di-MPGE2 may be beneficial during the early stages of inflammation, rather than during the later stages of remodelling.

Oxidative stress as a mechanism of cardiac failure in chronic volume overload in canine model

We investigated the effects of chronic volume overload in the absence or presence of vitamin E supplements on the cardiac function and contractility, cardiac malondialdehyde (MDA)--a lipid peroxidation product--cardiac antioxidant enzyme activity and antioxidant reserve in canine model. The dogs were divided into three groups of seven dogs each: group I, control; group II, mitral regurgitation (MR) of 4 months duration; and group III, MR of 4 months duration receiving vitamin E (40 U/kg/daily) orally. MR was created by detaching two or more chordae tendinae to raise left atrial pressure to 2.5 to three times normal. MR produced a decrease in the index of myocardial contractility with little change in myocardial function. Decrease in myocardial (left and right ventricles) contractility was associated with an increase in cardiac MDA, and a decrease in cardiac antioxidant reserve and antioxidant enzyme activity. Prevention of volume overload-induced decrease in myocardial contractility by vitamin E was associated with a decrease in cardiac MDA and an increase in cardiac antioxidant reserve and glutathione peroxidase activity towards control levels. Superoxide dismutase and catalase activity remained depressed in vitamin E-treated group. The results indicate that chronic volume overload decreases the contractility of both right and left ventricles and is associated with oxidative stress in both ventricles. These results support the hypothesis that oxygen free radicals are involved in the chronic volume overload-induced cardiac depression.

Anaesthesia for coronary artery bypass surgery supplemented with subarachnoid bupivacaine and morphine: a report of 18 cases

We report our experience with general anaesthesia (GA) supplemented with subarachnoid bupivacaine and morphine for coronary artery bypass surgery (CABG) in 18 patients. Fifteen patients were male, and mean age was 62 yr. Anaesthesia (GA) was induced with alfentanil 97 +/- 22 micrograms.kg-1 and midazolam 0.04 +/- 0.02 mg.kg-1 supplemented with a muscle relaxant, and maintained with isoflurane (0.25-0.5%) in oxygen throughout surgery. Spinal anaesthesia (SA) was then performed at a lumber level using hyperbaric bupivacaine (23-30 mg) and/or lidocaine (150 mg) with morphine (0.5-1 mg). Pooled data showed the following haemodynamic results (P < 0.05). Induction of GA produced a decrease in mean arterial pressure (MAP). Addition of SA produced a decrease in heart rate. Heart rate and MAP did not change with sternotomy. Phenylephrine support of arterial blood pressure was used at some time during operation in 17 patients. Supplementation of GA was minimal. Patients received 2.7 +/- 0.7 coronary grafts. Operating room time was 3.9 +/- 0.6 hr. Postoperative analgesic requirements were minimal, and in half of the patients tracheal extubation occurred on the day of surgery. Complications included one myocardial infarction, one resternotomy, a metabolic encephalopathy in a dialysis-dependent patient, and one case of herpes labialis. No patient recalled intraoperative events. Combined GA with SA may be an effective technique for CABG surgery. Further study of the cardiovascular, neurological and metabolic effects of the technique is required.

Very brief transient ischemic attack

TIA is an important risk factor for ischemic stroke. Early diagnosis and management can result in a significant reduction in the risk of subsequent stroke. We report the case of a 54-year-old man who developed a 5-second episode of leg weakness and in whom a tight stenosis of the appropriate carotid artery was found. TIAs can sometimes be brief and have an atypical presentation, requiring a high level of suspicion for early diagnosis.

Oxygen free radicals in volume overload heart failure

It has been suggested that oxygen free radicals (OFR) depress the excitation-contraction coupling in cardiac muscle. It is possible that a decrease in the cardiac contractility in the failing heart may be due to an increased OFR producing activity of polymorphonuclear (PMN) leukocytes. We studied the OFR producing activity (chemiluminescence) of PMN leukocytes from blood in dogs with heart failure due to chronic volume overload. The animals were divided into two groups: I) normal, (n = 10): II) dogs with mitral insufficiency (MI) of 6 to 9 months duration, (n = 10). Hemodynamic studies were done to establish the presence of heart failure. Blood samples were collected to measure PMN leukocyte chemiluminescence. There was a decrease in the cardiac index and index of myocardial contractility (dp/dt/IIP) and an increase in the left ventricular end-diastolic pressure in dogs with MI indicating left ventricular failure. The peak chemiluminescent activity of the PMN leukocytes in blood of dogs with failure was about four folds greater than that in the blood from normal dogs. These results suggest that there may be an increased OFR generation in dogs with volume overload heart failure. The decrease in the myocardial contractility in the failing heart might be due to an increase in the OFR produced by the PMN leukocytes.

Increased oxygen free radical activity in patients on cardiopulmonary bypass undergoing aortocoronary bypass surgery

Cardiac dysfunction after cardiopulmonary bypass (CPB) has been reported by various investigators. Oxygen free radicals have been shown to depress cardiac function and contractility. To evaluate the possible role of oxygen free radicals (OFR) in post-pump cardiac dysfunction, measurements of cardiac function, OFR producing activity of polymorphonuclear (PMN) leukocytes (PMN chemiluminescence) and malondialdehyde (MDA), a lipid peroxidation product, in blood were made at induction of anesthesia (T1), before cross clamping of the aorta (T2), after closure of the chest (T3), and 24 hours postoperatively (T4) in 21 patients undergoing aortocoronary bypass surgery. The total OFR-derived chemiluminescence at T1, T2, T3, and T4 was 1590 +/- 156, 3169 +/- 338, 1972 +/- 214, and 2614 +/- 366 mv.min.10(6) PMN-1, respectively. Superoxide dismutase (SOD)-inhibitable chemiluminescence at T1, T2, T3, and T4 was 1214 +/- 129, 2674 +/- 328, 1752 +/- 215, and 2139 +/- 292 mv.min.10(6) PMN-1, respectively. Superoxide anion at T1, T2, T3, and T4 was 0.99 +/- 0.14, 1.30 +/- 0.17, 1.07 +/- 0.14, and 1.19 +/- 0.12 nmol.10(6) PMN-1.30 min-1, respectively. Blood MDA at T1, T2, T3, and T4 was 0.17 +/- 0.02, 0.25 +/- 0.03, 0.20 +/- 0.03, and 0.23 +/- 0.02 nmol/ml, respectively. OFR-derived and SOD inhibitable chemiluminescence, superoxide anion, and blood MDA increased significantly during CPB and postoperatively. There were decreases in the blood pressure and stroke volume, and increases in the central venous pressure, capillary wedge pressure, and heart rate during CPB and postoperatively. Cardiac output remained unchanged during this procedure. There was leukopenia during CPB.(ABSTRACT TRUNCATED AT 250 WORDS)

Cardiac tamponade by loculated pericardial hematoma following open heart surgery: diagnosis by transesophageal echocardiography

Loculated pericardial hematoma following open heart surgery may cause significant hemodynamic compromise. Recognition of this entity may be delayed because of the absence of the classical signs of cardiac tamponade. A 54-year-old woman is described in whom transesophageal echocardiography allowed rapid diagnosis of right atrial compression by a pericardial hematoma, following mitral valve replacement. Transesophageal echocardiography should be considered for the detection of posterior loculated pericardial hematoma in the hypotensive cardiac surgical patient with a suboptimal transthoracic echocardiogram.

Transesophageal echocardiography in the diagnosis of left atrial appendage aneurysm

Intrapericardial left atrial appendage aneurysm is rare. We describe the transthoracic and transesophageal echocardiographic findings in a 42-year-old man with atrial arrhythmia and an abnormal left atrial appendage on chest roentgenogram. Presence of an intrapericardial left atrial appendage aneurysm was confirmed at surgery.

Effects of diltiazem on the functional recovery of the myocardium at organ and cellular level during prolonged hypothermic ischemic cardiac arrest

The effectiveness of diltiazem on the functional recovery of the heart, calcium (Ca++) uptake and binding, Ca++ ATPase of cardiac sarcoplasmic reticulum (SR), and MB fraction of creatine kinase (MBCK) of coronary sinus blood was investigated after one and a half hours of reperfusion following three hours of ischemic cardiac arrest. The dogs were divided into three groups: group I, sham bypass; group II, cold crystalloid cardioplegia; and group III, cold crystalloid cardioplegia with diltiazem. There was a decrease in aortic pressures left ventricular pressure development (dp/dt), left ventricular work index (LVWI), total systemic vascular resistance (TSVR), and left ventricular systolic pressure (LVSP) in the sham bypass group. There was a decrease in cardiac index (CI), LVWI, and mean right atrial pressure (mRAP) and an increase in TSVR and pulmonary vascular resistance (PVR) in group II as compared with group I. Although there was a tendency for a decrease in the indices of myocardial contractility in group II, they were not significantly different from those in group I. The indices of myocardial contractility, CI, and LVWI in group III were slightly higher than in group II, but they were not significantly different from each other. The values for calcium uptake by SR in groups II and III were similar but significantly lower than those in group I. Calcium binding in group III was significantly lower than that in group I. Calcium ATPase of SR in the three groups were similar. Although MBCK increased in all the groups, the increases were not significantly different among the three groups. The results of this study indicate that cold crystalloid cardioplegia with diltiazem was not better than cold crystalloid alone in preserving the cardiac contractility and cellular function during prolonged ischemic cardiac arrest. However, the cardiac function in terms of cardiac index was better preserved with diltiazem.

Use of a nasal continuous positive airway pressure mask in the treatment of postoperative atelectasis in aortocoronary bypass surgery

Pulmonary oxygen transfer, defined by PaO2/FIO2, and radiologic presence of atelectasis were measured pre-, intra-, and postoperatively to postoperative day 9 in elective cardiac aortocoronary bypass surgical patients, who were randomly allocated either to receive 18 h PEEP while on the ventilator followed by 12 h of nasal continuous positive airway pressure (nasal CPAP) or to be control subjects. The two groups were comparable in age, sex, forced expiratory volume in 1 sec (FEV1), the ratio of FEV1 over forced vital capacity (FVC), time on pump, units of blood transfused, New York Heart Association grading, and cardiac performance indices. The PaO2/FIO2 was significantly (p less than .05) better from half an hour after extubation until 24 h postextubation in the nasal CPAP group, but was decreased for the remainder of the study in both groups. Incidence of atelectasis/consolidation was not different in both groups during the study period. We conclude that nasal CPAP is well tolerated as a treatment of hypoxemia in the immediate postoperative period of aortocoronary bypass patients. CPAP does not change the course of postoperative atelectasis.

Increased chemiluminescence of polymorphonuclear leucocytes in dogs with volume overload heart failure

Polymorphonuclear leucocyte (PMN) stimulation is known to generate oxygen free radicals. Exogenous oxygen free radicals, generated by xanthine and xanthine oxidase, have been implicated in the decrease of cardiac contractility. It is possible that PMN have increased capacity to release oxygen free radicals in failing heart. It was, therefore, decided to investigate PMN chemiluminescence (oxygen free radicals) from blood in dogs with heart failure due to chronic volume overload. The dogs were divided into two groups: (A) normal, six dogs; (B) dogs with mitral insufficiency (MI) of 6-9 months' duration, six dogs. Haemodynamic parameters were recorded to assess cardiac failure. Mixed venous blood was collected to measure PMN chemiluminescence. Stimulation of PMN was initiated by addition of opsonized zymosan and chemiluminescence was monitored using a luminometer. The haemodynamic parameters in dogs with MI showed that these dogs had left ventricular failure. The peak chemiluminescent activity of PMN in blood of dogs with left ventricular failure was approximately four times that in the blood from normal dogs. This increase in chemiluminescence reflects an increase in the generation of oxygen free radicals from PMN in dogs with chronic heart failure. The decrease in the myocardial contractility in cardiac failure might be due to an increase in the oxygen free radicals produced by the PMN.

Increased production of oxygen free radicals by polymorphonuclear leukocytes in heart failure due to aortic stenosis

Oxygen free radicals have been linked to a wide variety of cellular damage in biological systems. Polymorphonuclear (PMN) leukocytes stimulation is one of the known sources for oxygen free radicals. It has been suggested that oxygen free radicals depress the excitation-contraction coupling in cardiac muscle. It is possible that a decrease in the myocardial contractility in heart failure might be due to an increased oxygen-free-radical-producing activity of PMN leukocytes. The authors studied, therefore, the release of oxygen free radicals, as measured by luminol-dependent chemiluminescence activity, from the PMN leukocytes in dogs with heart failure due to aortic stenosis. Hemodynamics and phagocytic activity of PMN leukocytes were studied in 6 control dogs and 6 dogs with aortic stenosis of six to nine months' duration. There was a significant decrease in the index of myocardial contractility and an increase in the left ventricular end-diastolic pressure in dogs with aortic stenosis, suggesting left ventricular failure in these dogs. Although there was a tendency for a decrease in the cardiac index in dogs with aortic stenosis, the decrease was not significant. Phagocytic activity of PMN leukocytes in blood was studied in control dogs and dogs with aortic stenosis. Phagocytosis was initiated by addition of opsonized zymosan and chemiluminescence was monitored by use of a luminometer. The peak chemiluminescence activity of the PMN leukocytes in blood of dogs with heart failure was about threefold greater than that in the blood from control dogs.(ABSTRACT TRUNCATED AT 250 WORDS)

Traumatic wound of the heart: value of intraoperative colour Doppler flow imaging

A patient who sustained a traumatic ventricular septal defect from a stab wound is presented. Intraoperative echo-Doppler imaging provided an additional diagnosis of avulsion of anterior papillary muscle of the tricuspid valve prior to cardiotomy. It was concluded that intraoperative echo-Doppler imaging proves a useful guide for cardiac surgery following penetrating trauma.

Intraoperative Doppler flow studies: emphasis on colour mapping

Colour Doppler flow imaging (CD) is a well-established method of assessing valvular and congenital disease of the heart. The technique has proven useful intraoperatively in patients undergoing valve repair or replacement or intracardiac reconstruction. In 21 patients with various cardiac anomalies, colour Doppler flow imaging was used intraoperatively, before cardiac cannulation and again after cardiopulmonary bypass. Previously undisclosed features were demonstrated preoperatively in two patients and important residual defects after cardiopulmonary bypass in three others. Adequacy of valve replacement was confirmed in four patients and small leaks in ventricular septal defect patches were shown in another three. The procedure facilitated repair of complex cardiac fistulas in two patients. There were no apparent complications from CD. As intracardiac repairs become more complex, the role of intraoperative CD will expand.

High 2,3-DPG blood cardioplegia and myocardial preservation during cardiopulmonary bypass

Blood may provide superior cardioplegia compared with crystalloid cardioplegic solution. However, the results are controversial. This may be due to a leftward shift of the hemoglobin (Hb)-O2 dissociation curve induced by hypothermia, increasing the oxygen affinity for Hb. This effect may negate the potential benefit of blood cardioplegia. The oxygen affinity for Hb can be decreased by increasing the red cell 2,3-diphosphoglycerate (2,3-DPG), and hence, more oxygen can be delivered to the myocardium. The present investigation was undertaken to study the effects of 2,3-DPG-enriched blood cardioplegia on the functional recovery of the myocardium and changes in the coronary sinus red blood cell (RBC) adenosine-triphosphate (ATP), lactate, and RBC DPG after one and a half hours of reperfusion following one hour of ischemic cardiac arrest in dogs. The dogs were divided into three groups: crystalloid (CR); stored blood (SB), and high 2,3-DPG blood (HDPG) cardioplegic groups. Incubation of canine RBC in phosphoenal pyruvate (PEP) led to a 36% increase in DPG and a rightward shift in the Hb-O2 dissociation curve. There was a 4 mm Hg shift in the P50. When compared with the CR group, there was a significant decrease in the cardiac index (CI) and left ventricular work index (LVWI) and a significant increase in the total systemic vascular resistance (TSVR) in the SB group. The CI and LVWI of the HDPG group were similar to those of the CR group, but the TSVR was significantly greater in the former group. The LVWI was significantly greater and the TSVR smaller in the HDPG group as compared with those in the SB group.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of blood and crystalloid cardioplegia on cardiac function at organ and cellular levels during hypothermic cardiac arrest

The present investigation was undertaken to compare the effects of cold crystalloid and blood cardioplegia on the functional recovery of the heart; on Ca++ binding and uptake, Ca++-ATPase of the sarcoplasmic reticulum (SR), and sarcolemmal (SL) ATPase; and on serum MB fraction of creatine kinase (MBCK) after one and half hours of reperfusion following one hour of ischemic cardiac arrest in dog. This study was made also to determine if the functional changes are related to the changes in biochemistry at the molecular level. The dogs were divided into three groups: sham bypass (SB), cold crystalloid cardioplegia (CC), and pump blood cardioplegia (PB). There was a decrease in the cardiac index (CI), left ventricular work index (LVWI), and mean aortic pressure (MAP) in all three groups. The index of myocardial contractility [dp/dt)/IIP) and CI were lower in the CC group as compared with the SB and PB groups. All the hemodynamic values for the PB group were similar to those of the SB group except total systemic vascular resistance (TSVR) and left ventricular end-diastolic pressure (LVEDP) which were lower in the PB group. The index of myocardial contractility and cardiac index appeared to be greater in the PB group than in the CC group. There was a decrease in the Ca++ uptake by SR from both the CC and PB groups. Ca++ binding and Ca++,-ATPase of SR from the PB group were depressed. The sarcolemmal ATPase was unaffected in both groups. The serum MBCK increased in both PB and CC groups, though the increase was smaller in the PB group. These results indicate that the functional recovery of the heart was slightly better with pump blood cardioplegia than with cold crystalloid cardioplegia. The depressed myocardial contractility and cardiac function in the CC group were associated with a decrease in the Ca++ uptake by SR. However, the decreases in the Ca++ binding, Ca++ uptake, and Ca++ ATPase by SR from the pump blood cardioplegic group were not accompanied by decreases in the cardiac contractility and cardiac function. Myocardial damage as assessed by serum MBCK was smaller in the PB group than in the CC group.

The resting surface electrocardiogram as a predictor of future hypertension

Resting supine and post-provocation (dynamic exercise, isometric exercise and cold pressor) levels of blood pressure were measured in 80 normotensive offspring of normotensive parents (control) and 55 normotensive offspring of parents with essential hypertension. The surface electrocardiogram (including conventional twelve leads, posterior chest leads, right-sided chest leads and bipolar precordial leads) was also recorded in all subjects. Twenty-eight offspring of parents with essential hypertension had their resting and/or post-provocation blood pressure above the upper limit of standard deviation in age- and sex-matched control group. Flat or upright T waves, with either S waves less than 0.2 mV, or S/R ratio less than 2, or T waves equal to or higher than the accompanying R waves in lead V4R, could identify these potential hypertensives with nearly 90% specificity and nearly 75% sensitivity. The criterion had been derived, however, by analysis of the data achieved retrospectively. Therefore, the exact discriminating value of this criterion can be assessed only by a long-term prospective study.

Right atrial myxoma presenting as Budd-Chiari syndrome

A 25-year-old man experienced rapidly progressing Budd-Chiari syndrome. Despite extensive radiological investigations, no atrial mass could be identified. At operation, a right atrial myxoma was found that originated from the eustachian valve and prolapsed into the inferior vena cava. Following successful removal of the myxoma, the ascites and peripheral edema resolved completely. Right atrial myxoma is a rare cardiac tumor that may present with embolic, obstructive, or constitutional signs and symptoms and is a potentially curable cause of Budd-Chiari syndrome.

Effect of crystalloid cardioplegia and verapamil on cardiac function and cellular biochemistry during hypothermic cardiac arrest

A study was undertaken to assess the effectiveness of cold crystalloid cardioplegia with or without verapamil on the functional recovery of the heart, Ca++ binding and uptake, Ca++ ATPase of sarcoplasmic reticulum, sarcolemmal ATPase and the MB fraction of creatine kinase (MBCK) after 1.5 h of reperfusion following 1 h of ischemic cardiac arrest. The dogs were divided into three groups: group I, sham bypass; group II, cold crystalloid cardioplegia; group III, cold crystalloid cardioplegia with verapamil. There was a decrease in the cardiac index (CI), left ventricular work index (LVWI) and mean aortic pressure (MAP) in the sham bypass group at the end of the protocol (time period corresponding to 60 mins off bypass). There was a decrease in the Cl and index of myocardial contractility in the cold crystalloid cardioplegic group compared to sham bypass group. The decrease in the cardiac function in cold crystalloid group was associated with a decrease in Ca++ uptake by sarcoplasmic reticulum and a tendency for an increase in the sarcolemmal Na+-K+ ATPase. The Ca++ binding and the Ca++ ATPase of sarcoplasmic reticulum were not affected. The index of myocardial contractility and cardiac function were better with cold crystalloid containing verapamil than with cold crystalloid alone. This improvement, although partial, in cardiac contractility and function with cold crystalloid cardioplegia containing verapamil was associated with an improvement in the Ca++ uptake by the sarcoplasmic reticulum. The Ca++ ATPase and Ca++ binding were depressed in group III. The MBCK in systemic and coronary sinus blood increased progressively in groups II and III. Although there was an increase in MBCK in group I the increase was not significant.(ABSTRACT TRUNCATED AT 250 WORDS)

Surgical ligation of patent ductus arteriosus in a neonatal intensive care setting is safe and cost effective

The physiological and biochemical status of two groups of neonates with patent ductus arteriosus (PDA) requiring surgical ligation were compared. One group (n = 14) had ductus ligation in the operating room (OR) and the other group (n = 14) had the same operation in an isolation room in the Neonatal Intensive Care Unit (NICU). The groups were closely matched in terms of gestational age and weight. Nursing time and disposable equipment savings were significantly different. We have confirmed that PDA ligation can be done safely in the NICU and is more cost efficient than ligation in the OR.

Effect of prazosin treatment on the cardiac sarcolemmal ATPase in failing heart due to mitral insufficiency in dogs

Prazosin has been used in the treatment of congestive heart failure. It is, however, not known whether prazosin gives only haemodynamic benefit or if it also produces a decrease in the cardiac sarcolemmal Na+-K+-ATPase which has been reported to be increased in the failing heart. The present investigation deals with the effect of 3 months of prazosin treatment in dogs with 3 months of induced mitral insufficiency (MI) on the sarcolemmal Na+-K+-ATPase activity. The dogs were divided into four groups each comprising of five dogs. A--normal; B--3 months of MI; C--6 months of MI; D--3 months of prazosin treatment after 3 months of MI. Three months of MI produced a decrease in the dp/dt and an increase in the end-diastolic pressure of left ventricle but no change in the index of left ventricular contractility and cardiac index. Also there was no change in the sarcolemmal Na+-K+-ATPase. There was a significant decrease in the index of left ventricular contractility and cardiac index and an increase in the LVEDP associated with a significant increase in the left ventricular sarcolemmal Na+-K+-ATPase at 6 months of MI. Sarcolemmal Mg2+-ATPase of both ventricles increased after 6 months of MI the significance of which is not known as yet. There was no change in the sarcolemmal Na+-K+-ATPase of the nonfailing right ventricle. Prazosin treatment prevented the deterioration of the left ventricular contractility and function and also prevented the increase in the sarcolemmal Na+-K+-ATPase observed in failing heart.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of chronic prazosin treatment on the cardiac function and electrolytes in failing heart due to chronic mitral insufficiency

The effect of three months of prazosin treatment on the hemodynamics, cardiac extracellular space; plasma, tissue and intra-cellular Na+, K+, and Ca++ were investigated in dogs with left ventricular failure due to chronic mitral insufficiency. Mitral insufficiency of 6 months duration significantly decreased the LV systolic pressure, LV dp/dt, LV (dp/dt)/IIP, LVWI, CI, and increased the LVEDP, mean right atrial pressure, heart rate and systemic vascular resistance. Associated with these hemodynamic changes were an increase in the extra-cellular space, tissue and intracellular K+; and a decrease in the tissue and intracellular Ca++. Prazosin treatment produced an improvement in the hemodynamics which was associated with a decreased in the extracellular space, and intracellular K+, and an increase in the intracellular Ca++. Plasma Na+ and Ca++ increased with 6 months of M.I. Prazosin treatment brought back the plasma Na+ and K+ to control level. However, plasma Ca+ decreased significantly with prazosin treatment. The changes in right ventricular hemodynamics and electrolytes were not consistent with the right ventricular failure. These results indicate that decrease in the myocardial contractility in chronic heart failure due to mitral insufficiency might be due to a decrease in the intracellular Ca++. Prazosin treatment was able to reverse the hemodynamic and electrolyte changes induced by failing heart due to mitral insufficiency.

Effects of chronic digoxin treatment on cardiac function, electrolytes, and sarcolemmal ATPase in the canine failing heart due to chronic mitral regurgitation

This study was designed to determine whether digoxin therapy in the canine heart failing because of mitral regurgitation (MR) provides only hemodynamic benefit and accompanying subjective improvement or if it also reverses the changes in intracellular Ca++ and sarcolemmal Na+-K+-ATPase. The dogs were divided into four groups: control, MR of 3 months' duration, MR of 6 months', and digoxin treatment for 3 months after 3 months of MR. Six months of MR produced a marked decrease in the index of myocardial contractility and function associated with a decrease in intracellular Ca++ and Na+, and an increase in intracellular K+, extracellular space, sarcolemmal Na+-K+-ATPase, and Mg++-ATPase. Digoxin treatment tended to return the changes in the index of myocardial contractility and cardiac function, intracellular Ca++, Na+, K+, extracellular space, and sarcolemmal Na+-K+-ATPase of the failing heart toward control levels. Digoxin treatment did not affect Mg++-ATPase. The right ventricle, which did not fail, also did not show any significant changes in the parameters measured. The results showed that digoxin treatment not only improved the index of myocardial contractility and cardiac function of the failing heart but also tended to return the electrolytes and sarcolemmal Na+-K+-ATPase toward control levels.

Effect of chronic digoxin treatment on cardiac function, electrolytes and ATPase in failing heart due to pressure overload

A decrease in the cardiac function and intracellular calcium, and an increase in the cardiac sarcolemmal ATPase have been reported in aortic stenosis of 6 to 9 months duration in dogs. The present investigation deals with the effect of 3 months of digoxin treatment on cardiac function, electrolytes and ATPase in dogs with 3 months of aortic stenosis in order to determine whether digoxin treatment gives only haemodynamic improvement or if it also improves the condition of the myocardium in terms of contractility and biochemical changes. There were no significant changes in any of the haemodynamic parameters of left and right ventricles except the left ventricular end-diastolic pressure which increased significantly at 3 months of aortic stenosis. All the hearts developed left ventricular hypertrophy. Concomitant with these changes, there was a tendency for a decrease in the total tissue Ca2+, intracellular Ca2+ and K+, and a tendency for an increase in the sarcolemmal ATPase. There were no significant differences in any of the haemodynamic parameters between the aortic stenotic and digoxin treated aortic stenotic dogs indicating that digoxin was at least maintaining the haemodynamics close to the pretreatment level. Although digoxin treatment prevented the changes in the sarcolemmal ATPase and extracellular space, it did not prevent the further decrease in the total or intracellular Ca2+. The total and intracellular Ca2+ was still significantly higher than previously observed after 6 to 9 months of aortic stenosis. These results suggest that digoxin treatment not only tended to prevent further deterioration of cardiac function but also tended to prevent further changes in the sarcolemmal ATPase and electrolytes.

Complex transposition with interrupted right aortic arch and partial Di George syndrome: successful palliation with combined medical and surgical therapy

A five-day-old infant with transposition of the great arteries, ventricular septal defect, and an interrupted right aortic arch underwent successful balloon septostomy, pulmonary artery banding, and aortic arch repair. The infant also had abnormal facies with severe refractory hypocalcemia and depressed T-lymphocyte number and function believed to represent a partial Di George syndrome. The hypocalcemia resolved following treatment with a vitamin-D analogue, T-cell number increased, and T-cell function improved, but both remained subnormal.

Effect of prolonged prazosin treatment on hemodynamic and biochemical changes in the dog heart due to chronic pressure overload

A decrease in cardiac function and intracellular calcium, and an increase in cardiac sarcolemmal ATPase have been reported in experimentally induced aortic stenosis of 6 to 9 months duration. Prazosin has been used in the treatment of heart failure due to mechanical ventricular overload. It is, however, not known whether prazosin treatment gives only hemodynamic benefit with accompanying subjective improvement or if it also improves the condition of the myocardium in terms of contractility and biochemical changes. The present investigation deals with the effects of 3 months of prazosin treatment on cardiac function, electrolytes, and ATPase in dogs with aortic stenosis of 3 months duration. Although there were no significant changes in most of the left and right ventricular hemodynamic parameters, the left ventricular end-diastolic pressure increased significantly after 3 months of aortic stenosis. Prazosin prevented further deterioration of cardiac function. All the dogs developed left ventricular hypertrophy and all chest X-rays showed cardiomegaly. Concomitant with these changes, there was a tendency towards a decrease in total tissue Ca++ and intracellular Ca++ and K+ and a tendency towards an increase in sarcolemmal Na+-K+-ATPase. Prazosin treatment, although it markedly reduced left ventricular end-diastolic pressure, did not reduce the cardiomegaly. There were no significant changes in any of the other hemodynamic parameters. Prazosin treatment decreased sarcolemmal ATPase and tended to increase intracellular Ca++. It appears therefore that prazosin not only tends to bring the cardiac function towards control values but also tends to correct the ATPase and intracellular Ca++ levels of the failing heart.

Mitral valve replacement in the neonate: a report of two cases

Mitral valve replacement was performed in two critically ill neonates with severe mitral stenosis and regurgitation. Both patients had coexisting severe aortic stenosis previously treated by transventricular aortic valve dilatation. Preoperative echocardiography showed a mitral annulus measuring between 11 and 12 mm in diameter--too small for any of the commercially available free-standing valve prostheses. Accordingly, the porcine valve from a commercially available 12-mm external-valved conduit was removed and sutured into position. The function of the valve was satisfactory in both cases and cardiopulmonary bypass was discontinued easily with a good cardiac output established in both. Both patients died--one at 20 h and one 36 h after surgery. In each case, the immediate cause of death was acute bleeding secondary to preexisting hepatic failure and depletion of coagulation factors. At autopsy, both prostheses had been correctly placed and were competent. Left ventricular outflow tract obstruction secondary to strut imposition was not evident. Both patients were very ill preoperatively. Although neither patient survived mitral valve replacement, we were encouraged by the relative hemodynamic improvement in the immediate postoperative period. We believe that prosthetic valve replacement could become a viable therapy for the neonate with severe mitral valve abnormalities.

Saccular aortic aneurysm in an asymptomatic child

An asymptomatic boy was found to have coarctation of the thoracic aorta. Despite no history of endocarditis or trauma, a large saccular aneurysm involving the coarctation site was identified angiographically, confirmed, resected surgically, and examined histologically.

Mechanism of cardiac contracture during anoxic arrest using cardiopulmonary by-pass

Cardiac contracture during anoxic cardiac arrest might result from a reduction in the adenosine triphosphate or from an accumulation of cytoplasmic calcium. The present study was undertaken to test the hypothesis that the accumulation of cytoplasmic calcium is a factor in the anoxic myocardial contracture in a setting similar to that used during cardiac surgery, using cardiopulmonary bypass. Anoxic cardiac arrest was produced for 30 and 60 minutes in 7 dogs each, by clamping the ascending aorta, using cardiopulmonary bypass. At the end of anoxic period, aorta was declamped for reperfusion of the heart for 30 minutes of termination of anoxic cardiac arrest. Total tissue and intracellular electrolytes were determined before and at various intervals (0, 5, 15, 30 minutes) after termination of anoxic cardiac arrest. Thirty minutes of anoxic cardiac arrest produced a significant decrease in the mean aortic and left ventricular systolic pressures, and left ventricular dp/dt/IIP; and a significant increase in the cardiac index. Total tissue and intracellular Na, Ca, and K did not change significantly at the end of 30 minutes of anoxia and during 30 minutes of reperfusion. Anoxic arrest for 60 minutes resulted in cardiac contracture in all dogs. The total and intracellular Ca decreased significantly at the end of 60 minutes of anoxia and during 30 minutes of reperfusion. Total tissue and intracellular Na, although, did not change during anoxic arrest, it increased significantly at 15 and 30 minutes of reperfusion. Cardiac potassium did not change significantly during the whole period of experiment. These studies suggest that total and intracellular calcium did not increase above the control values during anoxic myocardial contracture in a setting similar to that used during cardiac surgery, using cardiopulmonary bypass.

Effects of enflurane on cardiovascular function in dogs with induced chronic mitral valve disease

The effect of enflurane on cardiovascular function was investigated in normal dogs and in dogs with chronic heart failure because of induced mitral valve disease (MVD). No significant changes were observed in heart rate (HR), right atrial pressure (RAP) and total systemic vascular resistance (TSVR) in normal dogs. However, significant decreases in HR and increases in RAP and TSVR were observed in dogs with MVD. There were no changes in pulmonary arterial pressure and left ventricular end-diastolic pressure in either group. Cardiac output, cardiac index, arterial pressure, left ventricular work index and left ventricular dp/dt and dp/dtIIP showed a concentration-dependent decrease in both groups but the changes were greater in dogs with MVD.

Long-term follow-up of patients who underwent single valve replacement with Björk-Shiley prosthesis

Single heart-valve replacement with a Björk-Shiley prosthesis was undertaken in 118 patients between Jan. 3, 1970 and Dec. 31, 1977. The hospital mortality was 7% for patients who had aortic valve replacement and 9% for those who had mitral valve replacement. Recent improvements in techniques for myocardial preservation and cardiopulmonary bypass resulted in a notable reduction in hospital mortality during the period 1974 to 1977 compared with that in the period 1970 to 1973; the rate was 5% for aortic valve replacement and 4% for mitral valve replacement between 1974 and 1977 compared with 9% and 18%, respectively, during the period 1970 to 1973. There was an additional late mortality of 8% in patients who had an aortic valve replaced and 11% in those who had a mitral valve replaced; the mean follow-up was 2.3 years (range 6 months to 7.5 years). Seventy-one patients with an aortic valve prosthesis and 38 patients with a mitral valve prosthesis were alive at the time of late follow-up. In patients who received an aortic valve prosthesis, 73% had an excellent result after operation (New York Heart Association classes I or II) and 18% had some functional improvement. In patients who received a mitral valve prosthesis, 68% had an excellent result and 18% were functionally improved after operation. The incidence of thromboembolism was 8.3% and of anticoagulant-related complications, 13.8%.

Intra- and extracellular electrolytes and sarcolemmal ATPase in the failing heart due to pressure overload in dogs

An investigation of changes in the Mg2+ -dependent, Na+ -K+ -stimulated sarcolemmal ATPase and of intracellular electrolytes in the left failing heart due to pressure overload (aortic banding) was carried out in dogs. There was no change in the sarcolemmal Mg2+ -ATPase of the left or right ventricle for the whole duration (3 to 9 months) of left ventricular pressure overload. In the early phase (3 months) of aortic banding, when there was no haemodynamic evidence of left ventricular failure, there was also no significant change in the sarcolemmal Na+ -K+ -ATPase, extracellular space, or intra- and extracellular electrolytes. However, during 6 to 9 months of aortic binding when there was haemodynamic evidence of left ventricular failure (increased end-diastolic pressure, decreased cardiac index and (dP/dt)/IIP, enlarged heart), there was also a marked increase in the left ventricular sarcolemmal Na+ -K+ -ATPase and intracellular K+; and a decrease in the intracellular Na+ and Ca2+. The extracellular space in the left ventricle also increased significantly. Unlike the left ventricle, the right ventricle did not show any evidence of failure, not did it show any change in the sarcolemmal Na+ -K+ -ATPase and intracellular electrolytes during any period of aortic banding. These results suggest that the decrease in the myocardial contractility in failing heart due to pressure overload might be associated with a decrease in the intracellular Ca2+ as a result of an increase in the sarcolemmal Na+ -K+ -ATPase.

Cardiac intracellular and blood electrolytes in chronic mitral insufficiency

A study of the alterations in the intracellular electrolytes in the left failing heart due to induced mitral insufficiency was made in dogs. The extracellular space increased significantly. There was no significant change in the plasma Na+ and Ca++. However, there was a significant decrease in the plasma K+. The ratio of wet weight to dry weight increased during mitral insufficiency, although not significantly. There were no significant changes in the tissue Na+, K+ and Ca++. However, there were significant decreases in the intracellular Na+ and Ca++, and tendency for an increase in the intracellular K+ during mitral insufficiency. These results suggest that the decrease in the myocardial contractility in chronic heart failure due to mitral insufficiency might be due to a decrease in the intracellular Ca++ and associated changes in Na+ and K+ as a result of increased sarcolemmal ATPase.

Alterations in red cell metabolism during and following cardiac bypass surgery

Reduced concentrations of red cell organic phosphates and increased hemoglobin--oxygen affinity have been reported during and following cardiac bypass surgery. Some have related these changes to low concentrations of ATP and 2,3-diphosphoglycerate (DPG) in stored blood while others have related them to use of the pump oxygenator. There was a 10% decrease in DPG concentration in seven dogs on cardiac bypass although the animals received no transfusions. In 16 patients who received 0 to 7 units of blood during cardiac bypass there was a decrease of 10% in the red cell DPG concentration from the preoperative value, but it did not relate to the concentration of DPG in the transfused blood bags. The magnitude of the decrease was not sufficient to impair oxygen delivery severely. The results suggest that a re-evaluation of indications for the use of fresh red cells in cardiac surgery is necessary.

Inhibition and enhancement of platelet aggregation by collagen derivatives

Rat tail tendon tropocollagen rapidly caused the aggregation of blood platelets coincident with collagen multimerization. Several long-chain alkyl derivatives of collagen, however, were completely unable to induce platelet aggregation even at unusually high concentrations. These collagen derivatives varied in their polymerization properties , and the polymerization of tropocollagen derivatives was shown not necessarily to be a prerequisite for platelet aggregation. These collagen derivatives may enhance the antithrombogenic properties of collagenbased prosthese. A short-chain derivative, collagen-glycine ethyl ester, profoundly enhanced platelet aggregation in the absence of any measurable polymerization. This derivative may be useful as a growth-promoting burn dressing.

Biochemical modifications of fascia lata for autologous valve replacement

The biochemistry of canine fascia lata was studied to assess the feasibility of tissue modification with a variety of cross-linking reagents and growth inhibitors in order to provide a more suitable material for heart valves. Chemical determinants for maximal reactivity were consequently established for several growth inhibitors, of which the hydrophobic ligands difluorodinitrobenzene, octadecylamine, and oleylamine were the most effective in preventing invasive cellular growth. This enhanced the longevity of atrial grafts in dogs as judged from morphological and histological examination of excised grafts.