Rapid loss of vertebral mineral density after renal transplantation

BACKGROUND

Osteopenia is a major complication of renal transplantation. Immunosuppressive regimens including cyclosporine, which permit the use of lower doses of glucocorticoids, may reduce glucocorticoid-induced osteopenia.

METHODS

We prospectively studied the magnitude, distribution, and mechanism of bone loss in 20 adults who received renal allografts from living related donors, who had good renal function, and who were treated with azathioprine, cyclosporine, and low doses of prednisone. We measured serum biochemical markers of bone metabolism, determined the bone mineral density of the second, third, and fourth lumbar vertebrae and the shaft of the radius, and analyzed the histomorphometric features of iliac bone at the time of transplantation and six months later. Measurements of vertebral mineral density were repeated 18 months after transplantation in 17 of the patients.

RESULTS

After transplantation, the mean serum concentrations of parathyroid hormone, phosphorus, and alkaline phosphatase decreased and the serum calcitriol concentration increased. The mean (+/- SD) bone mineral density of the vertebrae had decreased 6.8 +/- 5.6 percent 6 months after transplantation (P less than 0.05) and 8.8 +/- 7.0 percent 18 months after transplantation. In contrast, the bone mineral density of the radius had increased six months after transplantation (P less than 0.05). The histomorphometric studies showed that the rate of bone formation decreased from 50.5 +/- 44.8 to 23.1 +/- 13.8 microns3 per square micrometer per year (P less than 0.05), and the formation period lengthened from 70 +/- 42 to 146 +/- 144 days (P less than 0.05). Consequently, the amount of bone replaced during a remodeling cycle diminished.

CONCLUSIONS

Osteopenia associated with renal transplantation remains a problem in the cyclosporine era. The loss of vertebral bone in our subjects was due to an imbalance in bone remodeling consistent with a toxic effect of glucocorticoids.

A new balanced operation for complex gastroesophageal reflux disease

Twenty-seven patients with advanced gastroesophageal reflux disease have been treated with combined transthoracic parietal cell vagotomy and Collis-Nissen fundoplication. Gastric acid analyses (n = 20) obtained preoperatively and 6 months postoperatively demonstrated a significant late reduction in gastric acid output. Twenty-six patients (96%) have experienced relief of gastroesophageal reflux disease at a mean of 13.3 months (range, 6 to 25 months) without postvagotomy symptoms. Transthoracic parietal cell vagotomy may be considered as an adjunct to mechanical surgical control of advanced gastroesophageal reflux disease.

Intrathoracic goiter: approaching the posterior mediastinal mass

The surgical management of posterior mediastinal goiters can pose considerable technical difficulty. We illustrate a method of sterile spoon extraction that can facilitate the cervical or limited cervicomediastinal approach to these lesions.

Neodymium:yttrium-aluminum garnet laser-assisted pulmonary resections

The neodymium:yttrium-aluminum garnet laser is a new approach to limited pulmonary resection. It avoids distortion of surrounding pulmonary tissue and potential pleural space problems, which can occur with mechanical stapler resections. We have recently used this laser to manage 39 pulmonary lesions in 20 patients. There were no major postoperative complications, and air leak after resection was minimal. Neodymium:yttrium-aluminum garnet laser excision is a useful method that may have an advantage over mechanical stapling techniques for the limited resection of many pulmonary lesions.

Strut fixation of an extensive flail chest

The indications for and preferred approaches to operative stabilization of posttraumatic chest wall instability are uncertain. We suggest this simple, rapid, and effective approach to surgical stabilization by Luque rod strutting of the flail segment when operation is required.

Management of an extensive tracheoesophageal fistula by cervical esophageal exclusion

Giant tracheoesophageal fistulae occurring in ventilator-dependent patients usually result in significant ventilatory embarrassment. Cervical exclusion of the fistula can safely control the fistula and quickly restore adequate ventilation to these critically ill patients.

Intraoperative myocardial infarction during open-heart ablation of an atrioventricular accessory pathway

We report a patient who suffered an intraoperative AMI from injury to the distal portion of a dominant left circumflex coronary artery in the atrioventricular groove. Depending upon coronary anatomy and location of accessory pathways, compromise of coronary circulation by nonintrinsic pathology can be a major cause of morbidity.

Distinguishing the causes of post-transplantation hypertension

The purpose of this article is to elucidate the causes of hypertension following kidney transplantation. In the months and years that follow their operation, most recipients of renal transplants develop or maintain blood pressures that are high. This complication has become more prominent since the widespread use of cyclosporine for immunosuppression. Children seem especially prone to hypertension after kidney transplantation. Absence of hypertension is a favorable long-term prognostic sign. It's presence suggests that allograft function is impaired. Impaired allograft function may be due to either lesions intrinsic to the allograft, or lesions that are extrinsic to the allograft but alter its function. Many transplant patients have more than one possible explanation for hypertension. This multifactorial nature of hypertension after transplantation complicates the management of patients.

New surgical approach to complicated gastroesophageal reflux disease: transthoracic parietal cell vagotomy

Surgical treatment of peptic stricture of the esophagus associated with columnar (Barrett) metaplasia can be a difficult problem. Collis-Nissen fundoplication restores an intraabdominal antireflux barrier for most cases of peptic stricture; however, 20% of patients may have persistence of pathological acid reflux. By reducing acidity of postoperative reflux, parietal cell vagotomy may complement nonresectional surgical results for Barrett stricture.

OKT3 first-dose reaction: association with T cell subsets and cytokine release

Use of the monoclonal antibody OKT3 to prevent or treat allograft rejection has become commonplace. Its administration is often complicated by serious side effects, usually occurring within one to two hours after OKT3 is given, and is termed first-dose reaction. The mechanism underlying these signs and symptoms is poorly defined, but may be related to cytokine release. Twenty-three kidney or kidney/pancreas transplant recipients received OKT3 as treatment of acute rejection. Signs and symptoms occurring after the first dose were observed and quantitated prospectively, and a reaction score was calculated. Blood was drawn immediately before, and at 2 and 24 hours after the first dose of OKT3 for determination of interleukin-2 (IL2), interferon-gamma (IFN gamma), and tumor necrosis factor-alpha (TNF alpha) levels, and flow cytometric analysis of T cell subsets. Two groups were defined based on severity of first-dose reaction. Group 1 patients (N = 11) had very mild reactions (reaction score less than or equal to 3); Group 2 patients (N = 12) had more severe reactions (score greater than or equal to 5). All patients demonstrated a significant rise in serum TNF alpha from baseline to two hours after OKT3 (9 +/- 3 pg/ml to 378 +/- 54 pg/ml, P less than 0.0001), and there was significant correlation between reaction scores and two-hour TNF alpha levels (P = 0.005). Group 2 patients had higher TNF alpha levels at two hours than did Group 1 patients (484 +/- 75 pg/ml vs. 263 +/- 62 pg/ml, P = 0.04). Levels of IL2 and IFN gamma were not elevated at any sampling time.(ABSTRACT TRUNCATED AT 250 WORDS)

The giant paraesophageal hernia: a particularly morbid condition of the esophageal hiatus

The giant paraesophageal hernia is an uncommon but particularly morbid disorder of the gastroesophageal hiatus that may have life-threatening complications. The authors present three cases of these hernias to illustrate the potential complications of true hernias of the gastroesophageal hiatus.

Heparin-induced thrombocytopenia in patients who undergo open heart surgery

To determine whether heparin-dependent antiplatelet antibodies (HAAb) have an effect on morbidity and/or mortality rates, we reviewed the cases of 3438 patients who underwent open heart surgery from 1981 to 1989. Forty-six patients (1.3%) had HAAb. The patients were divided into two groups: those patients who were known to have HAAb before surgery (group I) and those patients who were diagnosed with HAAb after surgery (group II). Group I patients (n = 5) were pretreated with platelet-inhibiting drugs before reexposure to heparin during cardiopulmonary bypass and were maintained with strict abstinence from heparin afterward. Their lowest observed platelet counts ranged from 42,000/mm3 to 89,000/mm3 (median, 63,00/mm3). Thromboembolic complications did not occur, and all patients survived. Group II patients (n = 41) who were diagnosed to have HAAb after surgery had not been pretreated with platelet-inhibiting drugs before surgery. Lowest platelet counts ranged from 11,000/mm3 to 128,000/mm3 (median, 42,000/mm3). Bleeding complications occurred in 21 patients (51%), and thromboembolic complications occurred in 13 patients (32%). Hospital mortality in group II patients was 37%. Late recognition of HAAb was associated with an increase in morbidity and mortality rates. Thromboembolic complications of HAAb, which had been diagnosed before surgery, were eliminated, and bleeding was reduced by pretreatment with platelet-inhibiting drugs and strict abstinence from heparin after surgery.

Post-transplant hypertension

Post-transplant hypertension remains an important risk factor for cardiovascular mortality and graft function. There are multiple mechanisms responsible for post-transplant hypertension. The details of these mechanisms are poorly understood. Steroids, acute and chronic rejection, recurrent renal disease, native kidney disease, and renal artery stenosis have all been implicated in causing post-transplant hypertension. With the addition of cyclosporine, a known hypertensive agent, to the immunosuppressive armamentarium, the evaluation of post-transplantation hypertension has become difficult. Presently, medical therapy is initially directed toward the complications of cyclosporine nephrotoxicity. Empirically, converting enzyme inhibitors are added to the antihypertensive regimen. Further management is aimed at identification of specific causes of post-transplant hypertension. Unfortunately, because of the multifactorial etiology of post-transplant hypertension and a lack of detailed information about the mechanisms, medical and surgical therapy are often unrewarding. Further study is needed to clarify the mechanisms involved in post-transplant hypertension, and thus direct therapy.

Internal mammary artery graft to pulmonary vasculature fistula: a cause of recurrent angina

Recurrent angina pectoris developed in a 59-year-old man 3 years after coronary artery bypass grafting using the left internal mammary artery. Cardiac catheterization showed a fistula between the left internal mammary artery and the pulmonary vasculature. This is an unusual documented case of postoperative internal mammary artery graft to pulmonary vasculature fistula after coronary artery bypass grafting. Division of this fistulous communication resulted in resolution of the patient's angina.

Prognosis of hospital survivors after salvage from cardiopulmonary bypass with centrifugal cardiac assist

Since October 1986, 6 hospital survivors who were salvaged from cardiopulmonary bypass (CPB) with the Sarns centrifugal pump were observed. Centrifugal assist was employed only after failure to wean with usual resuscitative measures, including multiple high dose inotropes and intraaortic balloon pumping. There were five men and one woman, 46-59 years of age (mean 61 years). All patients had undergone coronary artery bypass grafting, with two patients having had concomitant left ventricular aneurysmectomy and two aortic valve replacement. Five patients had left ventricular assist only and one had biventricular assist. Duration of assist ranged from 26 to 72 hr (mean 48 hr). Complications were ubiquitous, and the resultant prolonged hospitalization was resource intensive. All hospital survivors remain alive and are in New York Heart Association functional Class II, with an average follow-up of 24 months, (6-41 months). Compared with preoperative values, current left ventricular function is improved in 2 patients, has deteriorated in 3, and is unchanged in 1. Thus, the Sarns centrifugal pump will allow salvage of some patients who otherwise are not weanable from CPB. Survivors can expect a reasonable functional capacity as reflected by this experience.

Cyclosporine-induced changes in glomerular filtration rate and urea excretion

PURPOSE

Cyclosporine is the mainstay of many immunosuppressant protocols, but confers a significant risk of nephrotoxicity. We sought to clarify the effects of cyclosporine on renal function in renal transplant recipients after induction of mild intravascular volume depletion.

PATIENTS AND METHODS

Two groups of renal transplant patients with normal allograft function at least 6 months after transplantation whose immunosuppressive regimens differed only by the presence or absence of cyclosporine usage were enrolled in a 10-day in-hospital protocol. After a 3-day control period, intravascular volume depletion was produced by dietary restriction of sodium chloride for 4 days and the administration of furosemide. Creatinine and urea clearances, true glomerular filtration rate (GFR) (by radioisotope technique), and the fractional excretion of sodium were measured. The patients were subsequently given a high amount of sodium chloride by intravenous infusion (3.8 mEq/kg body weight/day) for 3 days and the studies were repeated.

RESULTS

Ten patients treated with azathioprine and prednisone (azathioprine-treated) and nine patients treated with cyclosporine, azathioprine, and prednisone (cyclosporine-treated) were enrolled. The two groups developed a similar degree of intravascular volume depletion; blood pressure did not change and urine flow rates did not differ between the groups throughout the protocol. The cyclosporine-treated patients showed significant decreases in GFR, creatinine clearance, and urea clearance, and increases in blood urea nitrogen (BUN) and percent urea reabsorption after intravascular volume depletion; these findings resolved after challenge with the sodium chloride load. In contrast, the azathioprine-treated patients' BUN, urea clearance, GFR, and creatinine clearance did not significantly change throughout the protocol. The decrease in the fractional excretion of sodium after intravascular volume depletion was significantly greater in the cyclosporine-treated patients.

CONCLUSION

Cyclosporine predisposes to acute reversible nephrotoxicity by compromising the renal compensatory mechanisms. Proximal tubular function, as manifested by urea and sodium reabsorption, remains intact.

Elevated hemidiaphragm after cardiac operations: incidence, prognosis, and relationship to the use of topical ice slush

We have reviewed chest roentgenograms of 745 patients before hospital dismissal after cardiac operations and serially to determine the incidence and prognosis of elevated hemidiaphragm and any relationship to the use of topical ice slush (TIS) in myocardial preservation. All patients had similar myocardial preservation techniques including moderate systemic hypothermia and 4 degrees C saline solution poured over the heart at aortic clamping. During a 12-month period, TIS was added to the saline bath. Two (2.4%) of 84 patients before TIS and 5 (2.5%) of 201 consecutive patients operated on since discontinuing TIS had elevated hemidiaphragm on the predismissal roentgenogram. Of 460 patients in whom TIS was employed, 109 (23.7%) had elevated hemidiaphragm (p less than 0.001). When TIS was employed, elevated hemidiaphragm developed in 72 (26%) of 280 patients without internal mammary artery takedown versus 13 of 33 patients (39.4%) with takedown of the internal mammary artery (p = 0.047). Ninety-nine patients with elevated hemidiaphragm were available for follow-up at 1 month, at which time 79 (79.8%) continued to have elevated diaphragm. At 1 year, 14 (21.9%) of 64 patients had persistent diaphragm elevation. We conclude that TIS predisposes to elevated diaphragm and that the incidence is increased when the internal mammary artery is harvested.

Adverse effects of permanent cardiac internal defibrillator patches on external defibrillation

At the time of left ventricular aneurysm resection, antiarrhythmic operations or other open-heart operative procedures in patients with ventricular dysrhythmia, permanent internal defibrillator patches may be inserted. Insertion of the energy source may be delayed due to its unavailability or to a desire for postoperative electrophysiologic study before its insertion. To assess the effects of permanent internal defibrillator patches on external defibrillation, 7 anesthetized calves were studied. Fibrillation-defibrillation studies were performed before and after insertion of permanent internal defibrillator patches (model L67, 27 cm2, Intec Systems), one on each ventricle. The values of percent successful defibrillation obtained before insertion of the patches, although much lower than values that would be expected in humans, are consistent with the results of an extensive earlier study involving this calf model. Similar values obtained after insertion of the patches are appreciably lower than the values obtained before implantation of the patches, and appreciably lower than the results predicted by the earlier study. A significant decrease in the percent of successful defibrillations (p less than 0.001) was observed for a shock intensity of approximately 400 J. Permanent internal cardiac defibrillator patches on the right and left ventricles reduce the probability of achieving successful defibrillation externally with unidirectional shocks. The wisdom of implanting permanent large internal cardiac defibrillator patches without the energy source is questioned.

Sarns centrifugal pump for repair of thoracic aortic injury: case reports

A new centrifugal pump (Sarns), originally designed for ventricular assist, was successfully used in two patients during repair of traumatic pseudoaneurysm of the descending thoracic aorta. The distal thoracic aorta was perfused without heparinization to avoid spinal cord and visceral ischemia, reduce afterload on the heart, and avoid clamp injury to the aorta. Distal mean aortic pressure was maintained above 50 mm Hg with a mean pump flow of 1.75 liter/minute. Proposed structural advantages of the Sarns centrifugal pump for perfusion of the distal thoracic aorta without heparin are resistance to thrombus formation, air embolus, and hemolysis.

Bronchopulmonary sequestration

Bronchopulmonary sequestration is an area of lung parenchyma that is devoid of normal connection to the trachebronchial tree. Arterial supply is from an aberrant systemic artery, usually a branch of the aorta. There are two broad types of bronchopulmonary sequestration: intralobar and extralobar. The former shares a common pleura with the lung while the latter is separated by its own pleura. Definitive therapy requires pulmonary resection.