Predictors of Low Anterior Resection Syndrome after Long-Course Chemoradiation for Locally Advanced Rectal Cancer

PURPOSE/OBJECTIVE(S)

Low anterior resection syndrome (LARS) describes disordered bowel function including tenesmus, frequent, clustered, incomplete, urgent or incontinent bowel movements. The impact of clinical and radiation dosimetric factors on LARS score is unknown. We aimed to evaluate the radiation plans for patients who received long course chemoradiation (LC-CRT) to identify potential dosimetric predictors of LARS.

MATERIALS/METHODS

We identified patients with rectal cancer treated with LC-CRT (50.4Gy in 28 fractions) at our institution from 2016-2020 who were alive and without disease. As a part of a larger patient-reported outcome survey, we obtained the Low Anterior Resection Syndrome Score (LARS) for patients without an ostomy at the time of the survey. We utilized clinical and dosimetric variables in a multivariate analysis including age at LC-CRT, body mass index, sex, distance of the tumor from the anal verge (AV), threatened mesorectal fascia (MRF) on staging imaging, T-stage, N-stage, receipt of surgery (vs non-operative management (NOM), radiation technique (3DCRT vs VMAT), mean dose and D0.03ccs for the anal canal (defined as 4cm from the anal verge) and D0.03cc, V30Gy and V45Gy for the small bowel loops. We then created a multiple linear regression model to predict LARS using P>.20 on univariate testing.

RESULTS

Of 110 patients treated with preoperative LC-CRT and who did not have an ostomy, 57 responded (51.8%). The median [interquartile range (IQR)] interval from completion of LC-CRT to survey completion was 38.4 months [26.3-48.9]. Thirty-four patients (60%) were men, the median [IQR] BMI was 28 [24-31.9], the median [IQR] distance of the tumor to the anal verge was 7cm [5-10], 40 (70%) had T3 tumors, 7 (12%) had T4 tumors, 45 (79%) were N+. Forty-one patients (72%) had surgery following LC-CRT, and 16 (28%) had non-operative management. 3D conformal technique was used for 47 (82%) and VMAT used for 10 patients (18%). The median [IQR] LARS score was 32 [24-38] with 35 patients (61%) classified as Major LARS (LARS score = 30-42). On multiple linear regression modeling (Table), only receipt of surgery significantly predicted for higher (worse) LARS score.

CONCLUSION

In our cohort, patients who received surgery after LC-CRT had a significantly higher LARS score. Of the dosimetric parameters tested, D0.03ccs was the best predictor and could potentially be significant with a larger number of patients. Further work is needed to improve bowel function and quality of life for patients treated with LC-CRT for rectal adenocarcinoma.

Pressure recovery in pediatric aortic valve stenosis

This study was designed to evaluate the phenomenon of pressure recovery in pediatric patients with aortic stenosis and also to evaluate how observed differences between catheter and Doppler gradients can be predicted by Doppler echocardiography. Doppler measurements of aortic valve stenosis gradients are known to overestimate observed gradients in the catheterization laboratory. Pressure recovery has been shown to be a contributing factor to this discrepancy. However, the clinical relevance of correcting Doppler gradients using the pressure recovery equation has not been evaluated in the pediatric population. Simultaneously obtained catheter and Doppler gradients were studied in 14 patients (range, 0.03-18 years; mean, 4.1 years) with aortic valve stenosis. A total of 23 data points were measured because 9 patients underwent balloon valvuloplasty and had both a pre- and a post-balloon valvuloplasty data point in the study. The catheter gradients were then compared to peak, mean, and pressure recovery corrected Doppler gradients. Pressure recovery was calculated using a previously validated equation. As expected, measured echocardiographic continuous-wave peak Doppler gradients overestimated the observed catheter gradients (range, 16-93 mmHg; mean, 43 mmHg). The continuous-wave peak Doppler gradients, mean, and pressure recovery adjusted gradients were equally as good in correlating the observed catheter gradients to those obtained by Doppler echocardiography (r = 0.92). However, pressure recovery corrected Doppler gradients were in better agreement with catheter gradients than echocardiographic mean or peak Doppler gradients (95% limit of agreement: -9 to 19 mmHg for pressure recovery corrected gradients, -30 to 11 mmHg for mean Doppler gradients, and 2-83 mmHg for peak Doppler gradients). Measured continuous-wave peak Doppler gradients consistently overestimated catheter gradients. The noted differences may be predicted using the pressure recovery equation. Pressure recovery is a significant factor in children with aortic valve stenosis.

Balloon pericardiotomy for recurrent pericardial effusions following fontan revision

Percutaneous balloon pericardiotomy (PBP) has been used in patients with recurrent pericardial effusions in which the chest and pericardium had not been previously entered and therefore concerns about adhesions were minimal. Few reports have depicted PBP for patients with recurrent pericardial effusions following open-heart surgery, in which adhesions may play a greater role. We report a successful creation of a pericardial window using PBP in a child with recurrent pericardial effusions after a Fontan revision. This technique offers a simpler approach to the treatment of recurrent pericardial effusions after open-heart surgery in patients with 8 congenital heart disease.

Initial experience using the Palmaz Corinthian stent for right ventricular outflow obstruction in infants and small children

The original Palmaz balloon expandable stent has been used extensively for the treatment of vascular stenoses in older children and young adults. Placement of the Palmaz stent in infants and small children, however, is limited by stent inflexibility, large delivery sheath size, and concerns about creating fixed obstructions after the placement of small diameter stents in growing patients. New Palmaz Corinthian stents were placed through 6 French sheaths in four high-risk patients with postoperative right ventricular outflow obstruction. Patients were not considered candidates for surgical repair. Median patient age and weight were 17 months (range 5-32 months) and 7.7 kg (range 4.6-11.1 kg), respectively. Median fluoroscopy time was 58.2 min (range 55.2-172 min). No complications were encountered. In each case, successful stent placement was achieved, and surgery with cardiopulmonary bypass was avoided. Palmaz Corinthian stents are more flexible, require a smaller delivery sheath, have equal or increased radial strength, and can be maximally expanded to a greater cross sectional area when compared to the original Palmaz stent. These characteristics make the Palmaz Corinthian stent a reasonable alternative for use in a select group of infants and small children who are not candidates for surgical repair of postoperative right ventricular outflow obstruction.

Treatment of primary cardiac malignancies with orthotopic heart transplantation

OBJECTIVE

Heart transplantation has become available as a possible treatment for patients with malignancies. Primary cardiac malignant tumors are extremely rare but several patients have been treated with this modality. Whether survival is improved over the direct removal of tumor or heart transplantation is not known. We compiled data regarding malignant primary heart tumors that have been treated at various transplant centers in order to determine if early diagnosis and treatment with cardiac transplantation has resulted in an improved mortality.

METHODS

A total of 173 questionnaires were sent to the heart transplant centers across the United States and Canada inquiring about those patients who were found to have a primary cardiac malignant tumor and who underwent heart transplantation. Cases reported in the literature, which had undergone transplantation, were also reviewed by a search in MEDLINE.

RESULTS

Twenty-four cases were collected. The overall survival time was from 1 month to 66 months. The actuarial survival was 54% at 12 months, 45% at 24 months and 35% at 36, 48 and 60 months respectively. Metastases were present in 10 out of the 14 deceased patients, possibly being one of the major factors affecting survival. Only 1 living patient developed metastases.

CONCLUSION

Survival rates of patients with primary cardiac malignancies treated with resection, radiation, chemotherapy, or a combination of them (conventional therapy) versus heart transplantation are similar. Early diagnosis and resection are the most important factors for a better outcome, however these factors will not guarantee success since the presence or development of metastasis is a major contributor to death in both groups of patients.

Risk factors for life-threatening cavopulmonary thrombosis in patients undergoing bidirectional superior cavopulmonary shunt: an exploratory study

We have observed six patients with life-threatening superior vena caval or pulmonary thrombosis after bidirectional superior cavopulmonary shunt. With the use of a case control study we sought to identify perioperative risk factors for this thrombotic complication. Medical records of six patients with cavopulmonary thrombosis and those of 24 patients in a control group were reviewed to abstract data for potential risk factors. Contingency tables and univariate logistic regression were used to determine associations between various perioperative parameters and occurrence of cavopulmonary thrombosis. Preoperative variables associated with thrombosis included bilateral superior vena cavae, odds ratio: 23, p = 0.02, increased age at surgery (p = 0.05), and female sex (odds ratio: 7, p = 0.05). The McGoon Ratio (index of relative pulmonary artery branch diameter) was inversely related to thrombosis risk (p = 0.08). Two torr increases in mean right atrial (p = 0.08) or ventricular end-diastolic (p = 0.05) pressures were associated with approximately 70% increases in thrombosis risk. Intraoperative prolongation of aortic cross-clamp time related directly to thrombosis risk (p = 0.06). Postoperative variables associated with thrombosis included increased superior vena caval pressure within 12 hours after surgery (odds ratio > or = 10 for 5 torr increase in pressure, p = 0.02) and poor ventricular function (odds ratio: 9, p = 0.06) We conclude that high risk variables for patients undergoing a cavopulmonary shunt include bilateral superior vena cavae, female sex, increasing age, decreased McGoon Ratio, and elevated right atrial and ventricular end-diastolic pressure (before surgery), patients with prolonged aortic cross-clamp time (during surgery), and patients with elevated superior vena caval pressure and poor ventricular function (after surgery).

Echocardiographic determinants of clinical course in infants with critical and severe pulmonary valve stenosis

OBJECTIVES

The purposes of this study were to determine the growth pattern of the pulmonary valve (PV) annulus and right heart structures in patients with critical and severe pulmonary stenosis (PS) after balloon dilation, and to determine any morphometric or hemodynamic differences between cyanotic infants with critical PS and asymptomatic infants with severe PS that may account for their varied clinical presentations.

BACKGROUND

Growth of the PV annulus and right heart structures in patients with critical PS after balloon valvuloplasty has not clearly been defined. In addition, the anatomic and hemodynamic factors that determine whether an infant with severe PS will present with cyanosis or without symptoms are not well understood.

METHODS

Measurements of the PV annulus, tricuspid valve (TV) annulus and main, right and left pulmonary arteries were obtained from initial and follow-up echocardiograms, and Z values were calculated. Hemodynamic data and balloon pulmonary valvuloplasty techniques were reviewed. Right ventricular (RV) volumes were measured from angiograms.

RESULTS

Fourteen patients with critical PS (mean [+/- SD] age 0.21 +/- 0.37 months) and 20 patients with severe PS (mean age 2.6 +/- 2.9 months) were evaluated at presentation and at 32 +/- 33 and 42 +/- 32 months of follow-up, respectively. Balloon pulmonary valvuloplasty was successful in 64% of patients with critical PS and in 90% of patients with severe PS. The PV, TV and pulmonary arteries increased in size after balloon pulmonary valvuloplasty in both groups at a rate that paralleled or exceeded the rate of somatic growth. The initial TV diameter and RV volume were smaller in patients with critical PS than in those with severe PS (p < 0.05 and p < 0.0008, respectively).

CONCLUSIONS

After balloon pulmonary valvuloplasty in infants with critical and severe PS, right heart structures increase in size at a rate that parallels or exceeds the rate of somatic growth. The primary morphometric differences between these groups are a smaller TV diameter and RV volume in infants with critical PS. This may contribute to increased right to left atrial shunting and account for the variations in clinical presentation.

Influence of age on the effect of bidirectional cavopulmonary anastomosis on left ventricular volume, mass and ejection fraction

OBJECTIVES

We sought to identify age-related differences in the ventricular response of patients after bidirectional cavopulmonary anastomosis (CPA) and to compare changes in the ventricular response among children < 3 years of age who underwent CPA with that of age-matched control subjects who had a systemic to pulmonary artery shunt alone.

BACKGROUND

Pre-Fontan CPA has been advocated over a systemic to pulmonary artery shunt alone in patients with a single ventricle to facilitate ventricular volume unloading and minimize risk of the Fontan operation.

METHODS

Our study evaluated 23 patients who initially received a systemic to pulmonary artery shunt as an initial procedure before subsequent Fontan palliation. In eight of these patients (group I), bidirectional CPA was performed before age 3 years, and in four (group II), it was performed after age 10 years. The remaining 11 patients (group III, age and weight control group for group I) were maintained with their initial shunt until they underwent Fontan palliation. Serial echocardiographic analysis was used retrospectively to evaluate left ventricular volume and mass and systolic pump function (ejection fraction) before and after bidirectional CPA.

RESULTS

Through 10 months of follow-up, group I patients showed significant decreases in indexed end-diastolic volume both after CPA (120 ml/m1.5 body surface area vs. 78 ml/m1.5, p = 0.001) and in comparison with values in patients in group II and III, who showed no changes in end-diastolic volume (p < 0.001). Indexed ventricular mass decreased moderately after bidirectional CPA in group I (from 228 g/m1.5 body surface area to 148 g/m1.5) but remained unchanged in groups II and III. The differences in trends between groups I and III were significant (p = 0.03). Ejection fraction decreased significantly in group II versus group I patients (0.48 to 0.27 vs. 0.51 to 0.52, p < 0.05) after CPA. Oxygen saturation measurements before and after bidirectional CPA revealed a significant increase in group I (73% to 86%, p < 0.001) and a decrease in group II (82% to 73%, p < 0.01).

CONCLUSIONS

Bidirectional CPA facilitates ventricular volume unloading and promotes regression of left ventricular mass in younger children (< 3 years) in preparation for a Fontan operation. In contrast, bidirectional CPA is of questionable value in older children as a staging procedure for Fontan palliation.

A study of the protein requirements of the mature breeding ewe. 2. Protein utilization in the pregnant ewe

1. An experiment was carried out in which protein utilization in the pregnant ewe was studied using the nitrogen balance technique.

2. Eight diets supplying four different intakes of crude protein and two different intakes of energy were each offered to eight individually penned ewes.

3. The mean crude protein intakes per day were 7·2, 5·5, 4·1 and 3·0 g/kg W0·73 (where W = body-weight) and the metabolizable energy intakes 134 and 113 kcal/kg W0·73.

4. N balances were carried out at 10–12, 14–16 and 18–20 weeks of gestation on five ewes from each treatment.

5. The apparent digestibility of both dry matter and crude protein decreased with decreasing protein intake. With the high energy intake, the apparent dry-matter digestibility was increased and the apparent digestibility of crude protein decreased. Stage of gestation had no significant effect on the apparent digestibility of either of these constituents.

6. N retention was not affected by the number of foetuses carried. With the higher energy intake and the higher protein intakes, the absolute retention of N was significantly increased at all stages of gestation. N retention increased with advancing pregnancy; the retentions at 10–12, 14–16 and 18–20 weeks of gestation being 0·086, 0·114 and 0·163 g/kg W0·73 per day respectively.

7. The efficiency of utilization of apparently digested N was calculated from the regression of retained N as a percentage of apparently digested N against apparently digested N.

8. The daily intakes of apparently digested N required for maximum efficiency were 0·551 and 0·620 g/kg W0·73 on the high and low energy intakes respectively. The daily intake for maximum efficiency decreased with advancing pregnancy, the values being 0·623, 0·587 and 0·567 g/kg W0·73 for the 10–12, 14–16 and 18–20 weeks of gestation respectively.

9. The levels of N retained at maximum efficiency were 0·235 and 0·202 g/kg W0·73 per day for the high and low energy intakes respectively. The levels of N retained increased during pregnancy from 0·170 g/kg W0·73 per day at 10–12 weeks to 0·286 g/kg W0·73 at 18–20 weeks. The requirements for zero N balance were 0·072 and 0·153 g apparently digested N/kg W0·73 per day for the high and low energy intakes respectively. The requirement for zero N balance decreased from 0·176 g/kg W0·73 per day at 10–12 weeks to 0·071 g/kg W0·73 at 18–20 weeks.

10. The results are discussed in relation to other research findings and current recommendations.

A study of the protein requirements of the mature breeding ewe. Maintenance requirement of the non-pregnant ewe

1. An experiment was carried out to study more precisely by nitrogen balance techniques the intake of digestible crude protein required for maintenance in the mature non-pregnant ewe. 2. Four isocaloric diets supplying adequate energy, approximately 90 kcal/kg W0.73 metabolizable energy daily, and differing in crude protein content were each given to eight individually penned ewes. The diets provided 2.4, 4.9, 7.7 and 9.5 g digestible N per ewe per day. 3. The average weight of the ewes was 57.4 kg. They were rationed according to metabolic body-weight (W0.73) at a rate of approximately 800 g dry matter per 50 kg ewe per day for a 4-week period before N balance studies were carried out over an 8-day collection period. 4. The mean apparent digestibilities of dry matter were 67.3±0.8, 68.1±0.7, 70.9±1.0 and 68.8±0.8 respectively. The apparent digestibilities of N, increasing with increasing N intake, were 30.6±2.1, 46.3±2.1, 58.2±0.6 and 61.5±1.3 respectively. 5. The intake of apparently digested N required for maintenance was calculated in three ways, from the regressions of apparently digested N on N retention or on urinary N and from the underlying relationship between N retention and urinary N. The estimates so obtained were respectively 0.185±0.037, 0.148±0.020 and 0.150±0.020 g N per kg W0.78 per day, corresponding to 1.16, 0.93 and 0.94 g apparently digestible crude protein per kg W0.73 per day. 6. Metabolic faecal N, determined by the extrapolation method, was 0.629±0.047 g/100 g dry matter consumed. 7. The results are discussed in relation to practical feeding standards and other research findings.