Morbidity and mortality of multivisceral resection with radical nephrectomy for locally advanced renal cell carcinoma: An analysis of the National Surgical Quality Improvement Program (NSQIP) database.

INTRODUCTION: Locally advanced renal cell carcinoma (RCC) can rarely invade into adjacent abdominal viscera without clinical evidence of distant metastases. The role of multivisceral resection (MVR) of involved adjacent organs at the time of radical nephrectomy (RN) remains poorly described and quantified. Using a national database, we aimed to evaluate the association between RN+MVR and 30-day postoperative complications. METHODS AND MATERIALS: We conducted a retrospective cohort study of adult patients undergoing RN for RCC with and without MVR between 2005 and 2020 using the ACS-NSQIP database. The primary outcome was a composite of any of the following 30-day major postoperative complications: mortality, reoperation, cardiac event, and neurologic event. Secondary outcomes included individual components of the composite primary outcome, as well as infectious and venous thromboembolic complications, unplanned intubation and ventilation, transfusion, readmission, and prolonged length of stay (LOS). Groups were balanced using propensity score matching. Likelihood of complications was assessed by conditional logistic regression adjusted for unbalanced total operation time. Postoperative complications were compared by Fisher's exact test among subtypes of resection. RESULTS: A total of 12,417 patients were identified: 12,193 (98.2%) undergoing RN alone and 224 (1.8%) undergoing RN+MVR. Patients undergoing RN+MVR were more likely to experience major complications (odds ratio [OR] 2.46; 95% confidence interval [CI] 1.28-4.74). However, there was no significant association between RN+MVR and postoperative mortality (OR 2.49; 95% CI 0.89-7.01). RN+MVR was associated with higher rates of reoperation (OR 7.85; 95% CI 2.38-25.8), sepsis (OR 5.45; 95% CI 1.83-16.2), surgical site infection (OR 4.41; 95% CI 2.14-9.07), blood transfusion (OR 2.24; 95% CI 1.55-3.22), readmission (OR 1.78; 95% CI 1.11-2.84), infectious complications (OR 2.62; 95% CI 1.62-4.24), and longer hospital stay (5 days [IQR 3-8] vs. 4 days [IQR 3-7]; OR 2.31 [95% CI 2.13-3.03]).  There was no heterogeneity in the association between subtype of MVR and major complication rate. CONCLUSION: Undergoing RN+MVR is associated with an increased risk of 30-day postoperative morbidity, including infectious complications, reoperation, blood transfusion, prolonged LOS, and readmission.

Comparative real-world survival outcomes of metastatic papillary and clear cell renal cell carcinoma treated with immunotherapy, targeted therapy, and combination therapy.

INTRODUCTION: While there are a plethora of studies supporting novel treatment approaches in metastatic clear cell renal cell carcinoma (ccRCC), much of the data used to inform care of patients with metastatic papillary RCC (pRCC) is extrapolated from ccRCC. Several recent phase III trials have supported the use of immunotherapy (IO) and targeted therapy (TT)+IO in ccRCC, without corresponding data for pRCC. Using ccRCC as a comparison group, we sought to describe real-world trends in the utilization of systemic therapy and its impact on overall survival (OS) among patients with metastatic pRCC. METHODS: Using the National Cancer Database (NCDB), we identified cases of metastatic pRCC and ccRCC between 2015 and 2018. Patients were stratified into groups based on histology and first-line treatments (TT, IO, TT + IO). Differences in baseline characteristics were assessed using the Kruskal-Wallis test for continuous variables, and the Chi-square or Fisher's exact test for categorical variables. Survival analysis was performed using Kaplan-Meier estimates and multivariable Cox regression analyses. RESULTS: A total of 6,920 patients with a diagnosis of metastatic RCC were identified: 594 (8.6%) with pRCC and 6,326 (91.4%) with ccRCC. Overall, 4,710 patients received TT (455 pRCC and 4,255 ccRCC), 1,585 received IO (77 pRCC and 1,508 ccRCC), and 625 received TT+IO (62 pRCC and 563 ccRCC). Temporal trend between 2015 and 2018 revealed an increased utilization of IO and TT + IO for pRCC and ccRCC. In patients with metastatic pRCC, neither IO (HR 1.03; 95% CI 0.75-1.42) nor TT+IO (HR 0.90, 95% CI 0.63-1.28) were associated with better OS compared to TT alone. In contrast, both IO and combination TT and IO were associated with significantly better OS than TT for patients with metastatic ccRCC (IO group: hazard ratio [HR] 0.75, 95% confidence interval [CI] 0.68-0.82; TT+IO group: HR 0.82, 95% CI 0.72-0.93). Cytoreductive nephrectomy was associated with better OS in both pRCC (HR 0.59, 95% CI 0.46-0.77) and ccRCC (HR 0.54, 95% CI 0.50-0.58). CONCLUSIONS: Although IO and TT + IO were associated with better OS among patients with metastatic ccRCC, this same effect was not observed among patients with pRCC.

Short-term Mortality Associated with Definitive Chemoradiotherapy Versus Radical Cystectomy for Muscle-invasive Bladder Cancer.

BACKGROUND: Muscle-invasive bladder cancer (MIBC) may be managed with radical cystectomy (RC) or chemoradiotherapy (CRT). Because patient selection for RC is important to avoid treatment-related mortality, this study addressed a knowledge gap by quantifying short-term mortality with both approaches, as well as predictors thereof. MATERIALS AND METHODS: The National Cancer Database was queried (2004-2014) for clinically staged T2-4aN0M0 MIBC that received either CRT or RC. Statistics included cumulative incidence comparisons of 30- and 90-day mortality between patients treated with either CRT or RC and Cox regression to evaluate predictors thereof. RESULTS: Of 16,658 patients, 15,208 (91.3%) underwent RC and 1450 (8.7%) CRT. Crude rates of post-treatment mortality at 30 days were 2.7% versus 0.6% (P < .001) and at 90 days were 7.5% versus 4.5% (P = .017) for patients treated with RC and CRT, respectively. When stratifying by age, worse 30- and 90-day mortality with RC was observed for patients aged ≥ 76 years. CONCLUSIONS: This study describes 30- and 90-day mortality following RC versus CRT. Both approaches yield statistically similar treatment-related mortality rates in patients ≤ 75 years of age; however, worse post-treatment mortality was observed with use of RC in patients ≥ 76 years of age. These results may be utilized to better inform shared decision-making between patients and providers when weighing both RC and CRT for MIBC.

Validation of a Simulation-training Model for Robotic Intracorporeal Bowel Anastomosis Using a Step-by-step Technique.

OBJECTIVE: To develop and validate a training model for the robotic intracorporeal bowel anastomosis. METHODS: For simulation, surgeons with varying levels of experience were instructed about bowel anastomosis robotic surgical simulation in a short educational video. All participants performed the required steps for the intracorporeal bowel anastomosis under standardized conditions. The procedure consists of the following steps: division of the bowel with a stapler (1), incision and opening of the bowel limbs at the antimesenteric angle (2), insertion of the stapler into the 2 bowel limbs for the side-to-side anastomosis (3), and transverse closure of the anastomosis with the stapler (4). All simulations were performed using the daVinci SI robotic system. Face and content validity were assessed using a standardized questionnaire. Construct validity was evaluated using the Global Evaluative Assessment of Robotic Skills, a validated global performance rating scale. RESULTS: Twenty-two surgeons participated including 6 robotic experts and 16 trainees. The expert participants rated the bowel anastomosis model highly for face validity (median 4/5; 64% agree or strongly agree), and all participants rated the content as a training model very highly (median 4.5/5; 100% agree or strongly agree). Discrimination between experts and trainees using Global Evaluative Assessment of Robotic Skills demonstrated construct validity (novice 17.6 vs expert 24.7, P = .03). CONCLUSION: We demonstrate that the bowel anastomosis robotic surgical simulator is a reproducible and realistic simulation that allows for an objective skills assessment. We establish face, content, and construct validity for this model. This step-by-step technique may be utilized in training surgeons desiring to acquire skills in robotic intracorporeal urinary diversion.

National Comprehensive Cancer Network® Favorable Intermediate Risk Prostate Cancer-Is Active Surveillance Appropriate?

PURPOSE: We compared pathological and biochemical outcomes after radical prostatectomy in patients at favorable intermediate risk who fulfilled current NCCN® (National Comprehensive Cancer Network®) Guidelines® for active surveillance criteria to outcomes in patients who met more traditional criteria for active surveillance. MATERIALS AND METHODS: We queried our institutional review board approved prostate cancer database for patients who met NCCN criteria for very low risk (T1c, Grade Group 1, 3 or fewer of 12 cores, 50% or less core volume and prostate specific antigen density less than 0.15 ng/ml), low risk (T1-T2a, Grade Group 1 and prostate specific antigen less than 10 ng/ml) or favorable intermediate risk (major pattern grade 3 and less than 50% positive biopsy cores) and who had 1 intermediate risk factor, including T2b/c, Grade Group 2 or prostate specific antigen 10 to 20 ng/ml. Men at intermediate risk who did not meet favorable criteria were labeled as being at unfavorable intermediate risk. Patients at favorable intermediate risk were compared to those at very low and low risk, and those at unfavorable intermediate risk to identify differences in rates of adverse pathological findings at radical prostatectomy, including Gleason score Grade Group 3-5, nonorgan confined disease or nodal involvement. Time to biochemical recurrence was compared among the groups using Cox regression. RESULTS: A total of 3,686 patients underwent radical prostatectomy between January 1, 2014 and December 31, 2015. Of these men 1,454, 250 and 1,362 fulfilled the criteria for low, favorable intermediate and unfavorable intermediate risk, respectively. The rate of adverse pathological findings in favorable intermediate risk cases was significantly higher than in low risk cases and significantly lower than in unfavorable intermediate risk cases (27.4% vs 14.8% and 48.5%, respectively, each p <0.001). Time to biochemical recurrence differed significantly among the risk groups (p <0.001). CONCLUSIONS: Relative to men at low risk those at favorable intermediate risk represent a distinct group. Care should be taken when selecting these patients for active surveillance and monitoring them once they are in an active surveillance program.

Robotic Left-sided Level II Caval Thrombectomy and Nephrectomy Using a Novel Supine, Single-dock Approach: Primary Description.

OBJECTIVE: To demonstrate a novel supine, single-dock approach for robotic nephrectomy and inferior vena cava (IVC) thrombectomy for a left-sided renal cell carcinoma with level II IVC thrombus. METHODS: We perform robotic nephrectomy and IVC thrombectomy in a 79-year-old man with a 6-cm left renal mass and level II IVC thrombus. For this approach, the patient is placed in steep Trendelenburg, and a 6-port transperitoneal technique is used, with the robot docked such that the arms are oriented in a cephalad direction. We describe key steps, including (1) exposure of the retroperitoneum, (2) IVC exposure and control, (3) left renal hilar control, (4) cavotomy, thrombectomy, and reconstruction, (5) nephrectomy and lymph node dissection. Perioperative outcomes are reported. RESULTS: Robotic left nephrectomy and level II IVC thrombectomy were successfully completed using this novel, single-dock approach. Total operative time was 7 hours with IVC clamp time of 27 minutes. Estimated blood loss was 500 cc without perioperative transfusion. There were no intraoperative or major perioperative complications. The patient was discharged on postoperative day 5. This approach allows rapid caval control, bilateral renal hilar access, and obviates the need for preoperative renal artery embolization or intraoperative redocking or repositioning steps, as has been previously described for other approaches. CONCLUSION: We demonstrate the first description of robotic left-sided level II IVC thrombectomy and radical nephrectomy using a supine, single-dock approach. This novel, versatile approach adds to the armamentarium for minimally invasive surgical management of renal cell carcinoma with IVC thrombus.

Robot-assisted Laparoscopic Resection of Renal Vein Leiomyosarcoma.

Leiomyosarcoma, a rare and aggressive retroperitoneal tumor, arises from the smooth muscle of the tunica media. Accurate preoperative diagnosis is rare as the origin is often unclear, and its involvement of the vessels makes biopsy prohibitively dangerous (Maturen et al, 20136). Herein, we describe the laparoscopic dissection of a retroperitoneal renal vein tumor using a robotic approach.

Performance of robotic simulated skills tasks is positively associated with clinical robotic surgical performance.

OBJECTIVE: To compare user performance of four fundamental inanimate robotic skills tasks (FIRST) as well as eight da Vinci Skills Simulator (dVSS) virtual reality tasks with intra-operative performance (concurrent validity) during robot-assisted radical prostatectomy (RARP) and to show that a positive correlation exists between simulation and intra-operative performance. MATERIALS AND METHODS: A total of 21 urological surgeons with varying robotic experience were enrolled. Demographics were captured using a standardized questionnaire. User performance was assessed concurrently in simulated (FIRST exercises and dVSS tasks) and clinical environments (endopelvic dissection during RARP). Intra-operative robotic clinical performance was scored using the previously validated six-metric Global Evaluative Assessment of Robotic Skills (GEARS) tool. The relationship between simulator and clinical performance was evaluated using Spearman's rank correlation. RESULTS: Performance was assessed in 17 trainees and four expert robotic surgeons with a median (range) number of previous robotic cases (as primary surgeon) of 0 (0-55) and 117 (58-600), respectively (P = 0.001). Collectively, the overall FIRST (ρ = 0.833, P < 0.001) and dVSS (ρ = 0.805, P < 0.001) simulation scores correlated highly with GEARS performance score. Each individual FIRST and dVSS task score also demonstrated a significant correlation with intra-operative performance, with the exception of Energy Switcher 1 exercise (P = 0.063). CONCLUSIONS: This is the first study to show a significant relationship between simulated robotic performance and robotic clinical performance. Findings support implementation of these robotic training tools in a standardized robotic training curriculum.

Multi-Institutional Validation of Fundamental Inanimate Robotic Skills Tasks.

PURPOSE: Our group has previously reported the development and validation of FIRST (Fundamental Inanimate Robotic Skills Tasks), a series of 4 inanimate robotic skills tasks. Expanding on the initial validation, we now report face, content and construct validity of FIRST in a large multi-institutional cohort of experts and trainees. MATERIALS AND METHODS: A total of 96 residents, fellows and attending surgeons completed the FIRST exercises at participating institutions. Participants were classified based on previous robotic experience and task performance was compared across groups to establish construct validity. Face and content validity was assessed from participant ratings of the tasks on a 5-point Likert scale. RESULTS: A total of 51 novice, 22 intermediate and 23 expert participants with a median previous robotic experience of 0 (range 0 to 3), 10 (range 5 to 30) and 200 cases (range 55 to 2,000), respectively (p<0.001), were assessed across all 4 inanimate robotic skills tasks. Expert and intermediate groups reliably outperformed novices (p<0.01). Experts also performed better than intermediates on all exercises (p<0.01). A survey of participants on their perceptions of the tasks yielded excellent face and content validity. CONCLUSIONS: We confirm robust face, content and construct validity of 4 inanimate robotic training tasks in a large multi-institutional cohort. FIRST tasks are reliably able to discern among expert, intermediate and novice robotic surgeons. Validation data from this large multi-institutional cohort is useful as we incorporate these tasks into a comprehensive robotic training curriculum.

Robotic Intracorporeal Continent Cutaneous Urinary Diversion: Primary Description.

The purpose is to present the first report and describe our novel technique for intracorporeal continent cutaneous diversion after robotic cystectomy. After completion of robot-assisted cystectomy using a standard six-port transperitoneal technique, three additional ports are placed, and the robot is redocked laterally over the patient's right side in the modified lateral position. Our technique replicates step-by-step the principles of the open approach. Ileocolonic anastomosis, ureteroenteral anastomoses, and construction of a hand-sewn right colonic pouch are all performed intracorporeally. Tapering of efferent ileal limb and reinforcement of the ileocecal valve are performed via the extraction site, while the stoma is matured through a prospective port site. Successful robotic intracorporeal creation of a modified Indiana pouch was achieved. Operative time for diversion was 3 hours, with negligible blood loss, and without any intraoperative complications. No major (Clavien III-V) 90-day complications were observed. At a follow-up of 1 year, the patient continues to catheterize without difficulty. We demonstrate the first description of robotic intracorporeal continent cutaneous urinary diversion after robot-assisted cystectomy. We present a systematic minimally invasive approach, replicating the principles of open surgery, which is technically feasible and safe with a good functional result.

External validation of Global Evaluative Assessment of Robotic Skills (GEARS).

BACKGROUND: We demonstrate the construct validity, reliability, and utility of Global Evaluative Assessment of Robotic Skills (GEARS), a clinical assessment tool designed to measure robotic technical skills, in an independent cohort using an in vivo animal training model. METHODS: Using a cross-sectional observational study design, 47 voluntary participants were categorized as experts (>30 robotic cases completed as primary surgeon) or trainees. The trainee group was further divided into intermediates (≥5 but ≤30 cases) or novices (<5 cases). All participants completed a standardized in vivo robotic task in a porcine model. Task performance was evaluated by two expert robotic surgeons and self-assessed by the participants using the GEARS assessment tool. Kruskal-Wallis test was used to compare the GEARS performance scores to determine construct validity; Spearman's rank correlation measured interobserver reliability; and Cronbach's alpha was used to assess internal consistency. RESULTS: Performance evaluations were completed on nine experts and 38 trainees (14 intermediate, 24 novice). Experts demonstrated superior performance compared to intermediates and novices overall and in all individual domains (p < 0.0001). In comparing intermediates and novices, the overall performance difference trended toward significance (p = 0.0505), while the individual domains of efficiency and autonomy were significantly different between groups (p = 0.0280 and 0.0425, respectively). Interobserver reliability between expert ratings was confirmed with a strong correlation observed (r = 0.857, 95 % CI [0.691, 0.941]). Experts and participant scoring showed less agreement (r = 0.435, 95 % CI [0.121, 0.689] and r = 0.422, 95 % CI [0.081, 0.0672]). Internal consistency was excellent for experts and participants (α = 0.96, 0.98, 0.93). CONCLUSIONS: In an independent cohort, GEARS was able to differentiate between different robotic skill levels, demonstrating excellent construct validity. As a standardized assessment tool, GEARS maintained consistency and reliability for an in vivo robotic surgical task and may be applied for skills evaluation in a broad range of robotic procedures.

Small high-yielding binary Ti vectors pLSU with co-directional replicons for Agrobacterium tumefaciens-mediated transformation of higher plants.

Small high-yielding binary Ti vectors of Agrobacterium tumefaciens were constructed to increase the cloning efficiency and plasmid yield in Escherichia coli and A. tumefaciens for transformation of higher plants. We reduced the size of the binary vector backbone to 4566bp with ColE1 replicon (715bp) for E. coli and VS1 replicon (2654bp) for A. tumefaciens, a bacterial kanamycin resistance gene (999bp), and the T-DNA region (152bp). The binary Ti vectors with the truncated VS1 replicon were stably maintained with more than 98% efficiency in A. tumefaciens without antibiotic selection for 4 days of successive transfers. The transcriptional direction of VS1 replicon can be the same as that of ColE1 replicon (co-directional transcription), or opposite (head-on transcription) as in the case of widely used vectors (pPZP or pCambia). New binary vectors with co-directional transcription yielded in E. coli up to four-fold higher transformation frequency than those with the head-on transcription. In A. tumefaciens the effect of co-directional transcription is still positive in up to 1.8-fold higher transformation frequency than that of head-on transcription. Transformation frequencies of new vectors are over six-fold higher than those of pCambia vector in A. tumefaciens. DNA yields of new vectors were three to five-fold greater than pCambia in E. coli. The proper functions of the new T-DNA borders and new plant selection marker genes were confirmed after A. tumefaciens-mediated transformation of tobacco leaf discs, resulting in virtually all treated leaf discs transformed and induced calli. Genetic analysis of kanamycin resistance trait among the progeny showed that the kanamycin resistance and sensitivity traits were segregated into the 3:1 ratio, indicating that the kanamycin resistance genes were integrated stably into a locus or closely linked loci of the nuclear chromosomal DNA of the primary transgenic tobacco plants and inherited to the second generation.

Prostate size as a predictor of Gleason score upgrading in patients with low risk prostate cancer.

PURPOSE: Gleason score upgrading between biopsy and surgical pathological specimens occurs in 30% to 50% of cases. Predicting upgrading in men with low risk prostate cancer may be particularly important since high grade disease influences management decisions and impacts prognosis. We determined whether prostate size predicts Gleason score upgrading in patients with low risk prostate cancer. MATERIALS AND METHODS: A total of 1,251 consecutive patients with D'Amico low risk disease and complete data available underwent radical prostatectomy at our institution between January 2000 and June 2008. Patients were divided into 3 groups by pathological Gleason score, including no, minor (3 + 4 = 7) and major (4 + 3 = 7 or greater) Gleason score upgrading. We developed bivariate and multivariate models to determine whether prostate size was an important predictor of upgrading while controlling for clinical and biopsy characteristics. RESULTS: Of 1,251 cases 387 (31.0%) were upgraded, including 324 (26%) and 63 (5%) with minor and major upgrading, respectively. As expected, Gleason score upgrading was associated with worse pathological and cancer control outcomes. On multivariate analysis smaller prostate size was an independent predictor of any and major upgrading (OR 0.58, 95% CI 0.48-0.69, p <0.01 and OR 0.67, 95% CI 0.49-0.96, p = 0.03, respectively). Men with prostate volume at the 25th percentile (36 cm(3)) were 50% more likely to experience upgrading than men with prostate volume at the 75th percentile (58 cm(3)). CONCLUSIONS: Of low risk cases 31% were upgraded at final pathology. Smaller prostate size predicts Gleason score upgrading in men with clinically low risk prostate cancer. This is important information when counseling patients on management and prognosis.

Determining factors for hospital discharge status after radical cystectomy in a large contemporary cohort.

PURPOSE: We describe hospital discharge status in patients after radical cystectomy for bladder cancer. We determined factors affecting discharge status. MATERIALS AND METHODS: The 445 patients underwent radical cystectomy for urothelial carcinoma from January 2004 to December 2007. Patients were grouped by hospital discharge status into 1 of 4 groups, including home under self-care without services, home with home health services, subacute, rehabilitation or skilled nursing facility, or hospice/in-hospital mortality. We compared clinical, perioperative and pathological variables in these groups. We also examined the association of discharge status with the hospital readmission rate and 90-day mortality. RESULTS: Of the 440 patients 250 (56.8%), 145 (32.9%), 39 (8.9%) and 6 (1.4%) were in the home without services, home with services, facility and mortality groups, respectively. On multivariate analysis older age, lower preoperative albumin, unmarried status and higher Charlson comorbidity index were predictors of discharge home with services while older age, poor preoperative exercise tolerance and longer hospital stay predicted discharge to a facility. Patients in the facility group were more likely to die within 90 days of surgery than those who returned home independently or with services. There was no difference in the likelihood of rehospitalization. CONCLUSIONS: Sociodemographic factors, preoperative performance status, and comorbidities and perioperative factors contribute to the discharge decision after radical cystectomy. Some subgroups can be predicted to have increased postoperative care needs and may be appropriate targets for disposition planning preoperatively.

Effect of preoperative nutritional deficiency on mortality after radical cystectomy for bladder cancer.

PURPOSE: Poor preoperative nutritional status is a risk factor for adverse outcomes after major surgery. We evaluated the effect of preoperative nutritional deficiency on perioperative mortality and overall survival in patients undergoing radical cystectomy for bladder cancer. MATERIALS AND METHODS: A total of 538 patients underwent radical cystectomy for urothelial carcinoma between January 2000 and June 2008, and had nutritional parameters documented. Patients with preoperative albumin less than 3.5 gm/dl, body mass index less than 18.5 kg/m(2) or preoperative weight loss greater than 5% of body weight were considered to have nutritional deficiency. Primary outcomes were 90-day mortality and overall survival. Survival was estimated using Kaplan-Meier analysis and compared using the log rank test. Cox proportional hazards models were used for multivariate survival analysis. RESULTS: Of 538 patients 103 (19%) met the criteria for nutritional deficiency. The 90-day mortality rate was 7.3% overall (39 deaths), with 16.5% in patients with nutritional deficiency and 5.1% in the others (p < 0.01). Nutritional deficiency was a strong predictor of death within 90 days on multivariate analysis (HR 2.91; 95% CI 1.36, 6.23; p < 0.01). Overall survival at 3 years was 44.5% (33.5, 54.9) for nutritionally deficient patients and 67.6% (62.4, 72.2) for those who were nutritionally normal (p < 0.01). On multivariate analysis nutritional deficiency cases had a significantly higher risk of all cause mortality (HR 1.82; 95% CI 1.25, 2.65; p < 0.01). CONCLUSIONS: Nutritional deficiency, as measured by preoperative weight loss, body mass index and serum albumin, is a strong predictor of 90-day mortality and poor overall survival. Prospective studies are needed to demonstrate the best indices of preoperative nutritional status and whether nutritional intervention can alter the poor prognosis for patients treated with radical cystectomy who have nutritional deficiencies.