Minimally Invasive Robotic Kidney Transplantation for Obese Patients Previously Denied Access to Transplantation

Abstract

The authors report results on a new robotic kidney transplantation technique for obese patients that has comparable patient outcomes compared to an open procedure. The authors report results on a new robotic kidney transplantation technique for obese patients that has comparable patient outcomes compared to an open procedure. Obese patients with end-stage renal disease (ESRD) are often excluded from kidney transplantation due to concerns about surgical site infections. To reduce infections, we developed a robotic kidney transplantation method for obese recipients. From June 2009 to December 2011, a prospective cohort of 39 obese patients underwent robotic kidney transplantation at a single center. The outcomes of patients with at least 6 months of follow-up (n = 28) were compared to a frequency-matched retrospective cohort of obese patients who underwent open kidney transplantation from 2004 to 2009 (n = 28). The 28 robotic patients were predominately African American (46.4%) or Hispanic (35.7%), with a mean age of 47.9 ± 10.7 years, similar to the control group. BMI in the robotic group was 42.6 ± 7.8 kg/m2 compared to 38.1 ± 5.4 kg/m2 in the control group (p = 0.02). There were no surgical site infections in the robotic group (0/28), while 28.6% (8/28) in the control group developed an infection (p = 0.004). Six-month creatinine (1.5 ± 0.4 vs. 1.6 ± 0.6 mg/dL; p = 0.47), and patient and graft survival (100%) were comparable between the two groups. Outcomes following robotic surgery compared favorably to conventional transplantation. Robotic surgery may therefore enable obese patients with ESRD to access kidney transplantation and may thereby reduce health disparities in groups with a high prevalence of obesity and ESRD. Epidemiological data indicate that 20–50% of patients on dialysis for end-stage renal disease (ESRD) are obese (body mass index [BMI] ≥30 kg/m2) (1U.S. Renal Data System. USRDS 2011Annual Data Report: Atlas of Chronic Kidney Disease and End-Stage Renal Disease in the United States.. National Institutes of Health, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD2011Google Scholar). Obese patients with chronic renal failure have longer wait times until kidney transplantation (2Segev DL Simpkins CE Thompson RE Locke JE Warren DS Montgomery RA Obesity impacts access to kidney transplantation.J Am Soc Nephrol. 2008; 19: 349-355Crossref PubMed Scopus (183) Google Scholar) and inferior patient outcomes (3Modlin CS Flechner SM Goormastic M et al.Should obese patients lose weight before receiving a kidney transplant?.Transplantation. 1997; 64: 599-604Crossref PubMed Scopus (144) Google Scholar, 4Meier-Kriesche HU Vaghela M Thambuganipalle R Friedman G Jacobs M Kaplan B The effect of body mass index on long-term renal allograft survival.Transplantation. 1999; 68: 1294-1297Crossref PubMed Scopus (136) Google Scholar, 5Pischon T Sharma AM Obesity as a risk factor in renal transplant patients.Nephrol Dial Transplant. 2001; 16: 14-17Crossref PubMed Scopus (76) Google Scholar, 6Meier-Kriesche HU Arndorfer JA Kaplan B The impact of body mass index on renal transplant outcomes: A significant independent risk factor for graft failure and patient death.Transplantation. 2002; 73: 70-74Crossref PubMed Scopus (476) Google Scholar, 7Meier-Kriesche HU Kaplan B Waiting time on dialysis as the strongest modifiable risk factor for renal transplant outcomes: A paired donor kidney analysis.Transplantation. 2002; 74: 1377-1381Crossref PubMed Scopus (627) Google Scholar). In the United States, for example, patients with a BMI < 25 kg/m2 have a median wait time of 39 months for a deceased donor kidney transplantation compared to 59 months in patients with a BMI > 40 kg/m2 (2Segev DL Simpkins CE Thompson RE Locke JE Warren DS Montgomery RA Obesity impacts access to kidney transplantation.J Am Soc Nephrol. 2008; 19: 349-355Crossref PubMed Scopus (183) Google Scholar). Higher BMIs in kidney transplant recipients are associated with excess risk of surgical site infections (SSIs), which negatively impact graft survival (8Lynch RJ Ranney DN Shijie C Lee DS Samala N Englesbe MJ Obesity, surgical site infection, and outcome following renal transplantation.Ann Surg. 2009; 250: 1014-1020Crossref PubMed Scopus (190) Google Scholar). Obesity is also associated with comorbidities such as diabetes, although data on whether obesity increases mortality in kidney transplanted patients remain unclear (8Lynch RJ Ranney DN Shijie C Lee DS Samala N Englesbe MJ Obesity, surgical site infection, and outcome following renal transplantation.Ann Surg. 2009; 250: 1014-1020Crossref PubMed Scopus (190) Google Scholar,9Aalten J Christiaans MH de Fijter H et al.The influence of obesity on short- and long-term graft and patient survival after renal transplantation.Transpl Int. 2006; 19: 901-907Crossref PubMed Scopus (101) Google Scholar). Provider perceptions of these risks accompanied by the expectation of some centers to give obese patients time to lose weight are the main reasons why a number of transplant centers are reluctant to list obese patients for transplantation (2Segev DL Simpkins CE Thompson RE Locke JE Warren DS Montgomery RA Obesity impacts access to kidney transplantation.J Am Soc Nephrol. 2008; 19: 349-355Crossref PubMed Scopus (183) Google Scholar,10Pham PT Pham PA Pham PC Parikh S Danovitch G Evaluation of adult kidney transplant candidates.Semin Dial. 2010; 23: 595-605Crossref PubMed Scopus (42) Google Scholar). Unfortunately, many of these obese patients have diabetes and hypertension likely secondary to their obesity (11Sugerman HJ Wolfe LG Sica DA Clore JN Diabetes and hypertension in severe obesity and effects of gastric bypass-induced weight loss.Ann Surg. 2003; 237: 751-758Crossref PubMed Scopus (440) Google Scholar) and such patients who remain on dialysis have a very high mortality rate. The 5-year mortality rate for diabetic and hypertensive dialysis patients is 75 and 70%, respectively (1U.S. Renal Data System. USRDS 2011Annual Data Report: Atlas of Chronic Kidney Disease and End-Stage Renal Disease in the United States.. National Institutes of Health, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD2011Google Scholar). A recent study demonstrated that obese patients who did not present with any SSIs had the same kidney transplant success rate as patients with a normal BMI (8Lynch RJ Ranney DN Shijie C Lee DS Samala N Englesbe MJ Obesity, surgical site infection, and outcome following renal transplantation.Ann Surg. 2009; 250: 1014-1020Crossref PubMed Scopus (190) Google Scholar). If surgical procedures could be developed that prevent SSIs and demonstrate successful outcomes, transplant centers may become less reluctant to list obese patients for kidney transplantation. Although any benefit would still have to be weighed against potential increased risks from obesity-related comorbidities. The prevalence of obesity and ESRD is higher among racial and ethnic minority populations, including African Americans and Hispanics, compared to non-Hispanic whites (12Institute of MedicineUnequal Treatment: Confronting Racial and Ethnic Disparities in Health Care.. The National Academies Press, Washington, D.C.2002Google Scholar, 13Coresh J Selvin E Stevens LA et al.Prevalence of chronic kidney disease in the United States.JAMA. 2007; 298: 2038-2347Crossref PubMed Scopus (3926) Google Scholar, 14Mehrotra R Kermah D Fried L Adler S Norris K Racial differences in mortality among those with CKD.J Am Soc Nephrol. 2008; 19: 1403-1410Crossref PubMed Scopus (113) Google Scholar, 15US Centers for Disease Control. Fact sheet: Health disparities in obesity 2011. http://www.cdc.gov/minorityhealth/reports/CHDIR11/FactSheets/Obesity.pdf. Accessed February 12, 2012.Google Scholar). These observations suggest developing kidney transplantation options for obese patients with ESRD may also help to reduce health disparities in racial and ethnic minorities. We therefore developed a new, minimally invasive, robotic kidney transplantation method using a short epigastric incision. This method avoids any incision in the infection prone lower quadrants of the abdomen. We hypothesized a priori that the robotic approach would reduce SSIs and improve outcomes in obese kidney transplant patients. Herein, we present our experience and outcomes of the patients undergoing minimal invasive, robotic kidney transplantation at a single institution compared to patients who underwent the conventional open procedure. From June 2009 to December 2011, a prospective cohort of 39 obese patients with ESRD underwent robotic kidney transplantation at the University of Illinois Hospital & Health Sciences System. Twenty eight of these patients completed a follow-up period of at least 6 months after transplant. We compared the posttransplant outcomes from these 28 patients with those of a retrospective cohort control group of 28 obese patients undergoing standard open kidney transplantation prior to June 2009 at our institution, also with at least 6 months of follow-up. They were frequency matched to the robotic surgery group on the following variables, listed in order of priority: BMI (30 kg/m2 ≤ BMI < 35 kg/m2 [obese], or BMI ≥35 kg/m2 [morbidly obese]); race (patient reported non-Hispanic white, Hispanic, African American); ABO incompatibility (yes/no); cross-match positivity (yes/no); gender (male/female); age; living/deceased donation; underlying disease and pretransplant dialysis (yes/no). Patient characteristics are described in Table 1.Table 1:Robotic kidney transplant and control patient characteristicsRobotic transplant (n = 28)Controls (n = 28)p-ValueDemographicsAge (years), mean (SD)47.9 (10.7)49.8 (10.8)0.51Gender (male), No. (%)13 (46.4)11 (39.3)0.59Race (African American/Hispanic/White), No. (%)13/10/5 (46.4/35.7/17.9)13/10/5 (46.4/35.7/17.9)ClinicalBMI (kg/m2), mean (SD)42.6 (7.8)38.1 (5.4)0.02Obese (30≤BMI< 35)/morbidly Obese (BMI≥35), No. (%)6/22 (21.4/78.6)6/22 (21.4/78.6)Creatinine pretransplant (mg/dl), mean (SD)7.6 (3.5)6.3 (2.5)0.11Dialysis, No. (%)19 (67.9)20 (71.4)0.77Duration on dialysis (months; n = 17/17), mean (SD)32.0 (34.7)15.6 (11.8)0.08Crossmatch positive, No. (%)7 (25.0)7 (25.0)ABO incompatible, No. (%)1 (3.6)1 (3.6)ComorbiditiesCAD, No. (%)9 (32.1)9 (32.1)CVD, No. (%)1 (3.6)4 (14.3)0.35PAV, No. (%)2 (7.1)4 (14.3)0.67Asthma/sleep apnea, No. (%)5 (17.9)3 (10.7)0.71Congestive heart failure, No. (%)2 (7.1)2 (7.1)Cause of kidney failureDiabetes, No. (%)7 (25.0)2 (7.1)0.14Hypertension, No. (%)8 (28.6)11 (39.3)0.40Diabetes + hypertension, No. (%)2 (7.1)10 (35.7)0.009FSGS, No. (%)2 (7.1)1 (3.6)0.99Graft failure/retransplant, No. (%)2 (7.1)00.49Lupus nephritis, No. (%)1 (3.6)00.99Obstructive uropathy, No. (%)1 (3.6)00.99Analgesic nephropathy, No. (%)1 (3.6)00.99Wegener’s granulomatosis, No. (%)1 (3.6)00.99Postinfectious crescentic glomerulonephritis, No. (%)1 (3.6)00.99Alport’s syndrome, No. (%)01 (3.6)0.99Hemolytic uremic syndrome, No. (%)01 (3.6)0.99Hypertension + nephrotic syndrome, No. (%)01 (3.6)0.99Unknown, No. (%)2 (7.1)1 (3.6)0.99BMI = body mass index; CAD = coronary artery disease; CVD = cerebrovascular disease; FSGS = focal segmental glomerulosclerosis; PAV = peripheral arterial disease; SD = standard deviation.To convert creatinine (mg/dL) to SI units (umol/L), multiply by 88.4. Open table in a new tab BMI = body mass index; CAD = coronary artery disease; CVD = cerebrovascular disease; FSGS = focal segmental glomerulosclerosis; PAV = peripheral arterial disease; SD = standard deviation. To convert creatinine (mg/dL) to SI units (umol/L), multiply by 88.4. The pretransplant workup for all patients regardless of surgical procedure followed Center of Medicare and Medicaid Services guidelines. Historically, our institution had never excluded any patient from transplantation based on body weight if the pretransplant workup did not show any formal contraindications. However, the average BMI of the control group was lower the robotic we were not to obese patients in the control group. The of the was not to patients. Kidney transplantation was to patients undergoing in the of a cross-match or ABO incompatibility to their prospective as as patients with a of kidney transplantation. The at the University of Illinois at Robotic kidney were as described et kidney transplantation in a obese J Transplant. 2010; PubMed Scopus Google Scholar). of the artery and the at least the in the of any However, with robotic for the were patients were on at a standard rate of and on until were as described S C A et donor is and regardless of the of 2006; 19: PubMed Scopus Google Scholar). who were African underwent the of with and by a of and a completed by In and patients underwent a with and as described et donor kidney transplantation The University of Illinois at 2009; PubMed Scopus Google Scholar). In were to the of of by and at that recipients underwent the same procedure as described Pham T J et associated with the of for and cross-match renal transplant Transplant. 2007; PubMed Scopus Google Scholar). recipients who were Hispanic or non-Hispanic and cross-match underwent the of with with the at the of and the on a of and and a completed by The by the Center for Disease and were to This a of infection, a from the and from the surgical The were as or to the of surgical site of of surgical PubMed Google Scholar). and were to the patient were to of United of Scholar). the robotic group (n = 28) and control group (n = 28) were frequency matched between the groups were using the for variables, with or and the for The outcomes of were and were two and was at p < was by and The of the patients were African American (46.4%) or Hispanic (35.7%), with a mean age of 47.9 ± 10.7 and ± for the robotic and control respectively (p = The control group had a lower average BMI the robotic transplant group ± 5.4 kg/m2 vs. 42.6 ± 7.8 p = the of patients who were obese was comparable between the two groups. The of kidney failure were hypertension, diabetes, or the in the robotic and control group of the 28 patients in groups underwent deceased donor kidney the patients had a The of donor a the graft for two and patients in the robotic and control group (p = There were no significant differences in mean and times and and p control patient an The of patients in groups and with (n = and (n = kidney transplant and control patient transplant (n = 28)Controls (n = time n = mean time n = mean n = mean No. (%)01 No. No. No. No. donor (n = No. donor (n = No. n = mean n = No. n = mean (n = No. (%)2 = body mass index; = SD = standard deviation. Open table in a new tab BMI = body mass index; = SD = standard deviation. In the robotic patient the after transplantation graft patients in the robotic group underwent kidney for as by and an in creatinine > in the of the of the graft in robotic the kidney were In the renal allograft was by and an open procedure a incision for the was in and patients in the robotic and control was in patients in the robotic group = or = and = or = K B et of chronic allograft and of chronic allograft J Transplant. 2007; PubMed Scopus Google Scholar). the patients were with a was in robotic including and in two kidney transplant and control patient transplant (n = 28)Controls (n = graft No. (%)1 were by the technique and was to open procedure by a incision the = = = To convert creatinine (mg/dL) to SI units (umol/L), multiply by No. (%)7 No. (%)1 infections, No. at mean at 6 months mean survival at 6 No. survival at 6 No. for mean 6 mean 6 mean 6 No. (%)01 for transplant n = mean 6 months mean follow-up mean diabetes No. infection, No. (%)2 (7.1)1 No. (%)1 No. (%)1 (3.6)1 No. (%)1 No. (%)1 No. (%)1 No. No. + No. (%)1 No. were by the technique and was to open procedure by a incision the = = = convert creatinine (mg/dL) to SI units (umol/L), multiply by 88.4. Open table in a new tab The creatinine at was higher in the robotic group (p = at 6 months follow-up creatinine were similar (1.5 ± 0.4 vs. 1.6 ± 0.6 mg/dL; p = The control group in eight patients compared to patient in the robotic group p = 0.02). The in the robotic group was a with secondary to eight in were as the of SSIs in the was higher that in the robotic group p = 0.004). with infections were for and the for infection in an patient characteristics (n = No. (%)8 No. (%)8 for No. No. (%)2 as No. (%)7 No. No. (%)7 No. (%)1 = surgical site Open table in a new tab = surgical site The mean follow-up was ± in the robotic group and ± in the control group (p = the follow-up new posttransplant diabetes (n = (n = robotic and n = and (n = robotic and n = Six-month rate and graft (100%) and patient survival (100%) were comparable between the two groups. However, for the transplant (p = and the 6 months following transplant (p = were higher in the robotic group compared to the reported by our et kidney transplantation in a obese J Transplant. 2010; PubMed Scopus Google the minimally robotic approach to kidney transplantation has to obese patients with a high risk of infection and Herein, we present outcomes from the cohort of robotic kidney in obese at SSIs and graft and patient SSIs and was in very of 28 obese patients. The of SSIs in the robotic group was a significant on the rate of SSIs in the control the rate in the control group was with (8Lynch RJ Ranney DN Shijie C Lee DS Samala N Englesbe MJ Obesity, surgical site infection, and outcome following renal transplantation.Ann Surg. 2009; 250: 1014-1020Crossref PubMed Scopus (190) Google Scholar). Robotic kidney transplant therefore an to dialysis for obese renal failure and may help to reduce health disparities due to ESRD in with a higher prevalence of et obesity to be an independent risk factor for SSIs (8Lynch RJ Ranney DN Shijie C Lee DS Samala N Englesbe MJ Obesity, surgical site infection, and outcome following renal transplantation.Ann Surg. 2009; 250: 1014-1020Crossref PubMed Scopus (190) Google and have to from in obese recipients and to for obese patients > 40 kg/m2) (8Lynch RJ Ranney DN Shijie C Lee DS Samala N Englesbe MJ Obesity, surgical site infection, and outcome following renal transplantation.Ann Surg. 2009; 250: 1014-1020Crossref PubMed Scopus (190) Google obesity is not a to kidney J Surg. PubMed Scopus Google Scholar). The higher of in obese patients has to be to the longer for a incision and a higher prevalence of In our robotic of 28 recipients had a BMI > 40 and had diabetes prior to transplant. of our robotic group are therefore in of and However, we did in the of a with secondary to that minimally invasive, robotic kidney transplantation would reduce the risk of infections was therefore we the of SSIs to the incision in a to access the in open kidney with a incision for of the kidney Obesity is also to S J M et of of for after in the United 2008; PubMed Scopus Google Scholar). et Pham PT Danovitch et and outcome following renal J Transplant. 2006; PubMed Scopus Google Scholar) that BMI impacts and long-term transplant outcomes by the of and the of graft In our was patient with graft in the robotic and the minimally approach for and of these obese patients. recipients in the robotic group had a compared with patients in the control group. and rate were also similar between the two groups. that in the patients not in the due to less months of follow-up from on after a surgery and graft patient with a BMI of kg/m2 developed a median months after transplantation and an of the 39 patients were to the standard open procedure. In to open surgery was by the of severe of developed a that and by secondary any is a very patient and the surgery and posttransplant follow-up be There is that obesity is a risk factor for The by et Pham PT Danovitch et and outcome following renal J Transplant. 2006; PubMed Scopus Google Scholar) a significant independent of obesity with increased and graft In our of 28 robotic and control we of in the robotic and compared with in the control and two patient or graft was in the robotic or control groups follow-up. There are some to with to the new robotic for kidney transplant. we a lower creatinine at in the in the robotic surgery group. The average time was longer in the of obese patients compared to the average for patients at our However, mean time was comparable between the robotic and open and time likely not the higher creatinine in the robotic group. we have to a influence of on the graft as AM Wolfe SM of on renal Surg. PubMed Scopus Google Scholar). However, at 6 months kidney was not from the open group. the of robotic kidney transplantation is the of the which in with the obesity of increases the risk for to standard kidney graft we to kidney graft by with increased in the many of these patients may kidney graft This to kidney graft could to increased on a therefore these patients or outcomes on the data for the or for the increased of the procedure also likely the of the new surgical procedure to However, these centers are often in with minority who could benefit from the procedure. our experience the procedure and with of the and the robotic procedure is in our at all times for and deceased The to the robotic surgery is peripheral disease in the and significant in the graft with a deceased the were higher for the robotic surgical technique compared to the open and outcomes were if not in of for the robotic group and the higher are a of the robotic surgical However, the higher have to be against the of obese renal failure patients on The has some The mean follow-up for the robotic surgery group is However, is in the that creatinine is of long-term graft survival Renal as a of long-term graft survival in renal transplant patients.Nephrol Dial Transplant. 2003; PubMed Google Scholar). The control group was also not to the robotic surgery group. This in a higher BMI in the robotic group compared to as the robotic procedure was and was to all obese patients after and obese patients with ESRD to be However, the same group of and were in all of the in with similar for and in the and and patient after transplant. The of in group did not time the lower of SSIs in the robotic group is likely not due to experience The study was not a such a would be based on the of patients to be to a open technique control group after of procedures were the time and with the robotic the to patients and to group would From a health the could be whether patients lose weight before undergoing transplantation. The success rate of weight has in the T M of vs. for weight A 2009; PubMed Scopus Google and of surgery indicate that months following the of excess weight PA M M A of procedures in gastric and gastric Surg. PubMed Scopus Google Scholar). the significant and mortality on dialysis for patients age (1U.S. Renal Data System. USRDS 2011Annual Data Report: Atlas of Chronic Kidney Disease and End-Stage Renal Disease in the United States.. National Institutes of Health, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD2011Google is that these patients a against the and may not have time to their body weight before kidney transplantation. weight would the pretransplant mortality for patients with a In the of deceased donor pretransplant weight for listed patients or patients with wait time may and is the at our and many with the of our patients with a we an approach that would the kidney and our patients weight and hypertension and diabetes In of that obese patients with no SSIs had the same kidney transplant success rate as patients with a normal BMI (8Lynch RJ Ranney DN Shijie C Lee DS Samala N Englesbe MJ Obesity, surgical site infection, and outcome following renal transplantation.Ann Surg. 2009; 250: 1014-1020Crossref PubMed Scopus (190) Google weight and after robotic transplant may improve follow-up is to long-term graft and patient in the for minimally surgery is based on and robotic in at our to transplantation to a that has to have a of for kidney transplantation compared to patients The robotic technique may also help to reduce health disparities due to ESRD in with a higher prevalence of that the robotic technique is for kidney transplant in obese patients at our the impact robotic surgery may have on wait access to of and There were no of The results were at the American The authors of have no of to as described by the American of