Laparoscopic adjustable gastric banding for massive superobesity ( > 60 body mass index kg/m<Superscript>2</Superscript>)

Surgery for massive super obesity is a formidable challenge. No existing open or laparoscopic procedure reduces BMI below 30 from a starting point above 55. Laparoscopic adjustable gastric banding has been used to treat 76 massive super obese patients with a BMI > 60 kgs/m². Median weight was 193 kgs +/-34.7 kgs (154–335 kgs). Five patients had a BMI > 100 kgs/m². There was neither mortality nor pulmonary emboli. hospital stay was 3 days (1–6 days). Excess weight loss was 46.69 +/-10.5 at 1 year; 59.14 +/- 11.7% at 3 years and 61 +/- 15.1% at 5 years. At 2 years, 84% of the patients had greater than 50% excess weight loss and this was maintained at 3, 4, and 5 years. BMI fell from 69 +/- 6.2 to 49 +/- 7.73 at 1 year to 37 +/- 4.45 at 3 years and this was maintained at 4 and 5 years. BMI in 13 patients with > 5 year follow up was 35.09 +/- 53 kgs/m² (27–44). Weight loss with laparoscopic adjustable gastric banding in this group of massive super obese patients has been similar to all other surgical techniques with reduction of BMI from 69 to 33 kgs/m² at 3 years. The relative safety of the Lapband avoids bowel surgery in these very big patients, suggesting that laparoscopic adjustable gastric banding is a valid surgical approach to these difficult patients.     

Gastric Bypass in the Treatment of Type 2 Diabetes in Patients with a BMI of 30 to 35 kg/m<Superscript>2</Superscript>

Background  

Type 2 diabetes mellitus (T2DM) and class I obesity, which are pandemics of considerable socioeconomic importance, require new treatment modalities due to inadequate control through normal clinical conduct. The aim of the present study was to assess the efficacy and safety of Roux-en-Y gastric bypass (RYGB) in the control of T2DM in patients with a body mass index (BMI) of 30 to 35 kg/m².     

Revisional versus primary Roux-en-Y gastric bypass: a case-matched analysis

Background

Laparoscopic adjustable gastric banding (LAGB) has been a widely performed bariatric procedure. Unfortunately, revisional surgery is required in 20–30 % of cases. Data comparing revisional and primary gastric bypass procedures are scarce. This study compared revisional malabsorptive laparoscopic very very long limb (VVLL) Roux-en-Y gastric bypass (RYGB) with primary VVLL RYGB and tested the hypothesis that one-stage revisional laparoscopic VVLL RYGB is an effective procedure after failed LAGB.

Methods

In this study, 48 revisional VVLL RYGBs were matched one-to-one with 48 primary VVLL RYGBs. The outcome measures were operating time, conversion to open surgery, excess weight loss (EWL), and early and late morbidity.

Results

Surgical and medical morbidities did not differ significantly. No conversions occurred. The revisional group showed an EWL of 41.8 % after 12 months of follow-up evaluation and 45.1 % after 24 months based on the pre-revisional weight. The total EWL based on the weight before the LAGB was calculated to be 54.3 % after 12 months and 57.2 % after 24 months. The EWL in the primary RYGB group was significantly higher for both types of calculation: 41.8 %/54.3 % versus 64.1 % (p < 0.001 and <0.01) after 12 months and 45.1 %/57.2 % versus 70.4 % (p < 0.001 and <0.002) after 24 months.

Conclusions

Revisional laproscopic VVLL RYGB can be performed as a one-stage procedure by experienced bariatric surgeons but shows less effective EWL than primary RYGB procedures.     

Effect of Laparoscopic Mini-Gastric Bypass for Type 2 Diabetes Mellitus: Comparison of BMI >35 and <35 kg/m<Superscript>2</Superscript>

Background Laparoscopic gastric bypass resulted in significant weight loss and resolution of type 2 diabetes mellitus (T2DM). The current indication for bariatric surgery is mainly applied for patients with body mass index (BMI) >35 kg/m² with comorbidity status. However, little is known concerning T2DM patients with BMI <35 kg/m². Recent studies have suggested that T2DM patients with BMI <35 kg/m² might benefit from gastric bypass surgery. Methods From Jan 2002 to Dec 2006, 820 patients who underwent laparoscopic mini-gastric bypass were enrolled in a surgically supervised weight loss program. We identified 201 (24.5%) patients who had impaired fasting glucose or T2DM. All the clinical data were prospectively collected and stored. Patients with BMI <35 kg/m² were compared with those of BMI >35 kg/m². Successful treatment of T2DM was defined by HbA1C <7.0%, LDL <100 mg/dl, and triglyceride <150 mg/dl. Results Among the 201 patients, 44 (21.9%) had BMI <35 kg/m², and 114 (56.7%) had BMI between 35and 45, 43 (21.4%) had BMI >45 kg/m². Patients with BMI <35 kg/m² are significantly older, female predominant, had lower liver enzyme and C-peptide levels than those with BMI >35 kg/m². The mean total weight loss for the population was 32.1, 33.4, 31.9, and 32.8% (at 1, 2, 3, 5 years after surgery), and percentage to change in BMI was 31.9, 34.2, 32.2, and 29.5% at 1, 2, 3, and 5 years. One year after surgery, fasting plasma glucose returned to normal in 89.5% of BMI <35 kg/m² T2DM and 98.5% of BMI >35 kg/m² patients (p = 0.087). The treatment goal of T2DM (HbA1C <7.0%, LDL <150 mg/dl and triglyceride <150 mg/dl) was met in 76.5% of BMI <35 kg/m² and 92.4% of BMI >350 kg/m² (p = 0.059). Conclusion Laparoscopic gastric bypass resulted in significant and sustained weight loss with successful treatment of T2DM up to 87.1%. Despite a slightly lower response rate of T2DM treatment, patients with BMI <35 still had an acceptable DM resolution, and this treatment option can be offered to this group of patients.     

Pre-resection gastric bypass reduces post-resection body mass index but not liver disease in short bowel syndrome

Background

Obese patients developing short bowel syndrome (SBS) maintain a higher body mass index (BMI) and have increased risk of hepatobiliary complications. Our aim was to determine the effect of pre-resection gastric bypass (GBP) on SBS outcome.

Methods

We reviewed 136 adults with SBS: 69 patients with initial BMI < 35 were controls; 43 patients with BMI > 35 were the obese group; and 24 patients had undergone GBP before SBS.

Results

BMI at 1, 2, and 5 years was similar in control and GBP groups, whereas obese patients had a persistently increased BMI. Eight (33%) of the GBP patients had a pre-resection BMI > 35, but post-SBS BMI was similar to those <35. Obese patients were more likely to wean off PN (47% vs 20% control and 12% GBP, P < .05). Radiographic fatty liver tended to be higher in the GBP group (54% vs 19% control and 35% obese). End-stage liver disease occurred more frequently in obese and GBP patients (30% and 33% vs 13%, P < .05).

Conclusions

Pre-resection GBP prevents the nutritional benefits of obesity but does not eliminate the increased risk of hepatobiliary disease in obese SBS patients. This occurs independent of pre-SBS BMI suggesting the importance of GBP itself or history of obesity rather than weight loss.     

Preoperative Factors Predicting Remission of Type 2 Diabetes Mellitus After Roux-en-Y Gastric Bypass Surgery for Obesity

Background  

Roux-en-Y gastric bypass (RYGB) is an effective treatment for morbid obesity. This bariatric procedure has also been noted to resolve hyperglycaemia in up to 70% of obese diabetics. We evaluated outcomes in diabetic patients undergoing RYGB in our institution, aiming to identify factors predicting diabetes remission.     

SLEEVEPASS: A randomized prospective multicenter study comparing laparoscopic sleeve gastrectomy and gastric bypass in the treatment of morbid obesity: preliminary results

Background

The long-term efficacy of laparoscopic Roux-en-Y gastric bypass (RYGB) in the treatment of morbid obesity has been demonstrated. Laparoscopic sleeve gastrectomy (SG) as a single procedure has shown promising short-term results, but the long-term efficacy of SG has not yet been demonstrated. The aim of this study was to determine the preliminary 30-day morbidity and mortality of RYGB and SG in a prospective multicenter randomized setting.

Methods

A total of 240 morbidly obese (BMI?=?35–66?kg/m2) patients evaluated by a multidisciplinary team were randomized to undergo either RYGB or SG. There were 117 patients in the RYGB group and 121 in the SG group; two patients had to be excluded after randomization. Both study groups were comparable regarding age, gender, BMI, and comorbidities.

Results

There was no 30-day mortality. The median operating time was significantly shorter in the SG group (66?min vs. 94?min, p?p?=?0.292). Nine (7.4 %) SG patients and 20 (17.1 %) RYGB patients had minor complications (p?=?0.023). The overall morbidity was 13.2 % after SG and 26.5 % after RYGB (p?=?0.010). There were three (2.5 %) early reoperations after SG and four (3.3 %) after RYGB (p?=?0.719).

Conclusions

At 30-day analysis SG is associated with a shorter operating time and fewer early minor complications compared to RYGB. There were no significant differences in major complications or early reoperations. Long-term follow-up is required to determine the effect on weight loss, resolution of obesity-related comorbidities, and improvement of quality of life.     

Revisional bariatric surgery at a single institution

Background

Bariatric surgery, although safe, can have long-term complications that require revision. Our series illustrates the spectrum of primary procedures, indications for surgery, and strategies for revision.

Methods

The study was a retrospective chart review. Sixty-three patients were identified. Of specific interest were complications and percentage of excess weight loss (EWL) during the follow-up period.

Results

Eighteen patients had a previous vertical banded gastroplasty (VBG), 26 had a Roux-en-Y gastric bypass (RYGB), 18 had a laparoscopic adjustable gastric banding (LAGB), and 1 had a jejunal-ileal bypass. All VBG patients were revised to RYGB. Seventeen RYGB patients were revised with RYGB. Eight LAGB patients were revised with RYGB. Eight RYGB patients had placement of LAGB. Two LAGB patients were revised with LAGB because of a slipped band. Eight LAGB patients had the band removed. The morbidity rate was 30% with a major morbidity rate of 11%. There were 2 leaks, neither required reoperation. Other major complications included 3 pneumonias, 2 reoperations, and 2 intra-abdominal abscesses. There were no mortalities. In the 15 patients who had conversion of VBG to RYGB, the mean EWL was 50%, with 60% of patients achieving more than 50% EWL. In the 10 patients who had revision of their RYGB, the mean EWL was 51%, with 60% of patients achieving more than 50%. In the 6 patients who had revision of LAGB to RYGB, the mean EWL was 39%, with 33% of patients achieving more than 50% EWL. In the 8 patients who had LAGB after RYGB the mean EWL was −2%, with 0% of patients achieving more than 50%.

Conclusions

Revisional surgery is effective, although complication rates are higher than primary bariatric surgery. The type of initial and revisional procedure affects EWL.     

Outcome of laparoscopic ventral hernia repair in morbidly obese patients with a body mass index exceeding 35 kg/m<Superscript>2</Superscript>

Background Laparoscopic ventral hernia repair (LVHR) for morbidly obese patients with a body mass index (BMI) exceeding 35 kg/m² has not been well investigated. Methods Hernia recurrence was evaluated by surveillance computed tomography. A p value less than 0.05 was considered significant. Results Between 2003 and 2006, LVHR was attempted for 27 patients with a BMI exceeding 35 kg/m². There was one conversion to open surgery (3.7%). The 27 patients included 8 men (29.6%) and 19 women (70.4%) with a mean age of 48 years (range, 33–73 years). The mean BMI was 46.9 kg/m² (range, 35–70 kg/m²). Nine patients (33%) were superobese (BMI > 50 kg/m²), and five patients (22.7%) underwent emergency LVHR because of small bowel obstruction. Concomitant LVHR with laparoscopic gastric bypass (LGB) was performed for 13 patients (48%). Primary, incisional, or recurrent incisional ventral hernia was present in 7 (26%), 15 (55%), and 5 (19%) patients, respectively. A large hernia (>50 cm²) was found in 20 patients (74%). The mesh used was porcine submucosal small intestine extracellular matrix for 15 patients (57%), Gore-Tex for 9 patients (35%), and Composix for 2 patients (8%). The mean hernia size was 158 cm² (range, 12–806 cm²), and the mean mesh size was 374 cm² (range, 117–2,400 cm²). The mean operative time was 190 min (range, 80–480 min), and the mean hospital length of stay (LOS) was 3.6 days (range, 1–11 days). Minor or major complications occurred in seven patients (25.9%), and five patients (18.5%) experienced recurrence during a mean follow-up period of 14.9 months (range, 3–32 months). Emergency setting, BMI, concomitant LGB, hernia type, hernia size, and mesh type had no statistically significant effect on operative time, LOS, morbidity, or recurrence rates. Conclusions For morbidly obese patients, LVHR is safe and effective, but it is associated with higher likelihood of recurrence, and patients should be appropriately informed. Presented at the 10th World Congress of Endoscopic Surgery Meeting, Berlin, Germany, September 2006     

Predictors of Weight Loss and Effectiveness of Roux-en-Y Gastric Bypass in the Morbidly Obese Hispano-American Population

Background  Co-morbidities and the metabolic response to intervention in morbid obesity have been reported to vary among different ethnic groups. We compared the rate of weight loss, effectiveness of gastric bypass surgery, and variables influencing success after gastric bypass in Hispanics compared to Caucasians. Methods  Morbidly obese adult (>18 years old) patients (body mass index [BMI] 40 or above) evaluated by our bariatric group from 2005 to 2006 who underwent Roux-en-Y gastric bypass (RYGBP) were studied. Every patient was evaluated for height, weight, BMI, percent body fat, fat mass, serum metabolic analysis (SMA) 12, lipid profile, complete blood count (CBC), iron, ferritin, Vitamins A, D, and B1, complete urinalysis and Fibrospect score II. Weight loss was evaluated at 1, 3, 6, and 12 months. Results  Seventy-five patients underwent successful open RYGBP with no mortality. Regardless of the significant difference in age and co-morbidities, the mean percentage of total weight loss after 1 year of follow-up was 32% for Hispanics and 30% for Caucasians with no significant difference (p > .5). When comparing the percentage of excess weight lost (% EWL) at 1, 3, 6, and 12 months, there was no significant difference between both groups. Using multiple regression analysis, we found that high-density lipoprotein (HDL) and systolic blood pressure (SBP) significantly predicted EWL at 12 months in Caucasians and Fibrospect predicted significantly EWL at 1 year. Conclusion  At 1 year after RYGBP, both ethnic groups lost ∼77–80% of their EWL and BMI. All Caucasians and 95.7% of Hispanics achieved successful weight loss (>50% EWL).     

Re-examining the BMI Threshold for Bariatric Surgery in the USA

Background

The optimal BMI threshold above which gastric bypass surgery should be offered to obese patients is controversial. The objective of this study was to compare the impact of Roux-en-Y gastric bypass (RYGB) vs. diet and exercise (D&E) on life expectancy to find the BMI at which patients experience an improvement in their life expectancy by undergoing surgery.

Methods

A Markov state transition model was designed to implement a decision tree that simulated the lives of obese patients. Life expectancies following RYGB and 2 years of D&E were estimated and compared. Ten thousand patients’ lives were simulated in each weight-loss intervention group in the model. In addition to base case analysis (45 kg/m² BMI pre-intervention), sensitivity analysis of initial BMI at the start of the study was completed. Markov model parameters were extracted from the literature.

Results

The impact of RYGB on survival relative to D&E depended on the patient’s initial BMI. Compared to patients who underwent 2 years of “optimal” diet and exercise (7 % total body weight loss/year), RYGB improved long-term survival for patients above a BMI of 31.3 kg/m².

Conclusions

Roux-en-Y gastric bypass can improve long-term survival for patients with class I obesity. This study suggests that RYGB should not be reserved solely for patients with class II or III obesity.     

Predictive factors of excess body weight loss 1?year after laparoscopic bariatric surgery

Background

Bariatric surgery (BS) is widely accepted for the treatment of patients with morbid obesity (MO). We aimed to determine presurgical predictors of and surgical technique-related differences in excess weight loss (EWL) 1?year after BS.

Methods

This retrospective study included 407 subjects (F/M 3:1, median age?=?44?years) who underwent laparoscopic Roux-en-Y gastric bypass (RYGB, n?=?307) or sleeve gastrectomy (SG, n?=?100) at our University Hospital and were evaluated 1?year after surgery.

Results

Baseline median (min–max) body mass index (BMI) was 47?kg/m² (range?=?36–71). BMI was higher in the SG than in the RYGB group (53 vs. 46?kg/m², p?p?p?=?0.2), was lower in diabetic than in nondiabetic subjects (71?±?17% vs. 79?±?17%, p?p?p?=?0.4) after taking into account baseline BMI. Multiple regression and logistic analysis showed that younger individuals with lower BMI but higher WC, and lower HbA1c and TG, had higher EWL and a higher rate of successful (EWL?≥?60%) weight loss.

Conclusions

Our data indicate that some of the characteristics that would have subjects referred early for BS were associated with higher weight loss. Therefore, the timing of laparoscopic BS might be an important factor for MO individuals in which medical weight loss intervention has failed.     

Laparoscopic gastric bypass for the treatment of type 2 diabetes: a comparison of Roux-en-Y versus single anastomosis gastric bypass

Background

In recent years, gastric bypass surgery has been found to have therapeutic potential for the treatment of type 2 diabetes (T2D). However, the difference between 2 bypass procedures, Roux-en-Y gastric bypass (RYGB) and another single anastomosis gastric bypass (SAGB), is not clear.

Portion Control Eating—a Determinant of Bariatric Outcomes

Introduction

Bariatric surgery leads to significant weight loss but the results vary. Application of dietary principles like portion-controlled eating leads to greater weight loss and fewer complications.

Aims

To evaluate the improvement in weight loss outcomes by incorporating portion-controlled eating behavior in postbariatric patients.

Methods

All patients who underwent bariatric surgery from January 2012 to December 2013 were included in the study. Portion-controlled eating behavior was incorporated in the post-bariatric nutritional protocol. Their demographic, preoperative, and postoperative data were prospectively maintained on Microsoft Office Excel and analyzed statistically.

Results

Three hundred and seventy-two (89.6%) underwent laparoscopic sleeve gastrectomy (LSG), while 43 (10.4%) underwent laparoscopic Roux-en-Y gastric bypass (RYGB). In the LSG group, lowest (nadir) BMI was 28.99?±?5.6 kg/m² and % Excess weight loss (EWL) was 87.3?±?27.2%, achieved between 1 and 2 years. In the RYGB group, lowest (nadir) BMI was 27.5?±?12.09 kg/m and % EWL was 94.32?±?33.12%. Surgical failure (less than 50% EWL) were 10 (3.27%) in the LSG group and 1 (3%) in the RYGB group. There were no leaks reported in our study.

Conclusion

Our study highlights the importance of postoperative nutritional interventions like portion-controlled eating for successful bariatric outcome.

     

Roux‐en‐Y gastric bypass is an effective bridge to kidney transplantation: Results from a single center

Body mass index (BMI) > 35‐40 kg/m² is often a contraindication, while Roux‐en‐Y gastric bypass (RYGB) is performed to enable kidney transplantation. This single‐center retrospective study evaluated pre‐ and post‐transplant outcomes of 31 morbidly obese patients with end‐stage renal disease having RYGB before kidney transplantation between July 2009 and June 2014. Fourteen RYGB patients were subsequently transplanted. Nineteen recipients not having GB with a BMI ≥ 36 kg/m² at transplantation were used as historical controls. Mean BMI (±SE) before RYGB was 43.5 ± 0.7 kg/m² (range: 35.4‐50.5 kg/m²); 87.1% (27/31) achieved a BMI < 35 kg/m². The percentage having improved diabetes/hypertension control was 29.0% (9/31); 25.8% (8/31) had complications (mostly minor) after RYGB. Among transplanted patients, blacks/Hispanics comprised 78.6% (11/14) and 84.2% (16/19) of RYGB and controls; 57.1% (8/14) and 63.2% (12/19) had a (mostly long‐standing) pretransplant history of diabetes. While biopsy‐proven acute rejection (BPAR) occurred significantly higher among RYGB vs control patients (6/14 vs 3/19, P = .03), patients developing T‐cell BPAR were also significantly more likely to have a tacrolimus (TAC) trough level < 4.0 ng/mL within 3 weeks of T‐cell BPAR (P = .0007). In Cox's model, the impact of having a TAC level < 4.0 ng/mg remained significant (P = .007) while the effect of RYGB was no longer significant (P = .13). Infections, graft, and patient survival were not significantly different. Despite obvious effectiveness in achieving weight loss, RYGB will need more careful post‐transplant monitoring given the observed higher BPAR rate.     

Loop Duodenojejunal Bypass with Sleeve Gastrectomy: Comparative Study with Roux-en-Y Gastric Bypass in Type 2 Diabetic Patients with a BMI &lt;35 kg/m<Superscript>2</Superscript>, First Year Results

Background

Roux-en-Y gastric bypass (RYGB) has shown good diabetes remission in obese patients with type 2 diabetes mellitus (T2DM), but long-term complications were observed. We developed loop duodenojejunal bypass with sleeve gastrectomy (LDJB-SG) to achieve diabetes remission and avoid the drawbacks of RYGB. We compare 1-year results between LDJB-SG and RYGB with body mass index (BMI) <35 kg/m² of T2DM patients.

Methods

We conducted a case-matched study of BMI?<?35 kg/m² T2DM patients who underwent RYGB and LDJB-SG matching on age, BMI, and duration of diabetes. The 1-year surgical results were compared.

Results

Sixty patients were included from March 2010 to August 2012. Thirty patients underwent RYGB and 30 underwent LDJB-SG. The operative time (mean?±?SD) and length of stay (median [IQR]) were significantly longer in the LDJB-SG group than in the RYGB group (127.0?±?40.2 vs. 105.0?±?64.7 min and 3[3, 4] vs. 3[2, 3] days, respectively). There were no statistical differences between the groups in the mean BMI, fasting plasma glucose, and %HbA1c either at baseline or at 1 year. However, these parameters dropped significantly from the preoperative values (p?<?0.01). The level of HOMA-%B at 1 year was significantly higher in the LDJB-SG group than in the RYGB group (p?=?0.004). The resolution of comorbidities was similar. Late complications seemed higher in the RYGB group (12 vs. 5, p?=?0.08). There were no deaths, but two patients in each group required reoperation.

Conclusions

LDJB-SG was comparable to RYGB in terms of weight loss, glycemic control, and comorbidity resolution in BMI <35 kg/m² T2DM patients in the short-term.

     

Gastric band conversion to Roux-en-Y gastric bypass shows greater weight loss than conversion to sleeve gastrectomy: 5-year outcomes

Background

Roux-en-Y gastric bypass (RYGB) and laparoscopic sleeve gastrectomy (LSG) are often used as revisional surgeries for a failed laparoscopic adjustable gastric band (LAGB). There is debate over which procedure provides better long-term weight loss.

Effectiveness of the Transoral Endoscopic Vertical Gastroplasty (TOGa?): a Good Balance Between Weight Loss and Complications, if Compared with Gastric Bypass and Biliopancreatic Diversion

Background

The effectiveness of restrictive procedures has been inferior to that of malabsorbitive ones. Recent variants of restrictive procedures, i.e., gastric banding and sleeve gastrectomy, confirm the strive for more efficacious solutions with less complications. We investigated the balance between effectiveness and complications for a new restrictive procedure, a Transoral Endoscopic Vertical Gastroplasty (TOGa?)

Methods

Seventy-nine morbidly obese patients were submitted to one out of three surgical procedures: TOGa? (29 patients), laparoscopic gastric bypass (LRYGBP; 20 patients), and biliopancreatic diversion (BPD; 30 patients). Mean BMI were 41.7 (35.4?C46.6), 44.8 (36.4?C54), and 47.5 (41?C60.3), respectively. All the patients reached a 2-year follow-up.

Results

In TOGa? group BMI, respectively at 12 and 24?months, was 34.5 and 35.5, with 44 and 48.3?% of patients with BMI lower than 35. In LRYGBP group, BMI was 30.7 and 29.2?kg/m², with 80 and 85?% of patients with BMI?<?35. In BPD group, BMI was 30 and 29.6?kg/m², with 100 and 93.3?% of patients with BMI?<?35. In TOGa? group, 59?% of patients with an initial BMI?<?45 reached a BMI?<?35, in comparison to 48?% recorded in the whole group and to 14.3?% in patients with initial BMI????45.

Conclusions

In selected patients, TOGa?, was associated with good results after two years in terms of weight loss, even in comparison with LRYGBP and BPD. Minimal trauma, absence of complications, and short hospital stay justify this procedure for patients with low BMI.     

Comparative effectiveness of bariatric procedures among adolescents: the PCORnet bariatric study

Background

Bariatric surgery has been used for treatment of severe obesity in adolescents but most studies have been small and limited in follow-up.