Mitochondrial Common Deletion Level in Adipose Tissue Is Not Associated with Obesity but Is Associated with a Structural Change in Triglycerides as Revealed by FTIR Spectroscopy.

OBJECTIVE: Several studies have shown that mitochondrial metabolism may be disrupted if the rate of the specific 4,977 bp deletion of mitochondrial DNA (mtDNA) reaches a threshold. This study aimed to investigate the possible associations between the mtDNA4977 deletion load and obesity-related metabolic abnormalities in the adipose tissue. METHODS: The study included thirty obese individuals, who underwent bariatric surgery, and twelve control subjects. mtDNA4977 deletion, adenine nucleotides, and lactate levels, which show the bioenergetic status were evaluated in visceral adipose tissues. Fourier transform infrared (FTIR) spectroscopy was used to investigate the structural variations and composition of adipose tissues in the context of deletion load. RESULTS: There were no differences between the two groups in terms of mtDNA4977 deletion, adenine nucleotides, and lactate levels. The FTIR spectra indicated a few obesity-related alterations in adipose tissues that were not related to the mtDNA deletion load. Also, statistical analysis showed a correlation between the deletion load and a band shift of 1,744 cm-1, which assigns C = O stretching of the carbonyl group of the ester group in triglycerides and other esterified fatty acids, although it is not associated with obesity. CONCLUSIONS: Our data suggest that the mtDNA4977 deletion in visceral adipose tissues of obese individuals do not have a significant impact on the bioenergetic status. However, the increased accumulation of deletion may be associated with a specific change in the ester bond, indicating structural differences in the lipids. These findings shed light on our understanding of the tissue-specific distribution of mtDNA deletions and obesity-related adipose tissue pathogeneses.

Sleeve gastrectomy with transit bipartition in a series of 883 patients with mild obesity: early effectiveness and safety outcomes.

BACKGROUND: At least 25 metabolic/bariatric procedures have been proposed globally, 5 formally endorsed. A newer procedure, sleeve gastrectomy with transit bipartition (SG + TB), appears to markedly reduce weight and improve metabolic syndrome while being relatively simple technically and protective of long-term nutritional stability. We aimed to investigate SG + TB effectiveness and safety. METHODS: In a single-center retrospective analysis of prospectively collected data, SG + TB patients were followed through 12 months. Primary outcomes were changes in weight [body mass index (BMI), total weight loss (TWL)], metabolic parameters [HbA1C, LDL cholesterol, triglycerides (TG), hypertension], and nutritional status. Repeated-measures analysis of variance (ANOVA) was used to assess changes in weight and metabolic parameters at 1, 3, 6, 9, and 12 months after surgery. RESULTS: Between 2015 and 2019, 883 patients (mean age 51.8 yrs, BMI 34.1 ± 5.0 kg/m2) underwent SG + TB. Mean operative time was 124 ± 25.4 min; hospitalization, 4.0 ± 2.5 days. ANOVA indicated significant reductions in weight and metabolic parameters (p < 0.005). In 646 patients with complete weight data at 12 months, mean BMI was reduced to 27.2 ± 3.4 kg/m2 (p < 0.001), TWL 19.8 ± 6.0%. HbA1C was normalized in 83.3% of SG + TB patients; hyperlipidemia, hypertension, and hypertriglyceridemia were significantly reduced (p < 0.001). Also, there was a significant reduction in the proportion of patients outside normal nutritional reference ranges. The overall complication rate was 10.2%. There was no mortality. CONCLUSION: In a series of 833 lower-BMI patients who underwent SG + TB and were followed through 12 months (73.2% follow-up), significant weight loss, comorbidity reduction, and nutritional stability were attained with few major complications and no mortality.

Original contribution: sleeve gastrectomy reduces soluble lectin-like oxidized low-density lipoprotein receptor-1 (sLOX-1) levels in patients with morbid obesity.

BACKGROUND: Early diagnosis of subclinical cardiovascular disease (CVD) in patients with morbid obesity is important. We investigated the effects of sleeve gastrectomy (SG) on serum soluble lectin-like oxidized low-density lipoprotein receptor-1 (sLOX-1), oxidized LDL (oxLDL), and other metabolic and inflammatory parameters associated with atherosclerosis in patients with morbid obesity. METHODS: Body mass index (BMI) measurements and assays of metabolic and inflammatory markers were taken in patients in an SG surgery group and a healthy control group and compared at baseline and 12 months after SG. Correlations with changes in these parameters and variations in sLOX-1 were analyzed. RESULTS: Metabolic and inflammatory marker values in the surgery (n = 20) and control (n = 20) groups were significantly different at baseline (p < 0.001). The majority of surgery group biomarker levels significantly decreased with mean BMI loss (- 11.8 ± 9.0, p < 0.001) at 12 months, trending toward control group values. Baseline albumin level as well as percentage reductions in oxLDL and the cholesterol retention fraction (CRF) were found to be significantly correlated with percentage reduction in sLOX-1 at 12 months following SG. CONCLUSION: Metabolic and inflammatory biomarkers elevated at baseline significantly decreased after SG weight loss. Weight loss induced by SG may limit endothelial damage by reducing levels of oxLDL and LOX-1 as assessed by sLOX-1. These findings suggest that sLOX-1 may function as a marker of atherosclerotic disease states in patients with morbid obesity and that metabolic/bariatric surgery can play a meaningful role in CVD prevention.

The Relationship between Bariatric Food Pyramid and Long-Term Anthropometric Measurements of Patients Undergoing Bariatric Surgery.

The bariatric food pyramid is a standard for long-term healthy living and nutritional habits of patients who have undergone bariatric surgery, taking their gastric capacity and special nutritional requirements into account. This study aimed to evaluate how the compliance with the pyramid affects the anthropometric change in patients who have undergone bariatric surgery, depending on the period after surgery. 81 patients who have undergone bariatric surgery between August 2016 and September 2018 participated in the study. The patients were evaluated in the postoperative period and were divided into three groups according to the year they had the operation. Food consumption frequency information was obtained from the patients, and the amount of food consumed per day was recorded in grams. Protein, vegetable, fruit, grain, and oil consumption was calculated according to the pyramid and calculated as portions. A statistically significant difference was found for all three groups in terms of weight loss and body mass index (BMI) changes before and after surgery (p < 0.001, p < 0.001, respectively). It was observed that the amount of protein consumed by the patients was sufficient, cereal was high, and fruit was insufficient. Patients who consumed foods that were not recommended slowed in weight loss. In conclusion, it is estimated that increased consumption of grains and nonrecommended foods may cause weight gains. In order to prevent this, it is necessary to ensure that patients are fed in accordance with the pyramid and followed for many years.

The utility of intraoperative ultrasound in modified radical neck dissection: a pilot study.

BACKGROUND: Although the value of surgeon-performed neck ultrasound (SPUS) for thyroid nodules has been validated, the utility of intraoperative ultrasound (US) in modified radical neck dissection (MRND) has not been reported in the literature. The aim of this study was to analyze the utility of intraoperative SPUS in assessing the completeness of MRND for thyroid cancer. METHODS: Between 2007 and 2011, a total of 25 patients underwent MRND by 1 surgeon for thyroid cancer. All patients underwent intraoperative SPUS, which was repeated at the end of the neck dissection (completion US) to look for missed lymph nodes (LNs). RESULTS: There were 10 male and 15 female patients. Pathology included 23 papillary and 2 medullary carcinomas. The number of LNs removed per case was 23 ± 2, and the number of positive was LNs 5 ± 1. In 4 (16%) cases, intraoperative US detected 7 residual LNs, which would have been missed, if completion US were not done. These missed LNs were located in low-level IV (3 nodes), high-level II (2 nodes), and posterior level V (2 nodes) and measured 1.4 ± 0.2 cm. At follow-up, recurrence was seen in 2 (8%) patients, including a superior mediastinal recurrence in a patient with tall cell cancer and a jugular LN recurrence at level II in another patient with papillary thyroid cancer. CONCLUSION: This pilot study shows that intraoperative SPUS can help assess the completeness of MRND. According to our results, intraoperative completion US identifies LNs missed by palpation 16% of the time.

Revision/Conversion Surgeries After One Anastomosis Gastric Bypass-An Experts' Modified Delphi Consensus.

PURPOSE: There is a lack of evidence for treatment of some conditions including complication management, suboptimal initial weight loss, recurrent weight gain, or worsening of a significant obesity complication after one anastomosis gastric bypass (OAGB). This study was designed to respond to the existing lack of agreement and to provide a valuable resource for clinicians by employing an expert-modified Delphi consensus method. METHODS: Forty-eight recognized bariatric surgeons from 28 countries participated in the modified Delphi consensus to vote on 64 statements in two rounds. An agreement/disagreement among ≥ 70.0% of the experts was regarded to indicate a consensus. RESULTS: A consensus was achieved for 46 statements. For recurrent weight gain or worsening of a significant obesity complication after OAGB, more than 85% of experts reached a consensus that elongation of the biliopancreatic limb (BPL) is an acceptable option and the total bowel length measurement is mandatory during BPL elongation to preserve at least 300-400 cm of common channel limb length to avoid nutritional deficiencies. Also, more than 85% of experts reached a consensus on conversion to Roux-en-Y gastric bypass (RYGB) with or without pouch downsizing as an acceptable option for the treatment of persistent bile reflux after OAGB and recommend detecting and repairing any size of hiatal hernia during conversion to RYGB. CONCLUSION: While the experts reached a consensus on several aspects regarding revision/conversion surgeries after OAGB, there are still lingering areas of disagreement. This highlights the importance of conducting further studies in the future to address these unresolved issues.

Robotic versus laparoscopic adrenalectomy in obese patients.

BACKGROUND: Recently, we demonstrated better perioperative outcomes with robotic versus laparoscopic adrenalectomy (LA) with the posterior retroperitoneal approach in general, and for removal of large adrenal tumors. It is unknown if robotic adrenalectomy (RA) is equivalent to LA in obese patients. The aim of this study is to compare perioperative outcomes of RA versus LA in obese patients. METHODS: Between 2003 and 2012, 99 obese (BMI ≥ 30 kg/m(2)) patients underwent adrenalectomy at a tertiary academic center. Of these, 42 patients had RA and 57 had LA. The perioperative outcomes of these patients were compared between the RA and LA groups. Data were collected from a prospectively maintained, institutional review board approved database. Clinical and perioperative parameters were analyzed using Student t and χ(2) tests. All data are expressed as mean ± standard error of the mean. RESULTS: The groups were similar in terms of age, gender, and tumor side. Body mass index was lower in the robotic versus laparoscopic group (35.4 ± 1.0 vs. 38.8 ± 0.8 kg/m(2), respectively, p = 0.01). Tumor size (4.0 ± 0.4 vs. 4.3 ± 0.3 cm, respectively, p = 0.56), skin-to-skin operative time (186.1 ± 12.1 vs. 187.3 ± 11 min, respectively, p = 0.94), estimated blood loss (50.3 ± 24.3 vs. 76.6 ± 21.3 ml, respectively, p = 0.42), and hospital stay (1.3 ± 0.1 vs. 1.6 ± 0.1 days, respectively, p = 0.06) were similar in both groups. The conversion to open rate was zero in the robotic and 5.2 % in the laparoscopic group (p = 0.06). The 30-day morbidity was 4.8 % in the robotic and 7 % in the laparoscopic group (p = 0.63). CONCLUSIONS: Our study did not show any difference in perioperative outcomes between RA and LA in obese patients. These results suggest that the difficulties in maintaining exposure and dissection in obese patients nullify the advantages of robotic articulating versus rigid laparoscopic instruments in adrenal surgery.

Laparoscopic versus open resection of colorectal liver metastasis.

BACKGROUND: Findings have shown laparoscopic liver resection (LLR) to be feasible and safe, but the data in the literature regarding oncologic outcomes are scant. This study aimed to compare the perioperative and short-term oncologic outcomes between LLR and open resection of colorectal liver metastasis (CLM). METHODS: Between January 2006 and April 2012, 40 patients underwent LLR of CLM. These patients were compared with a consecutive matched group of 40 patients who underwent open resection within the same period. Data were obtained from a prospective institutional review board (IRB)-approved database. Statistical analysis was performed using t test, Chi-square, and Kaplan-Meier survival. RESULTS: The groups were similar in terms of age, gender, tumor size, number of tumors, and type of resections performed. The operative time was similar in the two groups, but the estimated blood loss was less in the LLR group than in the open resection group. The length of stay was shorter in the LLR group (3.7 vs 6.5 days; p < 0.001). The 2-year overall survival rate was 89 % for LLR and 81 % for open resection. The median disease-free survival time was 23 months in each group. CONCLUSIONS: The findings suggest that LLR is associated with less blood loss and a shorter hospital stay than open resection for CLM. According to our short-term results, LLR is equivalent to open resection in terms of oncologic outcomes.

Robotic endocrine surgery: state of the art.

Over the last decade, developments in technology have led a rapid progress in robotic endocrine surgery applications. Robotics is attractive to the surgeon because of the three-dimensional image quality, articulating instruments, and stable surgical platform. Safety and effectiveness of robotic adrenalectomy and thyroidectomy have been shown in many studies. While these robotic procedures offer better ergonomics for the surgeon, they provide similar outcomes compared to the laparoscopic approach for adrenalectomy and better cosmetic results versus the conventional option for thyroidectomy. Recently, while the robotic approach for adrenalectomy has been popularized, enthusiasm for robotic thyroidectomy has decreased. In the present review we aim to describe emerging robotic procedures and review the literature regarding outcomes.

A comparison of laparoscopic radiofrequency ablation versus systemic therapy alone in the treatment of breast cancer metastasis to the liver.

OBJECTIVES: There is controversy about the roles of locoregional therapies in patients with liver metastases from breast cancer (LMBC). The aim of this study was to analyse survival after laparoscopic radiofrequency ablation (RFA) of LMBC and to compare this with survival in patients receiving systemic therapy (ST) alone. METHODS: During 1996-2011, 24 patients who had failed to respond or had shown an incomplete response to ST underwent laparoscopic RFA for LMBC. Outcomes in these patients were compared with those in 32 patients with LMBC matched by tumour size and number, but treated with ST alone. Clinical parameters and overall survival were compared using t-tests, chi-squared tests and Kaplan-Meier analysis. RESULTS: The groups were similar in hormone receptor status and chemotherapy exposure. In the laparoscopic RFA and ST groups, respectively, the mean ± standard deviation size of the dominant liver tumour and the number of tumours per patient were 3.7 ± 0.4 cm and 2.4 ± 0.4 cm, and 2.6 ± 0.4 tumours and 3.3 ± 0.4 tumours, respectively. These differences were not significant. At a median follow-up of 20 months in the laparoscopic RFA group, 42% of patients were found to have developed local liver recurrence, 63% had developed new liver disease and 38% had developed extrahepatic disease. Overall survival after the diagnosis of liver metastasis was 47 months in the laparoscopic RFA group and 9 months in the ST-only group (P = 0.0001). Five-year survival after the diagnosis of liver metastasis was 29% in the RFA group and 0% in the ST-only group. CONCLUSIONS: This is the first study to compare outcomes in RFA and ST, respectively, in LMBC. The results show that survival after laparoscopic RFA plus ST is better than that after ST alone.

Using saline bags instead of commercial retrieval bags to reduce the cost of splenic retrieval after laparoscopic splenectomy.

BACKGROUND: Laparoscopic splenectomy (LS) is considered the gold standard treatment in adults with idiopathic thrombocytopenic purpura (ITP) refractory to medical therapy. However, the retrieval of the spleen in LS is still a technical challenge, despite the use of various commercial retrieval bags. This study reports the feasibility and reliability of using a saline bag for spleen retrieval in a reduced port splenectomy. METHODS: Between 2007 and 2020, 55 consecutive patients underwent LS for ITP. Data were collected retrospectively. To retrieve the spleen, a 1 liter sterile saline bag was used. RESULTS: Fifty-five patients underwent LS. There was only one complication related to the saline bag: an iatrogenic ileal injury during the morselization process. CONCLUSION: One-liter saline bag is feasible, and widely available. No additional instruments or cost is required and there is no need to extend the wound for spleen retrieval during LS. KEY WORDS: Idiopathic thrombocytopenic purpura, Laparoscopic surgery, Splenectomy, Techniques.

Bariatric Evaluation Through AI: a Survey of Expert Opinions Versus ChatGPT-4 (BETA-SEOV).

BACKGROUND: Recent advancements in artificial intelligence, such as OpenAI's ChatGPT-4, are revolutionizing various sectors, including healthcare. This study investigates the use of ChatGPT-4 in identifying suitable candidates for bariatric surgery and providing surgical recommendations to improve decision-making in obesity treatment amid the global obesity epidemic. METHODS: We devised ten patient scenarios, thoughtfully encompassing a spectrum that spans from uncomplicated cases to more complex ones. Our objective was to delve into the decision-making process regarding the recommendation of bariatric surgery. From July 29th to August 10th, 2023, we conducted a voluntary online survey involving thirty prominent bariatric surgeons, ensuring that there was no predetermined bias in the selection of a specific type of bariatric surgery. This survey was designed to collect their insights on these scenarios and gain a deeper understanding of their professional experience and background in the field of bariatric surgery. Additionally, we consulted ChatGPT-4 in two separate conversations to evaluate its alignment with expert opinions on bariatric surgery options. RESULTS: In 40% of the scenarios, disparities were identified between the two conversations with ChatGPT-4. It matched expert opinions in 30% of cases. Differences were noted in cases like gastrointestinal metaplasia and gastric adenocarcinoma, but there was alignment with conditions like endometriosis and GERD. CONCLUSION: The evaluation of ChatGPT-4's role in determining bariatric surgery suitability uncovered both potential and shortcomings. Its alignment with experts was inconsistent, and it often overlooked key factors, emphasizing human expertise's value. Its current use requires caution, and further refinement is needed for clinical application.

International survey on complications of religious fasting after metabolic and bariatric surgery.

Religious fasting in Ramadan the 9th month of the lunar year is one of five pillars in Islam and is practiced for a full month every year. There may be risks with fasting in patients with a history of metabolic/bariatric surgery (MBS). There is little published evidence on the possible complications during fasting and needs stronger recommendations and guidance to minimize them. An international survey was sent to surgeons to study the types of complications occurring during religious fasting in patients with history of MBS to evaluate the risk factors to manage and prepare more evidence-based recommendations. In total, 21 centers from 11 countries participated in this survey and reported a total of 132 patients with complications occurring during religious fasting after MBS. The mean age of patients with complications was 36.65 ± 3.48 years and mean BMI was 43.12 ± 6.86 kg/m2. Mean timing of complication occurring during fasting after MBS was 14.18 months. The most common complications were upper GI (gastrointestinal) symptoms including [gastroesophageal reflux disease (GERD), abdominal pain, and dyspepsia], marginal ulcers and dumping syndrome in 24% (32/132), 8.3% (11/132) and 23% (31/132) patients respectively. Surgical management was necessary in 4.5% of patients presenting with complications (6/132) patients due to perforated marginal or peptic ulcer in Single Anastomosis Duodenoileostomy with Sleeve gastrectomy (SADI-S), one anastomosis gastric bypass (OAGB) and sleeve gastrectomy (SG), obstruction at Jejunojenostomy after Roux-en-Y gastric bypass (RYGB) (1/6) and acute cholecystitis (1/6). Patients after MBS should be advised about the risks while fasting including abdominal pain, dehydration, and peptic ulcer disease exacerbation, and a thorough review of their medications is warranted to minimize complications.

Robotic adrenalectomy.

Over the last decade, there has been a significant progress in general surgical applications of robotic surgery. Multiple groups have reported safe and effective techniques for robotic adrenalectomy. Our aim in this review is to describe these techniques and summarize the literature on outcomes.

Retroperitoneal tumors that may be confused as adrenal pathologies.

There are a number of retroperitoneal pathologies that may be confused with adrenal tumors. It is important to suspect and recognize these conditions as their management and work up might be different than adrenal tumors. This review will go in to the differential diagnosis and unique features of these conditions. A management strategy will also be provided.

Laparoscopic posterior retroperitoneal adrenalectomy.

Almost more than a decade ago laparoscopic retroperitoneal adrenalectomy was introduced as an alternative to lateral approach. Today both of the techniques have become standard in removal of adrenal tumors and many surgeons showed favorable results in malignant tumors. This review outlines the technical details of the procedure and provides a summary of the literature.

Malfunction and failure of robotic systems during general surgical procedures.

BACKGROUND: There has been recent interest in using robots for general surgical procedures. This shift in technique raises the issue of patient safety with automated instrumentation. Although the safety of robotics has been established for urologic procedures, there are scant data on its use in general surgical procedures. The aim of this study is to analyze the incidence of robotic malfunction and its consequences for general surgical procedures. METHODS: All robotic general surgical procedures performed at a tertiary center between 2008 and 2011 were reviewed from institutional review board (IRB)-approved prospective databases. RESULTS: A total of 223 cases were done robotically, including 102 endocrine, 83 hepatopancreaticobiliary, 17 upper gastrointestinal, and 21 lower gastrointestinal colorectal procedures. There were 10 cases of robotic malfunction (4.5%). These failures were related to robotic instruments (n = 4), optical system (n = 3), robotic arms (n = 2), and robotic console (n = 1). None of these failures led to adverse patient consequences or conversion to open. Six (2.7%) cases were converted to open due to bleeding (n = 3), difficult dissection plane (n = 1), invasion of tumor to surrounding structures (n = 1), and intolerance of pneumoperitoneum due to CO(2) retention (n = 1). There was no mortality, and morbidity was 1% (n = 2). CONCLUSION: To our knowledge, this is the largest North American report to date on robotic general surgical procedures. Our results show that robotic malfunction occurs in a minority of cases, with no adverse consequences. We believe that awareness of these failures and knowing how to troubleshoot are important to maintain the efficiency of these procedures.

Weight Loss, Type 2 Diabetes, and Nutrition in 355 Patients with Obesity Undergoing Sleeve Gastrectomy with Transit Bipartition: Two-Year Outcomes.

INTRODUCTION: This study examined whether 355 obese patients with type 2 diabetes (T2D) of varying duration and severity experienced equivalent weight loss and T2D remission following a newer sleeve gastrectomy (SG) procedure - SG with transit bipartition (SG-TB). METHODS: Primary outcomes were changes in body mass index (BMI), total weight loss (TWL), excess BMI loss (EBMIL), A1C, and diabetes medication use through 24 months. RESULTS: Between December 2015 and December 2019, 399 patients who underwent SG-TB reached the 2-year time point. Follow-up was possible in 355 patients (89.0%): 206 females (58.0%), mean age 51.5 years (24.0-73.0), BMI 34.0 kg/m2 (28.0-50.5), and T2D duration 12.0 years (4.0-37.0). At 2 years, total sample respective mean TWL and EBMIL were 20.2 ± 6.1% (95% CI: 19.5, 20.8) and 87.7 ± 35.2% (84.1, 91.4) corresponding to mean BMI change of 7.0 ± 2.7 kg/m2 (6.7, 7.3) (p < 0.001). T2D duration and severity subgroups experienced comparable BMI and A1C change from baseline (p < 0.001); 281 (79.2%) maintained complete remission. ANOVA showed significant mean increases in vitamin D, calcium, and albumin: overall complication rate, 10.2%; no mortality. DISCUSSION/CONCLUSION: In 355 patients with obesity who underwent SG-TB, excellent weight loss, T2D, and nutritional outcomes were seen at 2-year follow-up regardless of preoperative T2D duration and severity.

Trichophagia as a cause of acute appendicitis in a patient with bipolar disorder.

Acute appendicitis is one of the most common abdominal surgical emergencies worldwide. Clinical diagnosis is possible in most of the cases although imaging modalities may become necessary if the diagnosis is uncertain. Appendectomy, preferably the laparoscopic ap-proach, still remains the gold standard treatment to date. The pathophysiology usually includes luminal obstruction by an appendicolith or lymphoid hyperplasia and rarely parasitic infections. In this report, we present an extremely rare case of a patient with diagnosis of bipolar disorder and a history of trichophagia resulting in trichobezoar formation within the appendiceal lümen leading to acute appendicitis.

Comparison of a pre-bariatric surgery very low-calorie ketogenic diet and the Mediterranean diet effects on weight loss, metabolic parameters, and liver size reduction.

This study compared the effects on weight as well as on metabolic parameters and liver size of a very low-calorie ketogenic diet versus a Mediterranean diet in patients with morbid obesity preparing to undergo bariatric surgery. This prospective comparison study evaluated patients 18-65 years of age who enrolled for bariatric surgery. Study duration was limited to an immediate preoperative period of 15 days. The very low-calorie ketogenic diet incorporated 10-12 kcal/kg/day of energy and 1-1.2 g/kg of protein using Kalibra (Societa Dietetica Medica) (VLCKD-SDM). The Mediterranean diet (MD) included 15-20% protein, 45-50% carbohydrate, and 25-35% fat. Changes in body mass index (BMI), liver size, and anthropometric and metabolic measurements were assessed. Between January 2016 and March 2017, of 45 patients enrolled, 30 completed the study (VLCKD-SDM, n = 15; MD, n = 15). Respective median BMI loss after VLCKD-SDM was 2.7 kg/m2 versus MD 1.4 kg/m2 (p < 0.05); median fat percentage reduction was 3.2 units versus 1.7 units (p < 0.05). Median liver size decreased 5.5% in the VLCKD-SDM group versus 1.7% in the MD group (p < 0.05). Median total cholesterol, and LDL levels decreased in both groups (p < 0.05), with greater relative decreases in the VLCKD-SDM group. Short-term preoperative diet-based weight loss in patients with morbid obesity preparing for bariatric surgery was significantly greater following a very low-calorie ketogenic diet versus a Mediterranean diet. The very low-calorie diet also significantly improved anthropometric and metabolic parameters and reduced preoperative liver size above that of the MD.