Urological laparoscopy: basic physiological considerations and immunological consequences

The role of minimally invasive surgery in gynaecological cancer: an overview of current trends

Background

The capabilities of minimally invasive surgery, either as conventional laparoscopy, or as robotic surgery, have increased to an extent that it enables complex operations in the field of gynaecological oncology.

Objective

To document the role of minimally invasive gynaecological surgery in cancer.

Materials and methods

A review of the literature that shaped international guidelines and clinical practice.

Main outcome measures

Current guidelines of major international scientific associations and trends in accepted clinical practice.

Results

In recent years, evidence on oncologic outcome has limited the role of minimally invasive techniques in cervical cancer, while the treatment of early endometrial cancer with laparoscopy and robotic surgery has become the international standard. In ovarian cancer, the role of minimally invasive surgery is still limited. Current evidence on perioperative morbidity underlines the necessity to implicate minimally invasive techniques whenever possible.

Conclusion

The optimal surgical route for the treatment of gynaecological cancer remains in many cases controversial. The role of minimally invasive surgery remains increasing in the course of time.

What is new?

This comprehensive review offers an entire perspective on the current role of minimally invasive surgery in gynaecological cancer therapy.

The Impact of intra-abdominal Pressure on Perioperative Outcomes in Robotic-Assisted Radical Prostatectomy: A Systematic Review and Network Meta-Analysis of Randomized Controlled Trials

Objective. The aim of the study is to analyze the impact of intra-abdominal pressure (IAP) on perioperative outcomes in robotic-assisted radical prostatectomy (RARP). Methods. We searched the PubMed, Cochrane Library, Science, Embase, and CNKI databases systematically, and the retrieval date was from the inception of the databases to April 2022. Randomized controlled trials on high intraabdominal pressure (HIAP) and low intraabdominal pressure (LIAP) in RARP were included. The meta-analysis was performed using Review Manager software (version 5.3). Results. Six studies involving 2,271 patients were included in the meta-analysis. Compared with patients who experienced HIAP, those who experienced LIAP had a lower incidence of postoperative ileus (POI) (risk ratio (RR): 0.42; 95% confidence interval (CI): 0.24 to 0.72; $p=0.002$ ). However, there were no significant differences in hematoma (RR 2.22; 95% CI, 0.61 to 8.15; $p=0.23$ ), positive margin rate (RR, 1.06; 95% CI, 0.84 to 1.32; $p=0.64$ ), urinary retention (RR, 0.99; 95% CI, 0.51 to 1.94; $p=0.98$ ), operative time (mean difference (MD), −0.36; 95% CI, −12.24 to 6.12; $p=0.51$ ), or intraoperative blood loss (MD, −21.80; 95% CI, −55.28 to 11.68; $p=0.20$ ) among patients undergoing LIAP and HIAP. Conclusion. Our study of published trials indicates that using LIAP during RARP may reduce the incidence of POI, and there were no differences in terms of hematoma, positive margin rate, urinary retention, operative time, or intraoperative blood loss.

Lower vs standard pressure pneumoperitoneum in robotic-assisted radical prostatectomy: a systematic review and meta-analysis

Robotic-assisted laparoscopic radical prostatectomy (RARP) has been traditionally performed at a pneumoperitoneum insufflation pressure of 12-15 mmHg. This meta-analysis and systematic review aims to assess the current evidence comparing lower to standard pressure pneumoperitoneum in RARP. Systematic searches of MEDLINE, COCHRANE, SCOPUS and EMBASE were performed to identify articles published up until November 2021 comparing lower pressure with standard pressure pneumoperitoneum in RARP. Standard pressure was defined as > 12 mmHg and lower pressure ≤ 12 mmHg. Estimated blood loss, length of operation, length of hospital stay, post-operative ileus, 30-day readmissions, Clavien-Dindo complications and rate of positive surgical margins were extracted as endpoints of interest. Our searches identified 165 abstracts of which 4 articles with 1319 patients were eligible. Cumulative analysis demonstrated reduced length of stay when a lower pressure was used: WMD - 0.23 (- 0.45 to - 0.02) days (p = 0.03) as well as a reduced rate of post-operative ileus: OR 0.41 (0.22 to 0.77) (p = 0.006). There was no significant increase in length of operation WMD - 1.79 (- 15.96 to 12.38) (p = 0.8), estimated blood loss WMD - 2.89 (- 29.41 to 23.62) (p = 0.83), 30-day readmissions or positive surgical margins OR 1.04 (0.78 to 1.38) (p = 0.81) and RD - 0.01 (- 0.04 to 0.01) (p = 0.3) when using a lower pressure. We have demonstrated reduced length of stay and rates of post-operative ileus, when performing RARP at a lower pressure without a significant increase in length of operation, estimated blood loss, positive surgical margins or complications. The recommendation to use lower pressure pneumoperitoneum is moderate to weak and more randomised control trials are required to validate these results.

The Pathogenesis and Prevention of Port-Site Metastasis in Gynecologic Oncology

Port-site metastasis (PSM) is a specific and challenging complication of laparoscopic gynecologic oncologic procedures. Research has demonstrated that PSM is associated with significant morbidity and poor outcome. The exact pathogenesis of PSM in gynecologic patients is not clear. Several preventive measures of PSM have been addressed in the relevant literature, and novel approaches to prevent this uncommon complication keep emerging. In this review, we summarized the potential mechanisms of PSM and discuss the controversies and merits of proposed preventive measures of PSM in gynecologic oncology. We undertook a literature search using the Medline database to identify studies on the pathogenesis and prevention of laparoscopic PSM. Hypotheses of PSM pathogeneses center on the immune response, pneumoperitoneum, wound contamination, and surgical method. Cogent evidence of effective prevention of PSM after laparoscopic surgery is lacking. Traditional preventive actions such as irrigation and tumor manipulation should be taken individually. Insufflation of hyperthermic CO₂ and humidified CO₂ leads to a better outcome in patients with a malignant tumor who undergo a laparoscopic procedure compared with normal CO₂ pneumoperitoneum. Port-site resection shows no advantage in survival and results in more wound events. PSM prevention plays a crucial part in the overall care of patients with gynecologic malignancies who undergo laparoscopic procedures.

Do patients benefit from total intracorporeal robotic radical cystectomy?: A comparative analysis with extracorporeal robotic radical cystectomy from a Korean multicenter study

Purpose

This study aimed to compare complications, perioperative parameters, and oncologic outcomes between robot-assisted radical cystectomy (RARC) with extracorporeal urinary diversion (ECUD) and RARC with intracorporeal urinary diversion (ICUD).

Materials and Methods

Between 2007 and 2017, 362 patients who underwent RARC with ECUD or ICUD at multiple tertiary referral institutions were assessed. The primary endpoints were complication rates. The secondary outcomes were perioperative recovery parameters and oncological outcomes including estimated recurrence-free survival (RFS) and recurrence pattern between the 2 groups. Additionally, the complication rates of 2 expert surgeons with experience of >100 RARCs were analyzed.

Results

The ICUD group showed lower overall, gastrointestinal, and genitourinary complications (p=0.001, p=0.036, and p=0.036, respectively) than the ECUD group. Concerning perioperative outcomes, the ICUD group had a significantly longer operation time (p=0.002), although recovery parameters such as time to flatus passage, oral intake, and length of hospital stay were significantly shorter in this group (p=0.001, p<0.001, and p<0.001, respectively). There was no difference in oncologic outcomes such as positive margin rate (p=0.944) and 2-year RFS (p=0.496), and in the recurrence pattern between groups. In the comparison of the expert surgeons' complication rates, the major and total complication rates did not show differences (p=0.814 and p=0.102, respectively) while the minor complication rates were lower in the ICUD group (p=0.058).

Conclusions

This multi-institutional cohort study demonstrated the benefits of the ICUD approach, as indicated by lower complication rates and better recovery parameters, although the oncological results were similar to those of ECUD.

Postoperative C-reactive protein concentration and clinical outcome: comparison of open cystectomy to robot-assisted laparoscopic cystectomy with extracorporeal or intracorporeal urinary diversion in a prospective study

OBJECTIVE

This study aimed to compare clinical outcome and postoperative systemic inflammatory response using C-reactive protein (CRP) levels, to quantify the degree of tissue injury in open mini-laparotomy cystectomy (OMC) versus robot-assisted laparoscopic cystectomy with extracorporeal (RALC-EUD) or intracorporeal urinary diversion (RALC-IUD).

MATERIALS AND METHODS

From September 2012 to September 2015, 309 patients diagnosed with bladder cancer underwent radical cystectomy with urinary diversion. Of these, 175 patients were eligible for the study and underwent OMC (n = 125), RALC-EUD (n = 12) or RALC-IUD (n = 38). Blood samples were obtained preoperatively and postoperatively on days 1-7. Clinical and perioperative parameters, including demographics, comorbidity, tumour stage and postoperative outcomes, were collected from medical records.

RESULTS

Age, American Society of Anesthesiologists score and Charlson score were significantly higher in OMC than in the robotic groups (p = 0.020, 0.012 and 0.008, respectively). Other demographic data showed no significant group differences. Estimated blood loss and blood transfusion volume were higher in OMC (p < 0.001) and operative time was longer in the robotic groups (p < 0.001); no difference was found between RALC groups. Postoperative CRP levels changed over time (p < 0.001) and RALC-IUD appeared to have significantly higher CRP levels on postoperative days 3-7 compared to OMC and RALC-EUD (p < 0.031), but OMC CRP levels were higher than RALC-EUD.

CONCLUSIONS

In this study, robotic techniques seem less traumatic overall than open surgery, as OMC had higher postoperative CRP levels than RALC-EUD. The higher CRP levels in RALC-IUD may be more reflective of the urinary diversion technique than the true tissue trauma.

Port site recurrence after laparoscopic radical nephrectomy: a case report

Background

Due to the recent development of laparoscopic devices, laparoscopic radical nephrectomy is the standard procedure for localized renal cell carcinoma. However, some studies have reported postoperative port site metastasis in several cancers.

Case presentation

A 68-year-old Asian-Japanese man was referred to our hospital for a further examination of his right renal tumor in 2009. Due to a clinical suspicion of renal cell carcinoma, laparoscopic nephrectomy was performed. The histopathological diagnosis was clear cell renal cell carcinoma. Follow-up computed tomography revealed a mass between the internal oblique muscle of his abdomen and the transverse muscle of his abdomen in 2014. The tumor size gradually increased, and positron emission tomography-computed tomography revealed the accumulation of fludeoxyglucose in that tumor with maximum standardized uptake value of 2.7. Based on these findings, port site recurrence was suspected, and tumor resection was performed in 2017. The pathological diagnosis was metastatic clear cell renal cell carcinoma.

Conclusions

Here we report a rare case of port site metastasis that was successfully treated 7 years after laparoscopic nephrectomy.

Is robotic-assisted radical cystectomy (RARC) with intracorporeal diversion becoming the new gold standard of care?

BACKGROUND

Totally intracorporeal robotic-assisted radical cystectomy (RARC) has perceived difficulties compared to open radical cystectomy (ORC). As the technique is increasingly adopted around the world, the benefits of RARC with intra- or extracorporeal urinary diversion or ORC for the patients are still unclear. In this article, we consider the current evidence for this issue.

METHODS

We assessed two questions through using expert opinion and the medical literature: (A) Is RARC better than ORC for removing the cancer surgery and outcome? (B) Is RARC better than ORC for the urinary diversion?

OUTCOMES

(A) RARC is better than ORC for shorter length of stay, blood loss and complication rates. (B) Intracorporeal orthotopic neobladder may have a significant physiological and surgical benefit to the patient recovery.

CONCLUSIONS

RARC with total intracorporeal reconstruction has potential benefits to the patient. We recommend that all surgeons document patient-related outcome measures, urodynamics and enhanced recovery protocols for cystectomy patients to help us understand the real improvements within bladder cancer surgery and reconstruction.

Environmental impact of minimally invasive surgery in the United States: an estimate of the carbon dioxide footprint

PURPOSE

To attempt to quantitate the carbon footprint of minimally invasive surgery (MIS) through approximated scope 1 to 3 CO(2) emissions to identify its potential role in global warming.

PATIENTS AND METHODS

To estimate national usage, we determined the number of inpatient and outpatient MIS procedures using International Classification of Diseases, ninth revision-clinical modification codes for all MIS procedures in a 2009 sample collected in national databases. Need for surgery was considered essential, and therefore traditional open surgery was used as the comparator. Scope 1 (direct) CO(2) emissions resulting from CO(2) gas used for insufflation were based on both escaping procedural CO(2) and metabolic CO(2) eliminated via respiration. Scopes 2 and 3 (indirect) emissions related to capture, compression, and transportation of CO(2) to hospitals and the disposal of single-use equipment not used in open surgery were calculated.

RESULTS

The total CO(2) emissions were calculated to be 355,924 tonnes/year. For perspective, if MIS in the United States was considered a country, it would rank 189 th on the United Nations 2008 list of countries' carbon emissions per year. Limitations include the inability to account for uncertainty using the various models and tools for approximating CO(2) emissions.

CONCLUSION

CO(2) emission of MIS in the United States may have a significant environmental impact. This is the first attempt to quantify CO(2) emissions related to MIS in the United States. Strategies for reduction, while maintaining high quality medical care, should be considered.

Port-site metastasis after laparoscopic surgery for urological malignancy: forgotten or missed

Purpose. Port-site metastasis has been a concern with the common use of laparoscopy in urologic oncology. We conducted this study to provide a review of port-site metastases reported after the laparoscopy in managing urologic malignancies, possible contributing factors and preventative measures. Materials and Methods. An electronic search of MEDLINE using the combined MESH key words “port-site metastasis” and “Urology”. Results. 51 articles addressing port-site metastasis after laparoscopic surgery for urolo¬gical malignancy were identified. Conclusion. Port-site metastasis after laparoscopic surgery for urolo¬gical malignancy is rare. The incidence is comparable to the rate for surgical wound metastases.

Effects of CO(2) pneumoperitoneum on peritoneal macrophage function and peritoneal metastasis in mice with gastric cancer

BACKGROUND

Whether laparoscopy with CO(2) pneumoperitoneum affects the peritoneal metastasis of gastric cancer is a pressing question. In light of the important impact change in peritoneal macrophage function has on the peritoneal metastasis of gastric cancer, this study investigated the change in peritoneal macrophage function in gastric cancer in the CO(2) pneumoperitoneum environment, as well as its effect on the peritoneal metastasis of gastric cancer.

METHODS

An orthotopic transplantation model of murine forestomach carcinoma was established using the 615 mouse line. The mice bearing tumors were randomly divided into four groups (30 mice each group): anesthesia alone, laparotomy, mini-laparotomy, and CO(2) insufflation. After the operation, peritoneal macrophages were collected from 6 mice in each group and cultured. The phagocytosis of neutral red by macrophages and the levels of NO, TNF-α, IL-10, and VEGF produced by macrophages were measured after 12, 24, 48, and 72 h of culture. The remaining mice were observed after 2 weeks for the rate of peritoneal metastasis of forestomach carcinoma cells and the total weight of implanted nodules.

RESULTS

In the laparotomy group, 4 mice died intraoperatively and 2 died in the CO(2) insufflation group. The uptake of neutral red by peritoneal macrophages and the levels of NO, TNF-α, IL-10, and VEGF secreted by peritoneal macrophages in the laparotomy group and mini-laparotomy group after 12 h of culture were all significantly higher than those in the anesthesia-alone group (p < 0.05). The corresponding levels in the CO(2) insufflation group after 12 h were all significantly lower than those in the anesthesia-alone group (p < 0.05). There were no significant differences among the four groups at 24, 48, and 72 h after culture. Comparing with those in the laparotomy group, the uptake of neutral red by peritoneal macrophages and the levels of NO, TNF-α, IL-10, and VEGF secreted by peritoneal macrophages in the CO(2) insufflation group were all significantly lower after 12 h of culture (p < 0.05), but did not differ significantly at 24, 48, and 72 h of culture (p > 0.05), and did not differ significantly in the mini-laparotomy group at all the time (p > 0.05). The rate of peritoneal metastasis of mouse forestomach carcinoma was 50% in the laparotomy group, 45.83% in the mini-laparotomy group, and 45.45% in the CO(2) insufflation group; this difference was not statistically significant (p > 0.05). The total weight of implanted nodules of mouse forestomach carcinoma was 1.02 ± 0.38 g in the laparotomy group, 0.97 ± 0.41 g in the mini-laparotomy group, and 0.93 ± 0.45 g in the CO(2) insufflation group, which was not a statistically significant difference (p > 0.05).

CONCLUSION

CO(2) pneumoperitoneum neither significantly changes the phagocytosis and cytokine secretion functions of peritoneal macrophages in gastric cancer-bearing mice nor significantly promotes peritoneal metastasis of gastric cancer.

NOTES new frontier: Natural orifice approach to retroperitoneal disease

AIM: To develop a pure transvaginal access to the retroperitoneum, that is simple, reproducible and uses endoscopic material available on the market.

METHODS: From February 2008 to April 2009, 31 pigs were operated on, with 17 as an acute experiment and 14 with a survival protocol. The animals were placed in a supine position and a 12-mm double-channel endoscope (Karl Storz™, Tuttlingen) was used for vision and dissection. During the same time period, the access experiment was reproduced on 3 human cadavers using material similar to that used in the animal model.

RESULTS: In the animal model, 37 interventions were done on the kidney, adrenal gland and pancreas. The mean time to fashion the access was 10 min (range 5 to 20 min). No intraoperative death was observed. Two major (5%) intraoperative complications occurred: one hemorrhage on the aorta and one tearing of the right renal vein. Peritoneal laceration was encountered in 5 cases without impairing the planned task. In the survival group, good clinical outcome was observed at a mean follow-up of 3 wk (range 2 to 6 wk). In the 3 cadavers, access was performed correctly. The mean time to fashion the access was 52 min (range 40 to 60 min). All the anatomical landmarks described in the pig model were clearly identified in the same sequence.

CONCLUSION: A retroperitoneal natural orifice translumenal surgical transvaginal approach is feasible in both animal and human models and allows performance of a large panel of interventions.

Pneumoperitoneum with carbon dioxide inhibits macrophage tumor necrosis factor-alpha secretion: source of transitional-cell carcinoma port-site metastasis, with prophylactic irrigation strategies to decrease laparoscopic oncologic risks

PURPOSE

Peritoneal macrophages play a critical role in maintaining local host resistance to infection and malignancy through the secretion of tumor necrosis factor-alpha (TNF-alpha). We hypothesized that attenuated TNF-alpha secretion, as a result of CO(2) pneumoperitoneum, could alter local immune surveillance, thereby contributing to the development of carcinomatosis and incisional metastasis. We further sought to determine if port-site metastasis could be prevented with prophylactic irrigants.

MATERIALS AND METHODS

C57BL/6 mice (n = 50) and the syngenic murine bladder tumor (MBT-2) cell line were used. Experiment 1: Mice were subjected to either CO(2) pneumoperitoneum at 6 mm Hg (n = 10) or a 3-cm midline incision (n = 10). Peritoneal macrophages (1 x 10(6)/animal) were collected and subjected to lipopolysaccharide challenge. TNF-alpha levels were quantified using the Quantikine Mouse TNF-alpha/TNFSF1A Immunoassay. Experiment 2: Peritoneal and port-site metastasis were evaluated 1 week after 1 x 10(6) MBT-2 cells/animal were spilled in an open group (n = 5) and through 5-mm trocars of a pneumoperitoneal group (n = 5). Experiment 3: 1 x 10(6) MBT-2 cells/animal were spilled intraperitoneally through 5-mm trocars of four groups (n = 20). Port sites in each group were then irrigated with either sterile water, mitomycin C (1.0 mg/mL), betadine (10%), or heparin (1000 U/mL). At 1 week, incisional sites were evaluated for gross and microscopic metastasis. In each experiment, Student t-test was used to quantify statistical differences.

RESULTS

Peritoneal macrophage TNF-alpha secretion was significantly inhibited in mice subjected to CO(2) pneumoperitoneum v control at 10 and 20 minutes (P = 0.015, P = 0.001, respectively). When 1 x 10(6) MBT-2 cells were spilled, a significantly higher average tumor burden developed in animals subjected to CO(2) pneumoperitoneum than in controls at 1 week (9.2 gm v 3.8 g, P = 0.002). All irrigants prevented the development of port-site metastasis, yet sterile water did so without toxic effect.

CONCLUSION

In a syngenic murine model, CO(2) pneumoperitoneum causes inhibition of peritoneal macrophage TNF-alpha secretion. Heavier intraperitoneal and incisional metastasis develops in C57BL/6 mice subjected to CO(2) pneumoperitoneum and a tumor challenge with 1 x 10(6) MBT-2 tumor cells compared with open controls. Inhibition of peritoneal macrophage TNF-alpha secretion may be considered an adverse event contributing to the development of transitional-cell carcinoma (TCC) port-site metastasis, especially if surgical oncologic principles are violated. Irrigating trocar sites and the peritoneal cavity with sterile water at the conclusion of laparoscopic nephroureterectomy and laparoscopic radical cystectomy may offer a safe prophylactic strategy to prevent this unfavorable event. Our murine model presents a novel avenue for the development of adjunct immunomodulatory therapies to perhaps further reduce oncologic risks during laparoscopic management of TCC.

A reliable method for monitoring intraabdominal pressure during natural orifice translumenal endoscopic surgery

BACKGROUND

Natural orifice translumenal endoscopic surgery (NOTES) provides surgical access to the peritoneal cavity without skin incisions. The NOTES procedure requires pneumoperitoneum for visualization and manipulation of abdominal organs, similar to laparoscopy. Accurate measurement of the pneumoperitoneum pressure is essential to avoid potentially deleterious effects of intraabdominal compartment syndrome. A reliable method for monitoring pneumoperitoneum pressures during NOTES has not been identified. This study evaluated several methods of monitoring intraabdominal pressures with a standard gastroscope during NOTES.

METHODS

Four female pigs (25 kg) were sedated, and a single-channel gastroscope was passed transgastrically into the peritoneal cavity. Pneumoperitoneum was achieved via a pressure insufflator through a percutaneous, intraperitoneal 14-gauge catheter. Three other pressures were recorded via separate catheters. First, a 14-gauge percutaneous catheter passed intraperitoneally measured true intraabdominal pressure. Second, a 14-gauge tube attached to the endoscope was used to measure endoscope tip pressure. The third pressure transducer was connected directly to the accessory channel of the endoscope. The abdomen was insufflated to a range of pressures (10-30 mmHg), and simultaneous pressures were recorded from all three pressure sensors.

RESULTS

Pressure correlation curves were developed for all animals across all intraperitoneal pressures (mean error, -4.25 to -1 mmHg). Endoscope tip pressures correlated with biopsy channel pressures (R2 = 0.99). Biopsy channel and endoscope tip pressures fit a least-squares linear model to predict actual intraabdominal pressure (R = 0.99 for both). Both scope tip and biopsy channel port pressures were strongly correlative with true intraabdominal pressures (R2 = 0.98 and R2 = 0.99, respectively).

CONCLUSION

This study demonstrates that monitoring pressure through an endoscope is reliable and predictive of true intraabdominal pressure. Gastroscope pressure monitoring is a useful adjunct to NOTES. Future NOTES procedures should incorporate continuous intraabdominal pressure monitoring to avoid the potentially deleterious effects of pneumoperitoneum during NOTES. This can be achieved by the integration of pressure-monitoring capabilities into gastroscopes.

Perioperative care of patients undergoing bariatric surgery

The epidemic of obesity in developed countries has resulted in patients with extreme (class III) obesity undergoing the full breadth of medical and surgical procedures. The popularity of bariatric surgery in the treatment of extreme obesity has raised awareness of the unique considerations in the care of this patient population. Minimizing the risk of perioperative complications that contribute to morbidity and mortality requires input from several clinical disciplines and begins with the preoperative assessment of the patient. Airway management, intravenous fluid administration, physiologic responses to pneumoperitoneum during laparoscopic procedures, and the risk of thrombotic complications and peripheral nerve injuries in extremely obese patients are among the factors that present special intraoperative challenges that affect postoperative recovery of the bariatric patient. Early recognition of perioperative complications and education of the patient regarding postoperative issues, including nutrition and vitamin supplementation therapy, can improve patient outcomes. A suitable physical environment and appropriate nursing and dietetic support provide a safe and dignified hospital experience. This article reviews the multidisciplinary management of extremely obese patients who undergo bariatric surgery at the Mayo Clinic.

Laparoscopic surgery in urological oncology: brief overview

The authors report the experience of a high-volume center with laparoscopic surgery in urological oncology, as well as a review of other relevant series. Laparoscopic outcomes in the treatment of adrenal, kidney, upper tract transitional cell carcinoma, bladder, prostate, and testicular malignancy are described in this review. Specific considerations as complications and port-site recurrence are also addressed. The authors concluded that the intermediate-term oncological data is encouraging and comparable to open surgery.