JOURNAL OF LAPAROENDOSCOPIC & ADVANCED SURGICAL TECHNIQUES Volume 25, Number 5, 2015 ª Mary Ann Liebert, Inc. DOI: 10.1089/lap.2014.0516
Laparoscopic and Robotic Calyceal Diverticulectomy: Outcomes and Modifications of Technique Abby S. Taylor, MD, and David D. Thiel, MD
Abstract
Objective: To examine the technique and outcomes of robotic and laparoscopic calyceal diverticulectomy in the management of symptomatic calyceal diverticula at a single center. Subjects and Methods: Perioperative outcomes of six minimally invasive calyceal diverticulectomies (four laparoscopic and two robotic) between March 2011 and May 2014 were analyzed. Postoperative complications were categorized by Clavien–Dindo grade. Results: The median age of the cohort was 35 years (range, 24–51 years), and mean body mass index was 24 kg/m2. All 6 patients were female and presented with ipsilateral flank pain, and 3 of the 6 had coexisting recurrent urinary tract infections attributed to the calyceal diverticulum. Five of the 6 patients had failed prior surgical intervention with either endoscopic intervention or extracorporeal shock wave lithotripsy. Hilar clamping was performed in 2 of the 6 cases, with a mean warm ischemia time of 12 minutes (range, 10–14 minutes). Mean operative time was 162 minutes (range, 121–270 minutes), with no intraoperative complications. Mean blood loss was 150 mL (range, 50–300 mL), with no blood transfusions. There was one Clavien grade 1 complication and no major (Clavien grade 3 or higher) complications. Mean hospital stay was 2 days (range, 1–4 days). Four of the 6 patients were seen in follow-up, and all had complete resolution of flank pain and urinary tract infections, with no residual stones on imaging. Conclusions: Laparoscopic and robotic calyceal diverticulectomies for symptomatic calyceal diverticulum are safe, effective treatment options for symptomatic calyceal diverticula.
Introduction
A
calyceal diverticulum is a cavity within the renal parenchyma that is lined with transitional cell epithelium and communicates with the collecting system. The lining is nonfunctional with no urine production; however, the narrow connection to the calyx or renal pelvis leads to passive urine trapping within the dilation.1 Due to this stagnant urine, up to 50% of calyceal diverticulum will develop calculi.2 The presence of stones in the diverticulum can lead to a combination of symptoms including, but not limited to, recurrent urinary tract infections, ipsilateral flank pain, hematuria, or decreased renal function. Although most calyceal diverticula are asymptomatic, operative intervention may be necessary when any of the above symptoms is present.2 There are many surgical options, including extracorporeal shockwave lithotripsy (SWL), percutaneous nephrostolithotomy, ureteroscopy, laparoscopic diverticulectomy, or partial nephrectomy.3 Although success rates vary, management options are typically determined by
location and size of stone, with laparoscopic intervention commonly reserved for cases refractory to other treatment options.2 The aim of this study is to describe the role of laparoscopic or robotic calyceal diverticulectomy for definitive treatment of symptomatic calyceal diverticula by examining a single surgeon’s experience in laparoscopic and robotic calyceal diverticulectomy. Subjects and Methods
Following Institutional Review Board approval, we prospectively analyzed 6 laparoscopic and robotic calyceal diverticulectomies performed by a single, fellowship-trained, minimally invasive surgeon (D.D.T.) between June 2011 and May 2014. Surgical technique
It is imperative that the surgeon examine the films and have an idea of in exactly what portion of the kidney the
Department of Urology, Mayo Clinic, Jacksonville, Florida.
406
CALYCEAL DIVERTICULECTOMY
FIG. 1. Computed tomography scan image of a typical calyceal diverticulm demonstrates a right-sided calyceal diverticulm with a stone present. The hallmark of calyceal diverticulum is the thin parenchyma surrounding the calculous.
diverticulum lies (Fig. 1). For cases with a medial diverticulum in the lower pole, cystoscopy was performed for placement of a 5-French open-ended ureteral catheter. This aids in localizing the ureter during dissection of the medially located diverticulum. While under general anesthesia, patients were placed on an inflatable beanbag in the lateral decubitus position with the ipsilateral arm secured on an armboard above the patient’s head. Pneumoperitoneum was established with the Veress needle technique. All laparoscopic calyceal diverticulectomies used a 5-mm camera port placed off the midline and two 5-mm working ports (Fig. 2A). All robotic calyceal diverticulectomies were performed with the da Vinci Si Surgical System (Intuitive Surgical Corp., Sunnyvale, CA) using a robotic three-arm transper-
407
itoneal route (Fig. 2B). An assistant 12-mm port was placed in the infraumbilical midline. Dissection was completed with right-hand monopolar scissors and left-hand Maryland bipolar forceps. Renal hilar vessels were isolated, and perirenal fat was removed from the surface of the kidney. The calyceal diverticulum was identified with intraoperative ultrasonography. In 2 cases, the renal artery and vein were clamped with laparoscopic vascular bulldog clamps prior to unroofing of the cavity. The resected diverticulum wall was sent to pathology for examination. Stones were extracted, and the internal wall epithelium of the cavity was fulgurated in each case. No intervention was performed on the stenotic infundibular neck. When necessary, renorrhaphy was completed with the well-described sliding-clip technique commonly used for robotic and laparoscopic partial nephrectomies.4 A surgical drain was placed and later removed when output was low. The urethral catheter was removed on the first postoperative day. A renal ultrasound was performed 4–6 weeks following surgery to assess for hydronephrosis. Patient analysis
Estimated blood loss and intraoperative blood transfusions were recorded. Operative time was calculated as the time from Veress needle insertion until the last port site was closed. Warm ischemia time was calculated as the time from renal artery clamping until all clamps were removed. Perioperative outcomes
Postoperative complications were catergorized by Clavien– Dindo grade.5 Prolonged hospital stay was defined as a stay of over 3 days. Prolonged urinary drainage was defined as any patient who was discharged to home with a surgical drain in place.
FIG. 2. Port placement for laparoscopic and robotic calyceal diverticulectomy. (A) Laparoscopic calyceal diverticulectomy ports. Five-millimeter ports (circles) are used in the lower quadrant midclavicular line and the subxiphoid midline. A separate 5-mm camera port is placed between these ports off midline and lateral to the rectus muscle. A fourth 5-mm port (triangle) may be placed in the midaxillary line lateral to the camera port. (B) Robotic-assisted laparoscopic calyceal diverticulectomy ports. Eight-millimeter robotic ports (circles) are placed in the subxiphoid midline and in the lower quadrant midclavicular line. A 12-mm camera port (square) is placed in the midline a fist’s width below the subxiphoid port. A 12-mm assistant port (cross) is placed in the infraumbilical midline.
408
TAYLOR AND THIEL
Table 1. Patient Demographics, Laboratory Values, and Perioperative Data Value Age (years) [mean (range)] Gender (female) [n (%)] BMI (kg/m2) [mean (range)] ASA score [median (range)] Side (left) [n (%)] Size (cm) [mean (range)] Cr (mg/dL) [median (range)] Preoperative Postoperative Day 1 Hemoglobin (g/dL) [median (range)] Preoperative Postoperative Day 1 Length of drain (days) [mean (range)] Hospital stay (days) [median (range)] Follow-up (months) [median (range)]
35 7 24 2 3 1.5
(24–51) (100) (19–26) (1–3) (50) (1–2.5)
0.7 (0.6–0.8) 0.7 (0.6–0.8) 12.9 11.3 2 2 2
(11.7–14.2) (8.4–12.4) (1–7) (1–4) (0–12)
ASA, American Society of Anesthesiologists; BMI, body mass index; Cr, serum creatinine; eGFR, estimated glomerular filtration rate.
Results
All procedures were performed by a single surgeon at a single institution. Table 1 outlines the patient parameters. Table 2 outlines each patient’s individual scenario. All but 1 patient had multiple unsuccessful endoscopic interventions. Three patients had right-sided diverticula; two were located in the upper pole, and four were located in the lower pole, with a mean stone size of 1.53 cm (range, 1–2.5 cm). Mean operative time was 160 minutes (range, 121–260 minutes). Two patients had cystoscopy and open-ended ureteral stent placement for a medially located diverticulum on the lower pole of the kidney. In all cases, hilar dissection was performed, and 2 cases required hilar clamping with laparoscopic bulldog application with a median warm ischemia time of 12 minutes (10 minutes and 14 minutes). All cases used intraoperative ultrasonography to identify diverticula location. Diverticular closure following stone extraction was performed in 3 cases. In the other cases the diverticulum was left open, and the mucosa was fulgurated.
No intraoperative complications were observed. Mean estimated blood loss was 150 mL (range, 50–300 mL). There was no difference between preoperative and postoperative Day 1 serum creatinine level and estimated glomerular filtration rate. Mean decrease in serum hemoglobin concentration preoperatively to postoperative Day 1 was 2.3 g/dL (range, 0.4–5.8 g/dL), with no need for blood transfusion in any patient. Mean hospital stay was 2 days (range, 1–4 days), with one prolonged hospital stay of 4 days. One patient was discharged home with a surgical drain in place for 7 days (Clavien grade 1 complication). There were no major (Clavien grade 3 or higher) complications. The mean follow-up was 2 months (range, 1 week–12 months). All patients reported resolution of flank pain postoperatively, with no reported recurrence of symptoms. Postoperative renal ultrasonography did not reveal hydronephrosis in any patient. Patients were discharged from the urology clinic following an asymptomatic postoperative visit and absence of hydronephrosis on postoperative ultrasonography. Discussion
Although most calyceal diverticula are asymptomatic and less than 50% have calculi within, 96% of symptomatic patients will have stones within the diverticula at time of presentation.4 Surgical intervention for the treatment calyceal diverticulum can be justified in patients with flank pain, recurrent urinary tract infections, or symptomatic calculi within the diverticulum. Treatment options consist of extracorporeal SWL, ureteroscopy, and percutaneous nephrostolithotomy, as well as laparoscopic and robotic approaches.2,6–8 In a recent comprehensive review of the literature by Waingankar et al.,2 treatment options for management of symptomatic calyceal diverticulum were reviewed, success rates for each option were obtained, and recommendations for management were given. For SWL, the percentage of patients who become symptom free at follow-up ranged from 36% to 75%, and only 8%–40% were stone-free at follow-up. Although SWL may break up the stones, residual remnants of the stone remain in the diverticulum with a narrowed infundibulum as the underlying anatomic abnormality, which is not addressed.
Table 2. Diverticulum Descriptions and Surgical Indications Size (cm)
BMI (kg/m2)
Location
Previous therapy
Indication
26 25
Right, upper pole Right, lower pole Right, lower/posterior
SWL · 2 URS · 3 None
Ipsilateral flank pain
51
1.4 1 1
39
1.3
23
Left, upper/anterior
30
2.5
24
Right, lower/posterior
35
1
26
Left, lower pole
24
1.4 2
19
Left, mid/posterior Left lower pole
SWL · 1 URS · 1 SWL · 2 PCNL · 1 SWL · 2 URS · 1 PCNL · 2 SWL · 4 URS · 2 PCNL · 2
Age (years) 29
Ipsilateral flank pain Recurrent UTI Ipsilateral flank pain Ipsilateral flank pain Recurrent UTI Ipsilateral flank pain Recurrent UTI Ipsilateral flank pain
BMI, body mass index; PCNL, percutaneous nephrolithomy; SWL, shockwave lithotripsy; URS, ureteroscopy; UTI, urinary tract infection.
CALYCEAL DIVERTICULECTOMY
Ureteroscopy demonstrates stone-free rates ranging from 19% to 90% and symptom-free rates ranging from 35% to 90%. Although it is a less invasive approach, there can be significant difficulty in locating the ostia of the diverticulum as well as difficulty in ablation of the lining of the diverticulum. Waingankar et al.2 noted higher stone-free and symptom-free rates for percutaneous nephrostolithotomy; values increased with dilation of the ostium at time of surgery, which ranged from 72% to 100% stone-free and 77% to 100% symptom-free at follow-up. Although this approach allows for direct treatment of the underlying disorder, complication rates are reported as high as 54%. The invasiveness of the procedure and the difficulty in treating anteriorly located diverticula are possible drawbacks. Reviews of laparoscopic calyceal intervention demonstrated 100% stone-free rates as well as 100% symptom-free rates.2,9 Although management of stones located within calyceal diverticulum may relieve symptoms, it does not change the anatomical defect, thus allowing for recurrent symptomatology or stones in the future.7 The goal of management should ultimately be complete obliteration of the diverticulum; therefore, the potential cavity for stagnant urine and stone formation should be eliminated.10 Laparoscopic diverticulectomy has the highest success rates for ablation of the defect (90%–100%), percutaneous interventions are a distant second (60%), ureteroscopy rarely corrects the anatomical problem (20%), and SWL does not address the underlying issue.9 Because of the low success rates of the latter three interventions, patients need to be counseled on the likelihood that repeat procedures will be necessary in the future for recurrent stones or symptoms. Our series demonstrates that robotic or laparoscopic calyceal diverticulectomy definitively treats the symptoms as well as the underlying cause. All patients seen at follow-up were stone-free and symptom-free. As this is considered the most invasive of the minimally invasive treatments, it is commonly considered a second-line treatment; however, we argue that this can be considered as the first-line intervention necessary to treat a symptomatic calyceal diverticulum. Surgical decision-making was performed on a case-by-case basis. Laparoscopic or robotic calyceal diverticulectomy is useful for thin-walled diverticulum, ensuring a peripheral location and, therefore, ease in identifying and unroofing. Thickwalled, medially located diverticula can provide a challenge to this surgical approach, as they can be difficult to locate intraoperatively and, with excessive surrounding parenchyma, will bleed more readily. A laparoscopic approach is used for thin-walled, anteriorly located diverticula, whereas a robotic approach is preferred in cases where clamping and renorrhaphy are likely, with large diverticula with deep-seated stones or with posteriorly located diverticula. The primary benefits of the robotic-assisted diverticulectomy include three-dimensional visualization and the ability to perform complex reconstruction. The benefit of a purely laparoscopic approach includes one fewer port placed and smaller port sizes (when using 5-mm ports). In our series, isolation of the renal hilum was performed in all patients. If visualization was poor secondary to bleeding upon entry into the diverticulum, the hilum was then clamped with laparoscopic bulldog clamps. The size of the calyceal diverticulum did not have an impact on our surgical decisionmaking, although a very small diverticulum may be difficult to locate with intraoperative ultrasound. No intervention was
409
performed on the infundibular neck. We feel that by unroofing the diverticulum and fulgurating the lining, the cavity has been obliterated with no need for a communication to the renal pelvis. The mean operative time in our series was 150 minutes, consistent with previously reported laparoscopic interventions, with averages ranging from 150 to 190 minutes.3,9,10 The two longest cases in our series, 162 and 270 minutes, were the cases that required hilar clamping for increased bleeding during the unroofing. All surgeries, including posteriorly located diverticula, were performed in a transperitoneal approach. Although a retroperitoneal approach may aid in posteriorly located diverticula, with decreased risk of bowel injury, need for lysis of adhesions, and no risk for intraperitoneal urine leak,10 we feel that the transperitoneal approach gives easier access to the hilum, deals with familiar renal anatomy, and is only slightly more difficult for the posterior diverticulum with appropriate mobilization of the kidney. For medial, lower pole diverticulum, an open-ended ureteral catheter was placed cystoscopically to aid in locating the ureter prior to calyceal unroofing. Once the diverticulum is unroofed and fulgurated, there is minimal chance of recurrence.7 Therefore, our patients were discharged from urology care following an asymptomatic postoperative visit. No imaging was performed postoperatively in asymptomatic patients to ensure resolution of the diverticulum. A renal ultrasound was performed 4–6 weeks after hospital discharge to evaluate for postoperative hydronephrosis or urinoma. Conclusions
Laparoscopic and robotic calyceal diverticulectomy are safe, effective, definitive treatment options for symptomatic calculi within a calyceal diverticulum. The high success rate and low complication rate may make it a good first-line option as opposed to being reserved for refractory cases. Disclosure Statement
A.S.T. declares no competing financial interests exist. D.D.T. is a consultant for Cooper Surgical Corporation. References
1. Estrada CR, Datta S, Schneck FX, Bauer SB, Peters CA, Retik AB. Caliceal diverticula in children: Natural history and management. J Urol 2009;181:1306–1311; discussion 1311. 2. Waingankar N, Hayek S, Smith AD, Okeke Z. Calyceal diverticula: A comprehensive review. Rev Urol 2014;16: 29–43. 3. Akca O, Zargar H, Autorino R, Brandao LF, Laydner H, Samarasekera D, Krishnan J, Noble M, Haber GP, Kaouk JH, Stein RJ. Robotic partial nephrectomy for caliceal diverticulum: A single-center case series. J Endourol 2014; 28:958–961. 4. Bhayani SB, Figenshau RS. The Washington University Renorrhaphy for robotic partial nephrectomy: A detailed description of the technique displayed at the 2008 World Robotic Urologic Symposium. J Robot Surg 2008;2:139–140. 5. Dindo D, Demartines N, Clavien PA. Classification of surgical complications. Ann Surg 2004;240:205–213. 6. Koopman SG, Fuchs G. Management of stones associated with intrarenal stenosis: Infundibular stenosis and caliceal diverticulum. J Endourol 2013;27:1546–1550. 7. Gross AJ, Herrmann TR. Management of stones in calyceal diverticulum. Curr Opin Urol 2007;17:136–140.
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8. Rapp DE, Gerber GS. Management of caliceal diverticula. J Endourol 2004;18:805–810. 9. Gonzalez RD, Whiting B, Canales BK. Laparoscopic calyceal diverticulectomy: Video review of techniques and outcomes. J Endourol 2011;25:1591–1595. 10. Basiri A, Radfar MH, Lashay A. Laparoscopic management of caliceal diverticulum: Our experience, literature review, and pooling analysis. J Endourol 2013;27:583–586.
TAYLOR AND THIEL
Address correspondence to: David D. Thiel, MD Department of Urology Mayo Clinic 4500 San Pablo Road Jacksonville, FL 32224 E-mail: [email protected]
Laparoscopic and Robotic Calyceal Diverticulectomy: Outcomes and Modifications of Technique Abby S. Taylor, MD, and David D. Thiel, MD
Abstract
Objective: To examine the technique and outcomes of robotic and laparoscopic calyceal diverticulectomy in the management of symptomatic calyceal diverticula at a single center. Subjects and Methods: Perioperative outcomes of six minimally invasive calyceal diverticulectomies (four laparoscopic and two robotic) between March 2011 and May 2014 were analyzed. Postoperative complications were categorized by Clavien–Dindo grade. Results: The median age of the cohort was 35 years (range, 24–51 years), and mean body mass index was 24 kg/m2. All 6 patients were female and presented with ipsilateral flank pain, and 3 of the 6 had coexisting recurrent urinary tract infections attributed to the calyceal diverticulum. Five of the 6 patients had failed prior surgical intervention with either endoscopic intervention or extracorporeal shock wave lithotripsy. Hilar clamping was performed in 2 of the 6 cases, with a mean warm ischemia time of 12 minutes (range, 10–14 minutes). Mean operative time was 162 minutes (range, 121–270 minutes), with no intraoperative complications. Mean blood loss was 150 mL (range, 50–300 mL), with no blood transfusions. There was one Clavien grade 1 complication and no major (Clavien grade 3 or higher) complications. Mean hospital stay was 2 days (range, 1–4 days). Four of the 6 patients were seen in follow-up, and all had complete resolution of flank pain and urinary tract infections, with no residual stones on imaging. Conclusions: Laparoscopic and robotic calyceal diverticulectomies for symptomatic calyceal diverticulum are safe, effective treatment options for symptomatic calyceal diverticula.
Introduction
A
calyceal diverticulum is a cavity within the renal parenchyma that is lined with transitional cell epithelium and communicates with the collecting system. The lining is nonfunctional with no urine production; however, the narrow connection to the calyx or renal pelvis leads to passive urine trapping within the dilation.1 Due to this stagnant urine, up to 50% of calyceal diverticulum will develop calculi.2 The presence of stones in the diverticulum can lead to a combination of symptoms including, but not limited to, recurrent urinary tract infections, ipsilateral flank pain, hematuria, or decreased renal function. Although most calyceal diverticula are asymptomatic, operative intervention may be necessary when any of the above symptoms is present.2 There are many surgical options, including extracorporeal shockwave lithotripsy (SWL), percutaneous nephrostolithotomy, ureteroscopy, laparoscopic diverticulectomy, or partial nephrectomy.3 Although success rates vary, management options are typically determined by
location and size of stone, with laparoscopic intervention commonly reserved for cases refractory to other treatment options.2 The aim of this study is to describe the role of laparoscopic or robotic calyceal diverticulectomy for definitive treatment of symptomatic calyceal diverticula by examining a single surgeon’s experience in laparoscopic and robotic calyceal diverticulectomy. Subjects and Methods
Following Institutional Review Board approval, we prospectively analyzed 6 laparoscopic and robotic calyceal diverticulectomies performed by a single, fellowship-trained, minimally invasive surgeon (D.D.T.) between June 2011 and May 2014. Surgical technique
It is imperative that the surgeon examine the films and have an idea of in exactly what portion of the kidney the
Department of Urology, Mayo Clinic, Jacksonville, Florida.
406
CALYCEAL DIVERTICULECTOMY
FIG. 1. Computed tomography scan image of a typical calyceal diverticulm demonstrates a right-sided calyceal diverticulm with a stone present. The hallmark of calyceal diverticulum is the thin parenchyma surrounding the calculous.
diverticulum lies (Fig. 1). For cases with a medial diverticulum in the lower pole, cystoscopy was performed for placement of a 5-French open-ended ureteral catheter. This aids in localizing the ureter during dissection of the medially located diverticulum. While under general anesthesia, patients were placed on an inflatable beanbag in the lateral decubitus position with the ipsilateral arm secured on an armboard above the patient’s head. Pneumoperitoneum was established with the Veress needle technique. All laparoscopic calyceal diverticulectomies used a 5-mm camera port placed off the midline and two 5-mm working ports (Fig. 2A). All robotic calyceal diverticulectomies were performed with the da Vinci Si Surgical System (Intuitive Surgical Corp., Sunnyvale, CA) using a robotic three-arm transper-
407
itoneal route (Fig. 2B). An assistant 12-mm port was placed in the infraumbilical midline. Dissection was completed with right-hand monopolar scissors and left-hand Maryland bipolar forceps. Renal hilar vessels were isolated, and perirenal fat was removed from the surface of the kidney. The calyceal diverticulum was identified with intraoperative ultrasonography. In 2 cases, the renal artery and vein were clamped with laparoscopic vascular bulldog clamps prior to unroofing of the cavity. The resected diverticulum wall was sent to pathology for examination. Stones were extracted, and the internal wall epithelium of the cavity was fulgurated in each case. No intervention was performed on the stenotic infundibular neck. When necessary, renorrhaphy was completed with the well-described sliding-clip technique commonly used for robotic and laparoscopic partial nephrectomies.4 A surgical drain was placed and later removed when output was low. The urethral catheter was removed on the first postoperative day. A renal ultrasound was performed 4–6 weeks following surgery to assess for hydronephrosis. Patient analysis
Estimated blood loss and intraoperative blood transfusions were recorded. Operative time was calculated as the time from Veress needle insertion until the last port site was closed. Warm ischemia time was calculated as the time from renal artery clamping until all clamps were removed. Perioperative outcomes
Postoperative complications were catergorized by Clavien– Dindo grade.5 Prolonged hospital stay was defined as a stay of over 3 days. Prolonged urinary drainage was defined as any patient who was discharged to home with a surgical drain in place.
FIG. 2. Port placement for laparoscopic and robotic calyceal diverticulectomy. (A) Laparoscopic calyceal diverticulectomy ports. Five-millimeter ports (circles) are used in the lower quadrant midclavicular line and the subxiphoid midline. A separate 5-mm camera port is placed between these ports off midline and lateral to the rectus muscle. A fourth 5-mm port (triangle) may be placed in the midaxillary line lateral to the camera port. (B) Robotic-assisted laparoscopic calyceal diverticulectomy ports. Eight-millimeter robotic ports (circles) are placed in the subxiphoid midline and in the lower quadrant midclavicular line. A 12-mm camera port (square) is placed in the midline a fist’s width below the subxiphoid port. A 12-mm assistant port (cross) is placed in the infraumbilical midline.
408
TAYLOR AND THIEL
Table 1. Patient Demographics, Laboratory Values, and Perioperative Data Value Age (years) [mean (range)] Gender (female) [n (%)] BMI (kg/m2) [mean (range)] ASA score [median (range)] Side (left) [n (%)] Size (cm) [mean (range)] Cr (mg/dL) [median (range)] Preoperative Postoperative Day 1 Hemoglobin (g/dL) [median (range)] Preoperative Postoperative Day 1 Length of drain (days) [mean (range)] Hospital stay (days) [median (range)] Follow-up (months) [median (range)]
35 7 24 2 3 1.5
(24–51) (100) (19–26) (1–3) (50) (1–2.5)
0.7 (0.6–0.8) 0.7 (0.6–0.8) 12.9 11.3 2 2 2
(11.7–14.2) (8.4–12.4) (1–7) (1–4) (0–12)
ASA, American Society of Anesthesiologists; BMI, body mass index; Cr, serum creatinine; eGFR, estimated glomerular filtration rate.
Results
All procedures were performed by a single surgeon at a single institution. Table 1 outlines the patient parameters. Table 2 outlines each patient’s individual scenario. All but 1 patient had multiple unsuccessful endoscopic interventions. Three patients had right-sided diverticula; two were located in the upper pole, and four were located in the lower pole, with a mean stone size of 1.53 cm (range, 1–2.5 cm). Mean operative time was 160 minutes (range, 121–260 minutes). Two patients had cystoscopy and open-ended ureteral stent placement for a medially located diverticulum on the lower pole of the kidney. In all cases, hilar dissection was performed, and 2 cases required hilar clamping with laparoscopic bulldog application with a median warm ischemia time of 12 minutes (10 minutes and 14 minutes). All cases used intraoperative ultrasonography to identify diverticula location. Diverticular closure following stone extraction was performed in 3 cases. In the other cases the diverticulum was left open, and the mucosa was fulgurated.
No intraoperative complications were observed. Mean estimated blood loss was 150 mL (range, 50–300 mL). There was no difference between preoperative and postoperative Day 1 serum creatinine level and estimated glomerular filtration rate. Mean decrease in serum hemoglobin concentration preoperatively to postoperative Day 1 was 2.3 g/dL (range, 0.4–5.8 g/dL), with no need for blood transfusion in any patient. Mean hospital stay was 2 days (range, 1–4 days), with one prolonged hospital stay of 4 days. One patient was discharged home with a surgical drain in place for 7 days (Clavien grade 1 complication). There were no major (Clavien grade 3 or higher) complications. The mean follow-up was 2 months (range, 1 week–12 months). All patients reported resolution of flank pain postoperatively, with no reported recurrence of symptoms. Postoperative renal ultrasonography did not reveal hydronephrosis in any patient. Patients were discharged from the urology clinic following an asymptomatic postoperative visit and absence of hydronephrosis on postoperative ultrasonography. Discussion
Although most calyceal diverticula are asymptomatic and less than 50% have calculi within, 96% of symptomatic patients will have stones within the diverticula at time of presentation.4 Surgical intervention for the treatment calyceal diverticulum can be justified in patients with flank pain, recurrent urinary tract infections, or symptomatic calculi within the diverticulum. Treatment options consist of extracorporeal SWL, ureteroscopy, and percutaneous nephrostolithotomy, as well as laparoscopic and robotic approaches.2,6–8 In a recent comprehensive review of the literature by Waingankar et al.,2 treatment options for management of symptomatic calyceal diverticulum were reviewed, success rates for each option were obtained, and recommendations for management were given. For SWL, the percentage of patients who become symptom free at follow-up ranged from 36% to 75%, and only 8%–40% were stone-free at follow-up. Although SWL may break up the stones, residual remnants of the stone remain in the diverticulum with a narrowed infundibulum as the underlying anatomic abnormality, which is not addressed.
Table 2. Diverticulum Descriptions and Surgical Indications Size (cm)
BMI (kg/m2)
Location
Previous therapy
Indication
26 25
Right, upper pole Right, lower pole Right, lower/posterior
SWL · 2 URS · 3 None
Ipsilateral flank pain
51
1.4 1 1
39
1.3
23
Left, upper/anterior
30
2.5
24
Right, lower/posterior
35
1
26
Left, lower pole
24
1.4 2
19
Left, mid/posterior Left lower pole
SWL · 1 URS · 1 SWL · 2 PCNL · 1 SWL · 2 URS · 1 PCNL · 2 SWL · 4 URS · 2 PCNL · 2
Age (years) 29
Ipsilateral flank pain Recurrent UTI Ipsilateral flank pain Ipsilateral flank pain Recurrent UTI Ipsilateral flank pain Recurrent UTI Ipsilateral flank pain
BMI, body mass index; PCNL, percutaneous nephrolithomy; SWL, shockwave lithotripsy; URS, ureteroscopy; UTI, urinary tract infection.
CALYCEAL DIVERTICULECTOMY
Ureteroscopy demonstrates stone-free rates ranging from 19% to 90% and symptom-free rates ranging from 35% to 90%. Although it is a less invasive approach, there can be significant difficulty in locating the ostia of the diverticulum as well as difficulty in ablation of the lining of the diverticulum. Waingankar et al.2 noted higher stone-free and symptom-free rates for percutaneous nephrostolithotomy; values increased with dilation of the ostium at time of surgery, which ranged from 72% to 100% stone-free and 77% to 100% symptom-free at follow-up. Although this approach allows for direct treatment of the underlying disorder, complication rates are reported as high as 54%. The invasiveness of the procedure and the difficulty in treating anteriorly located diverticula are possible drawbacks. Reviews of laparoscopic calyceal intervention demonstrated 100% stone-free rates as well as 100% symptom-free rates.2,9 Although management of stones located within calyceal diverticulum may relieve symptoms, it does not change the anatomical defect, thus allowing for recurrent symptomatology or stones in the future.7 The goal of management should ultimately be complete obliteration of the diverticulum; therefore, the potential cavity for stagnant urine and stone formation should be eliminated.10 Laparoscopic diverticulectomy has the highest success rates for ablation of the defect (90%–100%), percutaneous interventions are a distant second (60%), ureteroscopy rarely corrects the anatomical problem (20%), and SWL does not address the underlying issue.9 Because of the low success rates of the latter three interventions, patients need to be counseled on the likelihood that repeat procedures will be necessary in the future for recurrent stones or symptoms. Our series demonstrates that robotic or laparoscopic calyceal diverticulectomy definitively treats the symptoms as well as the underlying cause. All patients seen at follow-up were stone-free and symptom-free. As this is considered the most invasive of the minimally invasive treatments, it is commonly considered a second-line treatment; however, we argue that this can be considered as the first-line intervention necessary to treat a symptomatic calyceal diverticulum. Surgical decision-making was performed on a case-by-case basis. Laparoscopic or robotic calyceal diverticulectomy is useful for thin-walled diverticulum, ensuring a peripheral location and, therefore, ease in identifying and unroofing. Thickwalled, medially located diverticula can provide a challenge to this surgical approach, as they can be difficult to locate intraoperatively and, with excessive surrounding parenchyma, will bleed more readily. A laparoscopic approach is used for thin-walled, anteriorly located diverticula, whereas a robotic approach is preferred in cases where clamping and renorrhaphy are likely, with large diverticula with deep-seated stones or with posteriorly located diverticula. The primary benefits of the robotic-assisted diverticulectomy include three-dimensional visualization and the ability to perform complex reconstruction. The benefit of a purely laparoscopic approach includes one fewer port placed and smaller port sizes (when using 5-mm ports). In our series, isolation of the renal hilum was performed in all patients. If visualization was poor secondary to bleeding upon entry into the diverticulum, the hilum was then clamped with laparoscopic bulldog clamps. The size of the calyceal diverticulum did not have an impact on our surgical decisionmaking, although a very small diverticulum may be difficult to locate with intraoperative ultrasound. No intervention was
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performed on the infundibular neck. We feel that by unroofing the diverticulum and fulgurating the lining, the cavity has been obliterated with no need for a communication to the renal pelvis. The mean operative time in our series was 150 minutes, consistent with previously reported laparoscopic interventions, with averages ranging from 150 to 190 minutes.3,9,10 The two longest cases in our series, 162 and 270 minutes, were the cases that required hilar clamping for increased bleeding during the unroofing. All surgeries, including posteriorly located diverticula, were performed in a transperitoneal approach. Although a retroperitoneal approach may aid in posteriorly located diverticula, with decreased risk of bowel injury, need for lysis of adhesions, and no risk for intraperitoneal urine leak,10 we feel that the transperitoneal approach gives easier access to the hilum, deals with familiar renal anatomy, and is only slightly more difficult for the posterior diverticulum with appropriate mobilization of the kidney. For medial, lower pole diverticulum, an open-ended ureteral catheter was placed cystoscopically to aid in locating the ureter prior to calyceal unroofing. Once the diverticulum is unroofed and fulgurated, there is minimal chance of recurrence.7 Therefore, our patients were discharged from urology care following an asymptomatic postoperative visit. No imaging was performed postoperatively in asymptomatic patients to ensure resolution of the diverticulum. A renal ultrasound was performed 4–6 weeks after hospital discharge to evaluate for postoperative hydronephrosis or urinoma. Conclusions
Laparoscopic and robotic calyceal diverticulectomy are safe, effective, definitive treatment options for symptomatic calculi within a calyceal diverticulum. The high success rate and low complication rate may make it a good first-line option as opposed to being reserved for refractory cases. Disclosure Statement
A.S.T. declares no competing financial interests exist. D.D.T. is a consultant for Cooper Surgical Corporation. References
1. Estrada CR, Datta S, Schneck FX, Bauer SB, Peters CA, Retik AB. Caliceal diverticula in children: Natural history and management. J Urol 2009;181:1306–1311; discussion 1311. 2. Waingankar N, Hayek S, Smith AD, Okeke Z. Calyceal diverticula: A comprehensive review. Rev Urol 2014;16: 29–43. 3. Akca O, Zargar H, Autorino R, Brandao LF, Laydner H, Samarasekera D, Krishnan J, Noble M, Haber GP, Kaouk JH, Stein RJ. Robotic partial nephrectomy for caliceal diverticulum: A single-center case series. J Endourol 2014; 28:958–961. 4. Bhayani SB, Figenshau RS. The Washington University Renorrhaphy for robotic partial nephrectomy: A detailed description of the technique displayed at the 2008 World Robotic Urologic Symposium. J Robot Surg 2008;2:139–140. 5. Dindo D, Demartines N, Clavien PA. Classification of surgical complications. Ann Surg 2004;240:205–213. 6. Koopman SG, Fuchs G. Management of stones associated with intrarenal stenosis: Infundibular stenosis and caliceal diverticulum. J Endourol 2013;27:1546–1550. 7. Gross AJ, Herrmann TR. Management of stones in calyceal diverticulum. Curr Opin Urol 2007;17:136–140.
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8. Rapp DE, Gerber GS. Management of caliceal diverticula. J Endourol 2004;18:805–810. 9. Gonzalez RD, Whiting B, Canales BK. Laparoscopic calyceal diverticulectomy: Video review of techniques and outcomes. J Endourol 2011;25:1591–1595. 10. Basiri A, Radfar MH, Lashay A. Laparoscopic management of caliceal diverticulum: Our experience, literature review, and pooling analysis. J Endourol 2013;27:583–586.
TAYLOR AND THIEL
Address correspondence to: David D. Thiel, MD Department of Urology Mayo Clinic 4500 San Pablo Road Jacksonville, FL 32224 E-mail: [email protected]
