Brian King
Head of Investor Relations at Intuitive Surgical
Thank you, Jamie. Overall, second quarter procedure growth was 17% compared to 22% for the second quarter of 2023 and 16% last quarter. In the US, second quarter 2024 procedure growth was 14% compared to 19% for the second quarter of 2023 and 14% last quarter. Second quarter growth was led by procedures within general surgery, with strength in cholecystectomy and foregut procedures and also thoracic procedures. Bariatric procedure growth declined in the mid single digit range. Outside of the US, second quarter procedure volume grew 22%, compared with 28% for the second quarter of 2023 and 20% last quarter.
Growth was led by non urology procedures with strength in colon resection, hysterectomy and lung resection procedures. In Europe, second quarter growth continued to be led by procedures beyond urology, primarily from general surgery and gynecology procedure categories. Germany, the UK and Italy procedure performance led the region with each experiencing strong growth in colon and rectal resection, hysterectomy and other general surgery procedures.
In Asia, growth in the second quarter was led by Japan and India, while growth in China was stressed and Korea procedure growth continued to be impacted by physician strikes. In Japan, overall procedure growth was solid with continued strength in colon and rectal resection, gynecology and lung resection procedures. In India, while still in the early stage of adoption, we saw strength in gynecology and general surgery procedures, particularly with growth in hysterectomy, cholecystectomy, and hernia repair.
China procedure growth was lower than prior period averages when compared to the same quarter a year ago, which experienced a recovery in procedures impacted by COVID. System utilization remained strong, while capital placements continue to be impacted by delayed tenders and emerging domestic robotic systems.
Now turning to the clinical side of our business. Each quarter on these calls, we highlight certain recently published studies that we deem to be notable. However, to gain a more complete understanding of the body of evidence, we encourage all stakeholders to thoroughly review the extensive detail of scientific studies that have been published over the years.
Earlier this year, Dr. Zhang and team from the Guangzhou University of Chinese Medicine published a systematic review and meta analysis in the International Journal of Surgery that looked at open, laparoscopic and robotic assisted surgery approaches to rectal cancer management. This meta analysis covered 56 studies and included over 25,000 patients, of which approximately 11,000 patients received robotic assisted surgery, over 13,000 patients laparoscopic surgery and over 390 patients received open surgery.
When compared to the control group of both laparoscopic and open procedures, patients undergoing a robotic assisted approach had an approximately 2 day shorter length of stay. Specifically, when compared to lap, the robotic assisted group was associated with a 1.7 day shorter length of stay. Relative to open surgery, the length of stay was 5.5 days shorter. The robotic assisted approach was also demonstrated a protective effect for converting to an open procedure, with 61% lower odds of conversion associated with robotics relative to the laparoscopic approach.
Finally, when compared to the laparoscopic and open control group, the robotic assisted approach showed less estimated blood loss, approximately 40% lower odds of urinary retention and when compared to open, a higher number of harvested lymph nodes. The authors concluded, "the robotic approach emerges as the most favorable option for managing rectal cancer when compared to open, laparoscopic and trans anal techniques, as it delivers the finest blend of oncological, functional and patient recovery outcomes. The digital interface of surgical robots enables a shift in the paradigm of surgical training, facilitating shorter learning curves that are more comprehensive and notably reducing the morbidity and mortality associated with them".
I will now turn to our financial outlook for 2024. Starting with procedures, on our last call, we forecasted full year 2024 procedure growth within a range of 14% and 17%. We are now narrowing our forecast and expect full-year 2024 procedure growth of 15.5% to 17%. The low end of the range assumes further softening in bariatric procedures, along with increasing headwinds in Asia from prolonged physician strikes in Korea and in China from delayed tenders and emerging domestic robotic systems, impacting capital placements and therefore procedure growth. At the high end of the range, we assume bariatric stabilizes at current quarter rates and headwinds in Korea and China do not get worse.
Turning to gross profit, we are increasing our pro forma gross profit margin to be within 68.5% and 69% of net revenue. Our actual gross profit margin will vary quarter-to-quarter, depending largely on product, regional and trade-in mix and the impact of new product introductions.
Turning to operating expenses, we are lowering our guidance for pro forma operating expense growth to be between 10% and 13%. We are refining our non cash stock compensation expense to range between $680 million to $700 million in 2024. We are narrowing our guidance for other income, which is comprised mostly of interest income to total between $300 million and $320 million in 2024.
With regard to capital expenditures, we continue to estimate a range of $1 billion to $1.2 billion, primarily for planned facility construction activities. With regard to income tax, there is no change to our guidance of 2024 pro forma income tax rate to be between 22% and 24% of pretax income.
That concludes our prepared comments. We will now open the call to your questions.